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Vol.42, No.3
February 2021
Semimonthly
ISSN 1002-0306
CN 11-1759/TS
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doi: 10.13386/j.issn1002-0306.2020070069
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doi: 10.13386/j.issn1002-0306.2020060045
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doi: 10.13386/j.issn1002-0306.2020060070
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doi: 10.13386/j.issn1002-0306.2020100157
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Application and Research Progress of Stable Isotope Technology in Animal and Plant Food Traceability
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doi: 10.13386/j.issn1002-0306.2020040141
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2021, 42(3): 1-5,12.
doi: 10.13386/j.issn1002-0306.2020030335
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The objective of this work was to investigate the difference of heat-induced gel properties between black carp(Mylopharyngodon piceus)and silver carp(Hypophthalmichthys molitrix). The secondary structure,surface hydrophobicity(S0-ANS),disulfide bonds,average particle size(dz)and dynamic rheology of myosin during heat-induced gel formation were also studied. The results showed that denaturation degree of black carp myosin was higher than that of silver carp during the heat-induced gel formation,indicating more hydrophobic amino acid residues were exposed to form a higher hydrophobic interaction in black carp myosin. Therefore,the dz of black carp myosin was about twice that of silver carp,and G' was higher than silver carp. The results showed that the myosin of black carp had a higher heat-induced gel forming ability than silver carp. The transformation of α-helix to β-fold or β-turn angle were conducive to the gelation of myosin.
The objective of this work was to investigate the difference of heat-induced gel properties between black carp(Mylopharyngodon piceus)and silver carp(Hypophthalmichthys molitrix). The secondary structure,surface hydrophobicity(S0-ANS),disulfide bonds,average particle size(dz)and dynamic rheology of myosin during heat-induced gel formation were also studied. The results showed that denaturation degree of black carp myosin was higher than that of silver carp during the heat-induced gel formation,indicating more hydrophobic amino acid residues were exposed to form a higher hydrophobic interaction in black carp myosin. Therefore,the dz of black carp myosin was about twice that of silver carp,and G' was higher than silver carp. The results showed that the myosin of black carp had a higher heat-induced gel forming ability than silver carp. The transformation of α-helix to β-fold or β-turn angle were conducive to the gelation of myosin.
2021, 42(3): 6-12.
doi: 10.13386/j.issn1002-0306.2020030353
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In order to effectively inhibit the formation of N-nitrosopyrrolidine(NPYR),in the simulated nitrosation reaction system in vitro,a single factor test was firstly conducted to study the eight common supercritical extraction spices essential oils(SEO),including pepper essential oil,star anise essential oil,green pepper oil,clove essential oil,rosemary essential oil,black pepper essential oil,angelica flavored ginger oil,amomum essential oil,inhibitory effect on NPYR,and response surface center combination test was used to screen the best ratio of compound spices essential oil(CSEO). The single-factor test results showed that,except for amomum villosum essential oil,the other seven SEOs all had an inhibitory effect on the formation of NPYR,and the inhibition rate had a certain relationship with its added concentration. Among them,rosemary essential oil(15、20.0 mL/L)had the strongest inhibitory effect on NPYR(more than 80%),followed by pepper essential oil(5.0,10.0 mL/L),green pepper oil(0.5 mL/L)and clove essential oil(15.0 mL/L)against NPYR. The inhibition rate could reach more than 68%,the inhibitory effect of angelica flavor ginger oil(10.0 mL/L)and star anise oil(15.0 mL/L)was slightly lower(more than 50%),while the inhibitory rate of black pepper essential oil on NPYR was relatively weak(less than 50%). The CSEO composition with the best NPYR inhibition effect was obtained from the response surface center design test:441.0 μL/L peppercorn essential oil,337.0 μL/L star anise essential oil,17.0 μL/L green pepper oil,14.0 μL/L clove essential oil,and 137.0 μL/L rosemary essential oil,the predicted value of the NPYR inhibition rate was 69.84% from the model optimization,the inhibition rate was 68.40% from the verification test,and the inhibition rate of CSEO against N-nitrosodimethylamine(NDMA)was 66.69%.
In order to effectively inhibit the formation of N-nitrosopyrrolidine(NPYR),in the simulated nitrosation reaction system in vitro,a single factor test was firstly conducted to study the eight common supercritical extraction spices essential oils(SEO),including pepper essential oil,star anise essential oil,green pepper oil,clove essential oil,rosemary essential oil,black pepper essential oil,angelica flavored ginger oil,amomum essential oil,inhibitory effect on NPYR,and response surface center combination test was used to screen the best ratio of compound spices essential oil(CSEO). The single-factor test results showed that,except for amomum villosum essential oil,the other seven SEOs all had an inhibitory effect on the formation of NPYR,and the inhibition rate had a certain relationship with its added concentration. Among them,rosemary essential oil(15、20.0 mL/L)had the strongest inhibitory effect on NPYR(more than 80%),followed by pepper essential oil(5.0,10.0 mL/L),green pepper oil(0.5 mL/L)and clove essential oil(15.0 mL/L)against NPYR. The inhibition rate could reach more than 68%,the inhibitory effect of angelica flavor ginger oil(10.0 mL/L)and star anise oil(15.0 mL/L)was slightly lower(more than 50%),while the inhibitory rate of black pepper essential oil on NPYR was relatively weak(less than 50%). The CSEO composition with the best NPYR inhibition effect was obtained from the response surface center design test:441.0 μL/L peppercorn essential oil,337.0 μL/L star anise essential oil,17.0 μL/L green pepper oil,14.0 μL/L clove essential oil,and 137.0 μL/L rosemary essential oil,the predicted value of the NPYR inhibition rate was 69.84% from the model optimization,the inhibition rate was 68.40% from the verification test,and the inhibition rate of CSEO against N-nitrosodimethylamine(NDMA)was 66.69%.
2021, 42(3): 13-18,24.
doi: 10.13386/j.issn1002-0306.2020040118
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The effect of sucrose addition on the quality of compound strain fermented products was studied. The shrimp heads of Litopenaeus vannamei was selected as raw materials,and sucrose of different concentrations was added in the early stage of fermentation. The physicochemical and safety indicators of shrimp head sauce during fermentation were tracked,including the monitoring of pH,histamine,TVB-N and AA-N. The nutritional components of the finished sauce were detected and sensory evaluation was carried out. The results showed that the pH of the sucrose group was stable at 8.6 in the late stage of fermentation,the total number of colonies decreased. After adding sucrose,there was no significant change in crude fat and protein content of shrimp head sauce(P>0.05),the total sugar content of shrimp head sauce added with 2%,4%,6% sucrose was 2.94,3.79 and 4.67 times of the control group when fermented for 14 d,respectively.With the increase of sucrose concentration,histamine content decreased in turn,and there was a dose-response relationship.The contents of histamine in the 2%,4% and 6% sucrose groups were 71.4%,60.0% and 47.4% of the control group,respectively. At the same time,the product was safe after sucrose addition,the TVB-N content decreased slightly,AA-N content was higher than 0.65 g/100 g,protein content was 9.55 g/100 g,and had high nutritional value. In addition,sucrose reduced the volatilization of fermentation pungent odor,significantly improved the sensory flavor,and optimized the rapid fermentation quality of the composite bacteria to a certain extent..
The effect of sucrose addition on the quality of compound strain fermented products was studied. The shrimp heads of Litopenaeus vannamei was selected as raw materials,and sucrose of different concentrations was added in the early stage of fermentation. The physicochemical and safety indicators of shrimp head sauce during fermentation were tracked,including the monitoring of pH,histamine,TVB-N and AA-N. The nutritional components of the finished sauce were detected and sensory evaluation was carried out. The results showed that the pH of the sucrose group was stable at 8.6 in the late stage of fermentation,the total number of colonies decreased. After adding sucrose,there was no significant change in crude fat and protein content of shrimp head sauce(P>0.05),the total sugar content of shrimp head sauce added with 2%,4%,6% sucrose was 2.94,3.79 and 4.67 times of the control group when fermented for 14 d,respectively.With the increase of sucrose concentration,histamine content decreased in turn,and there was a dose-response relationship.The contents of histamine in the 2%,4% and 6% sucrose groups were 71.4%,60.0% and 47.4% of the control group,respectively. At the same time,the product was safe after sucrose addition,the TVB-N content decreased slightly,AA-N content was higher than 0.65 g/100 g,protein content was 9.55 g/100 g,and had high nutritional value. In addition,sucrose reduced the volatilization of fermentation pungent odor,significantly improved the sensory flavor,and optimized the rapid fermentation quality of the composite bacteria to a certain extent..
2021, 42(3): 19-24.
doi: 10.13386/j.issn1002-0306.2020040208
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In order to understand the difference in stability of different MPs components,a yellow fraction F1 which mainly contained monascin and ankaflavin,and a orange fraction F2 which mainly contained monascorubrin and rubropunctatin,were separated from crude MPs extract by macroporous resin column chromatography. The yellow fraction F1 and orange fraction F2 were then used to analyze to the stability of yellow MPs(YMPs)and orange MPs(OMPs)under varying pH,temperature and light conditions based on UV-Vis spectra and residual values. Results showed that YMPs were stable in the pH range of 2~9,while OMPs were stable in the pH range of 2~4. When pH≥ 5,the λmax of OMPs shifted obviously. Both of the YMPs and OMPs exhibited good UV-light stability. After 270 min UV-light exposure,no shift of λmax was observed in UV-Vis spectra of YMPs and OMPs,and the residual percentages of YMPs and OMPs were 70.4%±0.2% and 64.4%±0.9%,respectively,which were significantly higher than that of curcumin(7.9%±0.7%). The thermal stability of YMPs was better than that of OMPs. After heated at 80 ℃ for 120 min,there was an obvious change in the shape of the UV-Vis spectrum of OMP,but not in that of YMPs. Additionally,residual percentage of OMPs after heating was 40.8%±1.9%,which was significantly lower than that of YMPs(87.4%±3.2%)and curcumin(90.9%±4.5%). These results suggested that YMPs was the stable components of MPs and could be used to develop MPs products with high stability.
In order to understand the difference in stability of different MPs components,a yellow fraction F1 which mainly contained monascin and ankaflavin,and a orange fraction F2 which mainly contained monascorubrin and rubropunctatin,were separated from crude MPs extract by macroporous resin column chromatography. The yellow fraction F1 and orange fraction F2 were then used to analyze to the stability of yellow MPs(YMPs)and orange MPs(OMPs)under varying pH,temperature and light conditions based on UV-Vis spectra and residual values. Results showed that YMPs were stable in the pH range of 2~9,while OMPs were stable in the pH range of 2~4. When pH≥ 5,the λmax of OMPs shifted obviously. Both of the YMPs and OMPs exhibited good UV-light stability. After 270 min UV-light exposure,no shift of λmax was observed in UV-Vis spectra of YMPs and OMPs,and the residual percentages of YMPs and OMPs were 70.4%±0.2% and 64.4%±0.9%,respectively,which were significantly higher than that of curcumin(7.9%±0.7%). The thermal stability of YMPs was better than that of OMPs. After heated at 80 ℃ for 120 min,there was an obvious change in the shape of the UV-Vis spectrum of OMP,but not in that of YMPs. Additionally,residual percentage of OMPs after heating was 40.8%±1.9%,which was significantly lower than that of YMPs(87.4%±3.2%)and curcumin(90.9%±4.5%). These results suggested that YMPs was the stable components of MPs and could be used to develop MPs products with high stability.
2021, 42(3): 25-30.
doi: 10.13386/j.issn1002-0306.2020020119
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To explore the effect of intermittent liquid nitrogen immersion freezing on the color difference,texture,sensory quality and microstructure of dumplings,in this paper the effect of liquid nitrogen immersion time,interval time and immersion times on dumplings with the index of freezing-cracking rate were studied. The effect of liquid nitrogen immersion freezing on the color,texture,sensory properties and microstructure of dumplings compared with the cryogenic refrigerator freezing and spiral tunnel freezing was studied by means of color difference meter,texture meter and scanning electron microscope. The results showed that when the single immersion time of liquid nitrogen was 2 s,the interval time was 10 s and the total immersion time was 86 s,the time was the shortest and the central temperature reached below-18 ℃ and the freeze-crack rate of dumplings was 0. Compared with the traditional cryogenic refrigerator freezing and spiral tunnel freezing,the L* of dumplings increased significantly after the immersion freezing with liquid nitrogen(P<0.05),the color and appearance were significantly improved,and the hardness,adhesion and chewability significantly reduced(P<0.05). The taste was more similar to the quality of fresh untreated dumplings. The SEM results showed that the number of pores in the dumpling skin was the smallest and the most in the liquid nitrogen freezing treatment group,and the excessive holes might damage the gluten network structure,resulting in poor boiling resistance of dumplings. This study provides a certain theoretical basis and technical support for the application of liquid nitrogen freezing in rice noodle products.
To explore the effect of intermittent liquid nitrogen immersion freezing on the color difference,texture,sensory quality and microstructure of dumplings,in this paper the effect of liquid nitrogen immersion time,interval time and immersion times on dumplings with the index of freezing-cracking rate were studied. The effect of liquid nitrogen immersion freezing on the color,texture,sensory properties and microstructure of dumplings compared with the cryogenic refrigerator freezing and spiral tunnel freezing was studied by means of color difference meter,texture meter and scanning electron microscope. The results showed that when the single immersion time of liquid nitrogen was 2 s,the interval time was 10 s and the total immersion time was 86 s,the time was the shortest and the central temperature reached below-18 ℃ and the freeze-crack rate of dumplings was 0. Compared with the traditional cryogenic refrigerator freezing and spiral tunnel freezing,the L* of dumplings increased significantly after the immersion freezing with liquid nitrogen(P<0.05),the color and appearance were significantly improved,and the hardness,adhesion and chewability significantly reduced(P<0.05). The taste was more similar to the quality of fresh untreated dumplings. The SEM results showed that the number of pores in the dumpling skin was the smallest and the most in the liquid nitrogen freezing treatment group,and the excessive holes might damage the gluten network structure,resulting in poor boiling resistance of dumplings. This study provides a certain theoretical basis and technical support for the application of liquid nitrogen freezing in rice noodle products.
2021, 42(3): 31-35.
doi: 10.13386/j.issn1002-0306.2020030363
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The fourteen kinds of flour produced in Hetao area were selected and made into steamed bread. The relationships between rheological properties of dough obtained by the alveograph and fermentation rheometer were studied. The results showed that the G and Ie of alveograph index were significantly positively correlated with the Hm(P<0.05),the P/L value was significantly negatively correlated with the Hm(P<0.05);and the P and W had significant positive effect on the specific volume of steamed bread(P<0.05);while P/L was significantly negatively correlated with steamed bread springiness and positively correlated with the hardness of steamed bread(P<0.05). Besides,dough retention of carbon dioxide volume and retention coefficient had the greatest effect on the quality index of steamed bread,among which maintaining carbon dioxide volume in dough had positive effect on steamed bread springiness;while retention coefficient had positive effect on steamed bread specific volume.
The fourteen kinds of flour produced in Hetao area were selected and made into steamed bread. The relationships between rheological properties of dough obtained by the alveograph and fermentation rheometer were studied. The results showed that the G and Ie of alveograph index were significantly positively correlated with the Hm(P<0.05),the P/L value was significantly negatively correlated with the Hm(P<0.05);and the P and W had significant positive effect on the specific volume of steamed bread(P<0.05);while P/L was significantly negatively correlated with steamed bread springiness and positively correlated with the hardness of steamed bread(P<0.05). Besides,dough retention of carbon dioxide volume and retention coefficient had the greatest effect on the quality index of steamed bread,among which maintaining carbon dioxide volume in dough had positive effect on steamed bread springiness;while retention coefficient had positive effect on steamed bread specific volume.
2021, 42(3): 36-42.
doi: 10.13386/j.issn1002-0306.2020020159
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The aim of the study was to purify and identify antibacterial lipopeptide produced by Bacillus coagulans XZQ-16 and to explore the functional characteristics in anti-spoilage bacteria. The antibacterial lipopeptide was isolated and purified by acid precipitation,column chromatography on silica gel and Sephadex LH-20. Lipopeptide compounds were identified by using Fourier infrared spectroscopy(FT-IR)and reversed phase high performance liquid chromatography(RP-HPLC)techniques. The results showed that three flow fractions obtained by silica gel column chromatography had significant antibacterial activity. Four elution peaks were isolated by Sephadex LH-20 chromatography,among which,elution peak Ⅲ had significant antibacterial activity. FT-IR analysis confirmed that the purified antibacterial substance contained lipopeptide compounds. RP-HPLC further identified the presence of three components in the isolated antimicrobial substances,and identified the two groups as homologues of iturin and surfactin compared with the standard sample. The purified antimicrobial lipopeptide was stable over a broad pH range(4.0~12.0)and at temperatures up to 120 ℃ for 30 min. Antibacterial lipopeptide could inhibit the growth of a broad range of foodborne Gram-positive bacteria,including Bacillus cereus,Staphylococcus aureus,Listeria monocytogenes,Micrococcus luteus and Gram-negative bacteria such as E. Coli,Salmonella,Shigella and Pseudomonas aeruginosa. Moreover,unlike commercially available nisin and polymyxin B,which only worked on bacteria,the lipopeptide produced by strain XZQ-16 also inhibited fungi such as Candida albicans,Pichia pastoris and Aspergillus niger.Lipopeptide produced by Bacillus pumilus XZQ-16 showed high stability and broad antibacterial activity.This paper lays a theoretical foundation for its application in the fields of food,animal husbandry,medicine,cosmetics and plant protection.
