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Effect of Poultry, Rabbit Meat and Fish Addition on Quality Attributes of Sichuan Sausages
PAN Tingting, JIHU Shili, ZHOU Pengxiang, CAO Jin, LI Chunhong, DAI Yan, ZHANG Jing
 doi: 10.13386/j.issn1002-0306.2023020279
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To balance the nutrition and improve quality of sausages. This research investigated quality improvements of Sichuan sausages by 41.5% poultry, rabbit meat and fish addition. The moisture, crude fat, crude protein contents, pH, Aw, colour, texture, TBARS, protein carbonyl, free thiol groups, fatty acids composition and sensory attributes of pork, poultry, rabbit meat and fish mixture group sausages were evaluated. The results showed that the hardness of pork and rabbit meat mixture group sausages (76.37, 68.01 kg) was significant (P<0.05) higher than that of other 2 groups. The TBARS values in poultry meat and fish mixture group sausages (0.60, 0.63 mg MDA/kg) were significant (P<0.05) higher than that of rabbit meat mixture group. Only EPA and DHA were detected in fish mixture sausages. The ∑poly unsaturated fatty acids (19.96%) and ∑n-6:∑n-3 (22) in poultry meat mixture group sausages were significant (P<0.05) higher than that of other 3 groups. The overall quality scores of poultry and rabbit meat mixture group sausages (7.33, 7.05 points) were significant (P<0.05) higher than those of fish mixture groups. The results of this study indicated that the rabbit meat mixture group sausages had improved quality attributes, the yield rate management and application of liquid fat (vegetable and fish oil) addition could improve nutrition value of Sichuan sausages in the future work. The fish mixture group sausages had better fatty acids composition, and a slightly higher fat oxidation level, thus the application of antioxidates and de-fishy substances could be added in fish-based sausages to control fat oxidation and improve whole sausage quality and sensory attributes.
Ameliorative Effect of D-α-Tocopherol Acetate Complexes on D-Galactose-Induced Aging in Mice
KAN Xutian, CHEN Weili, LI Jiaxu, HE Wenjiang, DING Liugang, LI Pan, DU Bing, LI Wenzhi
 doi: 10.13386/j.issn1002-0306.2022120187
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To investigate the ameliorative effect of the D-α-tocopheryl acetate compound on D-galactose-induced aging in mice, the in vitro antioxidant capacity of the compound of natural oils+phytosterols (VEO), the compound of D-α-tocopheryl acetate+phytosterol (VEZ), and the compound of D-α-tocopheryl acetat+phytosterol+astaxanthin (VEX) were measured. The aging model was established using mice injected with D-galactose on the back of the neck, while the intervention was carried out with different compounds. The results showed that all three groups of compounds had strong antioxidant effects, with the VEZ group showing better in vitro antioxidant effects. Compared with the aging model mice, the intervention of the three compounds increased glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC), decreased malondialdehyde (MDA) (P<0.01), and a decrease in the serum inflammatory factors interleukin-1β(IL-1β), interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and liver function indicators alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were significantly reduced (P<0.01). After the intervention, the mRNA and protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), quinone oxidoreductase (NQO-1) and heme oxygenase-1 (HO-1) in mice were significantly enhanced (P<0.0001). This indicated that the different combinations exerted their antioxidant effects through up-regulating the expression of Nrf2, NQO-1 and HO-1, thus achieving anti-aging effects, with the VEZ group showing the best expression effect. In conclusion, D-α-Tocopheryl acetate complex achieved their anti-aging effects by increasing the expression of antioxidant-related mRNAs and proteins, thus enhancing the levels of downstream antioxidant enzymes, among which D-α-tocopheryl acetate was more effective when combined with phytosterols.
Kinetic Study on the Effect of Slightly Acidic Electrolyzed Water Immersion on the Storage Quality of Fresh Gastrodia elata Slices
DENG Qiuqiu, PANG Wenting, KANG Kaijie, GAO Qing, HE Jinsong
 doi: 10.13386/j.issn1002-0306.2023010148
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For the purpose of demonstrating the kinetics of immersion in slightly acidic electrolyzed water (SAEW) on the storage quality of fresh-cut Gastrodia elata slices. Pretreated fresh-cut slices of Gastrodia elata were dipped in SAWE at solid-liquid ratios of 1:1, 1:3, 1:5 g/mL, and stored at 4 ℃ for comparison with the untreated group. Establish a quality decay dynamics model system based on a 28-day storage observation experiment, recording and analyzing its physical, chemical and nutritional indicators. SAEW impregnation significantly inhibited browning rate, browning degree, and spoilage occurrence. The total number of colonies in the untreated group, the solid-liquid ratio 1:1, 1:3, and 1:5 groups were 8.25, 5.11, 5.13, and 5.10 lg CFU/g, the vitamin C content was 4.42, 5.66, 4.79, and 4.79 mg/100 g, and the gastrodin content was 0.25%, 0.24%, 0.24%, 0.24%. By kinetic fitting, the variation law of the total number of colonies of Gastrodia elata fresh slices by SAEW immersion treatment conformed to the Logistic model. The water activity index change law was derived using Expdec2. The indicator variation rules were derived from the dynamic model system, and R2 was greater than 0.8, which indicated a good match between indicators. Moreover, SAEW dip treatment effectively suppresses browning, browning rate, rot index, and the total number of colonies of Gastrodia elata fresh slices, and gastrodin and vitamin C content were slowed. For application of SAEW dipping in the storage of fresh-cut products, the relevant results might provide technical guidance.
