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Vol.43, No.2
January 2022
Semimonthly
ISSN 1002-0306
CN 11-1759/TS
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2022, 43(2): 126-134.
doi: 10.13386/j.issn1002-0306.2021040126
Abstract:
The molecule self-assembly technology was used to prepare astaxanthin/whey protein nanocomplex, and the interaction mechanism between astaxanthin (AST) and whey protein was studied. By controlling the proportion of astaxanthin organic solution and whey protein aqueous phase, whey protein (α-lactalbumin, β-lactoglobulin, whey protein concentrate and bovine serum albumin) and astaxanthin were used for preparing well formed H aggregates or J aggregates astaxanthin/bovine serum albumin nanocomplexes, the resultant H/J AWC-NPs were spherical with 150~430 nm diameter, polydispersity index (PDI) showed good dispersity and −12~−1 mV Zeta potential measured by dynamic light scattering (DLS). Both H aggregates and J aggregates astaxanthin/whey protein nanocomplexes were near spherical with clear and smooth edges by transmission electron microscopy (TEM). The analysis by ultraviolet-visible absorption spectra revealed that the absorption maximum λmax of astaxanthin H aggregates was shifted from 480 nm of astaxanthin monomer blue to 388 nm, and the absorption maximum λmax of astaxanthin J aggregates was shifted red, showing a parallel peak at about 519 and 556 nm. The fluorescence spectrum analysis showed that the fluorescence intensity of astaxanthin/whey protein nanocomplex was significantly enhanced due to the specific structure of astaxanthin aggregates, and hydrophobic amino acids and hydrophobic regions in whey protein were exposed. In this study, the water dispersion of astaxanthin and its aggregates and the characteristics of whey protein carrier were investigated to provide theoretical basis for its subsequent development and application in the field of food and medicine.
The molecule self-assembly technology was used to prepare astaxanthin/whey protein nanocomplex, and the interaction mechanism between astaxanthin (AST) and whey protein was studied. By controlling the proportion of astaxanthin organic solution and whey protein aqueous phase, whey protein (α-lactalbumin, β-lactoglobulin, whey protein concentrate and bovine serum albumin) and astaxanthin were used for preparing well formed H aggregates or J aggregates astaxanthin/bovine serum albumin nanocomplexes, the resultant H/J AWC-NPs were spherical with 150~430 nm diameter, polydispersity index (PDI) showed good dispersity and −12~−1 mV Zeta potential measured by dynamic light scattering (DLS). Both H aggregates and J aggregates astaxanthin/whey protein nanocomplexes were near spherical with clear and smooth edges by transmission electron microscopy (TEM). The analysis by ultraviolet-visible absorption spectra revealed that the absorption maximum λmax of astaxanthin H aggregates was shifted from 480 nm of astaxanthin monomer blue to 388 nm, and the absorption maximum λmax of astaxanthin J aggregates was shifted red, showing a parallel peak at about 519 and 556 nm. The fluorescence spectrum analysis showed that the fluorescence intensity of astaxanthin/whey protein nanocomplex was significantly enhanced due to the specific structure of astaxanthin aggregates, and hydrophobic amino acids and hydrophobic regions in whey protein were exposed. In this study, the water dispersion of astaxanthin and its aggregates and the characteristics of whey protein carrier were investigated to provide theoretical basis for its subsequent development and application in the field of food and medicine.
2022, 43(2): 135-141.
doi: 10.13386/j.issn1002-0306.2021040234
Abstract:
This paper aimed to explore the effect of Lactobacillus plantarum microcapsules fermentation on the quality of carrot chips, and the change of viable cell count under freeze-drying and simulated gastric juice conditions. In this study, Lactobacillus plantarum microcapsules were prepared by extrusion method using sodium alginate and isolated whey protein as wall materials. The carrot chips fermented with Lactobacillus plantarum microcapsules were used as experimental group and the carrot chips fermented without microcapsules were used as control group. The results showed that there were no significant differences in texture, color, total sugar content, carotene content and ascorbic acid content between test group and control group (P>0.05). In freeze-drying and simulated gastric juice environment, the number of viable bacteria in the test group was significantly higher than that in the control group, which remained (8.47±0.02) and (8.31±0.01) lg(CFU/g), respectively. Microencapsulated Lactobacillus plantarum fermentation had no prominent effect on the quality of carrot chips and could improve the resistance of Lactobacillus plantarum to adverse environments (such as freeze-drying and gastric juice).
This paper aimed to explore the effect of Lactobacillus plantarum microcapsules fermentation on the quality of carrot chips, and the change of viable cell count under freeze-drying and simulated gastric juice conditions. In this study, Lactobacillus plantarum microcapsules were prepared by extrusion method using sodium alginate and isolated whey protein as wall materials. The carrot chips fermented with Lactobacillus plantarum microcapsules were used as experimental group and the carrot chips fermented without microcapsules were used as control group. The results showed that there were no significant differences in texture, color, total sugar content, carotene content and ascorbic acid content between test group and control group (P>0.05). In freeze-drying and simulated gastric juice environment, the number of viable bacteria in the test group was significantly higher than that in the control group, which remained (8.47±0.02) and (8.31±0.01) lg(CFU/g), respectively. Microencapsulated Lactobacillus plantarum fermentation had no prominent effect on the quality of carrot chips and could improve the resistance of Lactobacillus plantarum to adverse environments (such as freeze-drying and gastric juice).
2022, 43(2): 142-149.
doi: 10.13386/j.issn1002-0306.2021050066
Abstract:
In order to increase and stabilize the content of tetramethylpyrazine in liquor, 13 strains of Bacillus were isolated from Maotai Daqu samples, and 5 strains with excellent protease production were selected through the preliminary screening of protease transparent circle test. After a liquid fermentation test, a functional bacterium with high yield of tetramethylpyrazine was screened out. The content of tetramethylpyrazine in the fermentation broth was 12.22 mg/L, which was identified as Bacillus licheniformis GTBL-168. The seed culture solution of this strain was inoculated into the sauce-flavor liquor accumulation culture at 0%, 3%, 5%, and 7% (v/w) to synergize the fermentation with traditional Daqu, and accumulate acetoin and tetramethyl in the glutinous rice grains. The content of pyrazine increased, and the increasing was the largest when the inoculation amount was 7%, and the yield of tetramethylpyrazine increased by 24.88% compared with the control group, the overall changes in physical and chemical indexes were obvious, and the amino nitrogen and total acid increased, the addition of Bacillus licheniformis GTBL-168 had little effect on the microbial structure of the accumulated fermented grains. With the increasing of the inoculation amount, the abundance of Bacillus and other dominant bacteria in the fermented grains also increased. It would lay a foundation for the application of functional bacteria in the process of stacking fermentation.
In order to increase and stabilize the content of tetramethylpyrazine in liquor, 13 strains of Bacillus were isolated from Maotai Daqu samples, and 5 strains with excellent protease production were selected through the preliminary screening of protease transparent circle test. After a liquid fermentation test, a functional bacterium with high yield of tetramethylpyrazine was screened out. The content of tetramethylpyrazine in the fermentation broth was 12.22 mg/L, which was identified as Bacillus licheniformis GTBL-168. The seed culture solution of this strain was inoculated into the sauce-flavor liquor accumulation culture at 0%, 3%, 5%, and 7% (v/w) to synergize the fermentation with traditional Daqu, and accumulate acetoin and tetramethyl in the glutinous rice grains. The content of pyrazine increased, and the increasing was the largest when the inoculation amount was 7%, and the yield of tetramethylpyrazine increased by 24.88% compared with the control group, the overall changes in physical and chemical indexes were obvious, and the amino nitrogen and total acid increased, the addition of Bacillus licheniformis GTBL-168 had little effect on the microbial structure of the accumulated fermented grains. With the increasing of the inoculation amount, the abundance of Bacillus and other dominant bacteria in the fermented grains also increased. It would lay a foundation for the application of functional bacteria in the process of stacking fermentation.
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2022, 43(2): 1-8.
doi: 10.13386/j.issn1002-0306.2021040100
Abstract:
In order to further improve the printing quality of unwashed sturgeon surimi gel, this paper explored the influence of printing parameters such as printing speed, layering height, filling density, nozzle diameter, extrusion degree and temperature on the 3D printing effect of surimi gel, and evaluated the printing accuracy. The results showed that the layering height should be the same as or slightly lower than the nozzle diameter, and the higher the layering height, nozzle diameter and printing speed were, the higher the printing efficiency was. Based on the comprehensive printing effect and printing efficiency, the optimal printing parameters were determined as nozzle diameter 1.20 mm, layering height 1.2 mm, filling density 100%, extrusion degree 100%, printing speed 25 mm/s and temperature 25 °C. Under these printing parameters, the structure of the printed surimi was tight, and the formability was good and the printing accuracy was high, which could obtain high-quality 3D printing surimi.
In order to further improve the printing quality of unwashed sturgeon surimi gel, this paper explored the influence of printing parameters such as printing speed, layering height, filling density, nozzle diameter, extrusion degree and temperature on the 3D printing effect of surimi gel, and evaluated the printing accuracy. The results showed that the layering height should be the same as or slightly lower than the nozzle diameter, and the higher the layering height, nozzle diameter and printing speed were, the higher the printing efficiency was. Based on the comprehensive printing effect and printing efficiency, the optimal printing parameters were determined as nozzle diameter 1.20 mm, layering height 1.2 mm, filling density 100%, extrusion degree 100%, printing speed 25 mm/s and temperature 25 °C. Under these printing parameters, the structure of the printed surimi was tight, and the formability was good and the printing accuracy was high, which could obtain high-quality 3D printing surimi.
2022, 43(2): 9-19.
doi: 10.13386/j.issn1002-0306.2021040110
Abstract:
In order to explore the origin differences of black tea metabolites, the metabolites in black tea produced in Fu 'an and Youxi of Fujian province were compared and analyzed by using sensory evaluation method and extensive targeting metabolomic determination method of ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The results showed that, Fu'an black tea mainly tasted of “mellow and soft”, while Youxi black tea of “mellow and sweet”. A total of 937 metabolites including of flavonoids, phenolic acids, lipids, organic acids, amino acids and their derivatives were identified by metabonomics in the black tea of the two regions, through the principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) could significantly distinguish different producing area of black tea, and identified 410 species of metabolites with significant difference. The relative content of 291 different metabolites in Youxi black tea was higher than that of Fu 'an black tea, among which Astragalin, EC, L-glutamine, L-aspartic acid, L-lysine, L-tryptophan, L-glutamic acid, chlorogenic acid, phenethylamine, vitexin-2''-O-rhamnoside might have important contributions to the formation of different taste and quality of black tea from the two regions. Metabolic pathway analysis showed that the metabolism levels of amino acids and flavonoids of black tea between the two places were significantly different, which might be the reason for the difference in the taste and quality of black tea between the two places. The research would provide a theoretical basis for the identification of tea origin.
In order to explore the origin differences of black tea metabolites, the metabolites in black tea produced in Fu 'an and Youxi of Fujian province were compared and analyzed by using sensory evaluation method and extensive targeting metabolomic determination method of ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The results showed that, Fu'an black tea mainly tasted of “mellow and soft”, while Youxi black tea of “mellow and sweet”. A total of 937 metabolites including of flavonoids, phenolic acids, lipids, organic acids, amino acids and their derivatives were identified by metabonomics in the black tea of the two regions, through the principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) could significantly distinguish different producing area of black tea, and identified 410 species of metabolites with significant difference. The relative content of 291 different metabolites in Youxi black tea was higher than that of Fu 'an black tea, among which Astragalin, EC, L-glutamine, L-aspartic acid, L-lysine, L-tryptophan, L-glutamic acid, chlorogenic acid, phenethylamine, vitexin-2''-O-rhamnoside might have important contributions to the formation of different taste and quality of black tea from the two regions. Metabolic pathway analysis showed that the metabolism levels of amino acids and flavonoids of black tea between the two places were significantly different, which might be the reason for the difference in the taste and quality of black tea between the two places. The research would provide a theoretical basis for the identification of tea origin.
Determination of Freshness of Fish by Colorimetric Array Sensor Based on Anodic Aluminum Oxide Flake
2022, 43(2): 20-26.
doi: 10.13386/j.issn1002-0306.2021040233
Abstract:
In order to quickly and accurately non-destructive real-time monitoring of fish freshness, a visual colorimetric array sensor was constructed in this study based on anodized aluminum flakes as the substrate and 13 indicators selected as gas-sensitive materials. The freshness of turbot during storage was measured by using the constructed colorimetric array sensor. The results showed that the total volatile basic nitrogen (TVB-N) value of turbot reached 32.85 mg/100 g when the storage time was more than 22 h at 25 ℃, and the fish was rotten. At this time, the color of the array points in the colorimetric sensor array changed. The RGB values of sensor array points before and after response were extracted and subtracted, and the clustering analysis and principal component analysis were carried out. The results showed that the colorimetric array sensor was able to accurately distinguish the freshness of fish in different storage time periods. In addition, the array sensor was applied to detect the freshness of carp and American redfish at different storage times, and the results showed that there was no significant difference between the TVB-N values predicted by the colorimetric array sensor and the actual measured values. Therefore, it is feasible to apply the sensor to fish freshness monitoring.
In order to quickly and accurately non-destructive real-time monitoring of fish freshness, a visual colorimetric array sensor was constructed in this study based on anodized aluminum flakes as the substrate and 13 indicators selected as gas-sensitive materials. The freshness of turbot during storage was measured by using the constructed colorimetric array sensor. The results showed that the total volatile basic nitrogen (TVB-N) value of turbot reached 32.85 mg/100 g when the storage time was more than 22 h at 25 ℃, and the fish was rotten. At this time, the color of the array points in the colorimetric sensor array changed. The RGB values of sensor array points before and after response were extracted and subtracted, and the clustering analysis and principal component analysis were carried out. The results showed that the colorimetric array sensor was able to accurately distinguish the freshness of fish in different storage time periods. In addition, the array sensor was applied to detect the freshness of carp and American redfish at different storage times, and the results showed that there was no significant difference between the TVB-N values predicted by the colorimetric array sensor and the actual measured values. Therefore, it is feasible to apply the sensor to fish freshness monitoring.
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2022, 43(2): 150-156.
doi: 10.13386/j.issn1002-0306.2021040095
Abstract:
Wheat germ powder was hydrolyzed by compound protease, and the effects of ratio of material to liquid, amount of enzyme and hydrolysis time on the quality characteristics of wheat germ powder were analyzed. At the same time, three groups of enzyme hydrolyzed powder with the highest water solubility index of wheat germ hydrolyzed powder and milk powder were compounded and sensory evaluation was made to determine the best compound ratio. The results showed that the quality of wheat germ powder hydrolyzed by protease was better than that of wheat germ ultrafine powder. When the ratio of material to liquid was 1:5 g/mL, the amount of enzyme was 4400 U/g and the reaction time was 2.5 h, the water solubility index of wheat germ powder reached the maximum, which was 60.6 g/g. Compared with the water solubility index 30.22 and 30.65 g/g of raw powder and ultra-fine powder, the water solubility index of wheat germ powder increased by about two times after enzymatic hydrolysis. When the ratio of material to liquid was 1:4 g/mL, the amount of enzyme was 4400 U/g and the reaction time was 2.5 h, the absorbance value decreased from 0.501 to 0.348 of unhydrolyzed wheat germ powder, and the lipase activity in enzymatic hydrolyzed wheat germ powder reached the minimum. After enzymatic hydrolysis with compound protease, the water solubility index of wheat germ powder was greatly increased, the lipase activity of wheat germ powder decreased, and the effect of enzymatic hydrolysis on the color difference of wheat germ powder was not significant. In the experiment of compounding with milk powder, whether it was wheat germ powder, ultra-fine powder or enzyme hydrolyzed powder, the highest sensory scores was obtained when the addition amount was 30%.
Wheat germ powder was hydrolyzed by compound protease, and the effects of ratio of material to liquid, amount of enzyme and hydrolysis time on the quality characteristics of wheat germ powder were analyzed. At the same time, three groups of enzyme hydrolyzed powder with the highest water solubility index of wheat germ hydrolyzed powder and milk powder were compounded and sensory evaluation was made to determine the best compound ratio. The results showed that the quality of wheat germ powder hydrolyzed by protease was better than that of wheat germ ultrafine powder. When the ratio of material to liquid was 1:5 g/mL, the amount of enzyme was 4400 U/g and the reaction time was 2.5 h, the water solubility index of wheat germ powder reached the maximum, which was 60.6 g/g. Compared with the water solubility index 30.22 and 30.65 g/g of raw powder and ultra-fine powder, the water solubility index of wheat germ powder increased by about two times after enzymatic hydrolysis. When the ratio of material to liquid was 1:4 g/mL, the amount of enzyme was 4400 U/g and the reaction time was 2.5 h, the absorbance value decreased from 0.501 to 0.348 of unhydrolyzed wheat germ powder, and the lipase activity in enzymatic hydrolyzed wheat germ powder reached the minimum. After enzymatic hydrolysis with compound protease, the water solubility index of wheat germ powder was greatly increased, the lipase activity of wheat germ powder decreased, and the effect of enzymatic hydrolysis on the color difference of wheat germ powder was not significant. In the experiment of compounding with milk powder, whether it was wheat germ powder, ultra-fine powder or enzyme hydrolyzed powder, the highest sensory scores was obtained when the addition amount was 30%.
2022, 43(2): 157-165.
doi: 10.13386/j.issn1002-0306.2021040232
Abstract:
The essential oil of Litsea pungens Hemsl was used as the main raw material, and the method of vacuum freeze-drying was used to prepare the microcapsules of essential oil of Litsea pungens Hemsl, and the embedding rate of the microcapsules was used as an index. Optimizing the microcapsule embedding process of essential oils to determine the best process parameters. At the same time, the physical and chemical properties, microstructure, volatile rate and peroxide value of essential oil were analyzed during storage. The results showed that the best parameters of the microcapsules of essential oil were as follows: Composite wall material ratio (soy protein isolate: β-cyclodextrin) was 1:1 (g/g), core wall material ratio was 1:5(g/g), solid content was 15%, emulsifier content was 3%, emulsifier ratio was 1:4 (g/g), emulsifying temperature was 40 ℃, embedding rate of the microcapsules was 84.68%, its water content, solubility and bulk density were 3.05%, 91.04% and 0.35 g/cm3, respectively. The results of SEM showed that the microcapsules of Litsea pungens Hemsl essential oil were irregular in shape. With the extension of storage time, the volatilization rate and peroxide value of microcapsules of Litsea pungens Hemsl essential oil were lower than those of essential oil, which indicated that the microencapsulation of Litsea pungens Hemsl essential oil could effectively slow down the volatilization rate and reduce oxidation degree of essential oil.