The aim of the study was to purify and identify antibacterial lipopeptide produced by Bacillus coagulans XZQ-16 and to explore the functional characteristics in anti-spoilage bacteria. The antibacterial lipopeptide was isolated and purified by acid precipitation,column chromatography on silica gel and Sephadex LH-20. Lipopeptide compounds were identified by using Fourier infrared spectroscopy(FT-IR)and reversed phase high performance liquid chromatography(RP-HPLC)techniques. The results showed that three flow fractions obtained by silica gel column chromatography had significant antibacterial activity. Four elution peaks were isolated by Sephadex LH-20 chromatography,among which,elution peak Ⅲ had significant antibacterial activity. FT-IR analysis confirmed that the purified antibacterial substance contained lipopeptide compounds. RP-HPLC further identified the presence of three components in the isolated antimicrobial substances,and identified the two groups as homologues of iturin and surfactin compared with the standard sample. The purified antimicrobial lipopeptide was stable over a broad pH range(4.0~12.0)and at temperatures up to 120 ℃ for 30 min. Antibacterial lipopeptide could inhibit the growth of a broad range of foodborne Gram-positive bacteria,including Bacillus cereus,Staphylococcus aureus,Listeria monocytogenes,Micrococcus luteus and Gram-negative bacteria such as E. Coli,Salmonella,Shigella and Pseudomonas aeruginosa. Moreover,unlike commercially available nisin and polymyxin B,which only worked on bacteria,the lipopeptide produced by strain XZQ-16 also inhibited fungi such as Candida albicans,Pichia pastoris and Aspergillus niger.Lipopeptide produced by Bacillus pumilus XZQ-16 showed high stability and broad antibacterial activity.This paper lays a theoretical foundation for its application in the fields of food,animal husbandry,medicine,cosmetics and plant protection.
2021, 42(3): 43-47,52.
doi: 10.13386/j.issn1002-0306.2020030367
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The bean paste-flavored sausage made by natural air-drying in Sichuan area,China,was taken as the research object,and the product features were analyzed and compared with industrial baking-dried sausage and western fermented sausage. The result showed that the moisture activity(aw)was 0.68~0.85,pH5.84~6.01,NaCl content was 2.80%~3.52％,the peroxide value(POV),acid value(AV)and thiobarbituric acid(TBA)values were 0.55~0.66,2.28~3.71 and 0.23~0.74 mg/kg,respectively.The results of sodium nitrite residue showed that the naturally air-dried sausage was 2.21~2.71 mg/kg,the baked and dried sausage was(10.37±1.14) mg/kg,and the western-style fermented sausage was(9.51±1.06) mg/kg. In terms of microbial characteristics,very few microorganisms were detected in bake-dried sausage,while the content of lactic acid bacteria in western fermented sausage was high.The variety and quantity of microorganisms in the natural air-dried soy-flavored sausage in Sichuan were abundant,but the total number of colonies,micrococcus and lactic acid bacteria were lower than that of western fermented sausage,while the contents of yeast and mold were higher. Based on the principal component analysis(PCA)and hierarchical cluster analysis(HCA),the sausages of Chengdu plain in central part of Sichuan and the northern part of the province earned the highest scores.The results indicated that the natural air-dried sausage,baking-dried sausage and western fermented sausage were significantly different from each other in terms of physicochemical and microbial characteristics,and the Sichuan-style natural dried sauce-flavored sausages had significantly different characteristics from traditional sausages and western-style fermented sausages.
The bean paste-flavored sausage made by natural air-drying in Sichuan area,China,was taken as the research object,and the product features were analyzed and compared with industrial baking-dried sausage and western fermented sausage. The result showed that the moisture activity(aw)was 0.68~0.85,pH5.84~6.01,NaCl content was 2.80%~3.52％,the peroxide value(POV),acid value(AV)and thiobarbituric acid(TBA)values were 0.55~0.66,2.28~3.71 and 0.23~0.74 mg/kg,respectively.The results of sodium nitrite residue showed that the naturally air-dried sausage was 2.21~2.71 mg/kg,the baked and dried sausage was(10.37±1.14) mg/kg,and the western-style fermented sausage was(9.51±1.06) mg/kg. In terms of microbial characteristics,very few microorganisms were detected in bake-dried sausage,while the content of lactic acid bacteria in western fermented sausage was high.The variety and quantity of microorganisms in the natural air-dried soy-flavored sausage in Sichuan were abundant,but the total number of colonies,micrococcus and lactic acid bacteria were lower than that of western fermented sausage,while the contents of yeast and mold were higher. Based on the principal component analysis(PCA)and hierarchical cluster analysis(HCA),the sausages of Chengdu plain in central part of Sichuan and the northern part of the province earned the highest scores.The results indicated that the natural air-dried sausage,baking-dried sausage and western fermented sausage were significantly different from each other in terms of physicochemical and microbial characteristics,and the Sichuan-style natural dried sauce-flavored sausages had significantly different characteristics from traditional sausages and western-style fermented sausages.
2021, 42(3): 48-52.
doi: 10.13386/j.issn1002-0306.2020040236
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In the present study,the rheological properties of rice starch before and after heat-moisture treatment(HMT)were determined. The purpose of this study was to study the steady-state rheological behavior,dynamic rheological behavior and temperature rheological behavior of rice starch subjected to heat-moisture treatment. The results showed that rice starches showed shear thinning after HMT,which suggested that HMT increased their gel strength. In the dynamic rheological measurement,it was found that the elastic modulus(G')of starch samples was greater than the viscosity modulus(G″),and the elastic modulus(G')and viscosity modulus(G″)of rice starch samples increased after HMT,while the loss tangent(tan δ)decreased. In the determination of temperature rheology,it was found that the gelatinization temperature of rice starch treated with HMT increased,also the peak temperature of elastic modulus. The results showed HMT strengthened the interactions of starch molecular chains,thereby forming an strengthened gel network structure.
In the present study,the rheological properties of rice starch before and after heat-moisture treatment(HMT)were determined. The purpose of this study was to study the steady-state rheological behavior,dynamic rheological behavior and temperature rheological behavior of rice starch subjected to heat-moisture treatment. The results showed that rice starches showed shear thinning after HMT,which suggested that HMT increased their gel strength. In the dynamic rheological measurement,it was found that the elastic modulus(G')of starch samples was greater than the viscosity modulus(G″),and the elastic modulus(G')and viscosity modulus(G″)of rice starch samples increased after HMT,while the loss tangent(tan δ)decreased. In the determination of temperature rheology,it was found that the gelatinization temperature of rice starch treated with HMT increased,also the peak temperature of elastic modulus. The results showed HMT strengthened the interactions of starch molecular chains,thereby forming an strengthened gel network structure.
2021, 42(3): 53-60,67.
doi: 10.13386/j.issn1002-0306.2020040174
Abstract:
The objective of this study was to comprehensively evaluate fruit quality of 10 seedless table grapes cultivars cultivated in Yinchuan area by using analytic hierarchy process and principal component analysis,which was aimed to provide reference for selecting high-quality table grape cultivars. The 10 seedless table grapes were taken as materials,and 14 basic quality indicators were measured,the quality of fruit were further analyzed by using analytic hierarchy process and principal component analysis,and sorted according to the comprehensive score. The results showed that three levels were set up in the hierarchical-relational analysis,the target layer was the comprehensive quality of the fruits,and the criterion layer was divided into appearance quality and intrinsic quality. The intrinsic quality weight value was 0.6,and the appearance quality weight value was 0.4. The index layer had the highest flavor and flavor weights,which were 0.1535 and 0.1413,respectively. The spikelets and single grain weight were important factors affecting external quality,and the weight values were 0.1087 and 0.1062. ‘Ruifeng Wuhe’ had the best appearance quality,with a weighted correlation of 0.7477,and ‘Eros Rose’ had the best internal quality,with a weighted correlation of 0.9131. The best comprehensive quality performance was ‘Eros Rose’,followed by ‘Wuhecuibao’,then ‘Summer Black’,and the weighted correlations were 0.8006,0.7732,0.7291 in order. Four principal components were extracted by principal component analysis,and cumulative contribution rate reached 86.332%. The total acid,solid acid ratio,sugar-acid ratio,flavor and aroma of the first principal component played an important role. And the thickness of the second principal component,fruit grain uniformity,single panicle weight and fruit panicle compactness had a great influence on it. The single grain weight,soluble solids,soluble sugar and flavor of the third principal component had a great effect on it. The color consistency of the fourth principal component and the content of vitamin C had a great effect on it. The highest comprehensive score was ‘Wuhecuibao’,followed by ‘Summer Black’,and then ‘Eros Rose’,with 1.31,1.17 and 1.02 respectively. The lowest comprehensive score was ‘Centennial’,with-2.11. The top three scores were ‘Wuhecuibao’,‘Aishen Meigui’,and ‘Summer Black’,at the bottom of the ranking was ‘Centennial’,which comprehensive analyzed of analytic hierarchy process and principal component analysis. The combination of analytic hierarchy process and principal component analysis to evaluate fruit quality was reliable,which could be used as a theoretical basis for the regional test promotion of fine varieties in the future.
The objective of this study was to comprehensively evaluate fruit quality of 10 seedless table grapes cultivars cultivated in Yinchuan area by using analytic hierarchy process and principal component analysis,which was aimed to provide reference for selecting high-quality table grape cultivars. The 10 seedless table grapes were taken as materials,and 14 basic quality indicators were measured,the quality of fruit were further analyzed by using analytic hierarchy process and principal component analysis,and sorted according to the comprehensive score. The results showed that three levels were set up in the hierarchical-relational analysis,the target layer was the comprehensive quality of the fruits,and the criterion layer was divided into appearance quality and intrinsic quality. The intrinsic quality weight value was 0.6,and the appearance quality weight value was 0.4. The index layer had the highest flavor and flavor weights,which were 0.1535 and 0.1413,respectively. The spikelets and single grain weight were important factors affecting external quality,and the weight values were 0.1087 and 0.1062. ‘Ruifeng Wuhe’ had the best appearance quality,with a weighted correlation of 0.7477,and ‘Eros Rose’ had the best internal quality,with a weighted correlation of 0.9131. The best comprehensive quality performance was ‘Eros Rose’,followed by ‘Wuhecuibao’,then ‘Summer Black’,and the weighted correlations were 0.8006,0.7732,0.7291 in order. Four principal components were extracted by principal component analysis,and cumulative contribution rate reached 86.332%. The total acid,solid acid ratio,sugar-acid ratio,flavor and aroma of the first principal component played an important role. And the thickness of the second principal component,fruit grain uniformity,single panicle weight and fruit panicle compactness had a great influence on it. The single grain weight,soluble solids,soluble sugar and flavor of the third principal component had a great effect on it. The color consistency of the fourth principal component and the content of vitamin C had a great effect on it. The highest comprehensive score was ‘Wuhecuibao’,followed by ‘Summer Black’,and then ‘Eros Rose’,with 1.31,1.17 and 1.02 respectively. The lowest comprehensive score was ‘Centennial’,with-2.11. The top three scores were ‘Wuhecuibao’,‘Aishen Meigui’,and ‘Summer Black’,at the bottom of the ranking was ‘Centennial’,which comprehensive analyzed of analytic hierarchy process and principal component analysis. The combination of analytic hierarchy process and principal component analysis to evaluate fruit quality was reliable,which could be used as a theoretical basis for the regional test promotion of fine varieties in the future.
2021, 42(3): 61-67.
doi: 10.13386/j.issn1002-0306.2020040081
Abstract:
Filter paper diffusion method was used to study the bacteriostatic activity of ethanol extracts from water chestnut stem and water chestnut pericarp and their different solvent extracts. The effects of different temperature,pH and UV irradiation on the stability of bacteriostatic activity of ethyl acetate extracts from water chestnut stem and water chestnut pericarp were also investigated. Finally,the components of ethyl acetate extracts from water chestnut stem and water chestnut pericarp was studied by HPLC and HPLC-MS to identify. The results showed that the minimum inhibitory concentrations of the extracts of water chestnut stem and water chestnut pericarp to Staphylococcus aureus,Escherichia coli and Saccharomyces cerevisiae were 0.391,0.391,3.125 mg/mL and 0.098,0.195 and 1.563 mg/mL,respectively,the antibacterial effect showed that the ethyl acetate extract of the water chestnut pericarp was superior to the ethyl acetate extract of the water chestnut stem. Both extracts had a significant bacteriostatic effect on Gram-positive bacteria,and the effect was stronger than Gram-negative bacteria,and they had the weakest antibacterial effect on fungi. The ethyl acetate extracts of water chestnut stem and water chestnut pericarp showed good antibacterial stability when treated at 20~100 ℃,pH5~9 and ultraviolet light for 10~40 min. The content of gallic acid and 1,2,6-tri-O-galloyl-β-D-glucose in the ethyl acetate extract of water chestnut stem was 45.87%. The content of 1,2,3,6-tetra-O-galloyl-β-D-glucose,Quercetin-3-O-galactoside and 1,2,6-tri-O-galloyl-β-D-glucose in the ethyl acetate extract of water chestnut pericarp was 57.84%. This paper provides a reference for the practical application of the extracts of water chestnut stem and water chestnut pericarp as bacteriostatic agents.
Filter paper diffusion method was used to study the bacteriostatic activity of ethanol extracts from water chestnut stem and water chestnut pericarp and their different solvent extracts. The effects of different temperature,pH and UV irradiation on the stability of bacteriostatic activity of ethyl acetate extracts from water chestnut stem and water chestnut pericarp were also investigated. Finally,the components of ethyl acetate extracts from water chestnut stem and water chestnut pericarp was studied by HPLC and HPLC-MS to identify. The results showed that the minimum inhibitory concentrations of the extracts of water chestnut stem and water chestnut pericarp to Staphylococcus aureus,Escherichia coli and Saccharomyces cerevisiae were 0.391,0.391,3.125 mg/mL and 0.098,0.195 and 1.563 mg/mL,respectively,the antibacterial effect showed that the ethyl acetate extract of the water chestnut pericarp was superior to the ethyl acetate extract of the water chestnut stem. Both extracts had a significant bacteriostatic effect on Gram-positive bacteria,and the effect was stronger than Gram-negative bacteria,and they had the weakest antibacterial effect on fungi. The ethyl acetate extracts of water chestnut stem and water chestnut pericarp showed good antibacterial stability when treated at 20~100 ℃,pH5~9 and ultraviolet light for 10~40 min. The content of gallic acid and 1,2,6-tri-O-galloyl-β-D-glucose in the ethyl acetate extract of water chestnut stem was 45.87%. The content of 1,2,3,6-tetra-O-galloyl-β-D-glucose,Quercetin-3-O-galactoside and 1,2,6-tri-O-galloyl-β-D-glucose in the ethyl acetate extract of water chestnut pericarp was 57.84%. This paper provides a reference for the practical application of the extracts of water chestnut stem and water chestnut pericarp as bacteriostatic agents.
2021, 42(3): 68-76.
doi: 10.13386/j.issn1002-0306.2020040080
Abstract:
This research tested six Huiming tea infusions brewing by different types of water,including pure water(PW),bottled natural water(TR1,TR2),bottled mineral water(MW1,MW2)and tap water(TW). Comparisons had been made between their physicochemical characteristics,biochemical components,and sensory qualities. It also adopted solid-phase microextraction(SPME)combined with gas chromatography-mass spectrometry(GC-MS)to analyze aroma components. The results indicated that different types of water had significant effects on both the physical and chemical properties of Huiming tea infusions. Comparing with TR1,TR2,and PW tea infusions,MW1,MW2,and TW tea infusions with high Ca2+,Mg2+ ions had a lower increment of Mg2+ ion or electrical conductivity. Meanwhile,the concentration of Ca2+ ion in MW1,MW2,and TW also significantly reduced. For taste-producing substances,free amino acid and Ca2+,Mg2+,pH,also total soluble sugur and pH,as well as tea polyphenols and Ca2+,Mg2+,pH,electrical conductivity had a very significant negative conelation(P<0.01). As for aroma compounds,the contents in TR1(7429 μg·kg-1)and PW(7422 μg·kg-1)tea infusions were significantly higher than other samples(about 5100 μg·kg-1). Further,it also found that most aroma compounds had significant negative correlations(P<0.05)with Ca2+ ion and pH of the water,as well as positive correlations(P<0.05)with total soluble sugar and free amino acids. At last,for the sensory qualities,the evaluation granted TR1 and TR2 tea infusions of the most favorite among all samples. In detail,TR2 infusion had a more favorable color and taste when TR1 infusion had the best fragrance quality. Therefore,the lower the pH and Ca2+ concentration of water,the higher the content of aroma substances,and the better the aroma quality of tea infusions.
This research tested six Huiming tea infusions brewing by different types of water,including pure water(PW),bottled natural water(TR1,TR2),bottled mineral water(MW1,MW2)and tap water(TW). Comparisons had been made between their physicochemical characteristics,biochemical components,and sensory qualities. It also adopted solid-phase microextraction(SPME)combined with gas chromatography-mass spectrometry(GC-MS)to analyze aroma components. The results indicated that different types of water had significant effects on both the physical and chemical properties of Huiming tea infusions. Comparing with TR1,TR2,and PW tea infusions,MW1,MW2,and TW tea infusions with high Ca2+,Mg2+ ions had a lower increment of Mg2+ ion or electrical conductivity. Meanwhile,the concentration of Ca2+ ion in MW1,MW2,and TW also significantly reduced. For taste-producing substances,free amino acid and Ca2+,Mg2+,pH,also total soluble sugur and pH,as well as tea polyphenols and Ca2+,Mg2+,pH,electrical conductivity had a very significant negative conelation(P<0.01). As for aroma compounds,the contents in TR1(7429 μg·kg-1)and PW(7422 μg·kg-1)tea infusions were significantly higher than other samples(about 5100 μg·kg-1). Further,it also found that most aroma compounds had significant negative correlations(P<0.05)with Ca2+ ion and pH of the water,as well as positive correlations(P<0.05)with total soluble sugar and free amino acids. At last,for the sensory qualities,the evaluation granted TR1 and TR2 tea infusions of the most favorite among all samples. In detail,TR2 infusion had a more favorable color and taste when TR1 infusion had the best fragrance quality. Therefore,the lower the pH and Ca2+ concentration of water,the higher the content of aroma substances,and the better the aroma quality of tea infusions.