Analysis on the Nutritional Components and Texture Characteristics of Prefabricated Grilled Fish with Different Fish Species
ZHANG Yan, WANG Shengkai, NIE Qingyu, FU Xun, FENG Tingting
 doi: 10.13386/j.issn1002-0306.2023010082
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To explore the development value of different freshwater fish productions of prefabricated grilled fish and realize the diversified development of prefabricated grilled fish categories, an analysis was hereby carried out on the nutritional and textural characteristics of prefabricated grilled fish processed from six common freshwater fish. The results showed that there was no significant difference in the moisture and ash content (P>0.05), the protein content ranged from 21.87%~24.28%, and the fat content was low in all six types of grilled fish. Besides, the content of glutamic acid, aspartic acid and lysine was high, and that of the total essential amino acids ranged from 7.71~9.42 g/100 g. Among them, that of common carp and Wuchang fish was higher, followed by tilapia and grass carp, Wuchang fish, common carp and tilapia had a high fresh amino acid content. The ratio of the essential amino acids to the total amino acids of the six grilled fish was about 40%, which was a high-quality animal protein source. According to the amino acid score, the first limiting amino acid of all six grilled fish was methionine+cysteine, common carp had the highest essential amino acid index, followed by tilapia. Besides, a total of 22 fatty acids were detected in the six grilled fish species, which had a high proportion of unsaturated fatty acids. Tilapia and Wuchang fish contained high functional fatty acids with a high nutritional value, such as eicosapentaenoic acid and docosahexaenoic acid. Through the principal component analysis, the comprehensive score of nutritional indicators followed the order of tilapia>Wuchang fish>common carp>grass carp>crucian carp>pincer fish, while in terms of textural characteristics, the elasticity and chewiness of tilapia and Wuchang fish were significantly(P<0.05)higher than those of traditional common carp and grass carp, and the hardness was lower. In this case, it could be tentatively inferred that tilapia and Wuchang fish had a better muscle texture. As raw materials of grilled fish, all these six freshwater fish were excellent protein sources, reasonable amino acid composition and rich fatty acids, among which, tilapia and Wuchang fish produced prefabricated grilled fish with better nutrition and better taste. Overall, this study provides a theoretical basis for the development of grilled fish in multiple categories and the extension of the "breeding+processing" industry chain.
Composition Analysis of Sargassum Fusiforme in Different Marine Areas and Antioxidant Activity of Polysaccharides
LIANG Meina, ZHANG Lining, LIN Zhen, SU Laijin
 doi: 10.13386/j.issn1002-0306.2023020132
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Sargassum fusiforme, rich in a variety of nutrients and active substances, is one of the important economic seaweeds in China and its quality could be easily affected by environmental factors such as marine areas. This paper aimed to figure out the differences in nutritional composition of Sargassum fusiforme cultivated in different marine areas. This paper used Sargassum fusiforme cultivated in seven marine areas in Zhejiang Province as the research object, and determined the basic nutrients, amino acids and fatty acids using the National Food Safety Standard. The antioxidant activities of the seven Sargassum fusiforme polysaccharides were determined using DPPH· and ·OH scavenging as evaluation criteria, and the structural composition of seven kinds of Sargassum fusiforme polysaccharides were preliminarily analyzed. The results indicated that the moisture content of seven Sargassum fusiforme was highest, between (82.50±0.32) and (86.50±0.23) g/100 g. In addition to moisture content, the other main nutrient component was polysaccharide. The polysaccharide content of Sargassum fusiforme cultivated in No.7 marine area was the highest (P<0.05), which was 2.51 g/100 g. The fat content of Sargassum fusiforme of each marine area was relatively low, which was (0.30±0.01)~(0.40±0.01) g/100 g, indicating that Sargassum fusiforme was a kind of typically low-fat food. The amino acid content of Sargassum fusiforme varied greatly and the EAAI (Essential Amino Acid Index) values of Sargassum fusiforme in each marine area were all more than 0.9, indicating that Sargassum fusiforme in the seven marine areas were all high-quality protein sources. Furthermore, the amino acid composition ratios of Sargassum fusiforme cultivated in No.2 and No.6 marine areas were reasonable, which were closer to the ideal protein model recommended by WHO /FAO in 1937. A total of eight fatty acids were detected in Sargassum fusiforme from seven marine areas. Except for Sargassum fusiforme cultivated in No.2 marine area, the rest were mainly polyunsaturated fatty acids. The heavy metal content of Sargassum fusiforme complied with the requirements of in National Food Safety Standard - Maximum Levels of Contaminants in Foods (GB 2762-2017). The contents of Ca and K in Sargassum fusiforme cultivated in No.4 marine area were (131.44±6.36) mg/100 g and (1687.63±28.14) mg/100 g, respectively, which were good sources of Ca and K. The polysaccharide structures of Sargassum fusiforme in each marine area were similar, all of which contained sulfate groups and had the activity of scavenging ·OH and DPPH·. Among them, the polysaccharide of Sargassum fusiforme cultivated in No.5 marine area had the highest antioxidant activity, and the IC50 of scavenging ·OH and DPPH· were 0.534 mg/mL and 0.236 mg/mL, respectively. This study laid a certain foundation for the scientific breeding, processing and quality grade evaluation of Sargassum fusiforme.
Optimization of Solanum Lyratum Crude Polysaccharide Extraction Process Using Response Surface Methodology and Analysis ofIts In Vitro Antioxidant Activity
HUANG Minghao, HUANG Taiqi, DENG Lijuan
 doi: 10.13386/j.issn1002-0306.2023040182
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To optimize the extraction process of polysaccharide form Solanum lyratum and investigate its in vitro antioxidative activity.In this study, response surface methodology was employed to optimize the ultrasonic-assisted extraction process of polysaccharides from Solanum lyratum. Single-factor experiments were conducted to explore the effects of three factors: extraction temperature, extraction time, and solid-liquid ratio on the yield. Fourier transform infrared spectroscopy (FTIR) was used to analyze the structure of Solanum lyratum polysaccharide, and in vitro antioxidant activity was investigated. The results revealed that the optimal extraction conditions were the material-liquid ratio of 1:57 g/mL, the extraction time of 58 min, and the extraction temperature of 65 ℃. Under these conditions, the yield of polysaccharides was 7.54%±0.12%. Fourier transform infrared spectroscopy of the extracted polysaccharides exhibited a typical polysaccharide absorbance. Moreover, the half-maximal inhibitory concentrations (IC50) of polysaccharides against DPPH and ABTS+ free radicals were 1.104 and 1.408 mg/mL, respectively, indicating significant in vitro antioxidant activity. The results of this study provided a theoretical foundation for the further development and utilization of Solanum lyratum polysaccharides.
Preparation and Characterization of Gummies Loaded with Melatonin and Lycium barbarum L.