The essential oil of Litsea pungens Hemsl was used as the main raw material, and the method of vacuum freeze-drying was used to prepare the microcapsules of essential oil of Litsea pungens Hemsl, and the embedding rate of the microcapsules was used as an index. Optimizing the microcapsule embedding process of essential oils to determine the best process parameters. At the same time, the physical and chemical properties, microstructure, volatile rate and peroxide value of essential oil were analyzed during storage. The results showed that the best parameters of the microcapsules of essential oil were as follows: Composite wall material ratio (soy protein isolate: β-cyclodextrin) was 1:1 (g/g), core wall material ratio was 1:5(g/g), solid content was 15%, emulsifier content was 3%, emulsifier ratio was 1:4 (g/g), emulsifying temperature was 40 ℃, embedding rate of the microcapsules was 84.68%, its water content, solubility and bulk density were 3.05%, 91.04% and 0.35 g/cm3, respectively. The results of SEM showed that the microcapsules of Litsea pungens Hemsl essential oil were irregular in shape. With the extension of storage time, the volatilization rate and peroxide value of microcapsules of Litsea pungens Hemsl essential oil were lower than those of essential oil, which indicated that the microencapsulation of Litsea pungens Hemsl essential oil could effectively slow down the volatilization rate and reduce oxidation degree of essential oil.
2022, 43(2): 166-173.
doi: 10.13386/j.issn1002-0306.2021040240
Abstract:
In this paper, the ultrasonic extraction technology of Forsythia suspensa leaves was optimized based on multi-index components. The contents of forsythioside A, forsythin and rutin were determined by high performance liquid chromatography (HPLC). The ethanol concentration, liquid-solid ratio, extraction time and extraction temperature were taken as the factors. The entropy weight method was used to obtain comprehensive score by calculating the weight coefficient of each index. Subsequently, the comprehensive score was taken as the index. Finally the Box-Behnken response surface methodology was adopted to optimize the extraction process. The optimum extraction conditions of Forsythia suspensa leaves were as follow: Ethanol concentration 50%, liquid to material ratio 28:1 mL/g, extraction temperature 51 ℃, extraction time 25 min. The results of the validation tests showed that under the optimal conditions, the extraction amount of forsythioside A, forsythin and rutin were 69.69, 22.87 and 22.46 mg/g, respectively, the RSD was less than 3% and comprehensive score was 32.18. The extraction technology was stable and feasible, and the extraction quantity of active components was high. It was suitable for the extraction of Forsythia suspensa leaves.
In this paper, the ultrasonic extraction technology of Forsythia suspensa leaves was optimized based on multi-index components. The contents of forsythioside A, forsythin and rutin were determined by high performance liquid chromatography (HPLC). The ethanol concentration, liquid-solid ratio, extraction time and extraction temperature were taken as the factors. The entropy weight method was used to obtain comprehensive score by calculating the weight coefficient of each index. Subsequently, the comprehensive score was taken as the index. Finally the Box-Behnken response surface methodology was adopted to optimize the extraction process. The optimum extraction conditions of Forsythia suspensa leaves were as follow: Ethanol concentration 50%, liquid to material ratio 28:1 mL/g, extraction temperature 51 ℃, extraction time 25 min. The results of the validation tests showed that under the optimal conditions, the extraction amount of forsythioside A, forsythin and rutin were 69.69, 22.87 and 22.46 mg/g, respectively, the RSD was less than 3% and comprehensive score was 32.18. The extraction technology was stable and feasible, and the extraction quantity of active components was high. It was suitable for the extraction of Forsythia suspensa leaves.
Extraction and in Vitro Adsorption Properties of Dietary Fiber from Phyllanthus emblica Linn. Pomace
2022, 43(2): 174-181.
doi: 10.13386/j.issn1002-0306.2021040269
Abstract:
An investigation was carried out to optimize the extraction process of dietary fiber from Phyllanthus emblica Linn. pomace, and the physicochemical properties and in vitro adsorption capacity of Phyllanthus emblica Linn. pomace, total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble dietary fiber (SDF) were investigated. The results showed that the optimal extraction process using alkali method was: Concentration of NaOH 8 g/L, material-to-liquid ratio of 1:35 (g:mL), treatment at 70 °C for 40 min, and the yield of IDF and SDF were 61.72%±0.04% and 17.57%±0.03%, respectively. Phyllanthus emblica Linn. pomace and its dietary fiber both had good hydration properties and oil-holding capacity. TDF had the lowest water holding and the highest swelling capacity significantly different from Phyllanthus emblica Linn. pomace, SDF and IDF (P<0.05). SDF had lowly capacity to oil-holding, swelling and fat, however under simulated stomach (pH2) which had the higher adsorption capacity for cholesterol and NO2- than Phyllanthus emblica Linn. pomace, TDF and IDF (P<0.05). The adsorption capacity of Phyllanthus emblica Linn. pomace and its dietary fiber on cholesterol and NO2− was related with pH in vitro. The cholesterol adsorption capacity of TDF and SDF were higher under simulating stomach pH, while the adsorption capacity of Phyllanthus emblica Linn. pomace and IDF on cholesterol were higher under simulating small intestine. The Phyllanthus emblica Linn. pomace and its dietary fiber had higher adsorption capacity on NO2− under stomach pH than simulated small intestinal pH. This paper studied the extraction and properties of dietary fiber from Phyllanthus emblica Linn. pomace, which could provide some theoretical reference for its application in health food.
An investigation was carried out to optimize the extraction process of dietary fiber from Phyllanthus emblica Linn. pomace, and the physicochemical properties and in vitro adsorption capacity of Phyllanthus emblica Linn. pomace, total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble dietary fiber (SDF) were investigated. The results showed that the optimal extraction process using alkali method was: Concentration of NaOH 8 g/L, material-to-liquid ratio of 1:35 (g:mL), treatment at 70 °C for 40 min, and the yield of IDF and SDF were 61.72%±0.04% and 17.57%±0.03%, respectively. Phyllanthus emblica Linn. pomace and its dietary fiber both had good hydration properties and oil-holding capacity. TDF had the lowest water holding and the highest swelling capacity significantly different from Phyllanthus emblica Linn. pomace, SDF and IDF (P<0.05). SDF had lowly capacity to oil-holding, swelling and fat, however under simulated stomach (pH2) which had the higher adsorption capacity for cholesterol and NO2- than Phyllanthus emblica Linn. pomace, TDF and IDF (P<0.05). The adsorption capacity of Phyllanthus emblica Linn. pomace and its dietary fiber on cholesterol and NO2− was related with pH in vitro. The cholesterol adsorption capacity of TDF and SDF were higher under simulating stomach pH, while the adsorption capacity of Phyllanthus emblica Linn. pomace and IDF on cholesterol were higher under simulating small intestine. The Phyllanthus emblica Linn. pomace and its dietary fiber had higher adsorption capacity on NO2− under stomach pH than simulated small intestinal pH. This paper studied the extraction and properties of dietary fiber from Phyllanthus emblica Linn. pomace, which could provide some theoretical reference for its application in health food.
2022, 43(2): 182-194.
doi: 10.13386/j.issn1002-0306.2021040285
Abstract:
In this experiment, jujube kernel protein was extracted from defatted jujube kernel residue by alkali solution and acid precipitation, taking the inhibition rate of angiotensin converting enzyme (ACE) and degree of hydrolysis as indicators to screen the compound enzyme species. Using the response surface method, with proportion of neutral protease/alkaline protease, pH, substrate concentration, enzymolysis temperature, digestion time as test factors, the optimum enzymatic hydrolysis parameters of ACE inhibitory peptide from jujube kernel were optimized. The results showed that neutral protease and alkaline protease were selected as complex enzymes, and the optimal amount of enzyme was determined to be 6000 U/g. The order of influence of five factors on the ACE inhibition rate and hydrolysis degree was: Enzymatic hydrolysis temperature, enzymatic hydrolysis time, pH, ratio of neutral protease to alkaline protease, substrate concentration. Through the fitting equation analysis, the optimum conditions of ACE inhibition of peptidyl enzymatic hydrolysis of jujube kernel were as follows: Neutral protease/alkaline protease ratio 2.1:1, hydrolysis temperature 54 ℃, substrate concentration 3.1%, pH7.5, hydrolysis time 62 min. Under these conditions, the actual ACE inhibition rate and hydrolysis degree of the hydrolysate were (79.46%±0.49%) and (31.45%±0.85%), respectively, which were close to the theoretical values. Compared with captopril, the ACE inhibitory rate of the prepared ACE inhibitory peptide was (79.46%±0.49%), and the deviation from captopril was (19.28%±0.12%), which proved that the ACE inhibitory peptide had a significant antihypertensive effect. This study proved that the ACE inhibitory peptide could be effectively obtained by enzymatic hydrolysis of jujube kernel protein and optimized the enzymatic hydrolysis process, aiming to provide reference direction and theoretical basis for the reuse of jujube kernel residue.
In this experiment, jujube kernel protein was extracted from defatted jujube kernel residue by alkali solution and acid precipitation, taking the inhibition rate of angiotensin converting enzyme (ACE) and degree of hydrolysis as indicators to screen the compound enzyme species. Using the response surface method, with proportion of neutral protease/alkaline protease, pH, substrate concentration, enzymolysis temperature, digestion time as test factors, the optimum enzymatic hydrolysis parameters of ACE inhibitory peptide from jujube kernel were optimized. The results showed that neutral protease and alkaline protease were selected as complex enzymes, and the optimal amount of enzyme was determined to be 6000 U/g. The order of influence of five factors on the ACE inhibition rate and hydrolysis degree was: Enzymatic hydrolysis temperature, enzymatic hydrolysis time, pH, ratio of neutral protease to alkaline protease, substrate concentration. Through the fitting equation analysis, the optimum conditions of ACE inhibition of peptidyl enzymatic hydrolysis of jujube kernel were as follows: Neutral protease/alkaline protease ratio 2.1:1, hydrolysis temperature 54 ℃, substrate concentration 3.1%, pH7.5, hydrolysis time 62 min. Under these conditions, the actual ACE inhibition rate and hydrolysis degree of the hydrolysate were (79.46%±0.49%) and (31.45%±0.85%), respectively, which were close to the theoretical values. Compared with captopril, the ACE inhibitory rate of the prepared ACE inhibitory peptide was (79.46%±0.49%), and the deviation from captopril was (19.28%±0.12%), which proved that the ACE inhibitory peptide had a significant antihypertensive effect. This study proved that the ACE inhibitory peptide could be effectively obtained by enzymatic hydrolysis of jujube kernel protein and optimized the enzymatic hydrolysis process, aiming to provide reference direction and theoretical basis for the reuse of jujube kernel residue.
2022, 43(2): 195-205.
doi: 10.13386/j.issn1002-0306.2021040293
Abstract:
In this paper, defatted Antarctic krill powder was used as raw material to prepare hydrolysate with delicate taste by compound enzyme method. By means of sensory evaluation, peptide yield and degree of hydrolysis, the screening of exogenous enzymes and single factor experiments were carried out. In order to further optimize the taste of enzymatic hydrolysate, the total amount of amino acids with delicate flavor was used as the index to optimize the enzymatic hydrolysis condition. The results showed that the optimal hydrolysis conditions were as follows: The ratio of trypsin and pepsin 1:100, the total amount of enzyme 2800 U/g, the liquid and material ratio 1:4 g·mL−1, the pH of enzymatic hydrolysis 7.0, the temperature of enzymatic hydrolysis 40 ℃, and the time of enzymatic hydrolysis 3 h. Under these conditions, the content of free amino acids with delicate taste in the hydrolysate was 331.79 mg/100 mL. Except tryptophan, the remaining eight essential amino acids accounted for 63.66% of the total amino acids. Free bitter amino acids accounted for 27.83% of the total amino acids, and free sweet amino acids accounted for 26.22% of the total amino acids. Free glutamic acid and free aspartic acid, which played a key role in the formation of umami taste, accounted for 10.26% of the total free amino acids. This study could provide theoretical basis and technical guidance for the development of Antarctic krill flavoring products.
In this paper, defatted Antarctic krill powder was used as raw material to prepare hydrolysate with delicate taste by compound enzyme method. By means of sensory evaluation, peptide yield and degree of hydrolysis, the screening of exogenous enzymes and single factor experiments were carried out. In order to further optimize the taste of enzymatic hydrolysate, the total amount of amino acids with delicate flavor was used as the index to optimize the enzymatic hydrolysis condition. The results showed that the optimal hydrolysis conditions were as follows: The ratio of trypsin and pepsin 1:100, the total amount of enzyme 2800 U/g, the liquid and material ratio 1:4 g·mL−1, the pH of enzymatic hydrolysis 7.0, the temperature of enzymatic hydrolysis 40 ℃, and the time of enzymatic hydrolysis 3 h. Under these conditions, the content of free amino acids with delicate taste in the hydrolysate was 331.79 mg/100 mL. Except tryptophan, the remaining eight essential amino acids accounted for 63.66% of the total amino acids. Free bitter amino acids accounted for 27.83% of the total amino acids, and free sweet amino acids accounted for 26.22% of the total amino acids. Free glutamic acid and free aspartic acid, which played a key role in the formation of umami taste, accounted for 10.26% of the total free amino acids. This study could provide theoretical basis and technical guidance for the development of Antarctic krill flavoring products.
2022, 43(2): 206-214.
doi: 10.13386/j.issn1002-0306.2021040331
Abstract:
In order to alleviate the oxidation rate of hazelnut oil, increase the storage period and expand its application range, this study used β-cyclodextrin (β-CD) as the wall material and used the ultrasonic-assisted molecular embedding method to prepare hazelnut oil microcapsules, the process conditions of the microcapsules were optimized by response surface method, and their physical and chemical properties were measured at the same time. The results showed that when the wall material concentration (H2O/β-CD) was 16:1, the wall-to-core ratio was 5:1, the embedding time was 62 min, and the embedding temperature was 59.3 ℃, the embedding rate of microcapsules was up to 69.18%, and the yield rate reached 59.74%. The average particle size of the microcapsules was 880.4 nm, the moisture content was 2.85%, the solubility was 55.95%, and the angle of repose was 42.49°. The results of scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis showed that the microcapsules had a block, diamond-shaped flake or irregular columnar structure, the embedded material had been formed, and had good thermal stability. Accelerated oxidation experiments showed that microencapsulation could effectively slow down the oxidation rate of hazelnut oil, extend the shelf life, and expand its application range.
In order to alleviate the oxidation rate of hazelnut oil, increase the storage period and expand its application range, this study used β-cyclodextrin (β-CD) as the wall material and used the ultrasonic-assisted molecular embedding method to prepare hazelnut oil microcapsules, the process conditions of the microcapsules were optimized by response surface method, and their physical and chemical properties were measured at the same time. The results showed that when the wall material concentration (H2O/β-CD) was 16:1, the wall-to-core ratio was 5:1, the embedding time was 62 min, and the embedding temperature was 59.3 ℃, the embedding rate of microcapsules was up to 69.18%, and the yield rate reached 59.74%. The average particle size of the microcapsules was 880.4 nm, the moisture content was 2.85%, the solubility was 55.95%, and the angle of repose was 42.49°. The results of scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis showed that the microcapsules had a block, diamond-shaped flake or irregular columnar structure, the embedded material had been formed, and had good thermal stability. Accelerated oxidation experiments showed that microencapsulation could effectively slow down the oxidation rate of hazelnut oil, extend the shelf life, and expand its application range.
2022, 43(2): 215-225.
doi: 10.13386/j.issn1002-0306.2021050124
Abstract:
In this paper, a two-step hot air and microwave drying method was used to dry Porphyra, and the drying process was optimized. Taking the total drying time of Porphyra, the contents of protein and total sugar in dried Porphyra as indexes, the optimal drying process was obtained by using central composite design, model fitting by either quadratic polynomial or neural network, and genetic algorithm optimization. The results showed that the total drying time for sequential hot air drying(first) and microwave drying(later) was shorter than that for sequential microwave drying and hot air drying. In the case of sequential hot air drying(first) and microwave drying(later), the total drying time required to reduce the moisture content to 0.1 g/g DM was the shortest (62.5±1.4 min), if the hot air drying temperature and time were 65 ℃ and 1 h, and the subsequent microwave power was 400 W. Comparing the contents of protein and total sugar in dried Porphyra obtained under the optimal process conditions of the two drying methods, the quality of dried Porphyra obtained by sequential hot air drying(first) and microwave drying(later) was better than sequential microwave drying(first) and hot air drying(later). A highest protein content of 68.82±1.46 mg/g DM was obtained, when the hot air drying temperature and time were 48 ℃ and 3 h, and the subsequent microwave power was 240 W. Moreover, if the samples were first air dried at 65 ℃ for 2 h and then microwave processed at 240 W to the end, the total sugar content was the highest (124.72±7.17 mg/g DM). Generally, the sequential hot air drying(first) and microwave drying(later) would be suitable for the dehydration of Porphyra in terms of drying time and product quality.
In this paper, a two-step hot air and microwave drying method was used to dry Porphyra, and the drying process was optimized. Taking the total drying time of Porphyra, the contents of protein and total sugar in dried Porphyra as indexes, the optimal drying process was obtained by using central composite design, model fitting by either quadratic polynomial or neural network, and genetic algorithm optimization. The results showed that the total drying time for sequential hot air drying(first) and microwave drying(later) was shorter than that for sequential microwave drying and hot air drying. In the case of sequential hot air drying(first) and microwave drying(later), the total drying time required to reduce the moisture content to 0.1 g/g DM was the shortest (62.5±1.4 min), if the hot air drying temperature and time were 65 ℃ and 1 h, and the subsequent microwave power was 400 W. Comparing the contents of protein and total sugar in dried Porphyra obtained under the optimal process conditions of the two drying methods, the quality of dried Porphyra obtained by sequential hot air drying(first) and microwave drying(later) was better than sequential microwave drying(first) and hot air drying(later). A highest protein content of 68.82±1.46 mg/g DM was obtained, when the hot air drying temperature and time were 48 ℃ and 3 h, and the subsequent microwave power was 240 W. Moreover, if the samples were first air dried at 65 ℃ for 2 h and then microwave processed at 240 W to the end, the total sugar content was the highest (124.72±7.17 mg/g DM). Generally, the sequential hot air drying(first) and microwave drying(later) would be suitable for the dehydration of Porphyra in terms of drying time and product quality.
2022, 43(2): 226-232.
doi: 10.13386/j.issn1002-0306.2021050125
Abstract:
The polysaccharide was degraded by ascorbic acid and hydrogen peroxide, and the optimal degradation conditions were obtained by the index of DPPH free radical scavenging rate. Then the degradation products were classified by ultrafiltration to obtain different molecular weight components, and their activities were analyzed. The optimal degradation conditions were H2O2-VC 20 mmol/L, 45 ℃ and 3 h. Under these conditions, the DPPH free radical scavenging rate reached 61.23%, and the yield of degradation products was 73.16%. Electrophoretic results showed that the bands of the degraded polysaccharides were obviously in the low molecular weight region. Then the degradation products were classified into four different molecular weight fractions, as <5 kDa, 5~10 kDa, 10~30 kDa and >30 kDa by ultrafiltration. There were significant differences among the molecular weight segments (P<0.05), especially the <5 kDa component (main component 2.140×103 Da, 29.6%) had the best biological activity. The DPPH free radical scavenging rate was 59.27%, and the moisture retention rate was 75.75% after 60 h, the tyrosinase inhibition rate was 65.28%. The content of uronic acid of the <5 kDa component decreased slightly compared with polysaccharides. The results could provide theoretical basis for the application of polysaccharides in functional food and other fields.