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2021, 42(3): 77-81,89.
doi: 10.13386/j.issn1002-0306.2020040251
Abstract:
In this study,on the basis of L-lactic acid production by Lactobacillus paracasei,a high cell density strategy with the combination of cell growth dependent and independent modes was developed through investigating the optimal initial glucose concentration and the metabolic capacity of resting cells. The results indicated that the cells grew well under 140 g/L of initial glucose concentration,and all the glucose could be rapidly exhausted to produce L-lactic acid. Moreover,the cells could still maintain high metabolic activity within 6~7 h after the end of fermentation. Finally,based on the above results,the L-lactic acid productivity of high cell density phase was enhanced by 1.4-fold compared with that of normal batch fermentation,and the L-lactic acid yield was also improved significantly to 0.985 g/g. This study extended the highly efficient production period so as to improve the production efficiency of L-lactic acid. Otherwise,the auxiliary time required in the fermentation process could be effectively reduced,including seed preparation and cell growth. Thus,it would be potentially applied for future industrial lactic acid production.
In this study,on the basis of L-lactic acid production by Lactobacillus paracasei,a high cell density strategy with the combination of cell growth dependent and independent modes was developed through investigating the optimal initial glucose concentration and the metabolic capacity of resting cells. The results indicated that the cells grew well under 140 g/L of initial glucose concentration,and all the glucose could be rapidly exhausted to produce L-lactic acid. Moreover,the cells could still maintain high metabolic activity within 6~7 h after the end of fermentation. Finally,based on the above results,the L-lactic acid productivity of high cell density phase was enhanced by 1.4-fold compared with that of normal batch fermentation,and the L-lactic acid yield was also improved significantly to 0.985 g/g. This study extended the highly efficient production period so as to improve the production efficiency of L-lactic acid. Otherwise,the auxiliary time required in the fermentation process could be effectively reduced,including seed preparation and cell growth. Thus,it would be potentially applied for future industrial lactic acid production.
2021, 42(3): 82-89.
doi: 10.13386/j.issn1002-0306.2020040085
Abstract:
Objective:The epidemiological characteristics of methicillin-resistant Staphylococcus aureus(MRSA)isolated from fresh pork samples were investigated.Methods:MRSA isolates from fresh pork samples were conducted for MLST,spa and SCCmec typing. The enterotoxin genes,disinfectant resistance gene,biofilm genes and drug resistance genes carried by MRSA isolates were detected by polymerase chain reaction(PCR)method. The antibiotics sensitivity of MRSA was also investigated by K-B disc diffusion method. Results:In this study,24 strains of MRSA were screened from 297 S. aureus isolates of fresh pork origin,with an isolation rate of 8.08%.The main types of MRSA isolates were ST88-IVa-t1376,ST59-IVa-t437 and ST9-IVb-t3433. Most isolates carried 3~7 antibiotics resistant tested genes. All the MRSA strains were resistant to ampicillin and penicillin G,and multi-drug resistances existed. At the same time,MRSA strains carried multiple enterotoxin genes,of which,MRSA8 and MRSA13 carried the complete egc gene cluster. These isolates contained biofilm-forming related genes clfB,eno,icaBC and sasG. The anti-disinfectant genes qacA/B,qacC and qacG were carried by 62.5% of the isolates,and qacG gene was the main type. In addition,79.17% of MRSA carried hemolysin genes(hla,hlb). The pvl gene was not detected in all MRSA strains.Conclusion:The prevalence of pork-sourced MRSA in Chengdu might have cross-contamination and the monitoring of MRSA strains carried by animal-derived foods should be strengthened.
Objective:The epidemiological characteristics of methicillin-resistant Staphylococcus aureus(MRSA)isolated from fresh pork samples were investigated.Methods:MRSA isolates from fresh pork samples were conducted for MLST,spa and SCCmec typing. The enterotoxin genes,disinfectant resistance gene,biofilm genes and drug resistance genes carried by MRSA isolates were detected by polymerase chain reaction(PCR)method. The antibiotics sensitivity of MRSA was also investigated by K-B disc diffusion method. Results:In this study,24 strains of MRSA were screened from 297 S. aureus isolates of fresh pork origin,with an isolation rate of 8.08%.The main types of MRSA isolates were ST88-IVa-t1376,ST59-IVa-t437 and ST9-IVb-t3433. Most isolates carried 3~7 antibiotics resistant tested genes. All the MRSA strains were resistant to ampicillin and penicillin G,and multi-drug resistances existed. At the same time,MRSA strains carried multiple enterotoxin genes,of which,MRSA8 and MRSA13 carried the complete egc gene cluster. These isolates contained biofilm-forming related genes clfB,eno,icaBC and sasG. The anti-disinfectant genes qacA/B,qacC and qacG were carried by 62.5% of the isolates,and qacG gene was the main type. In addition,79.17% of MRSA carried hemolysin genes(hla,hlb). The pvl gene was not detected in all MRSA strains.Conclusion:The prevalence of pork-sourced MRSA in Chengdu might have cross-contamination and the monitoring of MRSA strains carried by animal-derived foods should be strengthened.
2021, 42(3): 90-95.
doi: 10.13386/j.issn1002-0306.2020040113
Abstract:
Objective:To establish a method for evaluating the productivity ratio of plate count agar(PCA)based on reference materials. Methods:The reference material of Escherichia coli(E. coli)was tested using PCA,and then the productivity ratio of E. coli on the evaluated PCA was calculated according to the formula. The repeatability and reproducibility of the established method were verified in the study. In addition,the productivity ratio of 9 brands PCA was evaluated by the established method. Results:The RSD of repeatability of the established method was 9.09%,and the RSD of reproducibility was 14.42%. The productivity ratios of 9 brands PCA could face with the requirements of 0.83≤PR≤1.17,although there were differences between them. Conclusion:A method for quality control of the culture medium based on the reference material was successfully established,which showed a good repeatability and reproducibility,and could effectively evaluate the productivity ratio of PCA rapidly and efficiently.
Objective:To establish a method for evaluating the productivity ratio of plate count agar(PCA)based on reference materials. Methods:The reference material of Escherichia coli(E. coli)was tested using PCA,and then the productivity ratio of E. coli on the evaluated PCA was calculated according to the formula. The repeatability and reproducibility of the established method were verified in the study. In addition,the productivity ratio of 9 brands PCA was evaluated by the established method. Results:The RSD of repeatability of the established method was 9.09%,and the RSD of reproducibility was 14.42%. The productivity ratios of 9 brands PCA could face with the requirements of 0.83≤PR≤1.17,although there were differences between them. Conclusion:A method for quality control of the culture medium based on the reference material was successfully established,which showed a good repeatability and reproducibility,and could effectively evaluate the productivity ratio of PCA rapidly and efficiently.
2021, 42(3): 96-100,107.
doi: 10.13386/j.issn1002-0306.2020030196
Abstract:
To study the yeast and its characteristics in tomato fermentation broth,the gradient dilution method was used to isolate and purify the yeast in the tomato fermentation broth for 30 days of natural fermentation. The strain was identified by colony morphology,microscopic characteristics and 26S rDNA sequence analysis,the growth characteristics and tolerance of the identified strain were analyzed. The results showed that three strains of yeast TY-1,TY-2 and TY-3 from tomato fermentation broth were all Pichia kudriavzevii. Among which TY-1 and TY-2 were identified as the same strain as P. kudriavzevii strain SLDY-035,their homology was 99%.The homology between TY-3 and P. kudriavzevii small subunit ribosomal was 100%. The optimum growth temperature and pH of TY-1 and TY-3 was 29 ℃ and 5.5,respectively,they were tolerant to 10%~30% glucose and 6%~9% alcohol. The yeast strains isolated from tomato fermentation broth had good growth performance,which could lay a foundation for the development of fruit and vegetable fermentation agents.
To study the yeast and its characteristics in tomato fermentation broth,the gradient dilution method was used to isolate and purify the yeast in the tomato fermentation broth for 30 days of natural fermentation. The strain was identified by colony morphology,microscopic characteristics and 26S rDNA sequence analysis,the growth characteristics and tolerance of the identified strain were analyzed. The results showed that three strains of yeast TY-1,TY-2 and TY-3 from tomato fermentation broth were all Pichia kudriavzevii. Among which TY-1 and TY-2 were identified as the same strain as P. kudriavzevii strain SLDY-035,their homology was 99%.The homology between TY-3 and P. kudriavzevii small subunit ribosomal was 100%. The optimum growth temperature and pH of TY-1 and TY-3 was 29 ℃ and 5.5,respectively,they were tolerant to 10%~30% glucose and 6%~9% alcohol. The yeast strains isolated from tomato fermentation broth had good growth performance,which could lay a foundation for the development of fruit and vegetable fermentation agents.
2021, 42(3): 101-107.
doi: 10.13386/j.issn1002-0306.2020040058
Abstract:
In order to understand the characteristics of cow milk in southern mountain pastures,improve the quality of raw milk in mountain pastures,and provide a theoretical basis for rational development and utilization,this article compared and analyzed the physical and chemical indicators(conventional ingredients,mineral elements,amino acid composition,volatile components)and microbial diversity of fresh milk in Nanshan Ranch and Suburb Ranch in Hunan. The results showed that:Nanshan Ranch cow milk and Chengjiao pasture cow milk had significant differences in their conventional nutrients. Among them,the milk in Nanshan Ranch content of free fatty acids was as high as 5.34 mg/kg,and the contents of iron and zinc were 5.200 and 6.390 mg/L,which were significantly higher than Milk in the suburban pastures;the total amino acid content in the milk in Nanshan pastures was 3.102 g/100 g,which was lower than that in the milks in the suburban pastures;a total of 13 volatile substances were detected in the milk in the suburban pastures,and a total of 11 substances were detected in the determination of volatile components in the milk in the Nanshan pastures Lower than cow milk in suburban pastures. The determination of microbial diversity found that the composition ratio of the bacterial groups between the two pastures was significantly different. The bacterial samples of the two suburban pastures were rich in diversity and the composition was roughly the same,the dominant abundance was Enterococcus,and Acinetobacter in the milk of Nanshan pasture for the dominant flora. Comprehensive analysis showed that the milk of the same breed was greatly affected by geographical environmental factors,and the conventional ingredients,minerals and amino acid content of milk in different pastures were significantly different;the microbial diversity was significantly affected by environmental factors.
In order to understand the characteristics of cow milk in southern mountain pastures,improve the quality of raw milk in mountain pastures,and provide a theoretical basis for rational development and utilization,this article compared and analyzed the physical and chemical indicators(conventional ingredients,mineral elements,amino acid composition,volatile components)and microbial diversity of fresh milk in Nanshan Ranch and Suburb Ranch in Hunan. The results showed that:Nanshan Ranch cow milk and Chengjiao pasture cow milk had significant differences in their conventional nutrients. Among them,the milk in Nanshan Ranch content of free fatty acids was as high as 5.34 mg/kg,and the contents of iron and zinc were 5.200 and 6.390 mg/L,which were significantly higher than Milk in the suburban pastures;the total amino acid content in the milk in Nanshan pastures was 3.102 g/100 g,which was lower than that in the milks in the suburban pastures;a total of 13 volatile substances were detected in the milk in the suburban pastures,and a total of 11 substances were detected in the determination of volatile components in the milk in the Nanshan pastures Lower than cow milk in suburban pastures. The determination of microbial diversity found that the composition ratio of the bacterial groups between the two pastures was significantly different. The bacterial samples of the two suburban pastures were rich in diversity and the composition was roughly the same,the dominant abundance was Enterococcus,and Acinetobacter in the milk of Nanshan pasture for the dominant flora. Comprehensive analysis showed that the milk of the same breed was greatly affected by geographical environmental factors,and the conventional ingredients,minerals and amino acid content of milk in different pastures were significantly different;the microbial diversity was significantly affected by environmental factors.
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2021, 42(3): 108-114.
doi: 10.13386/j.issn1002-0306.2020030331
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The raw material was sea buckthorn lyophilized powder,and the ultrasonic-assisted and ethanol solvent method was used to extract sea buckthorn polyphenols. The extraction conditions were optimized by single-factor test and response surface test. The macroporous resin was used for static adsorption-analysis test of sea buckthorn polyphenols. In vitro antioxidant tests were carried out on sea buckthorn polyphenols before and after purification. The test results showed that when the ratio of liquid to solid was 1∶24 (g/mL),the volume fraction of ethanol was 49%,the extraction time was 52 min,and the extraction temperature was 48 ℃,the extraction amount of polyphenol was the largest,reaching(8.61±0.25)mgECGC/g. The AB-8 was identified as suitable macroporous resin for purification of sea buckthorn polyphenols. The semi-inhibitory concentrations(IC50)of polyphenols from sea buckthorn on DPPH free radical before and after purification were 713.22 and 142.53 μg/mL,and The semi-inhibitory concentrations(IC50)of polyphenols from sea buckthorn on ABTS free radical before and after purification were 61.92,8.68 μg/mL. The results showed that the polyphenols from sea buckthorn after purification had good antioxidant capacity.
The raw material was sea buckthorn lyophilized powder,and the ultrasonic-assisted and ethanol solvent method was used to extract sea buckthorn polyphenols. The extraction conditions were optimized by single-factor test and response surface test. The macroporous resin was used for static adsorption-analysis test of sea buckthorn polyphenols. In vitro antioxidant tests were carried out on sea buckthorn polyphenols before and after purification. The test results showed that when the ratio of liquid to solid was 1∶24 (g/mL),the volume fraction of ethanol was 49%,the extraction time was 52 min,and the extraction temperature was 48 ℃,the extraction amount of polyphenol was the largest,reaching(8.61±0.25)mgECGC/g. The AB-8 was identified as suitable macroporous resin for purification of sea buckthorn polyphenols. The semi-inhibitory concentrations(IC50)of polyphenols from sea buckthorn on DPPH free radical before and after purification were 713.22 and 142.53 μg/mL,and The semi-inhibitory concentrations(IC50)of polyphenols from sea buckthorn on ABTS free radical before and after purification were 61.92,8.68 μg/mL. The results showed that the polyphenols from sea buckthorn after purification had good antioxidant capacity.
2021, 42(3): 115-121,126.
doi: 10.13386/j.issn1002-0306.2020030167
Abstract:
Objective:To optimize the moldability process of compound lipid lowering tablets and to study its lipid-lowering activity. Methods:Using Box-behnken response surface method,the compound lipid lowering tablet extract as the main drug,with the friability,disintegration time and dissolution rate as the evaluation indicators,the ratio of the main drug to the filler,the amount of disintegrant and the concentration of ethanol as the influencing factor,the moldability process of compound lipid lowering tablets were optimized. At the same time,the hyperlipemia rat model was used to evaluate the lipid-lowering activity of compound lipid lowering tablets. Results:The ratio of main drug and auxiliary materials was 80∶15,the amount of disintegrant was 5%,and the concentration of ethanol was 80%.Verification experiment results:The comprehensive score of each batch was 94.01%,and the relative error with the predicted value was 1.49%,and the friability and disintegration time limit were in compliance with pharmacopoeia. Lipid lowering activity test results:Compared with the experimental data of high-fat model group,except for high-density lipoprotein(HDL-C),other indexes in serum of rats in each dose group of compound lipid lowering tablet showed a downward trend,among which the levels of each index in high-dose group significantly decreased(P<0.01),AST and ALT levels in medium dose group significantly decreased(P<0.01),TC,TG and LDL-C levels significantly decreased(P<0.01).The level of HDL-C in medium dose group increased,and had significant difference with the model group(P<0.05). Conclusion:The preferred molding process of this experiment is stable and feasible,and the lipid lowering activity of compound lipid lowering tablets is good. The results of this study provide a reliable basis for the production and development of compound lipid lowering tablets.
Objective:To optimize the moldability process of compound lipid lowering tablets and to study its lipid-lowering activity. Methods:Using Box-behnken response surface method,the compound lipid lowering tablet extract as the main drug,with the friability,disintegration time and dissolution rate as the evaluation indicators,the ratio of the main drug to the filler,the amount of disintegrant and the concentration of ethanol as the influencing factor,the moldability process of compound lipid lowering tablets were optimized. At the same time,the hyperlipemia rat model was used to evaluate the lipid-lowering activity of compound lipid lowering tablets. Results:The ratio of main drug and auxiliary materials was 80∶15,the amount of disintegrant was 5%,and the concentration of ethanol was 80%.Verification experiment results:The comprehensive score of each batch was 94.01%,and the relative error with the predicted value was 1.49%,and the friability and disintegration time limit were in compliance with pharmacopoeia. Lipid lowering activity test results:Compared with the experimental data of high-fat model group,except for high-density lipoprotein(HDL-C),other indexes in serum of rats in each dose group of compound lipid lowering tablet showed a downward trend,among which the levels of each index in high-dose group significantly decreased(P<0.01),AST and ALT levels in medium dose group significantly decreased(P<0.01),TC,TG and LDL-C levels significantly decreased(P<0.01).The level of HDL-C in medium dose group increased,and had significant difference with the model group(P<0.05). Conclusion:The preferred molding process of this experiment is stable and feasible,and the lipid lowering activity of compound lipid lowering tablets is good. The results of this study provide a reliable basis for the production and development of compound lipid lowering tablets.
Study on Raw Material Pretreatment Process of Peanut Oil Prepared by Tween-assisted Aqueous Solution
2021, 42(3): 122-126.
doi: 10.13386/j.issn1002-0306.2020030387
Abstract:
A large amount of emulsion which decreased the extraction rate of peanut oil was easily formed when peanut oil was obtained by aqueous extraction,and it might be closely related to the characteristics of its raw materials.This paper researched the effects of peanut types,peanut paste storage conditions and peanut skin on the extraction rate of peanut free oil.This paper compared the free oil extraction rate of four different peanuts and analyzed the emulsification properties of their proteins by measuring peanut protein simulated emulsion.Peanut oil was extracted with 0.5% Tween 20 solution(water as a reference)followed by the peanut paste at different temperatures for 0,2,4,6,8 d.The results showed that the Dabaisha(old)peanuts had the highest free oil extraction rate obtained by water,and their proteins had good emulsification properties.Whether using water or 0.5% Tween20,the appropriate storage time(2~6 days)and storage temperature(room temperature or 37 ℃)could promote the accumulation of oil and finally improve the free oil extraction rate. However,as the storage time went on,the effect of Tween-assisted demulsification decreased. Low temperature roasting followed by removal of peanut skin greatly reduced the yield of free oil(P<0.05).