SUN Wen, YAN Jianan, LAI Bin, WANG Ce, WU Haitao
 doi: 10.13386/j.issn1002-0306.2023020137
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In order to expand the application of melatonin in gel food, convenient gummies loaded with melatonin and Lycium barbarum L. were developed in this study. The comprehensive effects of gelatin dose, Lycium barbarum L. powder level and drying time on the properties of melatonin gummies were investigated by color difference analysis, texture analysis, low field NMR analysis and sensory evaluation. The results showed that the gummies containing with 0.4% Lycium barbarum L. powder, 18% gelatin, 5% carrageenan, 17.5% sorbitol, 17.5% erythritol and drying for 18 h were elastic and palatable with smooth surface. The gummies had moisture content less than 20% and melatonin retention rate of 92.0%~97.7%, and high sensory evaluation with potential practical application.
Study on the Optimization of the Formula of Potato Scone andIts Texture Characteristics
FU Yuhu, XIN Shihua, WU Qing, YANG Xiaoping, LIU Huiyan, FANG Haitian
 doi: 10.13386/j.issn1002-0306.2023010187
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In order to enrich potato staple products and improve the sensory quality of scones, the rheological properties of mixed dough of potato flour and wheat flour were studied. With sensory score and texture characteristics as evaluation indexes, the formulation of potato flour scone was optimized by single factor test and orthogonal test. The results showed that potato flour could improve the water absorption of wheat flour and shorten the formation time of dough, but it would lead to the decline of dough elasticity and gluten strength and the decline of dough quality. Therefore, the appropriate substitution ratio for whole potato flour was considered to be 20%. The best process recipe for scones was based on a mixture of wheat flour and whole potato flour quality, with 20% whole potato flour added, 68% water added, 0.8% yeast added and 6% sugar added. The hardness of the scone prepared under the optimal condition was 342.63 g, and the chewiness was 106.76 N. The research results provided a theoretical basis for the quality improvement of the scones and the development of whole potato flour products.
Optimization of Extraction Process of Polysaccharide from Black Corn Kernel by Response Surface Method and Analysis ofIts Antioxidant Activity
WANG Yan, DUAN Xuewei, ZHANG Minjun, YANG Huiwen, LIU Bing, YOU Tianhui
 doi: 10.13386/j.issn1002-0306.2023020118
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In order to explore the optimum extraction process of polysaccharide and antioxidant activity in vitro in black corn kernel. In this study, black corn kernel was used as raw material, ultrasonic-assisted extraction was applied to extract polysaccharides from black corn kernel. To explore the effects of ultrasonic power, solid-liquid ratio, extraction time, temperature and frequency on the yield of polysaccharide. The extraction process of polysaccharide from black corn kernel was optimized by response surface methodology and the antioxidant activity of the polysaccharide was investigated by measuring its scavenging ability on DPPH·, ABTS+·, and ·OH. The results showed that the extraction yield of polysaccharide from black corn kernel could reach up to 41.09%±0.59%, in these conditions: the solid-liquid ratio was 1:20 g/mL, the extraction temperature was 74 ℃, the extraction time was 60 min and the extraction frequency was 3 times. The IC50 values of scavenging rates on DPPH·, ABTS+· and ·OH were 1.959, 1.529 and 0.3554 mg/mL, respectively, and the scavenging rates showed a certain dose-effect relationship with the sample concentration, indicating that the polysaccharide had a strong antioxidant activity, thus providing a theoretical basis for further research and utilization.
Effect and Process Conditions of Cold Plasma Combined withL-Glutamic Acid and Salt Stress on Germination and Enrichment ofγ-Aminobutyric Acid in Adzuki Bean
XU Qingpeng, JIANG Xiujie, ZHANG Jiayu, WEI Chunhong, ZHOU Hangqing, ZHANG Dongjie
 doi: 10.13386/j.issn1002-0306.2022120205
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This study aimed to investigate the effect of cold atmospheric pressure plasma (CAPP) treatment combined with salt stress on the enrichment of gamma-aminobutyric acid (GABA) in adzuki beans after germination. The effect of CAPP voltage, frequency, and duration of treatment of seeds, on their GABA content during germination was investigated using adzuki beans as raw material. In addition, the method of germination using L-glutamic acid (L-Glu) combined with salt stress was used to investigate the effect of single factors (germination time and concentrations of CaCl2, L-Glu, and NaCl) on enrichment of GABA. The optimal process conditions for enrichment of GABA using response surface optimization experiments were also determined. The results showed that the treatment of seeds with CAPP technology had a beneficial effect on their germination and enrichment of GABA. The CAPP treatment was more effective under the following conditions: voltage of 90 kV, frequency of 120 Hz, and duration of 20 min. When the germination time was 58 h and the CaCl2, L-Glu, and NaCl concentrations were 4.4 mmol/L, 3.2 mg/mL, and 66 mmol/L, respectively, the GABA content of germinated adzuki beans was 160.23±2.91 mg/100 g, which was 7.12 times higher than that of ungerminated adzuki beans. This method is efficient, reliable, cost-effective, and provides a technical reference for the industrial production of GABA-rich foods.
Isolation and Identification of Pediococcus lactis in Human Intestinal Tract and Its Performance Analysis of Fermented Goji Berry Juice
LI Xiaojing, WEI Xiaobo, CHENG Xue, ZHANG Zhigang, LIU Hongtao, LIU Huiyan, FANG Haitian
 doi: 10.13386/j.issn1002-0306.2023020207
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In order to obtain candidate strains with strong colonization ability and excellent fermentation performance of goji berry juice, 3 strains of lactic acid bacteria were isolated and screened from human intestinal tract. They were identified by morphological, physiological and biochemical, 16S rDNA sequence analysis and phylogenetic tree construction, and their acid resistance, bile salt resistance, artificial gastric fluid, intestinal fluid resistance and fermentation performance were studied. The results showed that all three strains were identified as Pediococcus lactis, numbered NXU_220218, NXU_220219 and NXU_220220, respectively. The growth rate from 2 to 8 h, the ability of NXU 220218 to produce acid was stronger, and the tolerance to acid, bile salt and artificial gastric juice was better than NXU 220219 and NXU 220220. The survival rate of NXU_220218 was 67% at pH2, 65% in bovine bile salt at 0.3% concentration, 72% tolerance to artificial gastric juice, and 95% tolerance to artificial intestinal juice. Finally, the NXU_220218 strain was inoculated and used in the preparation of fermented goji berry juice. It was found that the reducing sugar content and the free radical scavenging rate in the fermented goji berry juice were significantly reduced and increased, respectively, compared with the unfermented goji berry juice, indicating that the NXU_220218 strain had good fermentation performance for goji berry juice and could be used as a candidate strain of lactic acid bacteria for the fermentation of goji berry juice.