The polysaccharide was degraded by ascorbic acid and hydrogen peroxide, and the optimal degradation conditions were obtained by the index of DPPH free radical scavenging rate. Then the degradation products were classified by ultrafiltration to obtain different molecular weight components, and their activities were analyzed. The optimal degradation conditions were H2O2-VC 20 mmol/L, 45 ℃ and 3 h. Under these conditions, the DPPH free radical scavenging rate reached 61.23%, and the yield of degradation products was 73.16%. Electrophoretic results showed that the bands of the degraded polysaccharides were obviously in the low molecular weight region. Then the degradation products were classified into four different molecular weight fractions, as <5 kDa, 5~10 kDa, 10~30 kDa and >30 kDa by ultrafiltration. There were significant differences among the molecular weight segments (P<0.05), especially the <5 kDa component (main component 2.140×103 Da, 29.6%) had the best biological activity. The DPPH free radical scavenging rate was 59.27%, and the moisture retention rate was 75.75% after 60 h, the tyrosinase inhibition rate was 65.28%. The content of uronic acid of the <5 kDa component decreased slightly compared with polysaccharides. The results could provide theoretical basis for the application of polysaccharides in functional food and other fields.
2022, 43(2): 233-240.
doi: 10.13386/j.issn1002-0306.2021050138
Abstract:
This paper aimed to optimize the culture technology of polysaccharide, nucleoside and total terpene produced by liquid fermentation of Hericium ericium, and explore its antioxidant activity.With the yield of three active ingredients as the index, the suitable carbon source, nitrogen source, temperature, rotational speed, pH and inoculation amount were screened out through single factor experiment. The comprehensive score of the yield of three active ingredients calculated by entropy weight method was used as the response value. A mathematical model was established by Box-Behnken to determine the optimal conditions for liquid fermentation of Hericium ericium. The antioxidant activity of the fermentation products was evaluated. The results showed that: The optimal carbon source was soluble starch and corn meal, the nitrogen source was yeast extract and yam juice, temperature 23.5 ℃, rotating speed 128 r/min, pH5.9, inoculation quantity 8.5%. Under these conditions, the comprehensive score of liquid fermentation condition of Hericium ericium was 2.090, which was basically consistent with the comprehensive score of 2.164 predicted by the model. The yield of polysaccharide, nucleoside and terpene were 5.12, 1.17 and 0.42 mg/mL. The IC50 values of DPPH scavenging rate of fermentation liquid, fermentation liquid and mycelium (wet) were 166, 237, 53 mg/mL, and the IC50 values of ABTS+ scavenging rate were 68, 55, 72 mg/mL. The total reducing capacities at 500 mg/mL were 0.711, 0.708 and 0.841. The study would lay a foundation for the industrialized production of Hericium ericium liquid fermentation.
This paper aimed to optimize the culture technology of polysaccharide, nucleoside and total terpene produced by liquid fermentation of Hericium ericium, and explore its antioxidant activity.With the yield of three active ingredients as the index, the suitable carbon source, nitrogen source, temperature, rotational speed, pH and inoculation amount were screened out through single factor experiment. The comprehensive score of the yield of three active ingredients calculated by entropy weight method was used as the response value. A mathematical model was established by Box-Behnken to determine the optimal conditions for liquid fermentation of Hericium ericium. The antioxidant activity of the fermentation products was evaluated. The results showed that: The optimal carbon source was soluble starch and corn meal, the nitrogen source was yeast extract and yam juice, temperature 23.5 ℃, rotating speed 128 r/min, pH5.9, inoculation quantity 8.5%. Under these conditions, the comprehensive score of liquid fermentation condition of Hericium ericium was 2.090, which was basically consistent with the comprehensive score of 2.164 predicted by the model. The yield of polysaccharide, nucleoside and terpene were 5.12, 1.17 and 0.42 mg/mL. The IC50 values of DPPH scavenging rate of fermentation liquid, fermentation liquid and mycelium (wet) were 166, 237, 53 mg/mL, and the IC50 values of ABTS+ scavenging rate were 68, 55, 72 mg/mL. The total reducing capacities at 500 mg/mL were 0.711, 0.708 and 0.841. The study would lay a foundation for the industrialized production of Hericium ericium liquid fermentation.
Preparation of Starch Nanoparticle by Alcohol Precipitation and Simultaneous Embedding of Kaempferol
2022, 43(2): 241-247.
doi: 10.13386/j.issn1002-0306.2020060123
Abstract:
Using tapioca starch as raw material, starch nanoparticles were prepared by ultrasonic stirring, and characterized by scanning electron microscopy, laser nanoparticle sizer, and X-ray diffraction. In the sedimentation stage of starch nanoparticles, kaempferol solution was used as the non-solvent phase with 0.7 mg/mL kaempferol solution to simultaneously embed kaempferol to prepare kaempferol starch nanoparticles. The influence of ethanol concentration on the embedding rate of kaempferol was explored, and the release rate and stability of kaempferol after embedding were investigated. The results showed that when the ethanol concentration was 60%, starch nanoparticles were formed, and the size was uniformly distributed between 50 and 200 nm, when the ethanol concentration was less than 40%, V-shaped starch particles were formed. When the ethanol concentration was 30%, the entrapment rate of kaempferol was the highest, at 62.94%, and the embedding amount was 3.78 mg/g. In a simulated body fluid environment, the kaempferol starch nanoparticles can continuously release the drug for 20 h. The release rate was 88.75%, while the original kaempferol was almost completely released in 3 h, the release rate was 93.75%, and the release rate increased with the increasing of the ethanol concentration of the sustained-release medium. Compared with the aqueous solution of kaempferol, the retention rate of kaempferol increased from 43.17% to 75% when the kaempferol starch nanoparticles were allowed to stand at room temperature for 5 h, which had a stable embedding effect. It could be seen that the simultaneous embedding preparation technology would have a good embedding slow-release effect and stabilizing effect on kaempferol.
Using tapioca starch as raw material, starch nanoparticles were prepared by ultrasonic stirring, and characterized by scanning electron microscopy, laser nanoparticle sizer, and X-ray diffraction. In the sedimentation stage of starch nanoparticles, kaempferol solution was used as the non-solvent phase with 0.7 mg/mL kaempferol solution to simultaneously embed kaempferol to prepare kaempferol starch nanoparticles. The influence of ethanol concentration on the embedding rate of kaempferol was explored, and the release rate and stability of kaempferol after embedding were investigated. The results showed that when the ethanol concentration was 60%, starch nanoparticles were formed, and the size was uniformly distributed between 50 and 200 nm, when the ethanol concentration was less than 40%, V-shaped starch particles were formed. When the ethanol concentration was 30%, the entrapment rate of kaempferol was the highest, at 62.94%, and the embedding amount was 3.78 mg/g. In a simulated body fluid environment, the kaempferol starch nanoparticles can continuously release the drug for 20 h. The release rate was 88.75%, while the original kaempferol was almost completely released in 3 h, the release rate was 93.75%, and the release rate increased with the increasing of the ethanol concentration of the sustained-release medium. Compared with the aqueous solution of kaempferol, the retention rate of kaempferol increased from 43.17% to 75% when the kaempferol starch nanoparticles were allowed to stand at room temperature for 5 h, which had a stable embedding effect. It could be seen that the simultaneous embedding preparation technology would have a good embedding slow-release effect and stabilizing effect on kaempferol.
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2022, 43(2): 248-254.
doi: 10.13386/j.issn1002-0306.2021050127
Abstract:
In this paper, 1-methylcyclopropene (1-MCP) controlled release packaging paper was prepared by mixing 1-methylcyclopropene with different proportions of ethyl cellulose ether (EC) and polyacrylic acid (PAA) and then coating it on the paper base. The release mechanism was studied. Saimaiti apricot fruits stored at 2 ℃ were treated with 1-MCP controlled release packaging paper. The effects of 1-MCP controllable slow-release packaging paper on respiratory intensity, hardness, titratable acid, soluble solids, peel color and commodity rate of apricot fruit during storage were studied in order to obtain a kind of fresh-keeping paper which could effectively prolong the storage period of apricot fruit. The results showed that under the conditions of 95% RH, 2 ℃ and 80% polyacrylic acid (PAA), the particle collapse of 1-MCP powder made the gas release slowly, and the release mechanism parameter was 0.49, and the release rate increased with PAA content. Controlled release 1-MCP-coated paper could inhibit the arrival of the peak of respiration intensity of apricot fruit, delay the decrease of hardness, titratable acid and soluble solid content, and maintain the color of peel. The results showed that controlled release 1-MCP-coated paper could effectively maintain the quality of apricot fruits stored in low temperature environment, and would provide some reference for the application of controlled release 1-MCP-coated paper to the storage of other fruits and vegetables.
In this paper, 1-methylcyclopropene (1-MCP) controlled release packaging paper was prepared by mixing 1-methylcyclopropene with different proportions of ethyl cellulose ether (EC) and polyacrylic acid (PAA) and then coating it on the paper base. The release mechanism was studied. Saimaiti apricot fruits stored at 2 ℃ were treated with 1-MCP controlled release packaging paper. The effects of 1-MCP controllable slow-release packaging paper on respiratory intensity, hardness, titratable acid, soluble solids, peel color and commodity rate of apricot fruit during storage were studied in order to obtain a kind of fresh-keeping paper which could effectively prolong the storage period of apricot fruit. The results showed that under the conditions of 95% RH, 2 ℃ and 80% polyacrylic acid (PAA), the particle collapse of 1-MCP powder made the gas release slowly, and the release mechanism parameter was 0.49, and the release rate increased with PAA content. Controlled release 1-MCP-coated paper could inhibit the arrival of the peak of respiration intensity of apricot fruit, delay the decrease of hardness, titratable acid and soluble solid content, and maintain the color of peel. The results showed that controlled release 1-MCP-coated paper could effectively maintain the quality of apricot fruits stored in low temperature environment, and would provide some reference for the application of controlled release 1-MCP-coated paper to the storage of other fruits and vegetables.
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2022, 43(2): 255-262.
doi: 10.13386/j.issn1002-0306.2021040230
Abstract:
The research process and methods of the blue mandarin flavor syrup shelf life prediction model were mainly described and the multi-dimensional quality changes and shelf life of the blue mandarin flavor syrup during storage were evaluated and predicted by this article. Through the analysis of sensory indicators, soluble solid content, pH, reducing sugar content, 5-hydroxymethyl-furfural (HMF) content and other indicators, combined with the kinetic model and the arrhenius equation, the shelf life prediction model was completed at 4, 27 and 37 ℃. The results showed that the sensory score of 80 points, the soluble solid content of 85%, the pH of 2, the reducing sugar content of 100%, and HMF content of 35 mg/kg were taken as the end of the shelf life of blue mandarin flavor syrup. Under 4 ℃ refrigeration conditions, the theoretical shelf life of blue mandarin flavor syrup was about 48 months. Under 20 ℃ room temperature, the theoretical shelf life of blue mandarin flavor syrup was about 24 months, and unacceptable loss of the quality of blue mandarin flavor syrup was appeared at the end of the shelf life. A new idea for the prediction and modeling of the shelf life of syrup products was provided by the establishment of the prediction model for the shelf life of blue mandarin flavor syrup.
The research process and methods of the blue mandarin flavor syrup shelf life prediction model were mainly described and the multi-dimensional quality changes and shelf life of the blue mandarin flavor syrup during storage were evaluated and predicted by this article. Through the analysis of sensory indicators, soluble solid content, pH, reducing sugar content, 5-hydroxymethyl-furfural (HMF) content and other indicators, combined with the kinetic model and the arrhenius equation, the shelf life prediction model was completed at 4, 27 and 37 ℃. The results showed that the sensory score of 80 points, the soluble solid content of 85%, the pH of 2, the reducing sugar content of 100%, and HMF content of 35 mg/kg were taken as the end of the shelf life of blue mandarin flavor syrup. Under 4 ℃ refrigeration conditions, the theoretical shelf life of blue mandarin flavor syrup was about 48 months. Under 20 ℃ room temperature, the theoretical shelf life of blue mandarin flavor syrup was about 24 months, and unacceptable loss of the quality of blue mandarin flavor syrup was appeared at the end of the shelf life. A new idea for the prediction and modeling of the shelf life of syrup products was provided by the establishment of the prediction model for the shelf life of blue mandarin flavor syrup.
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2022, 43(2): 263-270.
doi: 10.13386/j.issn1002-0306.2021040071
Abstract:
A method for the determination of 15 sex hormones in shrimp meat by EMR solid phase extraction combined with ultra performance liquid chromatography-tandem mass spectrometry was established. The samples was extracted with 0.1 mol/L ethylenediaminetetraacetic acid disodium solution and acetonitrile solution, purified by Captiva EMR SPE cartridge, separated by CAPCELLPAK C18 BB-H (3 µm, 2.1 mm×150 mm) column, and scanned by positive and negative ions of electrospray ion source. Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with multiple reaction monitoring mode was used for detection, and blank matrix matching external standard method was used for quantification. The positive ion mobile phase was methanol and 0.1% formic acid, and androgen and progesterone were detected. The negative ion mobile phase was acetonitrile and 0.01% ammonia aqueous solution to detect estrogen. The results showed that the 15 kinds of sex hormone residues in shrimp meat samples purified by EMR solid phase extraction had a good linear relationship in the concentration range of 1~50 μg/kg, and the correlation coefficients (r) were all greater than 0.99. The detection limits of the method were 0.0015~0.436 μg/kg, and the quantitative limits were 0.0051~1.453 μg/kg. The average recoveries were 85.31%~119.84%, and the relative standard deviations were 2.11%~9.86% (n=6). The method was rapid, simple, reproducible and sensitive, which was suitable for the detection of 15 kinds of sex hormone residues in shrimp meat.
A method for the determination of 15 sex hormones in shrimp meat by EMR solid phase extraction combined with ultra performance liquid chromatography-tandem mass spectrometry was established. The samples was extracted with 0.1 mol/L ethylenediaminetetraacetic acid disodium solution and acetonitrile solution, purified by Captiva EMR SPE cartridge, separated by CAPCELLPAK C18 BB-H (3 µm, 2.1 mm×150 mm) column, and scanned by positive and negative ions of electrospray ion source. Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with multiple reaction monitoring mode was used for detection, and blank matrix matching external standard method was used for quantification. The positive ion mobile phase was methanol and 0.1% formic acid, and androgen and progesterone were detected. The negative ion mobile phase was acetonitrile and 0.01% ammonia aqueous solution to detect estrogen. The results showed that the 15 kinds of sex hormone residues in shrimp meat samples purified by EMR solid phase extraction had a good linear relationship in the concentration range of 1~50 μg/kg, and the correlation coefficients (r) were all greater than 0.99. The detection limits of the method were 0.0015~0.436 μg/kg, and the quantitative limits were 0.0051~1.453 μg/kg. The average recoveries were 85.31%~119.84%, and the relative standard deviations were 2.11%~9.86% (n=6). The method was rapid, simple, reproducible and sensitive, which was suitable for the detection of 15 kinds of sex hormone residues in shrimp meat.
2022, 43(2): 271-278.
doi: 10.13386/j.issn1002-0306.2021040260
Abstract:
The contents of cyanogenic glycosides (Cyanogenic Glycosides, CNGs) are very important to evaluate the safety of sweet cassava roots and their products. Using cassava roots and cassava products as test materials in this study, a method for rapid extraction and high performance liquid chromatography-evaporative light scattering (HPLC-ELSD) detection of two kinds of cyanogenic glycosides was established. The content of CNGs in different varieties of cassava roots, cassava flour, and their products were analyzed. The results showed that the optimal extraction concentrations of sulfuric acid solution for these two GNSs from cassava roots and flour were 0.025 and 0.100 mol/L, respectively. The HPLC-ELSD method was effective in the separation of linamarin and lotaustralin. The linear correlation was good in the range of 4.1 to 820.0 mg/L and 2.5 to 250.0 mg/L, which correlation coefficients (r) reached 0.9996 and 0.9993 respectively. The LOD was 2.1 and 0.5 mg/L, and the LOQ was 8.2 and 2.0 mg/kg, respectively. The relative standard deviation (RSD) of repeatability and sample stability are both less than 5.0%. The average recovery rates of two CNGs in cassava roots and cassava products were between 89.3%~96.3% and 107.5%~114.9%, respectively. And the RSD of the repeatability of the recovery was less than 3.4%. The results of sample verification showed that the content of CNGs in different cassava varieties were quite different, The content of CNGs was lower in cassava flour which was prepared from cassava grown for 8~9 months, and the cooking method could effectively remove CNGs in cassava food. This method was simple, stable and accurate, and had a strong application prospect in the analysis and evaluation of CNGs in sweet cassava roots and their products.
The contents of cyanogenic glycosides (Cyanogenic Glycosides, CNGs) are very important to evaluate the safety of sweet cassava roots and their products. Using cassava roots and cassava products as test materials in this study, a method for rapid extraction and high performance liquid chromatography-evaporative light scattering (HPLC-ELSD) detection of two kinds of cyanogenic glycosides was established. The content of CNGs in different varieties of cassava roots, cassava flour, and their products were analyzed. The results showed that the optimal extraction concentrations of sulfuric acid solution for these two GNSs from cassava roots and flour were 0.025 and 0.100 mol/L, respectively. The HPLC-ELSD method was effective in the separation of linamarin and lotaustralin. The linear correlation was good in the range of 4.1 to 820.0 mg/L and 2.5 to 250.0 mg/L, which correlation coefficients (r) reached 0.9996 and 0.9993 respectively. The LOD was 2.1 and 0.5 mg/L, and the LOQ was 8.2 and 2.0 mg/kg, respectively. The relative standard deviation (RSD) of repeatability and sample stability are both less than 5.0%. The average recovery rates of two CNGs in cassava roots and cassava products were between 89.3%~96.3% and 107.5%~114.9%, respectively. And the RSD of the repeatability of the recovery was less than 3.4%. The results of sample verification showed that the content of CNGs in different cassava varieties were quite different, The content of CNGs was lower in cassava flour which was prepared from cassava grown for 8~9 months, and the cooking method could effectively remove CNGs in cassava food. This method was simple, stable and accurate, and had a strong application prospect in the analysis and evaluation of CNGs in sweet cassava roots and their products.