A large amount of emulsion which decreased the extraction rate of peanut oil was easily formed when peanut oil was obtained by aqueous extraction,and it might be closely related to the characteristics of its raw materials.This paper researched the effects of peanut types,peanut paste storage conditions and peanut skin on the extraction rate of peanut free oil.This paper compared the free oil extraction rate of four different peanuts and analyzed the emulsification properties of their proteins by measuring peanut protein simulated emulsion.Peanut oil was extracted with 0.5% Tween 20 solution(water as a reference)followed by the peanut paste at different temperatures for 0,2,4,6,8 d.The results showed that the Dabaisha(old)peanuts had the highest free oil extraction rate obtained by water,and their proteins had good emulsification properties.Whether using water or 0.5% Tween20,the appropriate storage time(2~6 days)and storage temperature(room temperature or 37 ℃)could promote the accumulation of oil and finally improve the free oil extraction rate. However,as the storage time went on,the effect of Tween-assisted demulsification decreased. Low temperature roasting followed by removal of peanut skin greatly reduced the yield of free oil(P<0.05).
2021, 42(3): 127-132,139.
doi: 10.13386/j.issn1002-0306.2020040244
Abstract:
Quercetin was extracted from loquat flower dried in shade by microwave-assisted extraction with 60% ethanol as solvent.The effects of material-liquid ratio,microwave time and microwave power on quercetin extraction from loquat flower were studied.The Box-Behnken response surface method was used to optimize the extraction process by three factors and three levels.The results indicated that the optimum extraction conditions were solid-liquid ratio of 1∶15 (g/mL),microwave time of 25 min and microwave extraction power of 600 W;the extraction amount of quercetin from loquat flower was 8.26 mg/g. Quercetin from loquat flower was purified by HP-20 column chromatography,the purity of quercetin obtained was 64.87%. Infrared spectrum scans indicated that quercetin characteristic peaks existed at 1663,1611 and 1382 cm-1.The effects of quercetin from loquat flower on the activities of ADH,ALDH and CAT in the process of alcoholic intoxication were investigated. The results for the test showed that the enzyme activities were all improved to a certain extent and the activation rates were 24.83%,29.18%,22.36%. Quercetin from loquat flower has certain activation effect on key enzymes in alcohol intoxication process,which provides certain theoretical basis for the development of natural product anti-alcoholism and food of auxiliary liver protection.
Quercetin was extracted from loquat flower dried in shade by microwave-assisted extraction with 60% ethanol as solvent.The effects of material-liquid ratio,microwave time and microwave power on quercetin extraction from loquat flower were studied.The Box-Behnken response surface method was used to optimize the extraction process by three factors and three levels.The results indicated that the optimum extraction conditions were solid-liquid ratio of 1∶15 (g/mL),microwave time of 25 min and microwave extraction power of 600 W;the extraction amount of quercetin from loquat flower was 8.26 mg/g. Quercetin from loquat flower was purified by HP-20 column chromatography,the purity of quercetin obtained was 64.87%. Infrared spectrum scans indicated that quercetin characteristic peaks existed at 1663,1611 and 1382 cm-1.The effects of quercetin from loquat flower on the activities of ADH,ALDH and CAT in the process of alcoholic intoxication were investigated. The results for the test showed that the enzyme activities were all improved to a certain extent and the activation rates were 24.83%,29.18%,22.36%. Quercetin from loquat flower has certain activation effect on key enzymes in alcohol intoxication process,which provides certain theoretical basis for the development of natural product anti-alcoholism and food of auxiliary liver protection.
2021, 42(3): 133-139.
doi: 10.13386/j.issn1002-0306.2020030385
Abstract:
Mesona chinensis gum was mixed with sweet potato starch,heated and cooled. Based on the principle of central combination experiment design,a three-factor and three-level response surface analysis method was used to optimize the process of the new Chinese jelly made by Mesona chinensis Benth and sweet potato starch. Then its texture characteristics were studied. The optimal process conditions were obtained through the regression equation:gum 40%,starch 5%,and sucrose 6%. According to the verification experiment,the elasticity of back Chinese jelly was 0.78,which was basically consistent with the theoretical prediction. This research can provide a theoretical guidance for making new high-quality jelly.
Mesona chinensis gum was mixed with sweet potato starch,heated and cooled. Based on the principle of central combination experiment design,a three-factor and three-level response surface analysis method was used to optimize the process of the new Chinese jelly made by Mesona chinensis Benth and sweet potato starch. Then its texture characteristics were studied. The optimal process conditions were obtained through the regression equation:gum 40%,starch 5%,and sucrose 6%. According to the verification experiment,the elasticity of back Chinese jelly was 0.78,which was basically consistent with the theoretical prediction. This research can provide a theoretical guidance for making new high-quality jelly.
2021, 42(3): 140-146.
doi: 10.13386/j.issn1002-0306.2020040162
Abstract:
In order to optimize acid hydrolysis extraction process of 5 flavonoid aglycones(luteolin,quercetin,kaempferol,isorhamnetin and apigenin)from Ribes meyeri stem and evaluate their antioxidant activity and α-glucosidase inhibitory activity in vitro,the content of 5 flavonoid aglycones were determined simultaneously by UPLC-MS/MS. The acid hydrolysis extraction process of flavonoid aglycones of Ribes meyeri stem was optimized by single factor experiments and orthogonal test. The antioxidant and hypoglycemic activities of acid hydrolysis extract and 5 flavonoid aglycones from Ribes meyeri stem were evaluated by DPPH,ABTS free radical scavenging and α-glucosidase inhibitory activity assays. The results showed that the limit of detection and limit of quantification about the five flavonoid aglycones were 0.8~1.6 μg/L and 2.9~5.4 μg/L. The five flavonoid aglycones had good linear relationship(R2≥0.9962)within 3.2~207.0 μg/L. The precision,repeatability and stability of the method were good for the 5 flavonoids(RSD≤4.4%). The optimal extraction process of flavonoid aglycones from Ribes meyeri stem was established as follows:90% methanol solution(including 5% hydrochloric acid),the extraction temperature was 70 ℃,the extraction time was 100 min. In this optimized extraction conditions,the extraction rate of total flavonoid aglycones reached 4.06 mg/g(RSD<5%),which indicated the extraction method was stable and feasible. The acid-hydrolysis extract of Ribes meyeri stem and the 5 flavonoid aglycones showed significant α-glucosidase inhibitory activity and antioxidant activity. The α-glucosidase inhibitory activities of methanol acid-hydrolysis extract and 5 flavonoid aglycones were higher than the positive control,acarbose(IC50:(53.84±2.41) mg/L). Quercetin had the best DPPH free radical scavenging activity(IC50:(2.94±0.18) mg/L),while luteolin and kaempferol had higher ABTS free radical scavenging activity(IC50:(5.34±0.10),(5.55±0.17) mg/L,respectively),and their antioxidant activities were higher than the positive control VC. The established UPLC-MS/MS method is sensitive,reliable and accurate,which can be used for the simultaneous quantitative analysis of 5 flavonoid aglycones. The optimal acid hydrolysis process can effectively improve extraction rate of flavonoid aglycones from Ribes meyeri stem.
In order to optimize acid hydrolysis extraction process of 5 flavonoid aglycones(luteolin,quercetin,kaempferol,isorhamnetin and apigenin)from Ribes meyeri stem and evaluate their antioxidant activity and α-glucosidase inhibitory activity in vitro,the content of 5 flavonoid aglycones were determined simultaneously by UPLC-MS/MS. The acid hydrolysis extraction process of flavonoid aglycones of Ribes meyeri stem was optimized by single factor experiments and orthogonal test. The antioxidant and hypoglycemic activities of acid hydrolysis extract and 5 flavonoid aglycones from Ribes meyeri stem were evaluated by DPPH,ABTS free radical scavenging and α-glucosidase inhibitory activity assays. The results showed that the limit of detection and limit of quantification about the five flavonoid aglycones were 0.8~1.6 μg/L and 2.9~5.4 μg/L. The five flavonoid aglycones had good linear relationship(R2≥0.9962)within 3.2~207.0 μg/L. The precision,repeatability and stability of the method were good for the 5 flavonoids(RSD≤4.4%). The optimal extraction process of flavonoid aglycones from Ribes meyeri stem was established as follows:90% methanol solution(including 5% hydrochloric acid),the extraction temperature was 70 ℃,the extraction time was 100 min. In this optimized extraction conditions,the extraction rate of total flavonoid aglycones reached 4.06 mg/g(RSD<5%),which indicated the extraction method was stable and feasible. The acid-hydrolysis extract of Ribes meyeri stem and the 5 flavonoid aglycones showed significant α-glucosidase inhibitory activity and antioxidant activity. The α-glucosidase inhibitory activities of methanol acid-hydrolysis extract and 5 flavonoid aglycones were higher than the positive control,acarbose(IC50:(53.84±2.41) mg/L). Quercetin had the best DPPH free radical scavenging activity(IC50:(2.94±0.18) mg/L),while luteolin and kaempferol had higher ABTS free radical scavenging activity(IC50:(5.34±0.10),(5.55±0.17) mg/L,respectively),and their antioxidant activities were higher than the positive control VC. The established UPLC-MS/MS method is sensitive,reliable and accurate,which can be used for the simultaneous quantitative analysis of 5 flavonoid aglycones. The optimal acid hydrolysis process can effectively improve extraction rate of flavonoid aglycones from Ribes meyeri stem.
2021, 42(3): 147-152.
doi: 10.13386/j.issn1002-0306.2020030002
Abstract:
In order to prepare a kind of gel soft sweets with crystal clear appearance,elastic and soft texture with the unique flavor of Eucommia ulmoides Oliver,Eucommia ulmoides powder was used as the main raw material,gelatin and cassava starch as the compound gel,maltose as sweetener,citric acid as the sour agent,and optimized the formula by single factor and orthogonal experiments. Through sensory evaluation and texture analysis,the best formula of the Eucommia gel soft sweets was as follows:the ratio of gelatin to cassava starch was 5∶1,the extract of Eucommia water was 150 g/L,maltol was 200 g/L,the sugar content was 80%,and citric acid was 0.5 g/L. The gel soft sweets made from the best process formula was smooth and glossy,elastic and palatable,moderate in sweet and sour,and stable in quality. Sensory,textural and microbiological indicators were all up to the national standard. The soft sugar extract of Eucommia ulmoides had scavenging effect on DPPH and hydroxyl free radicals,and there was a good linear dose effect relationship between scavenging effect and concentration. Among them,the scavenging rate of hydroxyl free radical was 81.5%±2.1% at the maximum concentration(100 mg/mL),DPPH free radical was 51.5%±1.0% at the maximum concentration(100 mg/mL).
In order to prepare a kind of gel soft sweets with crystal clear appearance,elastic and soft texture with the unique flavor of Eucommia ulmoides Oliver,Eucommia ulmoides powder was used as the main raw material,gelatin and cassava starch as the compound gel,maltose as sweetener,citric acid as the sour agent,and optimized the formula by single factor and orthogonal experiments. Through sensory evaluation and texture analysis,the best formula of the Eucommia gel soft sweets was as follows:the ratio of gelatin to cassava starch was 5∶1,the extract of Eucommia water was 150 g/L,maltol was 200 g/L,the sugar content was 80%,and citric acid was 0.5 g/L. The gel soft sweets made from the best process formula was smooth and glossy,elastic and palatable,moderate in sweet and sour,and stable in quality. Sensory,textural and microbiological indicators were all up to the national standard. The soft sugar extract of Eucommia ulmoides had scavenging effect on DPPH and hydroxyl free radicals,and there was a good linear dose effect relationship between scavenging effect and concentration. Among them,the scavenging rate of hydroxyl free radical was 81.5%±2.1% at the maximum concentration(100 mg/mL),DPPH free radical was 51.5%±1.0% at the maximum concentration(100 mg/mL).
2021, 42(3): 153-158.
doi: 10.13386/j.issn1002-0306.2020030195
Abstract:
The hemicellulose in waste liquid of regenerated cellulose fiber was extracted by membrane separation,and the technical parameters and composition of hemicellulose were determined. The xylooligosaccharide was prepared by enzyme hydrolysis from the hemicellulose. The process parameters of enzymatic hydrolysis were determined by orthogonal experiment,and the composition and application performance of xylooligosaccharide were analyzed and measured. The results showed that the enrichment ratio was 3.5 times,the extraction rate of hemicellulose could reach 85% and the xylose content in hemicellulose could reach up to 79.2%. When the pH value was 5,the enzymatic hydrolysis temperature was 55 ℃ and the enzymatic hydrolysis time was 7 h,the yield of xylose oligomer could reach 36.2%. The test showed that the main component of the prepared xylooligosaccharide were xylotetrose,xylotriose,xylobiose and xylose,accounting for 90.7%. The performance index of the product met the national standard of feed grade oligosaccharide dry powder an had good application value.
The hemicellulose in waste liquid of regenerated cellulose fiber was extracted by membrane separation,and the technical parameters and composition of hemicellulose were determined. The xylooligosaccharide was prepared by enzyme hydrolysis from the hemicellulose. The process parameters of enzymatic hydrolysis were determined by orthogonal experiment,and the composition and application performance of xylooligosaccharide were analyzed and measured. The results showed that the enrichment ratio was 3.5 times,the extraction rate of hemicellulose could reach 85% and the xylose content in hemicellulose could reach up to 79.2%. When the pH value was 5,the enzymatic hydrolysis temperature was 55 ℃ and the enzymatic hydrolysis time was 7 h,the yield of xylose oligomer could reach 36.2%. The test showed that the main component of the prepared xylooligosaccharide were xylotetrose,xylotriose,xylobiose and xylose,accounting for 90.7%. The performance index of the product met the national standard of feed grade oligosaccharide dry powder an had good application value.
2021, 42(3): 158-164.
doi: 10.13386/j.issn1002-0306.2020040047
Abstract:
In this paper,texture,color difference and sensory score were used as indicators to study the effects of sugar/salt ratio,TG enzyme addition,baking temperature and baking time on the dried crayfish slice. On this basis,the sensory score and hardness as response value,process condition was optimized by using response surface design.The optimum parameters were ratio of sugar/salt 7.5∶2. 5 (10.0 g),TG enzyme amount 2.00 U/g,baking temperature 145 ℃,bake time 9 min,under this condition the dried crayfish slices were neat in shape,even in thickness,red and bright in color,moderatey salty and sweet with good elasticity,hardness and moderate chew ability.The sensory score was 89.00 and the hardness was 540.45 N. The test results and the theory prediction error was 0.84%,0.46% respectively. The fit of the model was good and the results was reliable.
In this paper,texture,color difference and sensory score were used as indicators to study the effects of sugar/salt ratio,TG enzyme addition,baking temperature and baking time on the dried crayfish slice. On this basis,the sensory score and hardness as response value,process condition was optimized by using response surface design.The optimum parameters were ratio of sugar/salt 7.5∶2. 5 (10.0 g),TG enzyme amount 2.00 U/g,baking temperature 145 ℃,bake time 9 min,under this condition the dried crayfish slices were neat in shape,even in thickness,red and bright in color,moderatey salty and sweet with good elasticity,hardness and moderate chew ability.The sensory score was 89.00 and the hardness was 540.45 N. The test results and the theory prediction error was 0.84%,0.46% respectively. The fit of the model was good and the results was reliable.
2021, 42(3): 165-170,178.
doi: 10.13386/j.issn1002-0306.2020030022
Abstract:
In order to improve the production efficiency of cross-linked starch,cross-linked cassava starch was prepared by mechanical activation assisted dry method,and using cassava starch as raw material and sodium trimetaphosphate as cross-linking agent..The effects of sodium trimeta phosphate dosage,sodium hydroxide dosage,reaction time,reaction temperature,rotational speed and stack volume of ball milling media on the cross-linking of cassava starch were investigated using the sedimentation volume as evaluation index. Based on the single factor experiment,the orthogonal test was selected to optimize the process conditions,and the physicochemical properties and structure of cross-linked cassava starch were also characterized and analyzed. The results showed that the best process conditions for the dry preparation of cross-linked cassava starch were as follows:dosage of sodium trimetaphosphate 4%,dosage of sodium hydroxide 2.5%,reaction temperature 40 ℃,reaction time 60 min,rotational speed 380 r·min-1,stack volume of ball milling media 500 mL,the sedimentation volume of products was 1.52 mL.The cross-linking reaction of cassava starch had been further confirmed by FTIR、XRD、SEM. The transmittance,turgidity,solubility decreased and settlement increased as increasing the cross-linking degree of cross-linked cassava starch. It will accommodate to the development of food industry.
In order to improve the production efficiency of cross-linked starch,cross-linked cassava starch was prepared by mechanical activation assisted dry method,and using cassava starch as raw material and sodium trimetaphosphate as cross-linking agent..The effects of sodium trimeta phosphate dosage,sodium hydroxide dosage,reaction time,reaction temperature,rotational speed and stack volume of ball milling media on the cross-linking of cassava starch were investigated using the sedimentation volume as evaluation index. Based on the single factor experiment,the orthogonal test was selected to optimize the process conditions,and the physicochemical properties and structure of cross-linked cassava starch were also characterized and analyzed. The results showed that the best process conditions for the dry preparation of cross-linked cassava starch were as follows:dosage of sodium trimetaphosphate 4%,dosage of sodium hydroxide 2.5%,reaction temperature 40 ℃,reaction time 60 min,rotational speed 380 r·min-1,stack volume of ball milling media 500 mL,the sedimentation volume of products was 1.52 mL.The cross-linking reaction of cassava starch had been further confirmed by FTIR、XRD、SEM. The transmittance,turgidity,solubility decreased and settlement increased as increasing the cross-linking degree of cross-linked cassava starch. It will accommodate to the development of food industry.