Characteristics of Growth and Metabolism of Thermoascus aurantiacus QH-1 Derived Hongxinqu
TANG Yijing, LAI Huanhuan, ZHAO Wei, CUI Meilin, ZHANG Xiuhong
 doi: 10.13386/j.issn1002-0306.2023010052
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To explore the growth metabolic characteristics of Thermoascus aurantiacus, the optimal growth conditions, ethanol tolerance, growth curve, saccharifying power and liquefaction power of Thermoascus aurantiacus QH-1 were analyzed. The results showed that Thermoascus aurantiacus QH-1 grew rapidly and had pigment in PDA, MEA and SDA mediums with rich in nutrients, and colonies growing on synthetic medium and G25N medium grew slowly and almost no pigment. The optimal growth conditions of T.aurantiacus QH-1 strain was as follows: Temperature 45 ℃, pH4.0, inoculum concentration 3%, liquied loading volume 160 mL. The lowest and highest growth temperatures of Th. aurantiacus QH-1 were 26 and 60 ℃, respectively. Among the raw materials for brewing Daqu, sorghum rice was the best for its growth, and the concentration of 6% ethanol had no effect on the grwoth of T.aurantiacus QH-1. T.aurantiacus QH-1 grew slowly with lower saccharifying power in the early stage, and the growth rate accelerated with the higher saccharifying power at 6~8 days in solid state medium of barley and pea. The growth curve of T.aurantiacus QH-1 was similar to its change curve of saccharifying power. However, its liquefying power was detected on day 10. The results provided necessary information for the further development and utilization of T.aurantiacus QH-1.
2023, 44(18).  
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2023, 44(18).  
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Papers Invited by Youth Editorial Committee
Research on the Preparation of Light Speckled Kidney Bean with High Resistance Starch by Autoclaving Processing
ZHANG Yaqi, DONG Ying, RUAN Changqing, ZHANG Dongjie, LI Zhijiang
2023, 44(18): 1-9.   doi: 10.13386/j.issn1002-0306.2022110228
Abstract(55) HTML(19) PDF(8)
In order to improve the content of resistant starch of light speckled kidney bean and reserve the other nutrients, an autoclaved method for preparing light speckled kidney bean with high resistant starch was studied. The essential nutrients, in vitro digestibility and structural characteristics of autoclaving light speckled kidney bean were evaluated. Results showed that, the process conditions of autoclaved method for preparing light speckled kidney bean with high resistant starch were optimized as follows: Autoclaving temperature 124 ℃, solid-liquid ratio 1:1.9 (g:g), retrograded time 73 h, and autoclaving time 24 min. Under the optimized conditions, the content of resistant starch was 35.63%, which was close to the corresponding theoretical value. An analysis on the structural characteristics showed that the original starch grains was changed significantly in morphology and in molecular crystal form, but no new group was generated. After autoclaving, the crude fat, crude protein in the light speckled kidney bean did not obviously changing, but the content of starch and resistant starch increased obviously (P<0.05). The in vitro digestion rate of high resistant starch in the light speckled kidney bean decreased significantly after autoclaving. The method of autoclaving improve the content of resistant starch of light speckled kidney bean would provide a reference for the commercialization and its application in food industry as well.
Future Food
Network Pharmacological Analyze and Experimental Verification of Lychee Kernel Extract Intervene of Non-alcoholic Fatty Liver Disease
ZHANG Yashuo, A Runa, MA Xinyan, PANG Zongran, LU Binan
2023, 44(18): 10-19.   doi: 10.13386/j.issn1002-0306.2022100271
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Objective: To investigate the effect and potential mechanism of lychee kernel extract in the intervention of non-alcoholic fatty liver disease (Nonalcoholic fatty liver disease, NAFLD) based on network pharmacology. Methods: The components and action targets of litchi nuclei were obtained from the Pharmacology Database and Analysis Platform (TCMSP) within the Chinese Medicine System, the disease targets of NAFLD were obtained using disease target data from GeneCard, the intersection and pathway-target interaction network diagram were obtained through Cytoscape, and the GO bioprocess analysis and KEGG pathway enrichment analysis were performed using Bioinformatics website. This study established an animal model with diet-induced obsisity mouse NAFLD and administered LKE via the gastric route. HE staining indicated lipid changes in the liver. The biological kits detect content of TG, TC, ALT, and AST. Results: Eighteen potential active ingredients of litchi nuclei were identified, and 52 targets intersected with NAFLD disease. The key targets were INS, TNF, and HSP90AA1. KEGG channel enrichment filtered 20 signal pathways, the main ones include: Pathways in cancer, fluid shear stress and atherosclerosis, AGE-RAGE signaling pathway in diabetic complications. The liver lesions of the mice in the model group were severe, the liver lesions of the mice in the drug group were significantly reduced compared with the model group, and the serum transaminases of the mice in the drug group were also significantly reduced, which was close to the normal group, and the blood lipid metabolism of the drug group also tended to be normal group,and the differences were significant (P<0.05). Conclusion: Litchi nuclei might play a role in the treatment of NAFLD by acting on such targets as INS, TNF and HSP90AA1, and modulate lipid and atherosclerotic pathways.
Research Progress on Material Composition, Processing Problems and Innovative Technology of Plant-based Milk
CHEN Yashu, LIU Rui, CHEN Hongjian, CHEN Wei, WANG Xue, MA Hongjiang, HAO Qian, QUAN Shuang, ZHOU Qi, HUANG Qingde, DENG Qianchun
2023, 44(18): 20-33.   doi: 10.13386/j.issn1002-0306.2022110308
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In broad sense, beverages made from nuts and plant fruits/pulp, as well as other plant-derived materials including proteins etc. are collectively known as plant-based milk. Plant-based milk has multiple advantages such as lactose free, cholesterol free, hormone free, low saturated fat, antibiotics free, special sensory flavor, as well as unique nutritional functions, which fit with the diversified needs of consumers. The market size of plant-based milk in China is huge, which also has great development potential. However, there are still many unsolved problems, such as backward processing technology, insufficient raw material development, unsatisfied sensory properties, vague nutritional and digestive characteristics, and incomplete academic discipline etc. From this, the processing problems of plant-based milk, new processing technology and equipment, innovative technology development trend, industrialization policy comprehensively are described and discussed in this paper. This paper will contribute to the industrial development of domestic plant-based milk, and further satisfying people's growing demand for nutrition and health.