2022, 43(2): 279-285.
doi: 10.13386/j.issn1002-0306.2021040280
Abstract:
C9~C33 n-alkane standard solution and Smart Database Pesticides database were used to establish a rapid analytical method for the determination of 32 fungicides in strawberry based on retention index. Thirty-two fungicides were selected as the target, the samples were extracted and purified by QuEChERS method. Gas chromatography tandem mass spectrometry was used for qualitative and quantitative analysis. Results showed that, the 32 fungicides showed good linear relationship in the range of 5~200 μg/L, and the correlation coefficients were greater than 0.9982. The recoveries of 32 fungicides spiked at 10, 50, 100 μg/kg were 70.3%~117.8% and therelative standard deviations were 0.01%~8.50%. The limits of detection were 0.01~2.91 μg/kg, and the limits of quantitative were 0.04~9.71 μg/kg. This method was rapid, simple, accurate, steady, and achieved good performance in strawberry sample analyses, and was suitable for monitoring fungicides using in strawberry, and provided reliable date and technical support for determination of multi-component pesticide residues studies．
C9~C33 n-alkane standard solution and Smart Database Pesticides database were used to establish a rapid analytical method for the determination of 32 fungicides in strawberry based on retention index. Thirty-two fungicides were selected as the target, the samples were extracted and purified by QuEChERS method. Gas chromatography tandem mass spectrometry was used for qualitative and quantitative analysis. Results showed that, the 32 fungicides showed good linear relationship in the range of 5~200 μg/L, and the correlation coefficients were greater than 0.9982. The recoveries of 32 fungicides spiked at 10, 50, 100 μg/kg were 70.3%~117.8% and therelative standard deviations were 0.01%~8.50%. The limits of detection were 0.01~2.91 μg/kg, and the limits of quantitative were 0.04~9.71 μg/kg. This method was rapid, simple, accurate, steady, and achieved good performance in strawberry sample analyses, and was suitable for monitoring fungicides using in strawberry, and provided reliable date and technical support for determination of multi-component pesticide residues studies．
2022, 43(2): 286-292.
doi: 10.13386/j.issn1002-0306.2021050078
Abstract:
A method was established for the detection of nonylphenol migration in instant noodle barrel by high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). Using this method, we conduct risk analysis and assessment to marketed instant noodle barrels. The chromatographic separation and solid phase extraction conditions were optimized. The calibration curves of the nonylphenol showed good linear relationship in the range of 1~500 μg/L. The limits of detection ranged from 0.002~0.004 μg/L. The recoveries of real samples migration fluid at different spiked levels were in the range of 79.8%~105.2%, and the relative standard deviations (RSDs) were 1.74%~9.88%. 54 batches commercial instant noodle barrel were determined with this method, 45 samples detected nonylphenol, and nonylphenol content was 0.006~0.079 µg/L. According to the test results, the safety of nonyphenol in the instant noodle barrel was analyzed. The maximum daily intake of nonyphenol was 0.0237 µg/d, which was far lower than the health guidance value of nonyphenol (3 µg/d), indicating that the instant noodle barrel in the market is relatively safe and has a low risk to human health.
A method was established for the detection of nonylphenol migration in instant noodle barrel by high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). Using this method, we conduct risk analysis and assessment to marketed instant noodle barrels. The chromatographic separation and solid phase extraction conditions were optimized. The calibration curves of the nonylphenol showed good linear relationship in the range of 1~500 μg/L. The limits of detection ranged from 0.002~0.004 μg/L. The recoveries of real samples migration fluid at different spiked levels were in the range of 79.8%~105.2%, and the relative standard deviations (RSDs) were 1.74%~9.88%. 54 batches commercial instant noodle barrel were determined with this method, 45 samples detected nonylphenol, and nonylphenol content was 0.006~0.079 µg/L. According to the test results, the safety of nonyphenol in the instant noodle barrel was analyzed. The maximum daily intake of nonyphenol was 0.0237 µg/d, which was far lower than the health guidance value of nonyphenol (3 µg/d), indicating that the instant noodle barrel in the market is relatively safe and has a low risk to human health.
2022, 43(2): 293-303.
doi: 10.13386/j.issn1002-0306.2021050084
Abstract:
The static headspace(HS) combined with gas chromatography-mass spectrometry(GC-MS) was used to analyze the volatile flavor compounds of Zanthoxylum bungeanum from 45 producing areas in Shanxi, Shandong, Sichuan and Gansu. Using automatic mass spectrometry deconvolution qualitative system(AMDIS) and Kováts Retention index(RI) analysis, a total of 99 volatile compounds were obtained. 79, 69, 68 and 63 volatile compounds were identified in Zanthoxylum bungeanum from Shanxi, Gansu, Shandong and Sichuan province. A variety of mathematical models were established to identify the origin. Among them, the Orthogonal partial least squares(OPLS-DA) model could accurately distinguish Zanthoxylum bungeanum samples from 4 provinces, the model fitting parameter Q2 was 0.84, and the 6 key difference substances(VIP>2) were piperonone, pinene, terpinene, 3-carene, ocirene and α-phellandrene. Further application of GC-MS full-spectrum data combined with Random Forest(RF) model for origin identification could successfully distinguish Zanthoxylum bungeanum from Shanxi, Gansu, Shandong and Sichuan provinces, with an accuracy rate of 100%.
The static headspace(HS) combined with gas chromatography-mass spectrometry(GC-MS) was used to analyze the volatile flavor compounds of Zanthoxylum bungeanum from 45 producing areas in Shanxi, Shandong, Sichuan and Gansu. Using automatic mass spectrometry deconvolution qualitative system(AMDIS) and Kováts Retention index(RI) analysis, a total of 99 volatile compounds were obtained. 79, 69, 68 and 63 volatile compounds were identified in Zanthoxylum bungeanum from Shanxi, Gansu, Shandong and Sichuan province. A variety of mathematical models were established to identify the origin. Among them, the Orthogonal partial least squares(OPLS-DA) model could accurately distinguish Zanthoxylum bungeanum samples from 4 provinces, the model fitting parameter Q2 was 0.84, and the 6 key difference substances(VIP>2) were piperonone, pinene, terpinene, 3-carene, ocirene and α-phellandrene. Further application of GC-MS full-spectrum data combined with Random Forest(RF) model for origin identification could successfully distinguish Zanthoxylum bungeanum from Shanxi, Gansu, Shandong and Sichuan provinces, with an accuracy rate of 100%.
2022, 43(2): 304-310.
doi: 10.13386/j.issn1002-0306.2021050109
Abstract:
Mature corn grains is an important food ration for residents in our country, but its edible flavor quality was rarely reported. The volatile organic components (VOCs) in whole grain powder with different treatment of 5 high-quality yellow grain maize varieties were detected with gas chromatography-mass spectrometry (GC-MS), the results showed that a total of 101 species of VOCs were identified, but only 60~70 species were found in a single variety. These VOCs could be divided into 12 categories, of which, the number of esters, alkanes and ketones were more, followed by alcohols, aldehydes and amides. When the composition of VOCs were analyzed, it was also found that there were about 20 species of components with high content at the level of over 106 peak area, which constituted 80% of the total volatile substances content, in these high content components, 13 were co-owned which were present in all samples, and 4~16 were specific which varied among varieties. There were two species of high content components at the level of 107 peak area, n-dodecane and tert-butanol were identified, which were considered to be important volatile substances in corn. The detection results also showed that the relative total content of VOCs in the samples distributed from 36.660 to 68.001 mg/kg. When they were compared each other, it was also found that the total content of VOCs was significantly different among varieties and samples, including different storage time and packages. The content of aroma substances in newly harvested grains was the highest. The ears or grains was stored naturally 1 year, its VOCs lost about 1/5. While the whole powder was stored naturally 1 year, its VOCs lost nearly a third. But the powder being stored in vacuum bags and under the low temperature 3 years, the loss of VOCs was slightly. These results suggested that the aroma substances content in corn was a variety characteristic. Excellent varieties and special production areas could effectively increase the kinds and the content of aroma substances in grains. Storage time and storage conditions could significantly affect the quality of aroma. Storage under the conditions of low temperature and vacuum could effectively maintain the quality of aroma. These results provided important reference data for quality evaluation of high quality edible corn.
Mature corn grains is an important food ration for residents in our country, but its edible flavor quality was rarely reported. The volatile organic components (VOCs) in whole grain powder with different treatment of 5 high-quality yellow grain maize varieties were detected with gas chromatography-mass spectrometry (GC-MS), the results showed that a total of 101 species of VOCs were identified, but only 60~70 species were found in a single variety. These VOCs could be divided into 12 categories, of which, the number of esters, alkanes and ketones were more, followed by alcohols, aldehydes and amides. When the composition of VOCs were analyzed, it was also found that there were about 20 species of components with high content at the level of over 106 peak area, which constituted 80% of the total volatile substances content, in these high content components, 13 were co-owned which were present in all samples, and 4~16 were specific which varied among varieties. There were two species of high content components at the level of 107 peak area, n-dodecane and tert-butanol were identified, which were considered to be important volatile substances in corn. The detection results also showed that the relative total content of VOCs in the samples distributed from 36.660 to 68.001 mg/kg. When they were compared each other, it was also found that the total content of VOCs was significantly different among varieties and samples, including different storage time and packages. The content of aroma substances in newly harvested grains was the highest. The ears or grains was stored naturally 1 year, its VOCs lost about 1/5. While the whole powder was stored naturally 1 year, its VOCs lost nearly a third. But the powder being stored in vacuum bags and under the low temperature 3 years, the loss of VOCs was slightly. These results suggested that the aroma substances content in corn was a variety characteristic. Excellent varieties and special production areas could effectively increase the kinds and the content of aroma substances in grains. Storage time and storage conditions could significantly affect the quality of aroma. Storage under the conditions of low temperature and vacuum could effectively maintain the quality of aroma. These results provided important reference data for quality evaluation of high quality edible corn.
2022, 43(2): 311-318.
doi: 10.13386/j.issn1002-0306.2021050119
Abstract:
Twelve varieties of kiwifruit from the three major lines of Meiwei, Zhonghua and Ruanzao from the two main producing areas of Shaanxi and Sichuan provinces were used as test materials. The main antioxidant active substances, polyphenols, flavonoids, VC, and the content of monomer phenols in fruit were determined. The antioxidant activity in vitro was compared, and the correlation analysis between the antioxidant activity and the antioxidant capacity of fruit juice was carried out, and the varieties with high antioxidant content and strong antioxidant activity were screened out. Results showed that there were significant differences in the antioxidant activity content and antioxidant capacity of different varieties of kiwifruit (P<0.05). The content of VC varied greatly among different varieties, ranging from 27.300 to 130.380 mg/100 g. The content of flavonoids in two varieties of Ruanzao (Yiyu and Lvmi) was significantly higher than that of other varieties (P<0.05). Protocatechin, catechin, chlorogenic acid, and epicatechin were the main polyphenol compounds in kiwifruit. Hongyang, Cuixiang, Yate, and Huayou had strong scavenging ability on DPPH· and ABTS+·, while Yiyu and Lvmi had strong scavenging ability and total reducing power on ·OH. The content of polyphenols in each kiwifruit had a significant correlation with the total reducing power (P<0.05), and there were also correlations between the content of monophenols, and between monophenols and antioxidant activity. According to cluster analysis based on antioxidant activity, twelve varieties of kiwifruit could be divided into six categories. Comprehensive analysis showed that among the 12 varieties, Ruanzao had the strongest antioxidant activity. The research results would provide a scientific basis for the selection of kiwifruit varieties with high antioxidant activity during fresh food and processing.
Twelve varieties of kiwifruit from the three major lines of Meiwei, Zhonghua and Ruanzao from the two main producing areas of Shaanxi and Sichuan provinces were used as test materials. The main antioxidant active substances, polyphenols, flavonoids, VC, and the content of monomer phenols in fruit were determined. The antioxidant activity in vitro was compared, and the correlation analysis between the antioxidant activity and the antioxidant capacity of fruit juice was carried out, and the varieties with high antioxidant content and strong antioxidant activity were screened out. Results showed that there were significant differences in the antioxidant activity content and antioxidant capacity of different varieties of kiwifruit (P<0.05). The content of VC varied greatly among different varieties, ranging from 27.300 to 130.380 mg/100 g. The content of flavonoids in two varieties of Ruanzao (Yiyu and Lvmi) was significantly higher than that of other varieties (P<0.05). Protocatechin, catechin, chlorogenic acid, and epicatechin were the main polyphenol compounds in kiwifruit. Hongyang, Cuixiang, Yate, and Huayou had strong scavenging ability on DPPH· and ABTS+·, while Yiyu and Lvmi had strong scavenging ability and total reducing power on ·OH. The content of polyphenols in each kiwifruit had a significant correlation with the total reducing power (P<0.05), and there were also correlations between the content of monophenols, and between monophenols and antioxidant activity. According to cluster analysis based on antioxidant activity, twelve varieties of kiwifruit could be divided into six categories. Comprehensive analysis showed that among the 12 varieties, Ruanzao had the strongest antioxidant activity. The research results would provide a scientific basis for the selection of kiwifruit varieties with high antioxidant activity during fresh food and processing.
2022, 43(2): 319-327.
doi: 10.13386/j.issn1002-0306.2021070239
Abstract:
In order to study the volatile composition of onion, the volatile flavoring substances of the onion were extracted by headspace solid phase microextraction and determined by gas chromatography-mass spectrometry. The effects of extraction fiber head, extraction temperature, extraction time and desorption time on the total peak area and the number of effective compounds were investigated. The optimum extraction conditions were determined as follows: Extraction fiber 50/30 μm DVB/CAR/PDMS, extraction temperature 60 ℃, extraction time 60 min and desorption time 5 min. Under the optimum experimental conditions, the volatile compounds of onion with three different colors were analyzed and identified. The results showed that a total of 61 kinds of volatile flavor compounds were identified. A total of 37, 40 and 49 volatile flavor compounds were detected in the white, red, and yellow onions, respectively, and the peak area content of these volatile flavor compounds accounted for 70.29%, 81.92% and 79.03% of the total volatile components, respectively. In the 61 volatile flavor compounds, 27 were sulfur compounds, 13 were aldehydes, 13 were alcohols, 4 were ketones and 4 were others. There were 22 kinds of volatile components in the three color onions, of which sulfur-containing compounds account for a relatively large proportion, especially the relative content of diisopropyl disulfide and (E)-1-propenyl-2-propenyl disulfide. The sum of the volatile components of the three color onions accounted for more than 20%, which contributed a lot to the formation of the characteristic flavor of onions. The relative content of sulfur compounds in red and yellow onions was much higher than that of white onions. The relative content of 2-methyl-2-pentenoaldehyde in red onions was higher than that of white and yellow onions.
In order to study the volatile composition of onion, the volatile flavoring substances of the onion were extracted by headspace solid phase microextraction and determined by gas chromatography-mass spectrometry. The effects of extraction fiber head, extraction temperature, extraction time and desorption time on the total peak area and the number of effective compounds were investigated. The optimum extraction conditions were determined as follows: Extraction fiber 50/30 μm DVB/CAR/PDMS, extraction temperature 60 ℃, extraction time 60 min and desorption time 5 min. Under the optimum experimental conditions, the volatile compounds of onion with three different colors were analyzed and identified. The results showed that a total of 61 kinds of volatile flavor compounds were identified. A total of 37, 40 and 49 volatile flavor compounds were detected in the white, red, and yellow onions, respectively, and the peak area content of these volatile flavor compounds accounted for 70.29%, 81.92% and 79.03% of the total volatile components, respectively. In the 61 volatile flavor compounds, 27 were sulfur compounds, 13 were aldehydes, 13 were alcohols, 4 were ketones and 4 were others. There were 22 kinds of volatile components in the three color onions, of which sulfur-containing compounds account for a relatively large proportion, especially the relative content of diisopropyl disulfide and (E)-1-propenyl-2-propenyl disulfide. The sum of the volatile components of the three color onions accounted for more than 20%, which contributed a lot to the formation of the characteristic flavor of onions. The relative content of sulfur compounds in red and yellow onions was much higher than that of white onions. The relative content of 2-methyl-2-pentenoaldehyde in red onions was higher than that of white and yellow onions.
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2022, 43(2): 328-337.
doi: 10.13386/j.issn1002-0306.2021060097
Abstract:
In order to evaluate the quality parameters for short-term stored paddy with slightly high moisture, this study determined the changes in intergranular air relative humidity (RH) and wetbulb temperature of grain bulk with an equilibrium moisture model and Newton-Raphson method, and analyzed the effect of their accumulation amount during storage on thermal and thermo-mechanical properties, and lipid components, and appearance quality indexes in milled rice. The japonica paddy with 15.3% MC was put into warehouse in winter and stored for 163 days, when the average dry temperature in bulk increased from 8.3 to 22.9°C, the average RH in bulk layer 1, 2, 3, and 4 respectively increased 3.6%, 3.0%, 2.9%, and 2.9% from 75.1%, and wetbulb temperature respectively increased 15.21, 13.57, 13.47 and 13.29 °C from 6.2 °C, showing no damage from stored insects and fungi. The gelatinization peak temperature of rice flour measured by DSC remained unchanged. A Mixolab analysis showed, during paddy storage from 45 to 213 d, dough development time and stability time, and starch setback torque gradually increased, but enzymatic speed decreased. GC-MS analysis showed the percent of the main fatty acid species kept unchanged during 213 d paddy storage. External indexes like accumulation of grain bulk maximum temperature, and accumulation of wetbulb temperature corresponding to bulk maximum temperature, and internal indexes such as the temperature, area and height of rice flour gelatinization peak measured by DSC, and dough development time and stability time, gelatinization peak torque and enzymatic speed in rice flour measured by a Mixolab, and fatty acid components (C14:1, C14:0, C20:5n3, C20:3n6, C20:2, C20:1, C24:1, C24:0), as well as rice appearance quality indexes like head rice percentage, small broken kernel rate, and kernel size could be used as the evaluation indexes for the low temperature storage of a japonica paddy with slightly high moisture.
In order to evaluate the quality parameters for short-term stored paddy with slightly high moisture, this study determined the changes in intergranular air relative humidity (RH) and wetbulb temperature of grain bulk with an equilibrium moisture model and Newton-Raphson method, and analyzed the effect of their accumulation amount during storage on thermal and thermo-mechanical properties, and lipid components, and appearance quality indexes in milled rice. The japonica paddy with 15.3% MC was put into warehouse in winter and stored for 163 days, when the average dry temperature in bulk increased from 8.3 to 22.9°C, the average RH in bulk layer 1, 2, 3, and 4 respectively increased 3.6%, 3.0%, 2.9%, and 2.9% from 75.1%, and wetbulb temperature respectively increased 15.21, 13.57, 13.47 and 13.29 °C from 6.2 °C, showing no damage from stored insects and fungi. The gelatinization peak temperature of rice flour measured by DSC remained unchanged. A Mixolab analysis showed, during paddy storage from 45 to 213 d, dough development time and stability time, and starch setback torque gradually increased, but enzymatic speed decreased. GC-MS analysis showed the percent of the main fatty acid species kept unchanged during 213 d paddy storage. External indexes like accumulation of grain bulk maximum temperature, and accumulation of wetbulb temperature corresponding to bulk maximum temperature, and internal indexes such as the temperature, area and height of rice flour gelatinization peak measured by DSC, and dough development time and stability time, gelatinization peak torque and enzymatic speed in rice flour measured by a Mixolab, and fatty acid components (C14:1, C14:0, C20:5n3, C20:3n6, C20:2, C20:1, C24:1, C24:0), as well as rice appearance quality indexes like head rice percentage, small broken kernel rate, and kernel size could be used as the evaluation indexes for the low temperature storage of a japonica paddy with slightly high moisture.