2021, 42(3): 171-178.
doi: 10.13386/j.issn1002-0306.2020020156
Abstract:
Taking yoghurt as the main raw material and collagen extracted from tendon as coagulant,the optimal formula of yoghurt jelly was studied by single factor experiment and Box-Behnken response surface experiment. The results showed that the optimized process parameters were 43% of the additive amount of colloidal solution,15.5% of the additive amount of sucrose and 0.11% of the additive amount of anhydrous citric acid. At this time,the elasticity of the yogurt jelly was 0.945 and the sensory score was 86.The optimized yogurt jelly had good texture and sensory quality,the physicochemical and physiological indexes of which were both in line with the national regulations. The processing technology could lay a theoretical basis for the development of yogurt jelly.
Taking yoghurt as the main raw material and collagen extracted from tendon as coagulant,the optimal formula of yoghurt jelly was studied by single factor experiment and Box-Behnken response surface experiment. The results showed that the optimized process parameters were 43% of the additive amount of colloidal solution,15.5% of the additive amount of sucrose and 0.11% of the additive amount of anhydrous citric acid. At this time,the elasticity of the yogurt jelly was 0.945 and the sensory score was 86.The optimized yogurt jelly had good texture and sensory quality,the physicochemical and physiological indexes of which were both in line with the national regulations. The processing technology could lay a theoretical basis for the development of yogurt jelly.
2021, 42(3): 179-185.
doi: 10.13386/j.issn1002-0306.2020020309
Abstract:
Objective:To optimize the technology of bread with natural leaven of raisins.Methods:Effects of natural leaven of raisins,sugar and butter on the technology of bread were investigated in this study,and the optimum formulation of bread was obtained through response surface method. And the physicochemical and microbial indexes were determined.Results:The optimum formulation was as follows:natural leaven of raisins 12%,sugar 18%,butter 9% and amendment 0.3%. Under this condition,the practical bread sensory score was 86,compared with the predictive value,the relative error was about 2.38%. Under these conditions,the physicochemical and microbial indexes of the bread were as follows:moisture content 30%,acidity value 5.1 °T,specific volume 5.8 mL/g,bacterial colony total 201 CFU/g,coliform group 0,mold count 2 CFU/g,pathogenic bacteria not detected.Conclusion:Therefore,the optimization of formulation is reasonable and feasible,and the bread with natural leaven of raisins has excellent quality properties.
Objective:To optimize the technology of bread with natural leaven of raisins.Methods:Effects of natural leaven of raisins,sugar and butter on the technology of bread were investigated in this study,and the optimum formulation of bread was obtained through response surface method. And the physicochemical and microbial indexes were determined.Results:The optimum formulation was as follows:natural leaven of raisins 12%,sugar 18%,butter 9% and amendment 0.3%. Under this condition,the practical bread sensory score was 86,compared with the predictive value,the relative error was about 2.38%. Under these conditions,the physicochemical and microbial indexes of the bread were as follows:moisture content 30%,acidity value 5.1 °T,specific volume 5.8 mL/g,bacterial colony total 201 CFU/g,coliform group 0,mold count 2 CFU/g,pathogenic bacteria not detected.Conclusion:Therefore,the optimization of formulation is reasonable and feasible,and the bread with natural leaven of raisins has excellent quality properties.
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2021, 42(3): 186-190,200.
doi: 10.13386/j.issn1002-0306.2020050009
Abstract:
The technology of microwave blanching was applied to the hot air drying of lily. The effects of different microwave time,microwave power and hot air temperature on the drying characteristics of lily were studied,and the drying dynamic curves of lily were fitted and analyzed by using Weibull distribution function. The results showed that Weibull function could better fit the drying process of lily under different test conditions,and lily drying was typical of drooping drying. The scale parameter α of the model was related to microwave time,microwave power and hot air temperature,which decreased with the increase of microwave time,microwave power and hot air temperature. The shape parameters β of the model were related to microwave time and microwave power,but the hot air temperature had little influence β on the model. The effective diffusion coefficient Deff was calculated to be between 3.374~5.563×10-9 m2·min-1 in the drying process. The numerical value increased with the increase of microwave time,microwave power and hot air temperature. According to the Arrhenius formula,the activation energy Ea of lily was 23.68 kJ/(mol·K).The results can provide theoretical and technical basis for microwave blanching and hot air drying of lily.
The technology of microwave blanching was applied to the hot air drying of lily. The effects of different microwave time,microwave power and hot air temperature on the drying characteristics of lily were studied,and the drying dynamic curves of lily were fitted and analyzed by using Weibull distribution function. The results showed that Weibull function could better fit the drying process of lily under different test conditions,and lily drying was typical of drooping drying. The scale parameter α of the model was related to microwave time,microwave power and hot air temperature,which decreased with the increase of microwave time,microwave power and hot air temperature. The shape parameters β of the model were related to microwave time and microwave power,but the hot air temperature had little influence β on the model. The effective diffusion coefficient Deff was calculated to be between 3.374~5.563×10-9 m2·min-1 in the drying process. The numerical value increased with the increase of microwave time,microwave power and hot air temperature. According to the Arrhenius formula,the activation energy Ea of lily was 23.68 kJ/(mol·K).The results can provide theoretical and technical basis for microwave blanching and hot air drying of lily.
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2021, 42(3): 191-200.
doi: 10.13386/j.issn1002-0306.2020040068
Abstract:
The purpose of this project was to study the absorption and enrichment characteristics of polycyclic aromatic hydrocarbons(PAHs)in vegetables,and to optimize the cleaning agent for PAHs degradation. In this experiment,tomato,pepper,eggplant,cucumber,radish,beans,Lactuca sativa were selected as experimental samples and soaked in 500 μg/kg PAHs solution for 2,4 h respectively. PAHs concentration characteristics of different vegetables were analyzed by detecting PAHs content in the exposed part of the peel and the pulp of vegetables. By comparing the coefficient of variation of PAHs average content in different vegetables,the uniform experimental materials were screened,and then the appropriate conditions of soaking were determined through further experiments. Eight kinds of cleaning agents were used to treat the toxic vegetables,and then chose the degradation effect as the evaluation standard to select the best cleaning agent. After soaking treatment,most of the vegetables showed that the PAHs enrichment ability of the peel was stronger than that of the pulp,and the PAHs migration ability decreased with the increase of PAHs ring number. By comparing the variation coefficient of PAHs content,except the Lactuca sativa,the changes of contents of vegetables were not consistent,and the average content of fruit pulp fluctuated greatly. With Lactuca sativa as the experimental material,the results showed that the appropriate immersion condition was 500 μg/kg of PAHs solution and 60 min of immersion time. The degradation rate of lightweight PAHs was higher than that of heavy PAHs in Lactuca sativa treated with five cleaning agents. By comparing the degradation rate of PAHs of different cleaning agents,and the results showed that detergents and ozone water had the worst degradation ability,and ultrasonic cleaning only had good degradation effect on light PAHs,with the degradation rate up to 72.72%. There were 7 groups of the optimal cleaning agent treatments,all of which were oxidant treatments. The degradation rate of each treatment group was compared,it was found that the best degradation effect was achieved when the concentration of Fenton(nH2O2∶nFeSO4=8∶1)reagent was 800 mg/L,with an average degradation rate of 79.29% for light and 59.07% for heavy PAHs in Lactuca sativa. By exploring the enrichment characteristics of vegetables for PAHs and comparing the degradation effects of different cleaning treatments on PAHs,this experiment provided theoretical guidance for effective pollution control and consumers to select the reasonable and efficient cleaning agents.
The purpose of this project was to study the absorption and enrichment characteristics of polycyclic aromatic hydrocarbons(PAHs)in vegetables,and to optimize the cleaning agent for PAHs degradation. In this experiment,tomato,pepper,eggplant,cucumber,radish,beans,Lactuca sativa were selected as experimental samples and soaked in 500 μg/kg PAHs solution for 2,4 h respectively. PAHs concentration characteristics of different vegetables were analyzed by detecting PAHs content in the exposed part of the peel and the pulp of vegetables. By comparing the coefficient of variation of PAHs average content in different vegetables,the uniform experimental materials were screened,and then the appropriate conditions of soaking were determined through further experiments. Eight kinds of cleaning agents were used to treat the toxic vegetables,and then chose the degradation effect as the evaluation standard to select the best cleaning agent. After soaking treatment,most of the vegetables showed that the PAHs enrichment ability of the peel was stronger than that of the pulp,and the PAHs migration ability decreased with the increase of PAHs ring number. By comparing the variation coefficient of PAHs content,except the Lactuca sativa,the changes of contents of vegetables were not consistent,and the average content of fruit pulp fluctuated greatly. With Lactuca sativa as the experimental material,the results showed that the appropriate immersion condition was 500 μg/kg of PAHs solution and 60 min of immersion time. The degradation rate of lightweight PAHs was higher than that of heavy PAHs in Lactuca sativa treated with five cleaning agents. By comparing the degradation rate of PAHs of different cleaning agents,and the results showed that detergents and ozone water had the worst degradation ability,and ultrasonic cleaning only had good degradation effect on light PAHs,with the degradation rate up to 72.72%. There were 7 groups of the optimal cleaning agent treatments,all of which were oxidant treatments. The degradation rate of each treatment group was compared,it was found that the best degradation effect was achieved when the concentration of Fenton(nH2O2∶nFeSO4=8∶1)reagent was 800 mg/L,with an average degradation rate of 79.29% for light and 59.07% for heavy PAHs in Lactuca sativa. By exploring the enrichment characteristics of vegetables for PAHs and comparing the degradation effects of different cleaning treatments on PAHs,this experiment provided theoretical guidance for effective pollution control and consumers to select the reasonable and efficient cleaning agents.
2021, 42(3): 201-207,283.
doi: 10.13386/j.issn1002-0306.2020030145
Abstract:
The aim of this study was to screen and identify strains producing bacteriocin(named BLF52)with broad-spectrum resistance to foodborne pathogens from Chinese traditional fermented vegetables,and to isolate and purify the bacteriocin and analyze its antibacterial characteristics. Molecular sieve gel filtration chromatography and semi-preparative high-performance liquid chromatography(RP-HPLC)were used to purify bacteriocin and the molecular weight was determined by Tricine-SDS-PAGE. A bacteriocin-producing Lactobacilus fermentum CH-16 strain was isolated. The highest inhibition of S. aureus(875 AU/mL)was noted at early stationary phase after 24~30 h of growth in MRS medium at 34 ℃. BLF52 was purified to homogeneity and its molecular mass was 5.6 kDa. It was stable in the range of 40~80 ℃(30 min)and pH2.0~7.0(2 h). After treatment with pepsin,papain,trypsin and proteinase K,the antibacterial activity of BLF52 was completely lost,and α-amylase had no effect on it,indicating that BLF52 had typical bacteriocin characteristics. BLF52 exhibited a broad antimicrobial spectrum against food-borne spoilage and pathogenic bacteria such as Listeria monocytogenes,Staphylococcus aureus,Bacillus cereus,Salmonella typhi,Pseudomonas aeruginosa,Escherichia coli,and Vibrio parahaemolyticus. Bacteriocins BLF52 inhibitted the growth of S. aureus in culture through bactericidal mode. BLF52 has the potential to be developed as a food preservative suitable for acidic or neutral foods.
The aim of this study was to screen and identify strains producing bacteriocin(named BLF52)with broad-spectrum resistance to foodborne pathogens from Chinese traditional fermented vegetables,and to isolate and purify the bacteriocin and analyze its antibacterial characteristics. Molecular sieve gel filtration chromatography and semi-preparative high-performance liquid chromatography(RP-HPLC)were used to purify bacteriocin and the molecular weight was determined by Tricine-SDS-PAGE. A bacteriocin-producing Lactobacilus fermentum CH-16 strain was isolated. The highest inhibition of S. aureus(875 AU/mL)was noted at early stationary phase after 24~30 h of growth in MRS medium at 34 ℃. BLF52 was purified to homogeneity and its molecular mass was 5.6 kDa. It was stable in the range of 40~80 ℃(30 min)and pH2.0~7.0(2 h). After treatment with pepsin,papain,trypsin and proteinase K,the antibacterial activity of BLF52 was completely lost,and α-amylase had no effect on it,indicating that BLF52 had typical bacteriocin characteristics. BLF52 exhibited a broad antimicrobial spectrum against food-borne spoilage and pathogenic bacteria such as Listeria monocytogenes,Staphylococcus aureus,Bacillus cereus,Salmonella typhi,Pseudomonas aeruginosa,Escherichia coli,and Vibrio parahaemolyticus. Bacteriocins BLF52 inhibitted the growth of S. aureus in culture through bactericidal mode. BLF52 has the potential to be developed as a food preservative suitable for acidic or neutral foods.
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2021, 42(3): 208-213,229.
doi: 10.13386/j.issn1002-0306.2020050245
Abstract:
Objective:To study the difference of aroma components of Toona sinensis with green phenotype from different provenances. Methods:The volatile components of Toona sinensis from from Taihe,Yongji,Shiyan and Langao were extracted and identified by headspace solid-phase microextraction(HS-SPME)combined with gas chromatography-smell-mass spectrometry(GC-O-MS),and the characteristic aroma components were analyzed. Results:When the temperature was 50 ℃,the extraction efficiency could be maximized by extracting the sample with 65 μm PDSM/DVB head for 40 min. GC-ME was used to analyze the volatile components,and 46 kinds of volatile components were identified in four green Toona sinensis,among which Yongji Toona sinensis was detected the most volatile components,40 kinds in total,and 23 kinds of terpenes accounted for the largest proportion. However,the volatile components detected in Shiyan Toona sinensis were the least,with 26 species in total and only 10 terpenes. After sniffing analysis,it was found that there were 18 characteristic aroma components in Toona sinensis,terpenes and sulfur compounds were the main volatile components of Toona sinensis,among which 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene had the highest aroma intensity. Conclusion:There are significant differences in the types and contents of terpenoids among the four different provenances of Toona sinensis,among which the types and contents of terpenoids in Qingyou Toona sinensis and Yongji Toona sinensis are higher,so their flavors are superior to Shiyan Toona sinensis and Langao Toona sinensis.
Objective:To study the difference of aroma components of Toona sinensis with green phenotype from different provenances. Methods:The volatile components of Toona sinensis from from Taihe,Yongji,Shiyan and Langao were extracted and identified by headspace solid-phase microextraction(HS-SPME)combined with gas chromatography-smell-mass spectrometry(GC-O-MS),and the characteristic aroma components were analyzed. Results:When the temperature was 50 ℃,the extraction efficiency could be maximized by extracting the sample with 65 μm PDSM/DVB head for 40 min. GC-ME was used to analyze the volatile components,and 46 kinds of volatile components were identified in four green Toona sinensis,among which Yongji Toona sinensis was detected the most volatile components,40 kinds in total,and 23 kinds of terpenes accounted for the largest proportion. However,the volatile components detected in Shiyan Toona sinensis were the least,with 26 species in total and only 10 terpenes. After sniffing analysis,it was found that there were 18 characteristic aroma components in Toona sinensis,terpenes and sulfur compounds were the main volatile components of Toona sinensis,among which 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene had the highest aroma intensity. Conclusion:There are significant differences in the types and contents of terpenoids among the four different provenances of Toona sinensis,among which the types and contents of terpenoids in Qingyou Toona sinensis and Yongji Toona sinensis are higher,so their flavors are superior to Shiyan Toona sinensis and Langao Toona sinensis.
2021, 42(3): 214-221,229.
doi: 10.13386/j.issn1002-0306.2020030375
Abstract:
In this study,different varieties of "Zhouning Cloud-Mist Mountain Tea" green tea with different altitudes were analyzed by biochemical-testing methods and SPME-GC-TOF-MS. Results showed that the water extract content was 44.78%,flavonoids content was 8.14 mg·g-1,polyphenols content was 13.66%,amino acids content was 3.01%,caffeine content was 4.93%,and the ratio of polyphenols to amino acids was 4.47. Among 172 detected aroma components,there were 51 hydrocarbons,48 esters,22 nitrogenous compounds,13 alcohols,10 ketones,9 aldehydes,8 oxygen-containing compounds,5 sulphur-containing compounds,4 other types of components,and 2 acids. Water content was abundant in samples from all altitudes with no significant difference(P>0.05),tea polyphenols and caffeine in high altitude samples were significantly lower than those in low altitude samples(P<0.01),flavonoids content was the highest in middle altitude samples,and the ratio of polyphenols to amino acids was moderate in all altitudes and varieties,while the ratio from samples in middle and high altitudes were significantly lower than that in low altitudes(P<0.01). Samples from middle and high altitudes had characteristic fruity and floral aroma component jasmone and(E)-α-farnesene,while samples from low altitudes had characteristic woody and floral aroma components phenylethyl alcohol,linalool(and its oxides)and trans-γ-caryophyllene. Oolong tea variety had a higher content of water extracts,caffeine,tea polyphenols and amino acids with characteristic floral aroma component geraniol and Linalool oxide,while "Caicha" variety had significantly higher flavonoids content with characteristic tender chestnut aroma components dimethylnona-triene,trimethyltrideca-tetraene,hexamethyl-tridecane and hexadecane. In this essay,the characteristic quality of "Zhouning Cloud-Mist Mountain Tea" and the variances of aroma and taste compounds were discussed. The result can be a reference for selecting species,promoting the conditions of cultivation,improving qualities of products and standardization.
In this study,different varieties of "Zhouning Cloud-Mist Mountain Tea" green tea with different altitudes were analyzed by biochemical-testing methods and SPME-GC-TOF-MS. Results showed that the water extract content was 44.78%,flavonoids content was 8.14 mg·g-1,polyphenols content was 13.66%,amino acids content was 3.01%,caffeine content was 4.93%,and the ratio of polyphenols to amino acids was 4.47. Among 172 detected aroma components,there were 51 hydrocarbons,48 esters,22 nitrogenous compounds,13 alcohols,10 ketones,9 aldehydes,8 oxygen-containing compounds,5 sulphur-containing compounds,4 other types of components,and 2 acids. Water content was abundant in samples from all altitudes with no significant difference(P>0.05),tea polyphenols and caffeine in high altitude samples were significantly lower than those in low altitude samples(P<0.01),flavonoids content was the highest in middle altitude samples,and the ratio of polyphenols to amino acids was moderate in all altitudes and varieties,while the ratio from samples in middle and high altitudes were significantly lower than that in low altitudes(P<0.01). Samples from middle and high altitudes had characteristic fruity and floral aroma component jasmone and(E)-α-farnesene,while samples from low altitudes had characteristic woody and floral aroma components phenylethyl alcohol,linalool(and its oxides)and trans-γ-caryophyllene. Oolong tea variety had a higher content of water extracts,caffeine,tea polyphenols and amino acids with characteristic floral aroma component geraniol and Linalool oxide,while "Caicha" variety had significantly higher flavonoids content with characteristic tender chestnut aroma components dimethylnona-triene,trimethyltrideca-tetraene,hexamethyl-tridecane and hexadecane. In this essay,the characteristic quality of "Zhouning Cloud-Mist Mountain Tea" and the variances of aroma and taste compounds were discussed. The result can be a reference for selecting species,promoting the conditions of cultivation,improving qualities of products and standardization.