Research and Investigation
Effect of Different Harvest Time on Physicochemical Properties and Aroma Components of Vitis quinquangularis Rehd. ‘Yeniang No.2’ Wine
HUANG Jing, HUANG Yu, CAO Muming, CHEN Guopin, HUANG Qiufeng, LI Wei, XIE Shuyu, GUAN Jingxi
2023, 44(18): 34-42.   doi: 10.13386/j.issn1002-0306.2022100088
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The study aimed to determine the influence of harvest date on ‘Yeniang No.2’ (Vitis quinquangularis Rehd.) wine basic chemical variables and aroma components. A series of three ‘Yeniang No.2’ wines were produced from grapes of different harvest dates, Harvest 1: 15 August, Harvest 2: 10 September and Harvest 3: 23 September. The physicochemical properties and aroma components were determined. Results showed that, the grapes of sequential harvest treatments showed an increase in total sugar and a decrease in titratable acidity. In the wines, alcoholic strength, phenol, tannin and flavonoid were enhanced with the sequential harvest, whereas residual sugar and acidity were decreased. there also existed significant difference among different harvest periods(P<0.05). There were 89 aroma components identified in 3 wines, including 22 alcohols, 37 esters, 7acids, 5 aldehydes , 5 terpenes and 13 others. The highest concentration of aroma components was in the last harvest date, 852370.83 μg/L. The main aroma characteristics of ‘Yeniang No.2’ wines were fruity, caramel, fatty and floral aromas, but the odor activity value (OAV) of the same aroma component of wines harvested on different dates was different, which led to differences in their aroma characteristics. The higher OAV of isovaleric acid and octoic acid in wines harvested on 15 August gave the wine a higher fatty flavor. The higher OAV of phenylacetaldehyde, β-damastone and TDN in wines harvested on 10 September gave the wine more floral and caramel characteristics. The higher OAV of ethylcaproate in wines harvested on 23 September gave the wine a higher fruity aroma. The analysis results of the fruit quality and aroma characteristics showed that the best harvest period of the ‘Yeniang No.2’ grape was between 10 September and 23 September.
Study on the Mechanism of Procyanidins Adsorption onto Chitosan Microflower
JIAO Siyu, XU Dingyu, YAO Xianchao, LIU Xin, LIN Chunyan, HE Lixin, LIN Rihui
2023, 44(18): 43-49.   doi: 10.13386/j.issn1002-0306.2022100097
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In order to understand the adsorption mechanism of chitosan microflower (CSMF) on procyanidins (PC), CSMF was used as an adsorbent to adsorb PC solutions under different adsorption conditions. The drug-loaded particles were characterized by scanning electron microscopy (SEM), Fourier infrared (FTIR), X-ray diffraction (XRD), etc. Through adsorption kinetics, adsorption isotherm, and adsorption thermodynamics, the mechanism of CSMF adsorption PC was systematically studied. The results showed that the FTIR pattern of the drug-loaded particles produced a new characteristic peak at 1456 cm−1, indicating that the PC was successfully loaded onto the CSMF. The results of SEM and XRD analysis showed that the morphology and crystallinity of CSMF did not change after loading. The adsorption kinetics showed that the adsorption of PC by CSMF conformed to the pseudo-second-order kinetic model, and the adsorption rate was affected by the interaction between particle diffusion and boundary layer diffusion. The adsorption isotherm showed that the Freundlich adsorption isotherm model could more accurately reflect the entire adsorption process, indicating that the adsorption process of CSMF to PC was multilayer adsorption with surface energy inhomogeneity. Finally, adsorption thermodynamics showed that the adsorption of PC by CSMF was a spontaneous physical adsorption process with reduced entropy.
Structural Characterization of Mango Core-shell Cellulose Nanofibers and Properties Analysis of Stable Pickering Emulsion
ZHANG Meng, LIU Yanping, ZHOU Wei, LI Ruyi, ZOU Ying, CHEN Mianhong, DAI Yaping, LI Jihua
2023, 44(18): 50-57.   doi: 10.13386/j.issn1002-0306.2022100199
Abstract(36) HTML(11) PDF(5)
In this study, mango core-shell cellulose nanofibers (CNFs) were prepared successfully after hypochlorite bleaching, alkalization TEMPO oxidation and high pressure homogenization. The effects of pH and ionic strength on emulsion stability were also investigated. The results showed that the mango core-shell CNFs prepared by TEMPO oxidation and high pressure homogenization method maintained the basic structure of cellulose, and some hydroxyl groups were oxidized to carboxyl group. The cellulose crystallinity was reduced to 57%, which was more sensitive to temperature, but still maintained high thermal stability. The particle size of Pickering emulsion stabilized by mango core-shell CNFs decreased significantly with the increase of pH. The smallest particle size was 469.5 nm at pH11, and the particle size distribution was more uniform. The 30 day CI was 58.8%, showing good stability. The ionic strength had a great influence on the stability of mango core-shell CNFs Pickering emulsion. Under the ionic strength of 50~100 mmol/L, a large number of positively charged sodium ions aggregated on the surface of CNFs and neutralize the negative charge on the surface, which weakened the electrostatic repulsion between droplets and makes droplets more likely to aggregate, which was not conductive to the stability of the emulsion. In summary, the mango core-shell CNFs could be used as excellent solid particles in Pickering emulsion, which would provide a new for the high value utilization of mango core-shell.