2022, 43(2): 338-345.
doi: 10.13386/j.issn1002-0306.2021060219
Abstract:
Objective: Evaluating the effects of plasma-activated water (PAW) used as a thawing medium on the microbial safety and fresh quality of beef. Methods: The PAW was prepared by treating the 300 mL deionized water with the plasma jet for various times (40, 60, 80, 100, 120 s). Using the PAW, which was placed at room temperature (25 ℃) to thaw the frozen beef tendon meat for 10 min, and the mass ratio of PAW to beef was 4:1. The beef’s and the thawing media’s physicochemical properties such as the total number of colonies, nitrite, and pH were assessed, and water retention (purge loss, water holding capacity), lipid oxidation, and protein loss of beef were evaluated. Results: As the preparation time of plasma-activated water prolonged, the antibacterial activity of PAW significantly increased (P<0.05), and the number of total viable bacteria in beef after thawing treatment was reduced by 0.91 lg (CFU/g). PAW treatment significantly enhanced the water holding capacity of beef (P<0.05). After thawing, the juice leakage, lipid oxidation and protein loss were reduced by 1.83%, 0.0944 mg/kg and 0.085 mg/mL, respectively. After thawing, the maximum content of nitrite content in beef was 3.38 mg/kg, which was still lower than the limit of quantification, while the pH value of thawed meat only increased by 0.06. The results showed that such a treatment had no significant effect on the nitrite content and pH of beef (P<0.05). This study would provide a theoretical basis and data reference for the application of PAW in the thawing of frozen meat products.
Objective: Evaluating the effects of plasma-activated water (PAW) used as a thawing medium on the microbial safety and fresh quality of beef. Methods: The PAW was prepared by treating the 300 mL deionized water with the plasma jet for various times (40, 60, 80, 100, 120 s). Using the PAW, which was placed at room temperature (25 ℃) to thaw the frozen beef tendon meat for 10 min, and the mass ratio of PAW to beef was 4:1. The beef’s and the thawing media’s physicochemical properties such as the total number of colonies, nitrite, and pH were assessed, and water retention (purge loss, water holding capacity), lipid oxidation, and protein loss of beef were evaluated. Results: As the preparation time of plasma-activated water prolonged, the antibacterial activity of PAW significantly increased (P<0.05), and the number of total viable bacteria in beef after thawing treatment was reduced by 0.91 lg (CFU/g). PAW treatment significantly enhanced the water holding capacity of beef (P<0.05). After thawing, the juice leakage, lipid oxidation and protein loss were reduced by 1.83%, 0.0944 mg/kg and 0.085 mg/mL, respectively. After thawing, the maximum content of nitrite content in beef was 3.38 mg/kg, which was still lower than the limit of quantification, while the pH value of thawed meat only increased by 0.06. The results showed that such a treatment had no significant effect on the nitrite content and pH of beef (P<0.05). This study would provide a theoretical basis and data reference for the application of PAW in the thawing of frozen meat products.
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2022, 43(2): 346-353.
doi: 10.13386/j.issn1002-0306.2021040049
Abstract:
Objective: To investigate the effects of conjugated linoleic acid (CLA) on lipid accumulation and intestinal microbiota in obese rats. Methods: Forty SPF male SD rats were randomly divided into four groups according to body weight, 10 rats in each group. The ND group was fed with ordinary diet, and the other groups were fed with high-fat diet. Among them, the ND group was intragastrically administered with peanut oil 1 g/kg, the model group (HD group) was intragastrically administered with peanut oil 1 g/kg, the low-dose group (LC group) was intragastrically administered with 0.2% conjugated linoleic acid 1 g/kg, and the high-dose group (HC group) was intragastrically administered with 2% conjugated linoleic acid 1 g/kg for 9 weeks of intervention. Bacterial DNA was extracted from feces of mice after collection of feces at the end of the experiment followed by 16S rDNA sequencing, after which blood was collected and sacrificed under anesthesia, and organ and visceral fat were taken and stored at −80 ℃. Results: The body weight, visceral fat, serum and liver triglycerides and total cholesterol of rats in the HD group were significantly higher than those in the ND group (P<0.05), and high-dose CLA intervention could significantly reduce the body weight, serum triglycerides, total cholesterol and liver total cholesterol of rats (P<0.05). High-fat diet could increase the relative abundance of Eubacterium_coprostanoligenes_group, Psychrobacter, Corynebacterium_1 and Staphylococcus in the intestinal microbiota level of rats. High-dose CLA could change the composition of intestinal microbiota in obese rats, such as significantly increasing the relative abundance of Bifidobacterium, Butyrivibrio and Ruminococcaceae_UCG-014 at the genus level (P<0.05) and reducing the relative abundance of Staphylococcus and Corynebacterium_1 (P<0.05). Conclusion: Conjugated linoleic acid could reduce body weight and lipid accumulation of obese rats induced by high fat diet, which might be related to the regulation of intestinal microbiotal diversity.
Objective: To investigate the effects of conjugated linoleic acid (CLA) on lipid accumulation and intestinal microbiota in obese rats. Methods: Forty SPF male SD rats were randomly divided into four groups according to body weight, 10 rats in each group. The ND group was fed with ordinary diet, and the other groups were fed with high-fat diet. Among them, the ND group was intragastrically administered with peanut oil 1 g/kg, the model group (HD group) was intragastrically administered with peanut oil 1 g/kg, the low-dose group (LC group) was intragastrically administered with 0.2% conjugated linoleic acid 1 g/kg, and the high-dose group (HC group) was intragastrically administered with 2% conjugated linoleic acid 1 g/kg for 9 weeks of intervention. Bacterial DNA was extracted from feces of mice after collection of feces at the end of the experiment followed by 16S rDNA sequencing, after which blood was collected and sacrificed under anesthesia, and organ and visceral fat were taken and stored at −80 ℃. Results: The body weight, visceral fat, serum and liver triglycerides and total cholesterol of rats in the HD group were significantly higher than those in the ND group (P<0.05), and high-dose CLA intervention could significantly reduce the body weight, serum triglycerides, total cholesterol and liver total cholesterol of rats (P<0.05). High-fat diet could increase the relative abundance of Eubacterium_coprostanoligenes_group, Psychrobacter, Corynebacterium_1 and Staphylococcus in the intestinal microbiota level of rats. High-dose CLA could change the composition of intestinal microbiota in obese rats, such as significantly increasing the relative abundance of Bifidobacterium, Butyrivibrio and Ruminococcaceae_UCG-014 at the genus level (P<0.05) and reducing the relative abundance of Staphylococcus and Corynebacterium_1 (P<0.05). Conclusion: Conjugated linoleic acid could reduce body weight and lipid accumulation of obese rats induced by high fat diet, which might be related to the regulation of intestinal microbiotal diversity.
2022, 43(2): 354-359.
doi: 10.13386/j.issn1002-0306.2021040074
Abstract:
Objective: To study the uric acid-lowering and renal protective effects of Portulaca oleracea to provide reference for clinical research. Methods: Male ICR mice were randomly divided into 5 groups. Blank group (CON), model group (HUA), allopurinol positive drug control group (ALLOP, 0.02 g/kg/d), purslane high-dose group (PO-H, 1.48 g/kg/d), Portulaca low-dose group (PO-L, 0.5 g/kg/d). Each group was given the corresponding dose for 21 d continuously, starting from the 7th day, except for the blank group, each group was intraperitoneally injected with hypoxanthine (HX, 0.3 g/kg) combined with potassium oxazine (OAPS, 0.3 g/kg) to establish a hyperuricemia model. Observe serum uric acid (SUA) and malondialdehyde (MDA) levels in mice, collect liver to detect xanthine oxidase (XOD) and superoxide dismutase (SOD) levels, collect kidney to detect glutathione (GSH), glutathione peroxidase (GSH-PX) level. 24 hours urine was collected the day before the end of the experiment to detect urine uric acid (UUA) and urine creatinine (UCr) levels, pathological observation of mouse kidney HE staining was performed. Results: Compared with the CON group, the HUA group significantly (P<0.01) increased the levels of MDA, SUA, and XOD, and significantly (P<0.01) decreased the levels of SOD, GSH, GSH-PX, UUA, and UCr, indicating that hyperuricemia was a cause of hyperuricemia. The model was successful. Compared with HUA group, PO-H group could significantly (P<0.01) reduce SUA, MDA, XOD (levels, significantly (P<0.01), increase SOD, GSH, GSH-PX, UCr levels. PO-L group could significantly (P<0.05 or P<0.01) reduce the levels of SUA, MDA, XOD, and significantly (P<0.05 or P<0.01) increase the levels of GSH, GSH-PX, UCr. HE staining results showed that PO could significantly improve the kidneys of HUA mice tissue pathological changes. Conclusion: Portulaca oleracea extract would have certain uric acid-lowering and renal protective functions on hyperuricemia mice.
Objective: To study the uric acid-lowering and renal protective effects of Portulaca oleracea to provide reference for clinical research. Methods: Male ICR mice were randomly divided into 5 groups. Blank group (CON), model group (HUA), allopurinol positive drug control group (ALLOP, 0.02 g/kg/d), purslane high-dose group (PO-H, 1.48 g/kg/d), Portulaca low-dose group (PO-L, 0.5 g/kg/d). Each group was given the corresponding dose for 21 d continuously, starting from the 7th day, except for the blank group, each group was intraperitoneally injected with hypoxanthine (HX, 0.3 g/kg) combined with potassium oxazine (OAPS, 0.3 g/kg) to establish a hyperuricemia model. Observe serum uric acid (SUA) and malondialdehyde (MDA) levels in mice, collect liver to detect xanthine oxidase (XOD) and superoxide dismutase (SOD) levels, collect kidney to detect glutathione (GSH), glutathione peroxidase (GSH-PX) level. 24 hours urine was collected the day before the end of the experiment to detect urine uric acid (UUA) and urine creatinine (UCr) levels, pathological observation of mouse kidney HE staining was performed. Results: Compared with the CON group, the HUA group significantly (P<0.01) increased the levels of MDA, SUA, and XOD, and significantly (P<0.01) decreased the levels of SOD, GSH, GSH-PX, UUA, and UCr, indicating that hyperuricemia was a cause of hyperuricemia. The model was successful. Compared with HUA group, PO-H group could significantly (P<0.01) reduce SUA, MDA, XOD (levels, significantly (P<0.01), increase SOD, GSH, GSH-PX, UCr levels. PO-L group could significantly (P<0.05 or P<0.01) reduce the levels of SUA, MDA, XOD, and significantly (P<0.05 or P<0.01) increase the levels of GSH, GSH-PX, UCr. HE staining results showed that PO could significantly improve the kidneys of HUA mice tissue pathological changes. Conclusion: Portulaca oleracea extract would have certain uric acid-lowering and renal protective functions on hyperuricemia mice.
2022, 43(2): 360-367.
doi: 10.13386/j.issn1002-0306.2021040252
Abstract:
Using absolute ethanol as an inducer, a rat model of acute gastric mucosal injury was constructed, and the protective effects of Hericium erinaceus crude extract prepared in several different ways on the model of acute gastric mucosal injury induced by absolute ethanol were studied. Female SD rats were randomly divided into 7 groups (n=12): Normal control group (NC), model control group (ETH), Hericium erinaceus fruit body polysaccharide intervention group(WEH1), Hericium erinaceus mycelium polysaccharide intervention group (WEH2), Hericium erinaceus water extract intervention group (WEH3), liquid fermentation water extract intervention group (WEH4) and bismuth potassium citrate granule drug group (YWZ). In each sample groups, the gavage dose (10 mL/kg) of the sample was adjusted according to the weight change, and the sample was given 167 mg/kg, bismuth potassium citrate granules (0.24 g/kg, containing 24.1 mg of bismuth) for continuous intragastric administration for 30 days. Then the normal control group and the model group were directly given distilled water, and 5 mL/kg of absolute ethanol was used to make the model. The degree of injury of gastric mucosal tissue slices, the level of inflammatory factors and the antioxidant capacity were compared. Finally the results showed that comparing with the model group, the experimental group had significantly reduced gastric mucosal bleeding, congestion, necrosis, and pathology, and the total pathological scores were significantly different (P<0.05), the activities of superoxide dismutase (SOD) and glutathione (GSH) were significantly increased (P<0.05), the content of malondialdehyde (MDA), tumor necrosis factor-α in serum and gastric tissue (TNF-α), interleukin-6(IL-6), interleukin-1β (IL-1β) inflammatory factors levels were significantly reduced (P<0.05). So the tests showed that several Hericium erinaceus extracts had varying degrees of protection against gastric mucosal damage in rats induced by absolute ethanol, among of them, the Hericium erinaceus mycelium polysaccharide had the best protective effect, while its mechanism of action might be similar to that of anti- oxidation was related to anti-inflammatory effects. The research results could provide a research foundation for the development and promotion of functional products of different Hericium erinaceus extracts.
Using absolute ethanol as an inducer, a rat model of acute gastric mucosal injury was constructed, and the protective effects of Hericium erinaceus crude extract prepared in several different ways on the model of acute gastric mucosal injury induced by absolute ethanol were studied. Female SD rats were randomly divided into 7 groups (n=12): Normal control group (NC), model control group (ETH), Hericium erinaceus fruit body polysaccharide intervention group(WEH1), Hericium erinaceus mycelium polysaccharide intervention group (WEH2), Hericium erinaceus water extract intervention group (WEH3), liquid fermentation water extract intervention group (WEH4) and bismuth potassium citrate granule drug group (YWZ). In each sample groups, the gavage dose (10 mL/kg) of the sample was adjusted according to the weight change, and the sample was given 167 mg/kg, bismuth potassium citrate granules (0.24 g/kg, containing 24.1 mg of bismuth) for continuous intragastric administration for 30 days. Then the normal control group and the model group were directly given distilled water, and 5 mL/kg of absolute ethanol was used to make the model. The degree of injury of gastric mucosal tissue slices, the level of inflammatory factors and the antioxidant capacity were compared. Finally the results showed that comparing with the model group, the experimental group had significantly reduced gastric mucosal bleeding, congestion, necrosis, and pathology, and the total pathological scores were significantly different (P<0.05), the activities of superoxide dismutase (SOD) and glutathione (GSH) were significantly increased (P<0.05), the content of malondialdehyde (MDA), tumor necrosis factor-α in serum and gastric tissue (TNF-α), interleukin-6(IL-6), interleukin-1β (IL-1β) inflammatory factors levels were significantly reduced (P<0.05). So the tests showed that several Hericium erinaceus extracts had varying degrees of protection against gastric mucosal damage in rats induced by absolute ethanol, among of them, the Hericium erinaceus mycelium polysaccharide had the best protective effect, while its mechanism of action might be similar to that of anti- oxidation was related to anti-inflammatory effects. The research results could provide a research foundation for the development and promotion of functional products of different Hericium erinaceus extracts.
2022, 43(2): 368-375.
doi: 10.13386/j.issn1002-0306.2021050117
Abstract:
Study the effects of aerobic exercise combined with D-ribose supplementation on the anti-fatigue and antioxidant enzyme activities of mice, the mice were divided into quiet control group, aerobic exercise control group, D-ribose control group, D-ribose+aerobic exercise group. The aerobic exercise group received aerobic treadmill training for 6 days a week, and the D-ribose group was given 2 mL of ribose (300 mg/100 g) per rat per day. After 12 weeks of regular aerobic treadmill training, an anti-fatigue animal model was established for mice swimming with weight, the time of exhausted swimming was recorded in mice, and hepaticr glycogen (HG), muscle glycogen (MG), and blood glucose in mice, blood urea nitrogen (BUN), blood lactic acid (BLA), malondialdehyde (MDA) content and total antioxidant capacity (T-AOC), glutathione Oxide dismutase (glutathione peroxide dismutase, GSH-Px), superoxide dismutase (SOD), catalase (catalase, CAT) and other activities were measured. The results showed that compared with the quiet control group, the weight-bearing swimming time of mice in the aerobic exercise control group, D-ribose control group, and D-ribose+aerobic exercise group significantly increased (P<0.05), and at the same time the mice's body hepatic glycogen, muscle glycogen and blood sugar content were significantly improved(P<0.05), and the blood urea nitrogen and blood lactic acid content in the body were significantly reduced(P<0.05). In addition, the results of its antioxidant activity showed that compared with the quiet control group, the T-AOC of the aerobic exercise control group, D-ribose control group, D-ribose+aerobic exercise group were all enhanced. The activity of SOD, CAT, GSH-Px also significantly increased (P<0.05), and MDA was significantly reduced (P<0.05). It showed that long-term regular aerobic exercise combined with D-ribose supplementation could significantly increase the liver glycogen, muscle glycogen, blood sugar content and oxidative stress ability in the body, and improve the body's anti-fatigue effect.
Study the effects of aerobic exercise combined with D-ribose supplementation on the anti-fatigue and antioxidant enzyme activities of mice, the mice were divided into quiet control group, aerobic exercise control group, D-ribose control group, D-ribose+aerobic exercise group. The aerobic exercise group received aerobic treadmill training for 6 days a week, and the D-ribose group was given 2 mL of ribose (300 mg/100 g) per rat per day. After 12 weeks of regular aerobic treadmill training, an anti-fatigue animal model was established for mice swimming with weight, the time of exhausted swimming was recorded in mice, and hepaticr glycogen (HG), muscle glycogen (MG), and blood glucose in mice, blood urea nitrogen (BUN), blood lactic acid (BLA), malondialdehyde (MDA) content and total antioxidant capacity (T-AOC), glutathione Oxide dismutase (glutathione peroxide dismutase, GSH-Px), superoxide dismutase (SOD), catalase (catalase, CAT) and other activities were measured. The results showed that compared with the quiet control group, the weight-bearing swimming time of mice in the aerobic exercise control group, D-ribose control group, and D-ribose+aerobic exercise group significantly increased (P<0.05), and at the same time the mice's body hepatic glycogen, muscle glycogen and blood sugar content were significantly improved(P<0.05), and the blood urea nitrogen and blood lactic acid content in the body were significantly reduced(P<0.05). In addition, the results of its antioxidant activity showed that compared with the quiet control group, the T-AOC of the aerobic exercise control group, D-ribose control group, D-ribose+aerobic exercise group were all enhanced. The activity of SOD, CAT, GSH-Px also significantly increased (P<0.05), and MDA was significantly reduced (P<0.05). It showed that long-term regular aerobic exercise combined with D-ribose supplementation could significantly increase the liver glycogen, muscle glycogen, blood sugar content and oxidative stress ability in the body, and improve the body's anti-fatigue effect.