2021, 42(3): 222-229.
doi: 10.13386/j.issn1002-0306.2020020187
Abstract:
In order to develop a new food flavor,maple leaves after enzymatic hydrolysis was used as material for Maillard reaction under different temperature. Then,the volatile components in the Maillard reaction samples were analyzed by GC-MS,and the principal component analysis was carried out. The results showed that:Maple leaf maple leaf enzymatic hydrolysate and maple maple leaf water extract after Maillard reaction increased the number and content of volatile substances. GC-MS analysis showed that the kind of volatile aroma components were found in the product of Maillard reaction at 90 ℃ was the most(67 kinds),and the total volatile aroma compounds content was also the most(235.9 μg/g). According to the principal component analysis,the Maillard reaction samples at 90,100,and 110 ℃ were far away from each other,indicating that the differences of their main components were large. The sample from Maillard reaction at 90 ℃ had the most volatile compounds distribution,it was considered that 3,4-dimethyl-3-cyclohexen-1-carboxaldehyde,6,10,14-trimethyl-5,9,13-pentadecatrien-2-one,.gamma.-terpinene,n-hexadecanoic acid,eugenol,(1s)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene,(-)-myrtenol,dodecanoic acid,trimethylsilyl ester,phenol,2,2'methylene bis-(4-methyl-6-tert-butylphenol)and methylheptene ketone,were the main characteristic compounds of the volatile components of maple. Combined with the above results,it could be considered that the sample obtained from Maillard reaction at 90 ℃ would have the best flavor and sense quality.
In order to develop a new food flavor,maple leaves after enzymatic hydrolysis was used as material for Maillard reaction under different temperature. Then,the volatile components in the Maillard reaction samples were analyzed by GC-MS,and the principal component analysis was carried out. The results showed that:Maple leaf maple leaf enzymatic hydrolysate and maple maple leaf water extract after Maillard reaction increased the number and content of volatile substances. GC-MS analysis showed that the kind of volatile aroma components were found in the product of Maillard reaction at 90 ℃ was the most(67 kinds),and the total volatile aroma compounds content was also the most(235.9 μg/g). According to the principal component analysis,the Maillard reaction samples at 90,100,and 110 ℃ were far away from each other,indicating that the differences of their main components were large. The sample from Maillard reaction at 90 ℃ had the most volatile compounds distribution,it was considered that 3,4-dimethyl-3-cyclohexen-1-carboxaldehyde,6,10,14-trimethyl-5,9,13-pentadecatrien-2-one,.gamma.-terpinene,n-hexadecanoic acid,eugenol,(1s)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene,(-)-myrtenol,dodecanoic acid,trimethylsilyl ester,phenol,2,2'methylene bis-(4-methyl-6-tert-butylphenol)and methylheptene ketone,were the main characteristic compounds of the volatile components of maple. Combined with the above results,it could be considered that the sample obtained from Maillard reaction at 90 ℃ would have the best flavor and sense quality.
2021, 42(3): 230-235.
doi: 10.13386/j.issn1002-0306.2020050206
Abstract:
Objective:An ultra-high performance liquid chromatography-tandem mass spectrometry method for detection of furoxime,spironolactone and bumetanilan in chicken and swine,which were banned in animal-derived foods,was established. Methods:The samples were purified with C18 powder after the extraction of ethyl acetate. The chromatographic column was Hypersil GOLD C18(1.9 μm,2.1 mm×50 mm).Mobile phase was acetonitrile and 0.1% formic acid water. The flow rate was 0.4 mL/min,and the column temperature was 40 ℃. The electrospray was operated in both positive and negative mode at the same time and the samples were detected by multiple reaction monitoring(MRM).Results:The liner relations of the three diuretics were good within the concentration range of 1.0~500.0 μg/L(r>0.996). The average standard recovery rate was 67.3%~111.6%. Limits of detection of the method were 0.5 μg/kg and limits of quantification were 1.0 μg/kg. Conclusion:This method is simple and accurate,and can be used as a rapid method for detection of diuretics in chicken and swine.
Objective:An ultra-high performance liquid chromatography-tandem mass spectrometry method for detection of furoxime,spironolactone and bumetanilan in chicken and swine,which were banned in animal-derived foods,was established. Methods:The samples were purified with C18 powder after the extraction of ethyl acetate. The chromatographic column was Hypersil GOLD C18(1.9 μm,2.1 mm×50 mm).Mobile phase was acetonitrile and 0.1% formic acid water. The flow rate was 0.4 mL/min,and the column temperature was 40 ℃. The electrospray was operated in both positive and negative mode at the same time and the samples were detected by multiple reaction monitoring(MRM).Results:The liner relations of the three diuretics were good within the concentration range of 1.0~500.0 μg/L(r>0.996). The average standard recovery rate was 67.3%~111.6%. Limits of detection of the method were 0.5 μg/kg and limits of quantification were 1.0 μg/kg. Conclusion:This method is simple and accurate,and can be used as a rapid method for detection of diuretics in chicken and swine.
2021, 42(3): 236-240.
doi: 10.13386/j.issn1002-0306.2020030386
Abstract:
This paper was to study the biochemical components and groups differences among 28 tea samples from different tea regions in yunnan. The biochemical components of 28 tea samples were analyzed by conventional method and high performance liquid chromatography. Principal component analysis and cluster analysis were used to classify 28 tea samples.The results showed that the mainly biochemical components of 28 tea samples,which included catechinepicatechin and epigallocatechin had large variation coefficients,56.88%,36.41% and 49.52%,respectively. The diversity index was 1.91,1.91 and 1.97,respectively. All above explained the characteristics of the samples in biochemical components were more abundant in the composition and performance of non-galloylatedcatechins. The samples were divided into 6 groups by cluster analysis,there were some differences in the content of biochemical components between the groups.
This paper was to study the biochemical components and groups differences among 28 tea samples from different tea regions in yunnan. The biochemical components of 28 tea samples were analyzed by conventional method and high performance liquid chromatography. Principal component analysis and cluster analysis were used to classify 28 tea samples.The results showed that the mainly biochemical components of 28 tea samples,which included catechinepicatechin and epigallocatechin had large variation coefficients,56.88%,36.41% and 49.52%,respectively. The diversity index was 1.91,1.91 and 1.97,respectively. All above explained the characteristics of the samples in biochemical components were more abundant in the composition and performance of non-galloylatedcatechins. The samples were divided into 6 groups by cluster analysis,there were some differences in the content of biochemical components between the groups.
2021, 42(3): 241-246.
doi: 10.13386/j.issn1002-0306.2020050061
Abstract:
To establish the quantification method for 23 low-molecular-weight organic components(nucleotides,nucleosides,organic acids and amino acids)in infant formulas,quantitative nuclear magnetic resonance(qNMR)technique was employed based on processing approach of global spectral deconvolution(GSD).The results revealed that it showed a good linear correlation for 23 components in the given concentration ranges(R2=0.9960~0.9997),with the RSD of precision between 1.02%~3.72%,the RSD of repeatability between 1.34%~3.68%,the RSD of stability between 1.62%~3.20%,and the recovery rate between 85.02%~110.00%.The choline content determined by this method was compared with the national standard method,and the results were consistent(RSD<15%).The results indicated that GSD-qNMR method was better than the traditional qNMR method,and was more suitable for the quantitative detection of low-molecular-weight organic components in complex food matrix such as infant formula.
To establish the quantification method for 23 low-molecular-weight organic components(nucleotides,nucleosides,organic acids and amino acids)in infant formulas,quantitative nuclear magnetic resonance(qNMR)technique was employed based on processing approach of global spectral deconvolution(GSD).The results revealed that it showed a good linear correlation for 23 components in the given concentration ranges(R2=0.9960~0.9997),with the RSD of precision between 1.02%~3.72%,the RSD of repeatability between 1.34%~3.68%,the RSD of stability between 1.62%~3.20%,and the recovery rate between 85.02%~110.00%.The choline content determined by this method was compared with the national standard method,and the results were consistent(RSD<15%).The results indicated that GSD-qNMR method was better than the traditional qNMR method,and was more suitable for the quantitative detection of low-molecular-weight organic components in complex food matrix such as infant formula.
2021, 42(3): 247-252.
doi: 10.13386/j.issn1002-0306.2020070313
Abstract:
Objective:To establish a method for determining the contents of six functional components including protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazinein in Chishui sun Vinegar by RP-HPLC. Methods:The separation was performed on the Waters xSelect HSS T3(5 μm,4.6 mm×250 mm)column with gradient elution. The mobile phase was 0.1% phosphoric acid water solution and acetonitrile,and the flow rate was set as 0.8 mL/min. The column temperature was kept at 30 ℃. The detection wavelength was set at 285 nm. Results:The linear ranges of protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazine were within 10.013~320.416,10.015~320.48,10.012~320.384,10.001~320.032,10.021~320.672,10.072~322.304 μg/mL,respectively. The average recovery rates for six components were within 92.93%~104.53% with RSD less than 3%. The limit of determination was 0.30~1.80 μg/mL and the limit of quantification was 1.02~5.52 μg/mL. Except for caffeic acid,the remaining 5 functional components were detected in the seven sun vinegar samples. The amount of vanillic acid in vinegar was much higher than other components. Conclusion:This method is simple,accurate and suitable for the determination of the protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazine in Chishui Sun Vinegar.
Objective:To establish a method for determining the contents of six functional components including protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazinein in Chishui sun Vinegar by RP-HPLC. Methods:The separation was performed on the Waters xSelect HSS T3(5 μm,4.6 mm×250 mm)column with gradient elution. The mobile phase was 0.1% phosphoric acid water solution and acetonitrile,and the flow rate was set as 0.8 mL/min. The column temperature was kept at 30 ℃. The detection wavelength was set at 285 nm. Results:The linear ranges of protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazine were within 10.013~320.416,10.015~320.48,10.012~320.384,10.001~320.032,10.021~320.672,10.072~322.304 μg/mL,respectively. The average recovery rates for six components were within 92.93%~104.53% with RSD less than 3%. The limit of determination was 0.30~1.80 μg/mL and the limit of quantification was 1.02~5.52 μg/mL. Except for caffeic acid,the remaining 5 functional components were detected in the seven sun vinegar samples. The amount of vanillic acid in vinegar was much higher than other components. Conclusion:This method is simple,accurate and suitable for the determination of the protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazine in Chishui Sun Vinegar.
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2021, 42(3): 253-257.
doi: 10.13386/j.issn1002-0306.2020040179
Abstract:
The aim of this study was to investigate the effect of CO2-cold seawater pretreatment and modified atmosphere packaging on the quality of Litopenaeus vannamei,under refrigeration storage at 4 ℃. Six treatments were carried out,air(CK1),vacuum(CK2),100% CO2(QT1),40% CO2/60% N2(QT2),85% CO2/5% O2/10% N2(QT3),40% CO2/30% O2/30% N2(QT4). The microorganisms,pH,total volatile basic nitrogen,polyphenoloxidase activity,and texture were monitored and compared. The total bacterial count,pH,and total volatile basic nitrogen displayed a positive correlation and increased along with the storage time. Polyphenoloxidase activity and shering force dropped gradually. Three treatments,including QT1,QT2 and QT3,retarded the values of the total bacterial count and total volatile basic nitrogen. According to the results of polyphenoloxidase activity determination,modified atmosphere packaging of QT2 and QT3 had a better browning inhibitiong effect. The shelf-life of these experimental groups was prolonged for another 2~3 days.
The aim of this study was to investigate the effect of CO2-cold seawater pretreatment and modified atmosphere packaging on the quality of Litopenaeus vannamei,under refrigeration storage at 4 ℃. Six treatments were carried out,air(CK1),vacuum(CK2),100% CO2(QT1),40% CO2/60% N2(QT2),85% CO2/5% O2/10% N2(QT3),40% CO2/30% O2/30% N2(QT4). The microorganisms,pH,total volatile basic nitrogen,polyphenoloxidase activity,and texture were monitored and compared. The total bacterial count,pH,and total volatile basic nitrogen displayed a positive correlation and increased along with the storage time. Polyphenoloxidase activity and shering force dropped gradually. Three treatments,including QT1,QT2 and QT3,retarded the values of the total bacterial count and total volatile basic nitrogen. According to the results of polyphenoloxidase activity determination,modified atmosphere packaging of QT2 and QT3 had a better browning inhibitiong effect. The shelf-life of these experimental groups was prolonged for another 2~3 days.
2021, 42(3): 258-264,271.
doi: 10.13386/j.issn1002-0306.2020040215
Abstract:
Carya illinoensis produced in Sihong City,Jiangsu Province was used as the materials to study the effect of 9 groups of preservatives with different concentrations of decolorized shellac,soy protein isolate,and emulsified lacquer wax as main film-forming agents on pure kernel rate,fat content,acid value,peroxide value and protein content during storage. The nano-polyethylene packaging group with oxygen-free under 4 ℃ was used as a blank control group. The results showed that the best fresh-keeping effect was that the group 4,decolorized shellac 10 g,isolated soy protein 10 g,boiling water 200 mL,emulsified lacquer wax 2 g,Qinglongyi extract 3 mL,EDTA-Na2 2 g and vitamin E 2 g. Compared with the control group,the decrease of pure kernel rate was 5%,the decrease of fat content was 6.60%,the increase of acid value was 0.43 times,the increase of peroxide value was 0.73 times,and the increase of soluble protein content was 0.47%. Therefore,preservative group 4 combined with low temperature,oxygen scavenger and nano-polyethylene packaging has a better fresh-keeping effect on Carya illinoensis,which can significantly delay the oxidation process of thin shell pecans,and maintain a high storage quality.
Carya illinoensis produced in Sihong City,Jiangsu Province was used as the materials to study the effect of 9 groups of preservatives with different concentrations of decolorized shellac,soy protein isolate,and emulsified lacquer wax as main film-forming agents on pure kernel rate,fat content,acid value,peroxide value and protein content during storage. The nano-polyethylene packaging group with oxygen-free under 4 ℃ was used as a blank control group. The results showed that the best fresh-keeping effect was that the group 4,decolorized shellac 10 g,isolated soy protein 10 g,boiling water 200 mL,emulsified lacquer wax 2 g,Qinglongyi extract 3 mL,EDTA-Na2 2 g and vitamin E 2 g. Compared with the control group,the decrease of pure kernel rate was 5%,the decrease of fat content was 6.60%,the increase of acid value was 0.43 times,the increase of peroxide value was 0.73 times,and the increase of soluble protein content was 0.47%. Therefore,preservative group 4 combined with low temperature,oxygen scavenger and nano-polyethylene packaging has a better fresh-keeping effect on Carya illinoensis,which can significantly delay the oxidation process of thin shell pecans,and maintain a high storage quality.
2021, 42(3): 265-271.
doi: 10.13386/j.issn1002-0306.2020040212
Abstract:
This article investigated the effect of pre-harvest bagging combined with low-concentration ethephon treatment on ethylene degreening behavior of mandarin fruits. The early ripening mandarin fruits from Beibei of Chongqing were bagged with yellow single-layer fruit bags before harvest. After harvest,the fruits were divided into six groups in this experiment,the control group(CK),the ethephon-degreened fruit(ETH,1000 mg/kg),bagging+0 mg/kg ETH,Bagging+250 mg/kg ETH,bagging+500 mg/kg ETHand bagging+1000 mg/kg ETH,respectively,and all the fruits were stored at 20 ℃ after treatment. The results indicated that with the extension of the storage period,bagging combined with ethephon treatment could better improve the color of early ripening mandarin fruits. After 6 days of storage,bagging+250 mg/kg ETH treatment,bagging+500 mg/kg ETH treatment and bagging+1000 mg/kg ETH treatment significantly improved the chromatographic parameters(a* and a*/b*)of the fruits(P<0.05). Throughout the storage period,bagging+250 mg/kg ETH treatment delayed the increase of the decay rate and browning index successfully and maintained the firmness of the mandarin fruit,besides,it had no adverse influence on the soluble solid content and VC content.In addition,pre-harvest bagging treatment on the total free amino acid content of mandarin fruits didn’t change significantly compared with the control group when harvesting(P>0.05),nordid affect the flavor adversely. But it could increase the content of the arginine acid of mandarin fruits which was related to aging and disease resistance. Based on the results mentioned above,not only the pre-harvest bagging combined with low-concentration ethephon(bagging+250 mg/kg ETH)can improve the degreening behaviors of mandarin fruits,reduce the problems of rot and browning of pedicles caused by conventional ethylene degreening treatment,but also this technology is easy to operate. Therefore,it has certain application prospects in the citrus industry.