Effect of Ultrasonic Assisted Salting on Quality of Microwave Snakehead Fillet
MAO Shucan, YANG Lifeng, WANG Lan, ZHOU Zhi, XIONG Guangquan, SHI Liu
2023, 44(18): 58-66.   doi: 10.13386/j.issn1002-0306.2022100283
Abstract(30) HTML(8) PDF(4)
In order to study the effect of ultrasound-assisted salting on the flavor quality of microwave heating snakehead fillet, the parameters of ultrasonic and brining of snakehead fillet were first investigated, then the electronic nose, electronic tongue, volatile substances and free amino acid substance of microwave heated snakehead fillets were determined. The results showed that the optimum parameters of ultrasound-assisted brining were as follows: Salt content 4 g/mL, solid-to-liquid ratio 1:4 g/mL, constant temperature (24±1) ℃, ultrasonic frequency 40 kHz, ultrasonic power 200 W and ultrasonic time 60 min. In electronic nose and volatile flavor substances analysis, ultrasonic assisted salting treatment effectively inhibited the formation of organic sulfide and increased the contents of five volatile substances (alcohols, aldehydes, ketones, acids and esters) in microwave heated fillets. In electronic tongue and free amino acid substance content analysis, the response of ultrasonic assisted salting treatment to sour and bitter taste was the lowest, and the response to salty, umami and sweet taste was the highest. And the ultrasonic treatment increased the contents of 13 free amino acids of microwave heated snakehead fillet, suggesting the improvement of flavor and taste. Two-factor analysis of variance found that ultrasonic treatment had a more significant effect on flavor, and salting treatment had a more significant effect on taste. The results of this study provide theoretical support for the industrial production of prefabricated aquatic products.
Isolation, Identification and Antimicrobial Activity Analysis of Antimicrobial Peptides from Epidermis Mucus of Sturgeon
DUAN Xiaolin, FAN Yan, WANG Jinlin, JIANG Xiaoming, XU Xinxing, ZHANG Xuqing, LIU Li, LIU Kang, ZHAO Yuanhui
2023, 44(18): 67-75.   doi: 10.13386/j.issn1002-0306.2022110148
Abstract(22) HTML(6) PDF(1)
To explore the antimicrobial activity of epidermis mucus, the basic components and amino acid composition were analyzed and the antimicrobial substances in the mucus were extracted in this study. Their antimicrobial activity, preservation effects on salmon were explored. The components with antimicrobial activity were isolated and purified by solid phase extraction, gel filtration chromatography and reverse phase high performance liquid chromatography. And the peptide sequences were identified. Then, the antimicrobial peptides were synthesized accordingly and their antimicrobial activities were verified. The results exhibited that the main composition of epidermis mucus of sturgeon was protein with 47.44%±0.59%. The total amino acid content was 459.68 mg/g, with a high content of basic amino acids and hydrophobic amino acids. The crude antimicrobial peptide exhibited significant antimicrobial activity against Bacillus subtilis. Crude antimicrobial peptide (50 mg/mL) significantly inhibited the growth of microorganisms and protein degradation during salmon preservation. The highest active component after final liquid chromatography purification exhibited an inhibition rate of 92.40%±4.50% against Bacillus subtilis and 75.43%±5.02% against Escherichia coli. The sequences of novel peptides were identified as HSETLHDV and PLTDWQL. The synthetic antimicrobial peptides of sturgeon epidermis mucus had obvious inhibitory effects on Bacillus subtilis, Escherichia coli and Shewanella baltica. Therefore, this study would provide a theoretical basis for exploring the antimicrobial value of sturgeon mucus and lay a foundation for the development and application of natural preservatives.
Comparative Analysis of Characteristics and in Vitro Biological Activities of Cordyceps militaris Polysaccharide Prepared by Two Methods
GU Dandan, HOU Jingyu, ZHANG Jinxiu, WANG Lian
2023, 44(18): 76-83.   doi: 10.13386/j.issn1002-0306.2022110183
Abstract(22) HTML(5) PDF(2)
Cordyceps militaris polysaccharides from the fermentation broth were prepared via chitosan flocculation and water extraction and alcohol precipitation methods to obtain the flocculated polysaccharide (XDT) and alcohol precipitation polysaccharide (CDT) respectively. The extraction yields, component content, average particle sizes and solubility of XDT and CDT were comparatively investigated. The microstructures, functional groups and spatial conformations were characterized by scanning electron microscopy, Fourier infrared spectroscopy and Congo red assay. The antioxidant activity was evaluated by scavenging ability of DPPH, superoxide anion and hydroxyl radical. The hypoglycemic activity was estimated by α-glucosidase inhibitory ability, and the antitumor cell activity was analyzed by inhibition of HepG2 cell proliferation. The results showed a yield of 3.58% for XDT, 1.91 times that of CDT. CDT and XDT exhibited different microstructures under electron microscopy, and similar absorption patterns under infrared spectrum, while XDT contained more triple helix structures than CDT. XDT displayed smaller average particle sizes but a faster dissolution rate than CDT. In vitro antioxidant tests showed that XDT exhibited significantly higher scavenging ability of DPPH, superoxide anion and hydroxyl radical than CDT at the same concentration. There was no significant difference between the XDT and CDT in the inhibition of α-glucosidase at low concentration, but XDT showed significantly higher inhibition than CDT as the increase of concentration. XDT was found to be a stronger inhibitor of HepG2 cells proliferation than CDT at the same treatment concentration. In summary, XDT showed higher yields, smaller average particle sizes, faster solubility, and higher antioxidant, hypoglycemic, and antitumor activity in vitro.
Effect of Chito-oligosaccharide on the Quality and Antioxidation of Dough and Crispy Biscuits
CHEN Dan, WANG Yuehui, ZHU Yue, CHEN Lei
2023, 44(18): 84-90.   doi: 10.13386/j.issn1002-0306.2022110208
Abstract(25) HTML(6) PDF(1)
In this work, the different proportions (0~2.0%, wt%) of chito-oligosaccharides were added into the low gluten wheat flour to prepare the crisp cookie, and the variations of flour properties, dough rheological properties, crisp cookie quality and antioxidation during storage (35 ℃, 28 d) were also investiated to evaluate the potential application of chito-oligosaccharides in flour food. Results showed that the addition of chito-oligosaccharide extended the formation time and stability time of dough but reduced the water absorption, weakening degree, gluten strength and viscoelasticity. Moreover, from the texture measurement, the crisp cookies containing 1.5% chito-oligosaccharide diplayed the lowest hardness (9422.80 gf) and chewability (2816.95 gf), which was accordance to the result of crisp taste test. However, color of the samples was gradually deepened with the increasing chito-oligosaccharide. In the sensory experiment, when the addition amount was 1.0%, the texture characteristics of cookies were not significantly different from those with 1.5% (P>0.05), and the color was golden with the highest sensory score. Therefore, the cooky with 1.0% chito-oligosaccharide showed the overall higher acceptability of consumers than that of others. Remarkably, the acid value, peroxide value and malondialdehyde (TBA) of the cookies with chito-oligosaccharide were lower than those of control group (P<0.05) after the storage (35 ℃, 28 d) experiment. These results indicated that the addition of chito-oligosaccharide could effectively promote the quality of cooky and delay the oxidation rout of cookies during the storage period, it could be used for quality improvement of wheat products.