2022, 43(2): 376-383.
doi: 10.13386/j.issn1002-0306.2021050136
Abstract:
Objective: To investigate the protective effect of Baihe Wuyao decoction (BWD) on mice with type 1 diabetes mellitus (T1DM) and liver damage, and to reveal its underlying mechanism. Methods: Ten of 70 mice were randomly selected as the blank group, and the rest were induced with intra-peritoneally (ip) streptozotocin (STZ) to induce T1DM. After successful modeling, the mice were randomly divided into 6 groups: Model group, positive control group and BWD groups (15, 5, 2.5, 1.25 g·kg−1·d−1). The mice in each group were given continuous administration for 6 weeks. The contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum of mice were measured, and the contents of superoxidedismutase (SOD) and malonaldehyde (MDA) in liver tissue homogenate were detected. The pathological changes of mouse liver were observed. The expression of Protein kinase B (AKT) in mouse liver was detected, the mRNA level of manganese superoxide dismutase (Mn-SOD) and nitric oxide synthase (iNOS), inflammatory factors including tumor necrosis factor (TNF-α), nuclear factor-κB (NF-κB), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), apoptosis factors including B-cell lymphoma-2 (Bcl2), Bcl2-associated X protein (Bax), Caspase 3 (CASP3) were measured. Results: BWD exhibited a good hepatic protection with ameliorating hepatic pathological morphology in T1DM mice. Compared with the model group, the levels of ALT and AST in each dose group were significantly reduced (P<0.01, P<0.05), and the effect of the low 1 dose group was more obvious. The low 1 dose of BWD could significantly up-regulate p-AKT/AKT(P<0.05), low dose 1 could significantly down-regulate MDA, iNOS, and up-regulate SOD and Mn-SOD content(P<0.01, P<0.05). Comparing with the model group, the ratio of Bcl2/Bax at the low dose increased significantly, Bax and CASP3 were down-regulated, the low dose significantly reduced the expression of TNF-α, NF-κB, IL-1β, IL-6 and IL-8 at the gene level (P<0.01, P<0.05). Conclusion: The BWD would have a good hepatic protective effect during T1DM, which underlying mechanisms through improving insulin resistance and suppresses oxidative stress, apoptosis, inflammation and promotion of cell proliferation.
Objective: To investigate the protective effect of Baihe Wuyao decoction (BWD) on mice with type 1 diabetes mellitus (T1DM) and liver damage, and to reveal its underlying mechanism. Methods: Ten of 70 mice were randomly selected as the blank group, and the rest were induced with intra-peritoneally (ip) streptozotocin (STZ) to induce T1DM. After successful modeling, the mice were randomly divided into 6 groups: Model group, positive control group and BWD groups (15, 5, 2.5, 1.25 g·kg−1·d−1). The mice in each group were given continuous administration for 6 weeks. The contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum of mice were measured, and the contents of superoxidedismutase (SOD) and malonaldehyde (MDA) in liver tissue homogenate were detected. The pathological changes of mouse liver were observed. The expression of Protein kinase B (AKT) in mouse liver was detected, the mRNA level of manganese superoxide dismutase (Mn-SOD) and nitric oxide synthase (iNOS), inflammatory factors including tumor necrosis factor (TNF-α), nuclear factor-κB (NF-κB), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), apoptosis factors including B-cell lymphoma-2 (Bcl2), Bcl2-associated X protein (Bax), Caspase 3 (CASP3) were measured. Results: BWD exhibited a good hepatic protection with ameliorating hepatic pathological morphology in T1DM mice. Compared with the model group, the levels of ALT and AST in each dose group were significantly reduced (P<0.01, P<0.05), and the effect of the low 1 dose group was more obvious. The low 1 dose of BWD could significantly up-regulate p-AKT/AKT(P<0.05), low dose 1 could significantly down-regulate MDA, iNOS, and up-regulate SOD and Mn-SOD content(P<0.01, P<0.05). Comparing with the model group, the ratio of Bcl2/Bax at the low dose increased significantly, Bax and CASP3 were down-regulated, the low dose significantly reduced the expression of TNF-α, NF-κB, IL-1β, IL-6 and IL-8 at the gene level (P<0.01, P<0.05). Conclusion: The BWD would have a good hepatic protective effect during T1DM, which underlying mechanisms through improving insulin resistance and suppresses oxidative stress, apoptosis, inflammation and promotion of cell proliferation.
2022, 43(2): 384-389.
doi: 10.13386/j.issn1002-0306.2021050182
Abstract:
To study the mechanism of curcumin and/or aerobic exercise improving pyroptosis in myocardium of hyperlipidemic rats. Fifty 5-week-old male SD rats were randomly divided into normal diet control group (RDC), high fat diet control group (HDC), high fat diet with curcumin group (HDCC), high fat diet with aerobic exercise group (HDM), high fat diet with curcumin and aerobic exercise group (HDCM), ten in each group. From the third week, group HDCC and HDCM were injected intragastrically with curcumin at 400 g/(kg·d), and the other groups were given an equal volume of 0.5% sodium carboxymethylcellulose. Group HDM and HDCM performed aerobic exercise intervention, and the other groups did not. Twenty-four hours after the end of 6-week-intervention, the myocardial microstructure in each group was observed, blood and myocardium related biochemical indicators were tested. The results showed that, serum total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), HDC were significantly higher than RDC (P<0.01). Serum TC and TG, HDCC, HDM and HDCM were significantly lower than HDC (P<0.01). Serum TC, HDCM decreased significantly compared with HDCC and HDM (P<0.05 or P<0.01). Serum LDL-C, HDCC and HDCM were significantly lower than HDC (P<0.05 or P<0.01), HDCM was significantly lower than HDCC and HDM (P<0.05 or P<0.01). Serum high-density lipoprotein cholesterol (HDL-C), HDC was significantly lower than RDC (P<0.05), HDCC, HDM and HDCM significantly were higher than HDC (P<0.05 or P<0.01), HDCM was significantly higher than HDM (P<0.01). The myocardial microstructure of RDC was normal, there were inflammatory injury in myocardium of HDC, injury in HDCC, HDM, HDCM were improved significantly, and HDCM was the most significant in the three. Myocardial interleukin-1β (IL-1β) and interleukin-18 (IL-18), HDC was significantly higher than RDC (P<0.01), HDCC, HDM and HDCM were significantly lower than HDC group (P<0.01), HDCC and HDM were significantly higher than HDCM (P<0.05 or P<0.01). Myocardial injury marker creatine kinase-MB (CK-MB), HDC was significantly higher than RDC (P<0.01), HDCC, HDM and HDCM were significantly lower than HDC (P<0.01), HDCM was significantly lower than HDCC and HDM (P<0.01). The H-score of myocardial NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC) and cysteinyl aspartate specific proteinase 1 (Caspase1), HDC was significantly lower than RDC (P<0.01), HDCC, HDM and HDCM were significantly higher than HDC (P<0.05 or P<0.01), HDCC and HDM were significantly lower than HDCM (P<0.05 or P<0.01). Therefore, the 6-week curcumin and/or aerobic exercise intervention could improve pyroptosis in myocardium of hyperlipidemic rats, inhibit excessive inflammatory response, and protect the heart function/structure, which might be related to inhibiting NLRP3/Caspase1 pathway. The effect of combined intervention was better.
To study the mechanism of curcumin and/or aerobic exercise improving pyroptosis in myocardium of hyperlipidemic rats. Fifty 5-week-old male SD rats were randomly divided into normal diet control group (RDC), high fat diet control group (HDC), high fat diet with curcumin group (HDCC), high fat diet with aerobic exercise group (HDM), high fat diet with curcumin and aerobic exercise group (HDCM), ten in each group. From the third week, group HDCC and HDCM were injected intragastrically with curcumin at 400 g/(kg·d), and the other groups were given an equal volume of 0.5% sodium carboxymethylcellulose. Group HDM and HDCM performed aerobic exercise intervention, and the other groups did not. Twenty-four hours after the end of 6-week-intervention, the myocardial microstructure in each group was observed, blood and myocardium related biochemical indicators were tested. The results showed that, serum total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), HDC were significantly higher than RDC (P<0.01). Serum TC and TG, HDCC, HDM and HDCM were significantly lower than HDC (P<0.01). Serum TC, HDCM decreased significantly compared with HDCC and HDM (P<0.05 or P<0.01). Serum LDL-C, HDCC and HDCM were significantly lower than HDC (P<0.05 or P<0.01), HDCM was significantly lower than HDCC and HDM (P<0.05 or P<0.01). Serum high-density lipoprotein cholesterol (HDL-C), HDC was significantly lower than RDC (P<0.05), HDCC, HDM and HDCM significantly were higher than HDC (P<0.05 or P<0.01), HDCM was significantly higher than HDM (P<0.01). The myocardial microstructure of RDC was normal, there were inflammatory injury in myocardium of HDC, injury in HDCC, HDM, HDCM were improved significantly, and HDCM was the most significant in the three. Myocardial interleukin-1β (IL-1β) and interleukin-18 (IL-18), HDC was significantly higher than RDC (P<0.01), HDCC, HDM and HDCM were significantly lower than HDC group (P<0.01), HDCC and HDM were significantly higher than HDCM (P<0.05 or P<0.01). Myocardial injury marker creatine kinase-MB (CK-MB), HDC was significantly higher than RDC (P<0.01), HDCC, HDM and HDCM were significantly lower than HDC (P<0.01), HDCM was significantly lower than HDCC and HDM (P<0.01). The H-score of myocardial NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC) and cysteinyl aspartate specific proteinase 1 (Caspase1), HDC was significantly lower than RDC (P<0.01), HDCC, HDM and HDCM were significantly higher than HDC (P<0.05 or P<0.01), HDCC and HDM were significantly lower than HDCM (P<0.05 or P<0.01). Therefore, the 6-week curcumin and/or aerobic exercise intervention could improve pyroptosis in myocardium of hyperlipidemic rats, inhibit excessive inflammatory response, and protect the heart function/structure, which might be related to inhibiting NLRP3/Caspase1 pathway. The effect of combined intervention was better.
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2022, 43(2): 390-396.
doi: 10.13386/j.issn1002-0306.2020060048
Abstract:
Compared with other microalgae, the edible algae as a new resource is rich in protein, algal polysaccharides, lipids, astaxanthin and carotenoids and other active substances. Therefore, it is of great significance to understand the new resource food algae active substance and its application in food health. This article mainly focuses on four types of microalgae: Haematococcus pluvialis, Dunaliella salina, Euglena, and Chlorella vulgaris, which can be used as new resource foods, to explain the components, extraction methods and applications of microalgae physiologically active substances and their applications and the development status in medicine, health care and food, as well as the expectations for the future, aim to provide a reference for scholars to study algae as a new resource food.
Compared with other microalgae, the edible algae as a new resource is rich in protein, algal polysaccharides, lipids, astaxanthin and carotenoids and other active substances. Therefore, it is of great significance to understand the new resource food algae active substance and its application in food health. This article mainly focuses on four types of microalgae: Haematococcus pluvialis, Dunaliella salina, Euglena, and Chlorella vulgaris, which can be used as new resource foods, to explain the components, extraction methods and applications of microalgae physiologically active substances and their applications and the development status in medicine, health care and food, as well as the expectations for the future, aim to provide a reference for scholars to study algae as a new resource food.
2022, 43(2): 397-404.
doi: 10.13386/j.issn1002-0306.2020100105
Abstract:
Mulberry leaves (MLs) have been used traditionally to raise silkworms and as herbs and herbal drinks . This article summarizes the pharmacological effects of mulberry leaves on the human body such as lowering blood sugar, lowering blood pressure, preventing cancer and urinating. The application of mulberry leaves in food and animal production are summarized, and the current problems in mulberry leaves research are carried out. The analysis and prospects for the further comprehensive utilization of mulberry leaves are aimed at providing theoretical references for mulberry leaf deep-processing technology innovation, high-efficiency comprehensive utilization of resources, and common key technology innovation and product development for high-value processing of resources.
Mulberry leaves (MLs) have been used traditionally to raise silkworms and as herbs and herbal drinks . This article summarizes the pharmacological effects of mulberry leaves on the human body such as lowering blood sugar, lowering blood pressure, preventing cancer and urinating. The application of mulberry leaves in food and animal production are summarized, and the current problems in mulberry leaves research are carried out. The analysis and prospects for the further comprehensive utilization of mulberry leaves are aimed at providing theoretical references for mulberry leaf deep-processing technology innovation, high-efficiency comprehensive utilization of resources, and common key technology innovation and product development for high-value processing of resources.
2022, 43(2): 405-410.
doi: 10.13386/j.issn1002-0306.2020110275
Abstract:
Microencapsulation of essential oils can provide sustained release properties of their products. The reasonable selection of microcapsule wall materials is considered to be the key to effectively controlling the action time of essential oils and improving the stability of the products. From the classification of proteins and polysaccharides, the research status of the wall materials of sustained-release microcapsule of essential oils are summarized, and their development trend and prospects are introduced. It is expected to provide a useful basis for the research and industrial production of essential oil microcapsules in food industry and other related fields.
Microencapsulation of essential oils can provide sustained release properties of their products. The reasonable selection of microcapsule wall materials is considered to be the key to effectively controlling the action time of essential oils and improving the stability of the products. From the classification of proteins and polysaccharides, the research status of the wall materials of sustained-release microcapsule of essential oils are summarized, and their development trend and prospects are introduced. It is expected to provide a useful basis for the research and industrial production of essential oil microcapsules in food industry and other related fields.
2022, 43(2): 411-419.
doi: 10.13386/j.issn1002-0306.2020110292
Abstract:
Cooking is a way of processing food materials to make food more delicious, better-looking and better-smelling. It not only makes people feel satisfied when eating, but also makes food nutrients more easily absorbed by the body. As a common edible ingredient, vegetables are indispensable whether in the home or restaurant. Vegetables are heated during the cooking process, so the nutrient composition and the color are changed. Compared with other cooking methods, steaming is a relatively healthy cooking method, which could retain more nutrients. In this paper, the effects of several cooking methods, such as steaming, boiling, microwaving, and stir-frying on various nutrients, antioxidant capacity and color in vegetables are investigated, in order to selectively provide reference for consumers to choose cooking methods.
Cooking is a way of processing food materials to make food more delicious, better-looking and better-smelling. It not only makes people feel satisfied when eating, but also makes food nutrients more easily absorbed by the body. As a common edible ingredient, vegetables are indispensable whether in the home or restaurant. Vegetables are heated during the cooking process, so the nutrient composition and the color are changed. Compared with other cooking methods, steaming is a relatively healthy cooking method, which could retain more nutrients. In this paper, the effects of several cooking methods, such as steaming, boiling, microwaving, and stir-frying on various nutrients, antioxidant capacity and color in vegetables are investigated, in order to selectively provide reference for consumers to choose cooking methods.
2022, 43(2): 420-426.
doi: 10.13386/j.issn1002-0306.2020120041
Abstract:
The freeze-thaw stability of Pickering emulsion refers to the relatively stable characteristics of Pickering emulsion after undergoing a freeze-thaw cycle. In recent years, the research on the freeze-thaw stability of Pickering emulsion has been intensified. Research suggests that Pickering emulsion has a viscoelastic layer and a gel network structure that can effectively block the damage caused by ice crystals stress, and has good freeze-thaw stability. At present, Pickering emulsion is widely used in food as an active substance embedding agent, food packaging material and lipid substitute. Therefore, Pickering emulsion with freeze-thaw stability has potential commercial value. There are many factors affecting freeze-thaw stability, mainly temperature, ionic strength, particle composition, modification and preparation techniques, etc. This paper reviews the mechanism of freeze-thaw stability of Pickering emulsion and the research progress of factors affecting freeze-thaw stability. With the development of Pickering emulsion in food and various fields, the mechanism of freeze-thaw stability of Pickering emulsion based on molecular level will arouse people's interest.
The freeze-thaw stability of Pickering emulsion refers to the relatively stable characteristics of Pickering emulsion after undergoing a freeze-thaw cycle. In recent years, the research on the freeze-thaw stability of Pickering emulsion has been intensified. Research suggests that Pickering emulsion has a viscoelastic layer and a gel network structure that can effectively block the damage caused by ice crystals stress, and has good freeze-thaw stability. At present, Pickering emulsion is widely used in food as an active substance embedding agent, food packaging material and lipid substitute. Therefore, Pickering emulsion with freeze-thaw stability has potential commercial value. There are many factors affecting freeze-thaw stability, mainly temperature, ionic strength, particle composition, modification and preparation techniques, etc. This paper reviews the mechanism of freeze-thaw stability of Pickering emulsion and the research progress of factors affecting freeze-thaw stability. With the development of Pickering emulsion in food and various fields, the mechanism of freeze-thaw stability of Pickering emulsion based on molecular level will arouse people's interest.
2022, 43(2): 427-433.
doi: 10.13386/j.issn1002-0306.2020120221
Abstract:
Rice is mild in nature, sweet in taste, and has higher nutritional value. Rice is the staple food for more than half of the world’s population, then the research progress of various rice has attracted extensive attention of many scholars. In this paper, the essential information, nutritional composition, efficiency of rice and rice products in processing problems are expounded, and the factors affecting the quality of rice product in the process of deep processing are analyzed, finally the effects of various exogenous additives on the quality of rice product are summarized, the effect of single exogenous additive is not very good, and the research on composite additives should be strengthened, with the aim of providing reference for the development of rice product processing industry in China.
Rice is mild in nature, sweet in taste, and has higher nutritional value. Rice is the staple food for more than half of the world’s population, then the research progress of various rice has attracted extensive attention of many scholars. In this paper, the essential information, nutritional composition, efficiency of rice and rice products in processing problems are expounded, and the factors affecting the quality of rice product in the process of deep processing are analyzed, finally the effects of various exogenous additives on the quality of rice product are summarized, the effect of single exogenous additive is not very good, and the research on composite additives should be strengthened, with the aim of providing reference for the development of rice product processing industry in China.
2022, 43(2): 434-441.
doi: 10.13386/j.issn1002-0306.2020120251
Abstract:
Corn gluten meal is a major by-product of corn wet-milling process in the starch industry. The low water solubility and deficiency of essential amino acids of corn gluten meal limits its application in the food industry, while corn polypeptides after enzymatic hydrolysis can greatly improve its functions and biological activities, it is one of the high value-added utilization methods. This review encompasses the studies reported to date on the main preparation methods of corn polypeptides, and also describes its bioactivities including antioxidant, antiglycemia, antihypertensive, hepatoprotective, pointing out the existing problems and future development prospects. The paper is of great significance for food enterprises to utilize corn gluten meal efficiently to develop bioactive peptides and improve economic benefits of the industry.