This article investigated the effect of pre-harvest bagging combined with low-concentration ethephon treatment on ethylene degreening behavior of mandarin fruits. The early ripening mandarin fruits from Beibei of Chongqing were bagged with yellow single-layer fruit bags before harvest. After harvest,the fruits were divided into six groups in this experiment,the control group(CK),the ethephon-degreened fruit(ETH,1000 mg/kg),bagging+0 mg/kg ETH,Bagging+250 mg/kg ETH,bagging+500 mg/kg ETHand bagging+1000 mg/kg ETH,respectively,and all the fruits were stored at 20 ℃ after treatment. The results indicated that with the extension of the storage period,bagging combined with ethephon treatment could better improve the color of early ripening mandarin fruits. After 6 days of storage,bagging+250 mg/kg ETH treatment,bagging+500 mg/kg ETH treatment and bagging+1000 mg/kg ETH treatment significantly improved the chromatographic parameters(a* and a*/b*)of the fruits(P<0.05). Throughout the storage period,bagging+250 mg/kg ETH treatment delayed the increase of the decay rate and browning index successfully and maintained the firmness of the mandarin fruit,besides,it had no adverse influence on the soluble solid content and VC content.In addition,pre-harvest bagging treatment on the total free amino acid content of mandarin fruits didn’t change significantly compared with the control group when harvesting(P>0.05),nordid affect the flavor adversely. But it could increase the content of the arginine acid of mandarin fruits which was related to aging and disease resistance. Based on the results mentioned above,not only the pre-harvest bagging combined with low-concentration ethephon(bagging+250 mg/kg ETH)can improve the degreening behaviors of mandarin fruits,reduce the problems of rot and browning of pedicles caused by conventional ethylene degreening treatment,but also this technology is easy to operate. Therefore,it has certain application prospects in the citrus industry.
2021, 42(3): 272-276.
doi: 10.13386/j.issn1002-0306.2020040216
Abstract:
The work aimed to investigate the effect of different preservative paper on the quality and physiological characteristics of loquat fruits during shelf life."Dawuxing" loquat fruits were used different preservative paper(500 mg·L-1 Natamycin,500 mg·L-1 ε-Polylysine,500 mg·L-1 chlorine dioxide)after harvest. The four groups of fruits were stored at normal atmospheric temperature(20±0.5) ℃ and the physiological indexes of the four groups were determined. The results showed that:Compared with the control(CK),the different preservative paper could inhibition the increase of loquat fruits decay rate and weight loss rate,delay the decrease of VC content,titratable acid content and soluble solids content,reduce the respiration rate and ethylene production rate of loquat fruit. The PPO activity and POD activity were effectively maintained. The decay rates of loquat fruits in groups CK,Natamycin,ε-Polylysine and chlorine dioxide were 27.45%,22.56%,18.76% and 14.62%,respectively after storage for 12 days. The effect of chlorine dioxide preservative paper was better than that with natamycin and ε-Polylysine.The best preservation method is chlorine dioxide preservative paper,which can be used for loquat fruits preservation.
The work aimed to investigate the effect of different preservative paper on the quality and physiological characteristics of loquat fruits during shelf life."Dawuxing" loquat fruits were used different preservative paper(500 mg·L-1 Natamycin,500 mg·L-1 ε-Polylysine,500 mg·L-1 chlorine dioxide)after harvest. The four groups of fruits were stored at normal atmospheric temperature(20±0.5) ℃ and the physiological indexes of the four groups were determined. The results showed that:Compared with the control(CK),the different preservative paper could inhibition the increase of loquat fruits decay rate and weight loss rate,delay the decrease of VC content,titratable acid content and soluble solids content,reduce the respiration rate and ethylene production rate of loquat fruit. The PPO activity and POD activity were effectively maintained. The decay rates of loquat fruits in groups CK,Natamycin,ε-Polylysine and chlorine dioxide were 27.45%,22.56%,18.76% and 14.62%,respectively after storage for 12 days. The effect of chlorine dioxide preservative paper was better than that with natamycin and ε-Polylysine.The best preservation method is chlorine dioxide preservative paper,which can be used for loquat fruits preservation.
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2021, 42(3): 277-283.
doi: 10.13386/j.issn1002-0306.2020040101
Abstract:
In this paper,the stability of nutrients in whole nutritional formula foods for special medical purposes(suitable for people over 10 years old)under accelerated test,influencing factors(high-temperature,high-humidity)test,and long-term test conditions were studied. The results showed that there was no significant change in product sensory and all nutrients had a certain attenuation during the accelerated test,the nutrients with the highest attenuation after 90 days and 180 days were vitamin A(11.53%)and vitamin C(30.73%),respectively. High-temperature test results showed that the sensory of the product changed obviously at 60 ℃,the color of the powder and the mixing solution became darker,while the product sensory had no obvious changes at 40 ℃.Under the two temperature conditions,vitamin A,vitamin C and copper were the nutrients greatly affected by temperature. High-humidity test showed that the humidity had a significant effect on the open samples,while tinplate had good barrier to humidity. Long-term test results showed that compared with macronutrients and minerals,the attenuation degree of vitamin nutrients was higher. The nutrient with the highest attenuation after 540 days was vitamin C(10.68%),the attenuation rates of vitamin A(32.95%),vitamin B1(24.32%),pantothenic acid(22.19%)and vitamin C(21.69%)after 720 days were all exceeded 20%. This study provided a reference for the development and application of formula foods for special medical purposes.
In this paper,the stability of nutrients in whole nutritional formula foods for special medical purposes(suitable for people over 10 years old)under accelerated test,influencing factors(high-temperature,high-humidity)test,and long-term test conditions were studied. The results showed that there was no significant change in product sensory and all nutrients had a certain attenuation during the accelerated test,the nutrients with the highest attenuation after 90 days and 180 days were vitamin A(11.53%)and vitamin C(30.73%),respectively. High-temperature test results showed that the sensory of the product changed obviously at 60 ℃,the color of the powder and the mixing solution became darker,while the product sensory had no obvious changes at 40 ℃.Under the two temperature conditions,vitamin A,vitamin C and copper were the nutrients greatly affected by temperature. High-humidity test showed that the humidity had a significant effect on the open samples,while tinplate had good barrier to humidity. Long-term test results showed that compared with macronutrients and minerals,the attenuation degree of vitamin nutrients was higher. The nutrient with the highest attenuation after 540 days was vitamin C(10.68%),the attenuation rates of vitamin A(32.95%),vitamin B1(24.32%),pantothenic acid(22.19%)and vitamin C(21.69%)after 720 days were all exceeded 20%. This study provided a reference for the development and application of formula foods for special medical purposes.
2021, 42(3): 284-289,337.
doi: 10.13386/j.issn1002-0306.2020030168
Abstract:
Objective:To study the effect of chicory polysaccharide on immune function in immunosuppressed mice. Methods:ICR mice were randomly divided into blank group,model group,drug group(Piantai),CP low,medium and high dose group. In addition to the blank group,the other groups used cyclophosphamide to cause immunosuppressed mouse model. Body weight,immune organ index,peripheral blood leukocytes and erythrocyte count,delayed hypersensitivity-induced toe swelling,peritoneal macrophage phagocytosis,serum levels of lysin and activity levels of interleukin 2(IL-2),interleukin 6(IL-6)and tumor necrosis factor α(TNF-α)in each group of mice were determined,respectively. Results:Compared with the model group,CP high dose group could significantly increase net body weight rate,immune organ index,macrophage phagocytosis rate and index,number of leukocytes and erythrocyte,and decrease toe swelling in immunosuppressed mice(P<0.05). Meanwhile,CP high dose group could also significantly improve phagocytosis of mouse peritoneal macrophages,serum lysin content,and regulate immune cytokines in immunosuppressed mice. Conclusion:CP could enhance immune activity in immunosuppressed mice.
Objective:To study the effect of chicory polysaccharide on immune function in immunosuppressed mice. Methods:ICR mice were randomly divided into blank group,model group,drug group(Piantai),CP low,medium and high dose group. In addition to the blank group,the other groups used cyclophosphamide to cause immunosuppressed mouse model. Body weight,immune organ index,peripheral blood leukocytes and erythrocyte count,delayed hypersensitivity-induced toe swelling,peritoneal macrophage phagocytosis,serum levels of lysin and activity levels of interleukin 2(IL-2),interleukin 6(IL-6)and tumor necrosis factor α(TNF-α)in each group of mice were determined,respectively. Results:Compared with the model group,CP high dose group could significantly increase net body weight rate,immune organ index,macrophage phagocytosis rate and index,number of leukocytes and erythrocyte,and decrease toe swelling in immunosuppressed mice(P<0.05). Meanwhile,CP high dose group could also significantly improve phagocytosis of mouse peritoneal macrophages,serum lysin content,and regulate immune cytokines in immunosuppressed mice. Conclusion:CP could enhance immune activity in immunosuppressed mice.
2021, 42(3): 290-298,303.
doi: 10.13386/j.issn1002-0306.2020050008
Abstract:
Objective:To investigate the effect of deodorized Triglyceride type-Docosahexaenoic acid(TG-DHA)fish oil on lipid metabolism in mice fed with high-fat diet. Methods:The deodorized TG-DHA fish oil was prepared by liposome embedding technology. Male C57BL/6J mice(6 weeks old)were housed and randomly divided into control group(C),model group(M),TG-DHA fish oil group(O-DHA),deodorized TG-DHA fish oil group(L-DHA).After 8 weeks,blood and liver were collected for lipid accumulation analysis. For gene expression mRNA was extracted from liver for fatty acid synthase(FAS),sterol regulatory element binding protein 1c(SREBP 1c),carnitine palmityl transferase 1(CPt1),lipoprotein lipase(LPL). Results:Liposome embedding could mask the fishy odour in fish oil such as hexanal,2,4-heptadienal. The content of DHA was 73.74%,the particle size was 159.50 nm,and the zeta potential was-43.10 mV. The liposome was stable and easy to be digested and absorbed in animals. L-DHA significantly improved the serum and hepatic lipid levels in mice fed with a high-fat diet(P<0.05),O-DHA significantly improved the serum level and liver TG content of mice fed with high-fat diet(P<0.05). Both of them significantly decreased FAS mRNA expression(P<0.01),and significantly increased CPT1 mRNA expression(P<0.05). The effects of L-DHA seemed to be better. Conclusion:Deodorized TG-DHA fish oil can improve lipid metabolism by high-fat diet. The mechanism is related to the down-regulation of liver fatty acid synthesis and the promotion of fatty acid catabolism.
Objective:To investigate the effect of deodorized Triglyceride type-Docosahexaenoic acid(TG-DHA)fish oil on lipid metabolism in mice fed with high-fat diet. Methods:The deodorized TG-DHA fish oil was prepared by liposome embedding technology. Male C57BL/6J mice(6 weeks old)were housed and randomly divided into control group(C),model group(M),TG-DHA fish oil group(O-DHA),deodorized TG-DHA fish oil group(L-DHA).After 8 weeks,blood and liver were collected for lipid accumulation analysis. For gene expression mRNA was extracted from liver for fatty acid synthase(FAS),sterol regulatory element binding protein 1c(SREBP 1c),carnitine palmityl transferase 1(CPt1),lipoprotein lipase(LPL). Results:Liposome embedding could mask the fishy odour in fish oil such as hexanal,2,4-heptadienal. The content of DHA was 73.74%,the particle size was 159.50 nm,and the zeta potential was-43.10 mV. The liposome was stable and easy to be digested and absorbed in animals. L-DHA significantly improved the serum and hepatic lipid levels in mice fed with a high-fat diet(P<0.05),O-DHA significantly improved the serum level and liver TG content of mice fed with high-fat diet(P<0.05). Both of them significantly decreased FAS mRNA expression(P<0.01),and significantly increased CPT1 mRNA expression(P<0.05). The effects of L-DHA seemed to be better. Conclusion:Deodorized TG-DHA fish oil can improve lipid metabolism by high-fat diet. The mechanism is related to the down-regulation of liver fatty acid synthesis and the promotion of fatty acid catabolism.
2021, 42(3): 299-303.
doi: 10.13386/j.issn1002-0306.2020040087
Abstract:
In order to analyze and evaluate the nutritional value of Akebia trifoliata fruit,Flame Atomic Absorption Spectrometry,Liquid Chromatography,Fluorescence Spectrophotometry and other experimental methods was used to detect and analyze the nutritional components in the peel,pulp and seed of Akebia trifoliata. Based on the detection and analysis,it could be seen that Akebia trifoliata fruit had high nutritional value. Among them:The peel of Akebia trifoliata contains mineral nutrients of Mn and K,the contents of Mn and K were 0.645 and 342 mg/100 g respectively. The total amino acid content in the peel of Akebia trifoliata was 0.313 mg/100 g,containing 15 kinds of amino acids,including 7 kinds of essential amino acids. The proportion of essential amino acids reached the ideal protein conditions proposed by WHO/FAO. The content of essential amino acids was less than that of pulp,and the nutritional value was lower than that of pulp. It contained a small amount of vitamin E,pectin,protein and fat. The seed of Akebia trifoliate contained many mineral nutrients,including K,P,Ca and Fe,with the contents of 586,180,191 and 2.85 mg/100 g,respectively. The seed of Akebia trifoliata was rich in many mineral nutrients,including Mn,Cu and Mg,with the contents of 4.63,1.3 and 157 mg/100 g,respectively. The fatty acid content was 2.662 g/100 g,and the proportion of unsaturated acid was 76%. The pulp of Akebia trifoliate contains Cu mineral nutrients and the content was 0.25 mg/100 g,was rich in Mn mineral nutrients and the content was 7.51 mg/100 g. The total amino acid content of Akebia trifoliata was 0.419 mg/100 g,containing 16 kinds of amino acids,including 8 kinds of essential amino acids. The proportion of essential amino acids reached the ideal protein conditions proposed by WHO/FAO,the content of essential amino acids was balanced and the nutritional value was high small amounts of vitamins,fats,proteins and flavonoids. This paper can provide theoretical support and technical guidance for the development and utilization of Akebia trifoliata,and promote the theoretical research process of Akebia trifoliata.
In order to analyze and evaluate the nutritional value of Akebia trifoliata fruit,Flame Atomic Absorption Spectrometry,Liquid Chromatography,Fluorescence Spectrophotometry and other experimental methods was used to detect and analyze the nutritional components in the peel,pulp and seed of Akebia trifoliata. Based on the detection and analysis,it could be seen that Akebia trifoliata fruit had high nutritional value. Among them:The peel of Akebia trifoliata contains mineral nutrients of Mn and K,the contents of Mn and K were 0.645 and 342 mg/100 g respectively. The total amino acid content in the peel of Akebia trifoliata was 0.313 mg/100 g,containing 15 kinds of amino acids,including 7 kinds of essential amino acids. The proportion of essential amino acids reached the ideal protein conditions proposed by WHO/FAO. The content of essential amino acids was less than that of pulp,and the nutritional value was lower than that of pulp. It contained a small amount of vitamin E,pectin,protein and fat. The seed of Akebia trifoliate contained many mineral nutrients,including K,P,Ca and Fe,with the contents of 586,180,191 and 2.85 mg/100 g,respectively. The seed of Akebia trifoliata was rich in many mineral nutrients,including Mn,Cu and Mg,with the contents of 4.63,1.3 and 157 mg/100 g,respectively. The fatty acid content was 2.662 g/100 g,and the proportion of unsaturated acid was 76%. The pulp of Akebia trifoliate contains Cu mineral nutrients and the content was 0.25 mg/100 g,was rich in Mn mineral nutrients and the content was 7.51 mg/100 g. The total amino acid content of Akebia trifoliata was 0.419 mg/100 g,containing 16 kinds of amino acids,including 8 kinds of essential amino acids. The proportion of essential amino acids reached the ideal protein conditions proposed by WHO/FAO,the content of essential amino acids was balanced and the nutritional value was high small amounts of vitamins,fats,proteins and flavonoids. This paper can provide theoretical support and technical guidance for the development and utilization of Akebia trifoliata,and promote the theoretical research process of Akebia trifoliata.
2021, 42(3): 304-309,319.
doi: 10.13386/j.issn1002-0306.2019120086
Abstract:
To explore the protective effect of Lycium barbarum polysaccharide(LBP)on lipopolysaccharide(LPS)-induced BV2 microglia. In this study,MTT assay was used to detect cell viability,ELISA was used to detect the secretion of inflammatory factors,and Western Blot was used to detect protein expression. The results showed that the activity of BV2 microglia treated with LPS alone had no significant change,but the release of inflammatory factors PGE2,IL-1 β,IL-6 and TNF-α in the supernatant of BV2 microglia cells increased significantly. After LBP gradient was co-incubated with LPS-induced BV2 microglia for 24 h,the activity of LPS-induced BV2 microglia was effectively enhanced and the release of LPS-activated BV2 microglia inflammatory factors was significantly inhibited(P<0.05). The results of flow cytometry showed that microglia in LPS group could produce a large amount of ROS,and the content of ROS in microglia was significantly decreased after being treated with different concentrations of LBP for 12 h. The results of Western Blot showed that the protein expression of NF-κB signaling pathway and nucleusp 65 protein were significantly up-regulated in LPS group and LBP group,and were inversely proportional to LBP concentration,while p65 protein expression in cytoplasm of control group was significantly higher than that in LPS group and LBP group,and decreased with the increase of LBP concentration. This study showed that LBP had a significant protective effect on LPS activated BV2 microglia,inhibited the inflammatory response induced by LPS activated BV2 microglia,and inhibited the content of ROS in microglia to play an anti-oxidation stress effect,and effectively inhibited the expression of p-TAK1,iκB,p-iκB and p-p65 after LPS stimulation.
To explore the protective effect of Lycium barbarum polysaccharide(LBP)on lipopolysaccharide(LPS)-induced BV2 microglia. In this study,MTT assay was used to detect cell viability,ELISA was used to detect the secretion of inflammatory factors,and Western Blot was used to detect protein expression. The results showed that the activity of BV2 microglia treated with LPS alone had no significant change,but the release of inflammatory factors PGE2,IL-1 β,IL-6 and TNF-α in the supernatant of BV2 microglia cells increased significantly. After LBP gradient was co-incubated with LPS-induced BV2 microglia for 24 h,the activity of LPS-induced BV2 microglia was effectively enhanced and the release of LPS-activated BV2 microglia inflammatory factors was significantly inhibited(P<0.05). The results of flow cytometry showed that microglia in LPS group could produce a large amount of ROS,and the content of ROS in microglia was significantly decreased after being treated with different concentrations of LBP for 12 h. The results of Western Blot showed that the protein expression of NF-κB signaling pathway and nucleusp 65 protein were significantly up-regulated in LPS group and LBP group,and were inversely proportional to LBP concentration,while p65 protein expression in cytoplasm of control group was significantly higher than that in LPS group and LBP group,and decreased with the increase of LBP concentration. This study showed that LBP had a significant protective effect on LPS activated BV2 microglia,inhibited the inflammatory response induced by LPS activated BV2 microglia,and inhibited the content of ROS in microglia to play an anti-oxidation stress effect,and effectively inhibited the expression of p-TAK1,iκB,p-iκB and p-p65 after LPS stimulation.