Effect of Soybean Meal Proteins on Gel Properties of Silver Carp Surimi
WU Fang, JIANG Shu, HU Manzi, LIU Bei, LUO Haiying, HU Ting
2023, 44(18): 91-96.   doi: 10.13386/j.issn1002-0306.2022120015
Abstract(23) HTML(9) PDF(5)
The influence of soybean meal protein addition to the gel properties of silver carp surimi was studied, and the potential causes were further analyzed from the perspective of chemical forces and protein secondary structures. The surimi gels were prepared by the addition of 0%, 0.5%, 1.0%, 1.5% and 2.0% of soybean meal protein, respectively, to the frozen surimi samples of silver carp. The water-holding capacity, cooking loss rate, whiteness value, texture characteristics, sensory quality, chemical strength, total sulfhydryl content and protein secondary structure of surimi gel were measured by a texture analyzer and Fourier transform infrared spectrometer. The results showed that when the amount of soybean meal protein accounted for 1.5% of the frozen silver carp surimi, the water holding capacity, hardness, springiness, cohesiveness and chewiness of the surimi gel increased to the maximum values of 87.59%±1.44%, 381.70±7.64 g, 12.41±0.67 mm, 0.89±0.02 and 38.60±0.14 mJ, respectively, while the cooking loss rate decreased to the minimum value of 10.20%±0.52%, the sensory quality reached the best, and the whiteness value decreased slightly. This could be explained that the addition of 1.5% soybean meal protein led to a maximum hydrophobic interaction and total sulfhydryl content of surimi gel, and a tight gel three-dimensional network structure was formed. Moreover, the addition of soybean meal protein had little effect on the secondary structure of surimi protein. Therefore, the addition of 1.5% soybean meal protein effectively improved the gelation properties of surimi products.
Effect of Exogenous Protease on Flavor of Soymilk Made by Automatic Soymilk Maker
ZHANG Jiaming, LU Xiaohong, LIU Ping
2023, 44(18): 97-105.   doi: 10.13386/j.issn1002-0306.2022120027
Abstract(20) HTML(8) PDF(0)
In order to study the mechanism of protease which influences on the flavor of soymilk, different kinds and concentrations of protease (papain, 15000, 30000, 45000, 60000 and 75000 U/L, aminopeptidase, 500, 1000, 1500, 2000 and 2500 U/L, flavor protease, 100, 150, 200, 250 and 300 U/L, alkaline protease, 500, 1500, 2500, 3500 and 4500 U/L) were added to the soymilk made by automatic soymilk maker. Sensory evaluation was carried out on the soymilk after heating. The content and difference of polypeptide and amino acid nitrogen in the soymilk after enzymatic hydrolysis and heating were determined, and the correlation between them and sensory flavor indexes was analyzed. The volatile flavor components of soymilk were analyzed by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (GC-MS). The results showed that in the blank control group prepared by automatic soymilk maker without protease, the unpleasant beany odor and pleasant bean aroma of soymilk after heating were both lighter than those prepared by traditional method named the raw bean control group, while the contents of polypeptide and amino acid nitrogen showed reductions of 37.98% and 25.78% as compared to the raw bean control group, respectively. The sensory evaluation was carried out after adding different proteases to the soymilk prepared by automatic soymilk maker. The results showed that the soymilk added with 250 U/L flavor protease had the highest sensory score, which increased by 118.41% compared with the blank control group. In all groups added with proteases, the sensory score was significantly higher (P<0.05) except when it was added with 4500 U/L alkaline protease, compared with blank control group. The contents of hexanal, 2-pentyl furan, hexanol, trans,trans-2,4-decadienal and other volatile compounds related to beany ador in the enzyme added samples were lower than those in the blank control group and the raw bean control group, and the contents and types of volatile compounds related to bean aroma were increased to varying degrees. The addition of exogenous protease could significantly improve the contents of polypeptide and amino acid nitrogen in soymilk, among which the content of polypeptide was the highest when adding 4500 U/L alkaline protease (2.30±0.15 g/L), and the content of amino acid nitrogen was the highest when adding 2500 U/L aminopeptidase (0.087±0.0045 g/L). The amino acid nitrogen content of enzymolized soymilk in the group added with flavor protease was significantly positively correlated with the score of bean aroma (P<0.05), the increase of polypeptide in groups added with the other three enzymes were significantly or extremely significantly positively correlated with the score of beany odor (P<0.05, P<0.01). The increase of amino acid nitrogen was significantly negatively correlated with the beany odor, bean aroma and total score in the group added with aminopeptidase (P<0.05). The above results indicated that proteases are beneficial for increasing the content of polypeptides and amino acids as flavor precursors, which give a lighter beany odor and a richer bean aroma to the soymilk. This study provides theoretical guidance for the optimization of soymilk preparation technology.
Influences of Xanthan Gum and Guar Gum on Gelation Properties of Chicken Blood
ZHANG Huilin, LIN Jie, ZHENG Hua, WU Shaozong, LIU Wenbo, HU Jiawei, LIU Zeqi, HUANG Yin
2023, 44(18): 106-114.   doi: 10.13386/j.issn1002-0306.2022120090
Abstract(19) HTML(7) PDF(0)
To improve the gel quality of chicken blood, a by-product of concentrated slaughter, the effects of different concentrations and formulations of xanthan gum (XG) and guar gum (GG) on the gel properties of chicken blood were investigated using the indices of water retention, texture, and rheological properties, as well as analysis of molecular interactions and sensory scores. The results showed that while individual treatment with either XG or GG improved the water-holding capacity of the chicken blood gel, the action of XG was superior. Addition of 4.0 g/L of XG resulted in a cooking loss rate of 10.02%, centrifugation loss of 12.73%, and syneresis rate of 10.96% (at 48 h), while the hardness, cohesiveness, gelation, mastication, and recovery of the gel were decreased. Addition of 6.0 g/L of GG significantly improved the textural properties of the gel, resulting in a hardness of 366.95 N, elasticity of 0.94 mm, cohesiveness of 0.77, adhesiveness of 281.94, masticatory value of 263.72 mJ, and recovery of 0.25. Analysis of dynamic rheology and intermolecular forces showed that the gelation transformation of the chicken blood gel system was mainly determined by the elastic response. The formulation of XG and GG had a synergistic effect in stabilizing the chicken blood gel, with strengthened ionic bonds (from 29.18% to 32.62%) and hydrogen bonds (from 2.48% to 6.43%), reduced hydrophobic force (from 22.68% to 16.28%), increased water-holding capacity of the gel, and enhanced gel stability. The addition of 4.0 g/L of formulated colloid (XG and GG in a ratio of 7:3) to chicken blood resulted in optimal water retention and texture, together with high sensory scores of the gel.