Corn gluten meal is a major by-product of corn wet-milling process in the starch industry. The low water solubility and deficiency of essential amino acids of corn gluten meal limits its application in the food industry, while corn polypeptides after enzymatic hydrolysis can greatly improve its functions and biological activities, it is one of the high value-added utilization methods. This review encompasses the studies reported to date on the main preparation methods of corn polypeptides, and also describes its bioactivities including antioxidant, antiglycemia, antihypertensive, hepatoprotective, pointing out the existing problems and future development prospects. The paper is of great significance for food enterprises to utilize corn gluten meal efficiently to develop bioactive peptides and improve economic benefits of the industry.
2022, 43(2): 442-453.
doi: 10.13386/j.issn1002-0306.2020120271
Abstract:
At present, the wine market in China is becoming more and more prosperous, and the quality of wine has increasingly become the primary concern of consumers. Cork taint is one of the common factors affecting the quality of wine, which seriously damages the flavor of wine. The detection of cork taint is difficult because of its large variety and low content. Therefore, the establishment and improvement of wine cork taint detection technology system will help strengthen the quality and safety control of wine, promote industrial development, and provide technical support for the improvement of corresponding regulatory capabilities. This paper discusses the research progress on detection techniques of wine cork taint in domestic and overseas, and focuses on the methods of concentration extraction and instrument detection. At the same time, it compares the advantages and disadvantages of detection methods, and provides a reference for the further development of cork taint detection technology.
At present, the wine market in China is becoming more and more prosperous, and the quality of wine has increasingly become the primary concern of consumers. Cork taint is one of the common factors affecting the quality of wine, which seriously damages the flavor of wine. The detection of cork taint is difficult because of its large variety and low content. Therefore, the establishment and improvement of wine cork taint detection technology system will help strengthen the quality and safety control of wine, promote industrial development, and provide technical support for the improvement of corresponding regulatory capabilities. This paper discusses the research progress on detection techniques of wine cork taint in domestic and overseas, and focuses on the methods of concentration extraction and instrument detection. At the same time, it compares the advantages and disadvantages of detection methods, and provides a reference for the further development of cork taint detection technology.
2022, 43(2): 454-462.
doi: 10.13386/j.issn1002-0306.2021010128
Abstract:
Pulsed light is a new efficient environment-friendly non-thermal sterilization technology and it has a great development potential in food industry. This article reviews the sterilization mechanism of pulsed light and its applications in fruits and vegetables, meat products, dairy products, food packaging materials and other fields, the coupling effects of pulsed light and other preservation technologies, practical applications of pulsed light in food industry as well as the safety of using pulsed light. Pulsed light can not only widely destroy a variety of pathogenic bacteria, but also basically do not change the properties of foods and food packaging materials. It has huge application potential in improving food safety and extending food shelf life. The coupling of pulsed light and other fresh-keeping technology also has better effects in terms of sterilization effect, sensory quality, and nutrient content retention than single fresh-keeping technology. This review hopes to provide a theoretical reference for researchers to further understand the pulsed light sterilization technology and expand its application fields.
Pulsed light is a new efficient environment-friendly non-thermal sterilization technology and it has a great development potential in food industry. This article reviews the sterilization mechanism of pulsed light and its applications in fruits and vegetables, meat products, dairy products, food packaging materials and other fields, the coupling effects of pulsed light and other preservation technologies, practical applications of pulsed light in food industry as well as the safety of using pulsed light. Pulsed light can not only widely destroy a variety of pathogenic bacteria, but also basically do not change the properties of foods and food packaging materials. It has huge application potential in improving food safety and extending food shelf life. The coupling of pulsed light and other fresh-keeping technology also has better effects in terms of sterilization effect, sensory quality, and nutrient content retention than single fresh-keeping technology. This review hopes to provide a theoretical reference for researchers to further understand the pulsed light sterilization technology and expand its application fields.
2022, 43(2): 463-471.
doi: 10.13386/j.issn1002-0306.2021060202
Abstract:
Metal-Organic Frameworks (MOFs) are porous crystalline materials formed by self-assembly of metal centers and organic ligands through coordination. MOFs have the characteristics of strong stability, large specific surface area, high porosity, and reusability. As a new type of immobilized carrier material, it has a wide range of application prospects. In this article, the synthesis method of biological enzyme immobilized on MOFs carrier is mainly summarized and analyzed, the characteristics and application of MOFs-biological enzyme composite material, and the future research direction of the synthetic method of enzyme immobilized on MOFs carrier are prospected. A theoretical basis would be provided for the development research and applications in the biological and pharmaceutical industries.
Metal-Organic Frameworks (MOFs) are porous crystalline materials formed by self-assembly of metal centers and organic ligands through coordination. MOFs have the characteristics of strong stability, large specific surface area, high porosity, and reusability. As a new type of immobilized carrier material, it has a wide range of application prospects. In this article, the synthesis method of biological enzyme immobilized on MOFs carrier is mainly summarized and analyzed, the characteristics and application of MOFs-biological enzyme composite material, and the future research direction of the synthetic method of enzyme immobilized on MOFs carrier are prospected. A theoretical basis would be provided for the development research and applications in the biological and pharmaceutical industries.
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2022, 43(2): 27-34.
doi: 10.13386/j.issn1002-0306.2020100158
Abstract:
In order to explore the effect of hammering time on the quality of beef gel, beef gel prepared by beating process was used as control group, the color difference, myofibrillar protein oxidation degree, cooking loss rate, fat exudation rate and texture characteristics of beef gel with different beating time were determined, and the mechanism of the impact of beat time on beef gel quality was studied through observing the changes of meat size, protein two level structure and microstructure of beef gel. The results showed that with the extension of beating time, the L* value and W value first decreased and then increased, and the a* value and b* value increased first and then decreased. The oxidation degree of myofibrillar protein increased, total thiol decreased, the carbonyl value and bromphenol blue binding capacity increased, cooking loss rate decreased and then increased with fat exudation, and the hardness and chewiness of gel texture increased gradually. Resilience, cohesion and resilience increased first and then decreased. 30 min was the cut-off point, and the gel quality of 30 min was on the rise, which was more than 30 min. The increasing of gel quality was due to the decreasing of meat particle size and the increasing of protein two level structure beta fold. The degradation of gel quality after 30 min was due to the deepening of protein oxidation and the change of gel microstructure. The results showed that the hammering process could improve the quality of minced meat, but excessive hammering could cause the quality deterioration of minced meat.
In order to explore the effect of hammering time on the quality of beef gel, beef gel prepared by beating process was used as control group, the color difference, myofibrillar protein oxidation degree, cooking loss rate, fat exudation rate and texture characteristics of beef gel with different beating time were determined, and the mechanism of the impact of beat time on beef gel quality was studied through observing the changes of meat size, protein two level structure and microstructure of beef gel. The results showed that with the extension of beating time, the L* value and W value first decreased and then increased, and the a* value and b* value increased first and then decreased. The oxidation degree of myofibrillar protein increased, total thiol decreased, the carbonyl value and bromphenol blue binding capacity increased, cooking loss rate decreased and then increased with fat exudation, and the hardness and chewiness of gel texture increased gradually. Resilience, cohesion and resilience increased first and then decreased. 30 min was the cut-off point, and the gel quality of 30 min was on the rise, which was more than 30 min. The increasing of gel quality was due to the decreasing of meat particle size and the increasing of protein two level structure beta fold. The degradation of gel quality after 30 min was due to the deepening of protein oxidation and the change of gel microstructure. The results showed that the hammering process could improve the quality of minced meat, but excessive hammering could cause the quality deterioration of minced meat.
2022, 43(2): 35-41.
doi: 10.13386/j.issn1002-0306.2021020241
Abstract:
This paper aimed to analyze the antioxidant activity and structure of flavonoid compounds extracted from mung bean hull. The product of mung bean hull flavonoid extraction was purified by gradient elution with different concentrations of alcohol, such as 20%, 40%, 60% and 80%. The abilities of various eluents in T-AOC, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, 2, 2′-azinobis-3- ethylbenzothia zoline-6-sulphonic acid (ABTS) free radical and hydroxyl radicals, and the compounds with high antioxidant activity were analyzed for structure. The results showed that 60% eluent of mung bean hull flavonoid possess strong antioxidant activity, DPPH scavenging capacity was 48.03%, ABTS+ radical scavenging capacity was 57.53%, hydroxyl radicals scavenging capacity was 12.02%, T-AOC was 207.64 U/mL, which was significantly higher than other eluents (P<0.05). The flavonoid compounds mainly consisted of three components, such as vitexin, isovitexin, and saccharol-6-C-β-D-glucopyranoside.
This paper aimed to analyze the antioxidant activity and structure of flavonoid compounds extracted from mung bean hull. The product of mung bean hull flavonoid extraction was purified by gradient elution with different concentrations of alcohol, such as 20%, 40%, 60% and 80%. The abilities of various eluents in T-AOC, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, 2, 2′-azinobis-3- ethylbenzothia zoline-6-sulphonic acid (ABTS) free radical and hydroxyl radicals, and the compounds with high antioxidant activity were analyzed for structure. The results showed that 60% eluent of mung bean hull flavonoid possess strong antioxidant activity, DPPH scavenging capacity was 48.03%, ABTS+ radical scavenging capacity was 57.53%, hydroxyl radicals scavenging capacity was 12.02%, T-AOC was 207.64 U/mL, which was significantly higher than other eluents (P<0.05). The flavonoid compounds mainly consisted of three components, such as vitexin, isovitexin, and saccharol-6-C-β-D-glucopyranoside.
2022, 43(2): 42-49.
doi: 10.13386/j.issn1002-0306.2021040093
Abstract:
Objective: To study the effect of galactomannan on the spectral characteristics of human serum albumin (HSA) and the mechanism of their interaction. Methods: Multispectroscopic analyses were used to determine the quenching method, number of binding sites, type of binding force, and changes in secondary structure between galactomannan and HSA. The type and length of binding force were obtained by molecular docking simulation, which further proved that the mechanism of interaction between galactomannan and HSA. Results: Under the action of galactomannan, the endogenous fluorescence of HSA was regularly quenched. The quenching process was spontaneous. The mechanism was static quenching. The number of binding sites was about 1, and the α-helix of HSA was reduced by 7.7%. The results of molecular docking showed that galactomannan interacted in HSA subdomain IIB through hydrogen bonds and van der Waals forces. Conclusions: The interaction between galactomannan and HSA was strong, and the binding was spontaneous.
Objective: To study the effect of galactomannan on the spectral characteristics of human serum albumin (HSA) and the mechanism of their interaction. Methods: Multispectroscopic analyses were used to determine the quenching method, number of binding sites, type of binding force, and changes in secondary structure between galactomannan and HSA. The type and length of binding force were obtained by molecular docking simulation, which further proved that the mechanism of interaction between galactomannan and HSA. Results: Under the action of galactomannan, the endogenous fluorescence of HSA was regularly quenched. The quenching process was spontaneous. The mechanism was static quenching. The number of binding sites was about 1, and the α-helix of HSA was reduced by 7.7%. The results of molecular docking showed that galactomannan interacted in HSA subdomain IIB through hydrogen bonds and van der Waals forces. Conclusions: The interaction between galactomannan and HSA was strong, and the binding was spontaneous.
2022, 43(2): 50-57.
doi: 10.13386/j.issn1002-0306.2021040099
Abstract:
This study explored the effect of six different cooking methods (steaming, roasting, microwave, combined mode, inductor cooker steaming and inductor cooker) on the retention and absorption of vitamin C and nitrate of broccoli during in-vitro simulated gastrointestinal digestion, in search of healthy cooking technology which was easy to digestion and absorption. The results showed that the cooking time of the induction cooker (1~3 min) was the shortest while the one for roasting (6~11 min) was the longest in achieving the same maturity of broccoli. In addition, the samples treated with microwave or steaming had the highest retention and digestion of vitamin C, and the samples of roasted, combined mode or induction cooker steaming displayed the highest retention and absorption rate of nitrate. Therefore, inductor cooker steaming mode (P5 and P9) was considered the most suitable method in cooking broccoli to obtain the most appropriate digestion and absorption of vitamin C and nitrate.
This study explored the effect of six different cooking methods (steaming, roasting, microwave, combined mode, inductor cooker steaming and inductor cooker) on the retention and absorption of vitamin C and nitrate of broccoli during in-vitro simulated gastrointestinal digestion, in search of healthy cooking technology which was easy to digestion and absorption. The results showed that the cooking time of the induction cooker (1~3 min) was the shortest while the one for roasting (6~11 min) was the longest in achieving the same maturity of broccoli. In addition, the samples treated with microwave or steaming had the highest retention and digestion of vitamin C, and the samples of roasted, combined mode or induction cooker steaming displayed the highest retention and absorption rate of nitrate. Therefore, inductor cooker steaming mode (P5 and P9) was considered the most suitable method in cooking broccoli to obtain the most appropriate digestion and absorption of vitamin C and nitrate.
2022, 43(2): 58-63.
doi: 10.13386/j.issn1002-0306.2021040129
Abstract:
In order to clarify the degradation pathway of anthocyanins in blueberry during storage and processing, the mechanism of coupled oxidation of anthocyanins-polyphenol oxidase-catechol was systematically studied, and the dose-response relationship among them was discussed. The enzymatic oxidation of catechol to quinones and the oxidation of anthocyanins with quinones were two main reactions in the coupled oxidation system. The coupled oxidation of anthocyanins degradation followed the first-order reaction kinetic model. Moreover, although the degradation rate of anthocyanins increased with the increasing of catechol concentration, when catechol concentration was higher than 1.33 mmol/L, the effect of catechol concentration on the degradation rate of anthocyanins decreased. The higher the initial concentration of anthocyanins, the lower the oxidation rate of catechol and the degradation rate of anthocyanins. The degradation rate of anthocyanins increased linearly with the increasing of enzyme concentration. It could be inferred that during the storage and processing of blueberry, PPO in the tissue would combine with its phenolic substrates to produce corresponding quinones, which would lead to the degradation of anthocyanins in blueberry through coupled oxidation reaction, and eventually lead to browning of fruit or related products. The browning rate was closely related to enzyme activity, phenolic substrate and anthocyanin content.
In order to clarify the degradation pathway of anthocyanins in blueberry during storage and processing, the mechanism of coupled oxidation of anthocyanins-polyphenol oxidase-catechol was systematically studied, and the dose-response relationship among them was discussed. The enzymatic oxidation of catechol to quinones and the oxidation of anthocyanins with quinones were two main reactions in the coupled oxidation system. The coupled oxidation of anthocyanins degradation followed the first-order reaction kinetic model. Moreover, although the degradation rate of anthocyanins increased with the increasing of catechol concentration, when catechol concentration was higher than 1.33 mmol/L, the effect of catechol concentration on the degradation rate of anthocyanins decreased. The higher the initial concentration of anthocyanins, the lower the oxidation rate of catechol and the degradation rate of anthocyanins. The degradation rate of anthocyanins increased linearly with the increasing of enzyme concentration. It could be inferred that during the storage and processing of blueberry, PPO in the tissue would combine with its phenolic substrates to produce corresponding quinones, which would lead to the degradation of anthocyanins in blueberry through coupled oxidation reaction, and eventually lead to browning of fruit or related products. The browning rate was closely related to enzyme activity, phenolic substrate and anthocyanin content.
2022, 43(2): 64-69.
doi: 10.13386/j.issn1002-0306.2021040222
Abstract:
Taking fresh water surimi and Poria cocos full powder as research subjects, different contents of Poria cocos full powder(0, 1%, 2%, 3%, 4%, 5%) were added into the surimi of silver carp to analyze the effects of water retention, cooking degree, gel strength, whiteness value and texture profile analysis(TPA) index. The results showed that with the increasing of Poria cocos full powder, the water holding capacity, cooking rate and whiteness value of the surimi products all increased first and then decreased. Compared with the blank group, the addition of Poria cocos full powder could significantly improve the gel strength, hardness, elasticity and chewiness of surimi gel. When the Poria cocos full powder was 2%, the best water holding capacity of silver carp surimi products was 80.73%, the maximum gel strength was 642.886 g·cm, the minimum cooking loss rate was 6.94%, and the maximum whiteness value was 79.93. The hardness, elasticity, cohesion, and chewiness all reached the maximum, which were 2299.245 g, 0.973%, 0.859 g, and 1838.410 g, respectively, with the best textural properties. This experiment would provide a theoretical basis for the production of freshwater surimi products.
Taking fresh water surimi and Poria cocos full powder as research subjects, different contents of Poria cocos full powder(0, 1%, 2%, 3%, 4%, 5%) were added into the surimi of silver carp to analyze the effects of water retention, cooking degree, gel strength, whiteness value and texture profile analysis(TPA) index. The results showed that with the increasing of Poria cocos full powder, the water holding capacity, cooking rate and whiteness value of the surimi products all increased first and then decreased. Compared with the blank group, the addition of Poria cocos full powder could significantly improve the gel strength, hardness, elasticity and chewiness of surimi gel. When the Poria cocos full powder was 2%, the best water holding capacity of silver carp surimi products was 80.73%, the maximum gel strength was 642.886 g·cm, the minimum cooking loss rate was 6.94%, and the maximum whiteness value was 79.93. The hardness, elasticity, cohesion, and chewiness all reached the maximum, which were 2299.245 g, 0.973%, 0.859 g, and 1838.410 g, respectively, with the best textural properties. This experiment would provide a theoretical basis for the production of freshwater surimi products.
2022, 43(2): 70-76.
doi: 10.13386/j.issn1002-0306.2021040226
Abstract:
In order to study the changes of protein oxidation during heat processing, cattle tendon and shoulder were treated at different temperatures (40, 50, 60, 70, 80, 90, 100 ℃, holding time 30 min) and at 70 kPa high pressure for different times (15, 20, 25, 30, 35 min). The changes of carbonyl content, sulfhydryl content, protein particle size, surface hydrophobicity, SDS-PAGE electrophoresis and protein secondary structure were analyzed. The results showed that temperature could lead to the increasing of protein carbonyl content, sulfhydryl content first increased and then decreased, protein particle size increased, protein surface hydrophobicity first increased and then decreased. High pressure resulted in the increasing of protein carbonyl content, the decreasing of protein sulfhydryl content, the increasing of protein particle size and the increasing of protein hydrophobicity. In addition, myofibrillar proteins were degraded and aggregated obviously under different heat treatments, and a large number of small molecular proteins appeared. Infrared studies showed that the secondary structure of myofibrillar protein changes during heat processing, which urged the formation of the secondary structure of myofibrillar protein α-spiral β-the conversion between folding and irregular curling. It was concluded that temperature and pressure could promote the oxidation of beef protein and change the chemical force and secondary structure of beef protein. This study would provide a theoretical basis for the industrial regulation of low-temperature beef products.