2021, 42(3): 310-314,319.
doi: 10.13386/j.issn1002-0306.2019100084
Abstract:
In this study,the ICR mice were divided into normal control group,high-fat model group and soybean peptide dose group. The dose of gavage was 200,400 mg/kg and 800 mg/kg respectively. The effects of soybean active peptide on obesity and dyslipidemia induced by high-fat were analyzed by analyzing the changes of body weight and blood lipid. The results showed that the body weight,Lee’s index,food intake,liver and adipose tissue weight of obese mice in the high-fat model group decreased significantly(P<0.05)after high dose of soybean active peptide was administered to the stomach. The contents of total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C)were significantly decreased(P<0.05),while the contents of high-density lipoprotein cholesterol(HDL-C)were significantly increased(P<0.05). The content of TC in liver decreased significantly(P<0.05),while that in feces increased significantly(P<0.05). Compared with the normal control group,there was no significant difference in body weight,Lee’s index,food intake,liver weight,fat coefficient,TC,TG,LDL-C and HDL-C in the high dose group(P>0.05),while the TC content in feces increased significantly(P<0.05). The results of liver tissue section showed that soybean active peptide could reduce the degree of fatty degeneration of liver,and the effect of high dose group was the most obvious. Therefore,the soybean polypeptide has a good weight-loss effect.
In this study,the ICR mice were divided into normal control group,high-fat model group and soybean peptide dose group. The dose of gavage was 200,400 mg/kg and 800 mg/kg respectively. The effects of soybean active peptide on obesity and dyslipidemia induced by high-fat were analyzed by analyzing the changes of body weight and blood lipid. The results showed that the body weight,Lee’s index,food intake,liver and adipose tissue weight of obese mice in the high-fat model group decreased significantly(P<0.05)after high dose of soybean active peptide was administered to the stomach. The contents of total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C)were significantly decreased(P<0.05),while the contents of high-density lipoprotein cholesterol(HDL-C)were significantly increased(P<0.05). The content of TC in liver decreased significantly(P<0.05),while that in feces increased significantly(P<0.05). Compared with the normal control group,there was no significant difference in body weight,Lee’s index,food intake,liver weight,fat coefficient,TC,TG,LDL-C and HDL-C in the high dose group(P>0.05),while the TC content in feces increased significantly(P<0.05). The results of liver tissue section showed that soybean active peptide could reduce the degree of fatty degeneration of liver,and the effect of high dose group was the most obvious. Therefore,the soybean polypeptide has a good weight-loss effect.
2021, 42(3): 315-319.
doi: 10.13386/j.issn1002-0306.2020030336
Abstract:
Objective:In order to provide scientific basis for the development and utilization of Artemisia verlotorum Lamotte,this paper analyzed and evaluated its nutritional components and edible safety. Methods:According to the national standards of food safety,the nutritional components,edible value and toxicology of Artemisia verlotorum Lamotte were analyzed and evaluated. Results:The order of the main nutritional components in Artemisia verlotorum Lamotte was:Dietary fiber(59.6 g/100 g) > protein(18.9 g/100 g) > ash(10.0 g/100 g) > available carbohydrate(6.0 g/100 g) > fat(5.5 g/100 g),and no sugar was detected in available carbohydrate. There were many mineral elements such as Na,Zn,Ca,Fe,Mg,K,Mn existed in the Artemisia verlotorum Lamotte,of which Ca content was the highest,up to 1.25×104 mg/kg. There were 16 kinds of common amino acids in the protein,7 kinds of which were essential amino acids. Meanwhile,the essential amino acids accounted for 40.97% of the total amino acids,and the functional amino acids accounted for 53.6%. The oral acute toxicity index for Artemisia verlotorum Lamotte to rats was LD50>5100 mg/kg body weight,which indicated that the acute toxicity of this herbal plant was classified to actually non-toxic. Conclusions:Artemisia verlotorum Lamotte is safe and non-toxic. It is a kind of food with high dietary fiber,low sugar,low fat and high calcium. It has a broad application prospect in the development and utilization for healthy food industry.
Objective:In order to provide scientific basis for the development and utilization of Artemisia verlotorum Lamotte,this paper analyzed and evaluated its nutritional components and edible safety. Methods:According to the national standards of food safety,the nutritional components,edible value and toxicology of Artemisia verlotorum Lamotte were analyzed and evaluated. Results:The order of the main nutritional components in Artemisia verlotorum Lamotte was:Dietary fiber(59.6 g/100 g) > protein(18.9 g/100 g) > ash(10.0 g/100 g) > available carbohydrate(6.0 g/100 g) > fat(5.5 g/100 g),and no sugar was detected in available carbohydrate. There were many mineral elements such as Na,Zn,Ca,Fe,Mg,K,Mn existed in the Artemisia verlotorum Lamotte,of which Ca content was the highest,up to 1.25×104 mg/kg. There were 16 kinds of common amino acids in the protein,7 kinds of which were essential amino acids. Meanwhile,the essential amino acids accounted for 40.97% of the total amino acids,and the functional amino acids accounted for 53.6%. The oral acute toxicity index for Artemisia verlotorum Lamotte to rats was LD50>5100 mg/kg body weight,which indicated that the acute toxicity of this herbal plant was classified to actually non-toxic. Conclusions:Artemisia verlotorum Lamotte is safe and non-toxic. It is a kind of food with high dietary fiber,low sugar,low fat and high calcium. It has a broad application prospect in the development and utilization for healthy food industry.
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2021, 42(3): 320-325,337.
doi: 10.13386/j.issn1002-0306.2020040243
Abstract:
In July 2016,the dietary supplement implemented a dual registration and filing system. The first dietary supplement to go on record are vitamins and minerals. So far,the dietary supplement has been in place for three years. The number of registered vitamin mineral products has reached more than 5,100,exceeding the total number of previously approved vitamin mineral products. According to the products on record,supplement contains calcium,vitamin C,vitamin D and other products are more popular. Based on the materials used for the record,calcium carbonate,vitamin D3,l-ascorbic acid are commonly used compounds. Look at the dosage form of the registered product,tablets and soft capsules account for 85 percent of recorded products. In this paper,the basic information of dietary supplement products in the past 3 years,including the types of raw materials used,compatibility,product dosage forms,etc. According to the consumption information prompt of vitamin mineral products and the analysis of the approved products in China,it is suggested that consumers should rationally choose nutrient supplement products. Finally,it is suggested that the production enterprise,as the responsible person of product quality,should ensure the quality controllability of the product during the research and development and production according to the development trend of dietary supplement.
In July 2016,the dietary supplement implemented a dual registration and filing system. The first dietary supplement to go on record are vitamins and minerals. So far,the dietary supplement has been in place for three years. The number of registered vitamin mineral products has reached more than 5,100,exceeding the total number of previously approved vitamin mineral products. According to the products on record,supplement contains calcium,vitamin C,vitamin D and other products are more popular. Based on the materials used for the record,calcium carbonate,vitamin D3,l-ascorbic acid are commonly used compounds. Look at the dosage form of the registered product,tablets and soft capsules account for 85 percent of recorded products. In this paper,the basic information of dietary supplement products in the past 3 years,including the types of raw materials used,compatibility,product dosage forms,etc. According to the consumption information prompt of vitamin mineral products and the analysis of the approved products in China,it is suggested that consumers should rationally choose nutrient supplement products. Finally,it is suggested that the production enterprise,as the responsible person of product quality,should ensure the quality controllability of the product during the research and development and production according to the development trend of dietary supplement.
2021, 42(3): 326-331.
doi: 10.13386/j.issn1002-0306.2020040321
Abstract:
As a natural antibacterial agent,plant polyphenols has attracted much attention in the field of antibacterial film materials due to their excellent antioxidant and antibacterial activities. Aiming at the research status of plant polyphenol-chitosan composite antibacterial film,this paper summarizes the research progress of chitosan plastic film with plant polyphenol as the main bacteriostatic agent,and focuses on the plant polyphenol-chitosan antibacterial plastic wrap film formation method,film formation mechanism,antibacterial performance,antibacterial performance and mechanism,food applications and other aspects. The research prospects based on plant polyphenol-chitosan antibacterial cling film are discussed,and some suggestions for further research on plant polyphenol-chitosan antibacterial cling film are discussed.
As a natural antibacterial agent,plant polyphenols has attracted much attention in the field of antibacterial film materials due to their excellent antioxidant and antibacterial activities. Aiming at the research status of plant polyphenol-chitosan composite antibacterial film,this paper summarizes the research progress of chitosan plastic film with plant polyphenol as the main bacteriostatic agent,and focuses on the plant polyphenol-chitosan antibacterial plastic wrap film formation method,film formation mechanism,antibacterial performance,antibacterial performance and mechanism,food applications and other aspects. The research prospects based on plant polyphenol-chitosan antibacterial cling film are discussed,and some suggestions for further research on plant polyphenol-chitosan antibacterial cling film are discussed.
2021, 42(3): 331-337.
doi: 10.13386/j.issn1002-0306.2020040050
Abstract:
Tea tree oil(TTO)is a colorless to pale yellow essential oil extracted from the fresh leaves of the genus Melaleuca. TTO has a broad-spectrum antibacterial activity,and it has a good killing or inhibiting effect on many bacteria and fungi. It has a large use in biomedical science,pharmaceutical,cosmetic,food,agricultural and veterinary applications as preservatives,antibacterials and fragrances.This paper reviews the antibacterial activity and mechanism,antiviral activity and antiparasitic activity of tea tree oil on bacteria and fungi in recent years,and summarizes the main active substances of the anti-microbial action of tea tree oil. This paper is aiming at providing reference for the application of tea tree oil in reducing resistance.
Tea tree oil(TTO)is a colorless to pale yellow essential oil extracted from the fresh leaves of the genus Melaleuca. TTO has a broad-spectrum antibacterial activity,and it has a good killing or inhibiting effect on many bacteria and fungi. It has a large use in biomedical science,pharmaceutical,cosmetic,food,agricultural and veterinary applications as preservatives,antibacterials and fragrances.This paper reviews the antibacterial activity and mechanism,antiviral activity and antiparasitic activity of tea tree oil on bacteria and fungi in recent years,and summarizes the main active substances of the anti-microbial action of tea tree oil. This paper is aiming at providing reference for the application of tea tree oil in reducing resistance.
2021, 42(3): 338-345,350.
doi: 10.13386/j.issn1002-0306.2020030365
Abstract:
Plant based meat are made from plant-based proteins as the main raw material by reshaping the dissociation and polymerization behavior of protein to induce the formation of meat-like fiber texture,and fat/oil,pigment and other non-animal food ingredients are added during the process to resemble the appearance,color,flavor,and texture of animal meat. Due to its potential to solve the problem of insufficient meat supply,and high food safety as well as green and sustainable production mode,plant based meat has been developed rapidly as the substitute of meat in recent years,and has received a lot of attentions from food industry. This paper reviews the development of proteins and other raw materials,extrusion and other processing technology in the production of plant based meat,as well as the research on the texture characteristics and nutritional composition of modern plant based meat products,in aim to provide reference for the further production,development and application of modern meat analogues.
Plant based meat are made from plant-based proteins as the main raw material by reshaping the dissociation and polymerization behavior of protein to induce the formation of meat-like fiber texture,and fat/oil,pigment and other non-animal food ingredients are added during the process to resemble the appearance,color,flavor,and texture of animal meat. Due to its potential to solve the problem of insufficient meat supply,and high food safety as well as green and sustainable production mode,plant based meat has been developed rapidly as the substitute of meat in recent years,and has received a lot of attentions from food industry. This paper reviews the development of proteins and other raw materials,extrusion and other processing technology in the production of plant based meat,as well as the research on the texture characteristics and nutritional composition of modern plant based meat products,in aim to provide reference for the further production,development and application of modern meat analogues.
2021, 42(3): 346-350.
doi: 10.13386/j.issn1002-0306.2020040214
Abstract:
Nisin is a natural biological preservative synthesized in the metabolic process of some strains of Lactococcus lactis subspecies lactis. Nisin has good bacteriostasis and can effectively inhibit the growth of gram-positive bacteria(Staphylococcus aureus,Bacillus subtilis,Listeria and Micrococcus,etc),especially bacterial spores. And is widely used in the field of fresh-keeping of food because it can be quickly digested and decomposed into various amino acids by protease in the human body after being ingested without toxic effect on the human body. This article mainly reviews the antibacterial mechanism of nisin and its application in the field of food preservation in the past 10 years. It focuses on the application of nisin in the preservation of fruits and vegetables,and finally analyzes the future development direction of nisin,which provides theoretical reference on further research and application of nisin in food preservation.
Nisin is a natural biological preservative synthesized in the metabolic process of some strains of Lactococcus lactis subspecies lactis. Nisin has good bacteriostasis and can effectively inhibit the growth of gram-positive bacteria(Staphylococcus aureus,Bacillus subtilis,Listeria and Micrococcus,etc),especially bacterial spores. And is widely used in the field of fresh-keeping of food because it can be quickly digested and decomposed into various amino acids by protease in the human body after being ingested without toxic effect on the human body. This article mainly reviews the antibacterial mechanism of nisin and its application in the field of food preservation in the past 10 years. It focuses on the application of nisin in the preservation of fruits and vegetables,and finally analyzes the future development direction of nisin,which provides theoretical reference on further research and application of nisin in food preservation.
2021, 42(3): 351-358.
doi: 10.13386/j.issn1002-0306.2020050016
Abstract:
Polysaccharides is a kind of macromolecule polymer which the widely exists in life,some of which have biological activities such as improving immunity,antioxidant,anticoagulant,anticancer,antiviral,hypoglycemic,etc. Therefore,active polysaccharides play an important role in food,medical treatment,chemical industry and many other fields. Compared with other extraction methods,enzymatic extraction has the advantages of mild reaction conditions,high extraction efficiency,high product activity,low cost,energy saving and environmental protection. In this paper,the research progress of enzymatic extraction of polysaccharides in recent years was reviewed,including the principle and influencing factors of enzymatic extraction of polysaccharides,single and multiple enzyme extraction,the combination other technologies with enzymatic extraction technology,and the advantages of enzymatic extraction of polysaccharides. The application prospect of this method is prospected.
Polysaccharides is a kind of macromolecule polymer which the widely exists in life,some of which have biological activities such as improving immunity,antioxidant,anticoagulant,anticancer,antiviral,hypoglycemic,etc. Therefore,active polysaccharides play an important role in food,medical treatment,chemical industry and many other fields. Compared with other extraction methods,enzymatic extraction has the advantages of mild reaction conditions,high extraction efficiency,high product activity,low cost,energy saving and environmental protection. In this paper,the research progress of enzymatic extraction of polysaccharides in recent years was reviewed,including the principle and influencing factors of enzymatic extraction of polysaccharides,single and multiple enzyme extraction,the combination other technologies with enzymatic extraction technology,and the advantages of enzymatic extraction of polysaccharides. The application prospect of this method is prospected.
2021, 42(3): 359-366,372.
doi: 10.13386/j.issn1002-0306.2020070342
Abstract:
A reasonable intake of dietary fiber is essential for maintaining the health of the body.In order to develop dietary fiber-fortified foods that take into account nutrition,sensory and health,the separation,extraction and modification of insoluble dietary fiber(IDF)has attracted wide spread attention in recent years.A large number of studies have used physical forces,chemical reactions or enzymatic hydrolysis to enhance the functionality of dietary fiber with respect to food processing and nutrition and health.The modified IDF as an added ingredient showed positive impact on food processing,product quality and health effects,and is beneficial to the development of various dietary fiber-enhanced products.This article summarized the latest research progress on the extraction,modification and application of IDF,in order to provide references for regulating functional properties of dietary fiber and developing high-quality functional foods.
A reasonable intake of dietary fiber is essential for maintaining the health of the body.In order to develop dietary fiber-fortified foods that take into account nutrition,sensory and health,the separation,extraction and modification of insoluble dietary fiber(IDF)has attracted wide spread attention in recent years.A large number of studies have used physical forces,chemical reactions or enzymatic hydrolysis to enhance the functionality of dietary fiber with respect to food processing and nutrition and health.The modified IDF as an added ingredient showed positive impact on food processing,product quality and health effects,and is beneficial to the development of various dietary fiber-enhanced products.This article summarized the latest research progress on the extraction,modification and application of IDF,in order to provide references for regulating functional properties of dietary fiber and developing high-quality functional foods.
2021, 42(3): 367-372.
doi: 10.13386/j.issn1002-0306.2020030381
Abstract:
Acrylamide is a by-product of Maillard reaction in foods processed at high temperatures. It is commonly found in fried and baked goods and has been considered as a potential carcinogen. More and more studies have shown that the formation of acrylamide during food processing can be inhibited by adding natural active ingredients extracted from plants,because natural plants are naturally environmentally friendly,easy to obtain,and low in cost. It is therefore an additive that meets the needs of industry. This article reviewed the research on the effect of spice extracts,fruit extracts,leaf and stem extracts,and cereal legume extracts on acrylamide inhibition. Presents prospects for potential research directions in the future. It is expected to provide more methods for inhibiting acrylamide in the food industry.
Acrylamide is a by-product of Maillard reaction in foods processed at high temperatures. It is commonly found in fried and baked goods and has been considered as a potential carcinogen. More and more studies have shown that the formation of acrylamide during food processing can be inhibited by adding natural active ingredients extracted from plants,because natural plants are naturally environmentally friendly,easy to obtain,and low in cost. It is therefore an additive that meets the needs of industry. This article reviewed the research on the effect of spice extracts,fruit extracts,leaf and stem extracts,and cereal legume extracts on acrylamide inhibition. Presents prospects for potential research directions in the future. It is expected to provide more methods for inhibiting acrylamide in the food industry.
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