In order to study the changes of protein oxidation during heat processing, cattle tendon and shoulder were treated at different temperatures (40, 50, 60, 70, 80, 90, 100 ℃, holding time 30 min) and at 70 kPa high pressure for different times (15, 20, 25, 30, 35 min). The changes of carbonyl content, sulfhydryl content, protein particle size, surface hydrophobicity, SDS-PAGE electrophoresis and protein secondary structure were analyzed. The results showed that temperature could lead to the increasing of protein carbonyl content, sulfhydryl content first increased and then decreased, protein particle size increased, protein surface hydrophobicity first increased and then decreased. High pressure resulted in the increasing of protein carbonyl content, the decreasing of protein sulfhydryl content, the increasing of protein particle size and the increasing of protein hydrophobicity. In addition, myofibrillar proteins were degraded and aggregated obviously under different heat treatments, and a large number of small molecular proteins appeared. Infrared studies showed that the secondary structure of myofibrillar protein changes during heat processing, which urged the formation of the secondary structure of myofibrillar protein α-spiral β-the conversion between folding and irregular curling. It was concluded that temperature and pressure could promote the oxidation of beef protein and change the chemical force and secondary structure of beef protein. This study would provide a theoretical basis for the industrial regulation of low-temperature beef products.
2022, 43(2): 77-83.
doi: 10.13386/j.issn1002-0306.2021040246
Abstract:
In order to explore the effect of heating method and heating time on physicochemical properties of fish gelatin, the protein composition, viscosity, rheological properties and thermal stability of heated gelatin solutions, and the gel strength, texture profile analysis (TPA) parameters and microstructure of gelatin gels were analyzed and compared. The results showed that the viscosity, rheological properties and thermal stability of fish gelatin solutions decreased significantly with the increase of heating time, while the change extents of these properties in the intermittent heated gelatin were less than those in the continuous heated gelatin. When gelatin was heated for 48 h continuously, the β band disappeared in the electrophoresis pattern, and the α1 and α2 subunits degraded obviously after being heated for 96 h. When gelatin was heated for 96 h intermittently, the β band disappeared. The gel strength and TPA parameters of the gel prepared by fish gelatin gradually decreased with the increase of heating time, whereas the gel properties of the intermittent heated gelatin were superior to those of the continuous heated gelatin. Scanning electron microscope results showed that the surfaces of continuous heated gels were smooth and flat, while the structure of gel prepared by intermittent heated gelatin was rougher and more porous. The results suggested that intermittent heating and the heating less than 12 h could reduce the heat degradation of gelatin.
In order to explore the effect of heating method and heating time on physicochemical properties of fish gelatin, the protein composition, viscosity, rheological properties and thermal stability of heated gelatin solutions, and the gel strength, texture profile analysis (TPA) parameters and microstructure of gelatin gels were analyzed and compared. The results showed that the viscosity, rheological properties and thermal stability of fish gelatin solutions decreased significantly with the increase of heating time, while the change extents of these properties in the intermittent heated gelatin were less than those in the continuous heated gelatin. When gelatin was heated for 48 h continuously, the β band disappeared in the electrophoresis pattern, and the α1 and α2 subunits degraded obviously after being heated for 96 h. When gelatin was heated for 96 h intermittently, the β band disappeared. The gel strength and TPA parameters of the gel prepared by fish gelatin gradually decreased with the increase of heating time, whereas the gel properties of the intermittent heated gelatin were superior to those of the continuous heated gelatin. Scanning electron microscope results showed that the surfaces of continuous heated gels were smooth and flat, while the structure of gel prepared by intermittent heated gelatin was rougher and more porous. The results suggested that intermittent heating and the heating less than 12 h could reduce the heat degradation of gelatin.
2022, 43(2): 84-92.
doi: 10.13386/j.issn1002-0306.2021040322
Abstract:
In this study, the defatted jujube kernel residue was extracted by alkali solubilization and acid seperation method to obtain jujube kernel protein, and the angiotensin converting enzyme (ACE) inhibitory peptide was obtained by enzymatic hydrolysis of neutral protease and alkaline protease. Taking jujube kernel as the research object, the physicochemical properties of ACE inhibitory peptide were studied. In this paper, the functional activity and nutritional value of ACE inhibitory peptide in defatted jujube kernel were demonstrated from the aspect of amino acids by analyzing the basic nutrients of defatted jujube kernel and the amino acid composition of ACE inhibitory peptide in enzymolyzed jujube kernel. The enzymatic hydrolysis effect of jujube kernel protein was proved by molecular weight distribution, particle size distribution and microscopic structure observation. Finally, the physical and chemical properties of jujube seed, including solubility, thermal stability, water and oil retention, foaming and foaming stability, emulsification and emulsification stability, and sensory characteristics before and after proteolysis, were compared and analyzed. It was found that the protein content of defatted jujube kernel was (73.40±0.23) g/100 g, and the protein content was higher. The essential amino acid content and hydrophobic amino acid content in ACE inhibitory peptide of jujube kernel were 36.48% and 51.14%, and the content of glutamate was the highest. The molecular weight of ACE inhibitory peptides in Zizyphus jujube kernel was mainly in the range of 1000~3000 Da, accounting for 97.50%, and the polydispersity index was 1.088, indicating a narrow molecular weight distribution. The protein structure of jujube kernel was broken before and after enzymolysis of ACE inhibitory peptides, and the enzymolysis was sufficient. The study of physical and chemical properties showed that compared with the protein before enzymolysis, the thermal stability, solubility, water holding capacity, oil holding capacity and emulsification stability of the ACE inhibitory peptide of jujube kernel were significantly improved, while the foaming, foaming stability and emulsification ability significantly decreased（P<0.05）. The results showed that the physicochemical properties of ACE inhibitory peptides in jujube kernel were significantly improved compared with those before enzymolysis（P<0.05）. The discovery of related physicochemical properties laid a research foundation for the follow-up research, and provided a theoretical basis for the production and application of ACE inhibitory peptides in jujube kernel.
In this study, the defatted jujube kernel residue was extracted by alkali solubilization and acid seperation method to obtain jujube kernel protein, and the angiotensin converting enzyme (ACE) inhibitory peptide was obtained by enzymatic hydrolysis of neutral protease and alkaline protease. Taking jujube kernel as the research object, the physicochemical properties of ACE inhibitory peptide were studied. In this paper, the functional activity and nutritional value of ACE inhibitory peptide in defatted jujube kernel were demonstrated from the aspect of amino acids by analyzing the basic nutrients of defatted jujube kernel and the amino acid composition of ACE inhibitory peptide in enzymolyzed jujube kernel. The enzymatic hydrolysis effect of jujube kernel protein was proved by molecular weight distribution, particle size distribution and microscopic structure observation. Finally, the physical and chemical properties of jujube seed, including solubility, thermal stability, water and oil retention, foaming and foaming stability, emulsification and emulsification stability, and sensory characteristics before and after proteolysis, were compared and analyzed. It was found that the protein content of defatted jujube kernel was (73.40±0.23) g/100 g, and the protein content was higher. The essential amino acid content and hydrophobic amino acid content in ACE inhibitory peptide of jujube kernel were 36.48% and 51.14%, and the content of glutamate was the highest. The molecular weight of ACE inhibitory peptides in Zizyphus jujube kernel was mainly in the range of 1000~3000 Da, accounting for 97.50%, and the polydispersity index was 1.088, indicating a narrow molecular weight distribution. The protein structure of jujube kernel was broken before and after enzymolysis of ACE inhibitory peptides, and the enzymolysis was sufficient. The study of physical and chemical properties showed that compared with the protein before enzymolysis, the thermal stability, solubility, water holding capacity, oil holding capacity and emulsification stability of the ACE inhibitory peptide of jujube kernel were significantly improved, while the foaming, foaming stability and emulsification ability significantly decreased（P<0.05）. The results showed that the physicochemical properties of ACE inhibitory peptides in jujube kernel were significantly improved compared with those before enzymolysis（P<0.05）. The discovery of related physicochemical properties laid a research foundation for the follow-up research, and provided a theoretical basis for the production and application of ACE inhibitory peptides in jujube kernel.
2022, 43(2): 93-100.
doi: 10.13386/j.issn1002-0306.2021040327
Abstract:
In this study, sugar-citric acid reaction systems were applied to study the formation of 3-deoxyglucosone(3-DG) and 5-hydroxymethylfurfural(5-HMF). Fructose/sucrose/glucose-citric acid reaction systems were constructed, the effects of sugar type, pH, temperature, types of metal ions and compounds with different valences of sulfur on the formation of 3-DG and 5-HMF were evaluated. The formation kinetics of 3-DG and 5-HMF were analyzed. Results indicated that the three types of sugar had different effects on the formation of 3-DG and 5-HMF. The amounts of 3-DG and 5-HMF produced in fructose and sucrose reaction systems were much higher than those in glucose reaction system. The amounts of 3-DG and 5-HMF in the fructose-citric acid reaction system increased with the decreasing of pH and the increasing of temperature. Ca2+, Mg2+ and Al3+ promoted the formation of 3-DG and 5-HMF. K+ accelerated the formation of 3-DG, but had no significant effect on the formation of 5-HMF(P>0.05). Na2S2O3 and Na2SO3 inhibited 3-DG and 5-HMF formation, while Na2S2O5 had no significant effect on 3-DG formation, but it inhibited the formation of 5-HMF(P<0.05). Na2SO4 promoted 3-DG and 5-HMF formation. The formation kinetics of 3-DG were in accordance with zero-order kinetics model at 70~90 oC while it followed second-order kinetics model at 100 oC. The formation of 5-HMF followed zero-order kinetics model at 70~100 oC.
In this study, sugar-citric acid reaction systems were applied to study the formation of 3-deoxyglucosone(3-DG) and 5-hydroxymethylfurfural(5-HMF). Fructose/sucrose/glucose-citric acid reaction systems were constructed, the effects of sugar type, pH, temperature, types of metal ions and compounds with different valences of sulfur on the formation of 3-DG and 5-HMF were evaluated. The formation kinetics of 3-DG and 5-HMF were analyzed. Results indicated that the three types of sugar had different effects on the formation of 3-DG and 5-HMF. The amounts of 3-DG and 5-HMF produced in fructose and sucrose reaction systems were much higher than those in glucose reaction system. The amounts of 3-DG and 5-HMF in the fructose-citric acid reaction system increased with the decreasing of pH and the increasing of temperature. Ca2+, Mg2+ and Al3+ promoted the formation of 3-DG and 5-HMF. K+ accelerated the formation of 3-DG, but had no significant effect on the formation of 5-HMF(P>0.05). Na2S2O3 and Na2SO3 inhibited 3-DG and 5-HMF formation, while Na2S2O5 had no significant effect on 3-DG formation, but it inhibited the formation of 5-HMF(P<0.05). Na2SO4 promoted 3-DG and 5-HMF formation. The formation kinetics of 3-DG were in accordance with zero-order kinetics model at 70~90 oC while it followed second-order kinetics model at 100 oC. The formation of 5-HMF followed zero-order kinetics model at 70~100 oC.
2022, 43(2): 101-111.
doi: 10.13386/j.issn1002-0306.2021050071
Abstract:
In order to understand the effect of air-borne ultrasound on the catabolic pathway of glucosinolates in broccoli florets during air drying, the drying property, contents of key components (glucosinolates, sulforaphane, ascorbic acid, Fe2+ and phenolic acids), myrosinase activity and antioxidant capacity in vitro in broccoli florets during air drying at 60 oC coupled with air-borne ultrasound (20 kHz, 125.2 and 180.1 W/dm2) were analyzed. The results showed that air-borne sonication accelerated the drying process. The drying times were shortened by 11.1% and 17.8% under sonication at 125.2 and 180.1 W/dm2, respectively. Meanwhile, glucobrassicin content and myrosinase activity increased during ultrasound-intensified air drying. In the end of drying, the contents of glucobrassicin and sulforaphane as well as myrosinase activity in ultrasound-treated samples at 180.1 W/dm2 were 10.7%, 26.0% and 15.2% higher than those in samples dried without sonication, respectively. Reversely, sonicated samples at 180.1 W/dm2 possessed 8.1% less amount of Fe2+ than only air-dried samples after drying. The results implied that ultrasound treatment alleviated the interference of Fe2+ on the enzymatic degradation of glucosinolates, as well as promoted the degradation of glucoraphanin to sulforaphane. Besides, air-borne sonication had no significant influence on the contents of ascorbic acid and phenolic acids, and antioxidant capacity in vitro of broccoli under air drying. This study demonstrated that air-borne ultrasound assisted-air drying could not only speed up the drying process of broccoli florets, but also promote the conversion of glucoraphanin and preserve the bioactive components in certain aspects.
In order to understand the effect of air-borne ultrasound on the catabolic pathway of glucosinolates in broccoli florets during air drying, the drying property, contents of key components (glucosinolates, sulforaphane, ascorbic acid, Fe2+ and phenolic acids), myrosinase activity and antioxidant capacity in vitro in broccoli florets during air drying at 60 oC coupled with air-borne ultrasound (20 kHz, 125.2 and 180.1 W/dm2) were analyzed. The results showed that air-borne sonication accelerated the drying process. The drying times were shortened by 11.1% and 17.8% under sonication at 125.2 and 180.1 W/dm2, respectively. Meanwhile, glucobrassicin content and myrosinase activity increased during ultrasound-intensified air drying. In the end of drying, the contents of glucobrassicin and sulforaphane as well as myrosinase activity in ultrasound-treated samples at 180.1 W/dm2 were 10.7%, 26.0% and 15.2% higher than those in samples dried without sonication, respectively. Reversely, sonicated samples at 180.1 W/dm2 possessed 8.1% less amount of Fe2+ than only air-dried samples after drying. The results implied that ultrasound treatment alleviated the interference of Fe2+ on the enzymatic degradation of glucosinolates, as well as promoted the degradation of glucoraphanin to sulforaphane. Besides, air-borne sonication had no significant influence on the contents of ascorbic acid and phenolic acids, and antioxidant capacity in vitro of broccoli under air drying. This study demonstrated that air-borne ultrasound assisted-air drying could not only speed up the drying process of broccoli florets, but also promote the conversion of glucoraphanin and preserve the bioactive components in certain aspects.
2022, 43(2): 112-119.
doi: 10.13386/j.issn1002-0306.2021050100
Abstract:
Under different storage conditions, rapid viscosity analysis (RVA) properties of indica rice were studied. Samples of Liangyou 234 type indica with 13.5%, 14.5% and 15.5% moisture content were chosen to store under 15, 20, 25, 30 and 35 ℃ for 720 d, respectively. RVA eigenvalues of the corresponding rice samples were measured by rapid viscosity analyzer every 60 days. The results showed that the storage temperature, storage time and moisture content of rice had very significant effect on RVA eigenvalues (P<0.01), in which the temperature affected mainly. With the extension of storage time, the peak viscosity and breakdown viscosity of rice increased at the early stage of the storage, and decreased in the late storage period. Moreover, the peak viscosity of rice and breakdown viscosity at 30 and 35 ℃ temperature in late apparently decreased faster than the others. Final viscosity, consistence viscosity, setback value, pasting temperature increased during the storage period, in which these three eigenvalues under the high temperature (30 and 35 ℃) storage were greater than the normal temperature and quasi-low temperature storage (25, 20 and 15 ℃). It reflected the quality of rice eating during storage period. With the increasing of storage temperature and the prolonging of storage time, the edible quality of rice decreased significantly, and the deterioration accelerated when the storage temperature exceeded 25 ℃. It could be used as reference conditions for the control of rice storage.
Under different storage conditions, rapid viscosity analysis (RVA) properties of indica rice were studied. Samples of Liangyou 234 type indica with 13.5%, 14.5% and 15.5% moisture content were chosen to store under 15, 20, 25, 30 and 35 ℃ for 720 d, respectively. RVA eigenvalues of the corresponding rice samples were measured by rapid viscosity analyzer every 60 days. The results showed that the storage temperature, storage time and moisture content of rice had very significant effect on RVA eigenvalues (P<0.01), in which the temperature affected mainly. With the extension of storage time, the peak viscosity and breakdown viscosity of rice increased at the early stage of the storage, and decreased in the late storage period. Moreover, the peak viscosity of rice and breakdown viscosity at 30 and 35 ℃ temperature in late apparently decreased faster than the others. Final viscosity, consistence viscosity, setback value, pasting temperature increased during the storage period, in which these three eigenvalues under the high temperature (30 and 35 ℃) storage were greater than the normal temperature and quasi-low temperature storage (25, 20 and 15 ℃). It reflected the quality of rice eating during storage period. With the increasing of storage temperature and the prolonging of storage time, the edible quality of rice decreased significantly, and the deterioration accelerated when the storage temperature exceeded 25 ℃. It could be used as reference conditions for the control of rice storage.
2022, 43(2): 120-125.
doi: 10.13386/j.issn1002-0306.2021060084
Abstract:
Objective: To investigate the inhibitory effect of Tremella fuciformis polysaccharide (TP) on pancreatic α-amylase and α-glucosidase and its action mechanism. Methods: TP with a total sugar content of 92.45% was obtained by alkaline extraction from dried Tremella fuciformis, enzymatic deproteinization and column chromatography separation in turn. The inhibitory effect of TP on pancreatic α-amylase and α-glucosidase was measured by visible spectrophotometry, and its action on the structures of these two enzymes was characterized by fluorescence spectrometry and circular dichroism. Results: TP could inhibit the activities of these two enzymes, and its inhibition on pancreatic α-amylase was significantly higher than that on α-glucosidase, and its half inhibitory concentrations (IC50) on these two enzymes were 7.6835 and 16.9306 mg/mL, respectively. TP inhibited the activity of the enzymes by interacting with them. TP interacted strongly with pancreatic α-amylase. It could statically quench pancreatic α-amylase and change its secondary structure. However, TP interacted weakly with α-glucosidase and could not change its secondary structure. Conclusion: TP inhibited the activity of starch-digestive enzymes by interacting with them.
Objective: To investigate the inhibitory effect of Tremella fuciformis polysaccharide (TP) on pancreatic α-amylase and α-glucosidase and its action mechanism. Methods: TP with a total sugar content of 92.45% was obtained by alkaline extraction from dried Tremella fuciformis, enzymatic deproteinization and column chromatography separation in turn. The inhibitory effect of TP on pancreatic α-amylase and α-glucosidase was measured by visible spectrophotometry, and its action on the structures of these two enzymes was characterized by fluorescence spectrometry and circular dichroism. Results: TP could inhibit the activities of these two enzymes, and its inhibition on pancreatic α-amylase was significantly higher than that on α-glucosidase, and its half inhibitory concentrations (IC50) on these two enzymes were 7.6835 and 16.9306 mg/mL, respectively. TP inhibited the activity of the enzymes by interacting with them. TP interacted strongly with pancreatic α-amylase. It could statically quench pancreatic α-amylase and change its secondary structure. However, TP interacted weakly with α-glucosidase and could not change its secondary structure. Conclusion: TP inhibited the activity of starch-digestive enzymes by interacting with them.
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