Study on the Effects of Wheat Bran Dietary Fiber on Quality of Fermented Dried Noodles
NING Heng, MA Sen, LI Li
2023, 44(18): 115-122.   doi: 10.13386/j.issn1002-0306.2022120118
Abstract(27) HTML(11) PDF(5)
Fermented dried noodles are a popular nutritional noodle flour product in current market. Wheat bran dietary fiber (WBDF) can improve the nutritional value of fermented dried noodles, but also affect the quality characteristics of fermented dried noodles. In this paper, the effects of WBDF content on the cooking characteristics, texture characteristics and porosity of fermented dried noodles were investigated by single factor experiments, and the correlation analysis for WBDF content and the quality characteristics of fermented dried noodles was taken. The results showed that the porosity, breaking strength, water absorption, optimal cooking time, cohesiveness, resilience and tensile distance decreased significantly with the increase of bran dietary fiber addition (P<0.05), while the flexibility, rate of cooking loss, hardness, adhesiveness, chewiness and tensile resistance increased significantly (P<0.05) and the sensory evaluation score decreased. Adding 2% wheat bran dietary fiber had weaker influence on the cooking characteristics, texture characteristics and sensory evaluation score of fermented dried noodles. The research could lay a theoretic basis for the investigation of dietary fiber fermented dried noodles.
Speculate on the Formation Mechanism of Nonanal and Decanal from LPC (18:1) and LPE (18:1) in the Steaming of Chinese Water Chestnut Based on the in Vitro Model Study
LUO Xiujuan, LUO Yanghe, LI Guanli, LI Xiaochun, ZHANG Yitao, NIE Hui, WU Shujie
2023, 44(18): 123-130.   doi: 10.13386/j.issn1002-0306.2022120189
Abstract(29) HTML(8) PDF(0)
The in vitro models of oleoyl lysophosphatidylcholine 18:1 (LPC(18:1)), oleoyl lysophosphatidyl ethanolamine 18:1 (LPE(18:1)) and oleic acid were constructed by simulating the pH, LPC(18:1) and LPE(18:1) contents and steaming conditions of Chinese water chestnut (CWC). The content of nonanal, decanal and oleic acid, and peroxide value (POV) produced by the in vitro models were used as indicators to investigate the formation mechanism of nonanal and decanal from LPC(18:1) and LPE(18:1) during the steaming of CWC. The results showed that the possible mechanism of the oxidation of LPC(18:1) and LPE(18:1) to form nonanal and decanal was as follows. First of all, the C8 and C11 positions close to the double bond on the unsaturated acyl chain of LPC(18:1) and LPE(18:1) lost H respectively, and then formed R·. In the second step, the R· directly reacted with O2 and H to form 8-hydroperoxide (8-ROOH), or reacted with O2 and H to form 9-hydroperoxide (9-ROOH) and 10-hydroperoxide (10-ROOH) after electron rearrangement. Finally, 8-ROOH split homogeneously to form decanal, 9-ROOH and 10-ROOH split homogeneously to form nonanal. The results can provide scientific reference for the formation mechanism of flavor substances and the regulation of flavor quality of fruits and vegetables.
Analysis of Hong Qu Quality and Microbial Taxa Based on Physicochemical Indicators and MiSeq High-throughput Sequencing Technology
ZHENG Sifang, CHENG Chixinxiao, LONG Shuchang, WANG Yurong, TIAN Longxin, GUO Zhuang
2023, 44(18): 131-138.   doi: 10.13386/j.issn1002-0306.2022080163
Abstract(29) HTML(7) PDF(7)
In this study, to reveal the physicochemical properties and microbial taxa of Hong Qu produced in Shandong, China three Hong Qu samples were collected from a Shandong Qu-making company, and based on the determination of their physicochemical indexes and fermentation characteristics, the microbial taxa were resolved using MiSeq high-throughput sequencing technology, and the Bacillus and lactic acid bacteria contained in them were isolated and identified. The results showed that the moisture content of the three Hong Qu samples ranged from 8.27% to 10.30%, acidity ranged from 1.0 to 1.3 mmol/10 g, amino acid nitrogen content ranged from 131.65 to 172.76 mg/100 g, saccharification power ranged from 476 to 764 U/g, esterification power ranged from 331 to 548 U/g, and fermentation power, liquefaction power and alcoholization power were less than 10 U/g. The bacterial taxa of Hong Qu were mainly composed of Weissella (41.93%) and Acetobacter (9.99%), and the fungal taxa were mainly composed of Pichia (55.83%) and Monascus (21.24%), where the correlation between bacteria and alcoholization power was significant, and while the correlation between fungi and saccharification power was significant (P<0.05). Bacillus siamensis (B. siamensis) accounted for 79.17% of the Bacillus isolates and Pediococcus pentosaceus (P. pentosaceus) accounted for 55.55% of the lactic acid bacteria isolates. This shows that the Bacillus and lactic acid bacteria taxa included in this study mainly consisted of B. siamensis and P. pentosaceus, and the low content of Monascus and high content of Pichia might be the main reason for their low saccharification power.
Optimization of Fermentation Conditions, Enzymatic Properties and Degradation Products of Agarase Produced by Marine Bacterium Sphingomonas sp. Q2
QIAN Xiqian, QIAO Leke, ZHANG Hongfeng, JIANG Xiaolu, WANG Peng, ZHANG Jingliang
2023, 44(18): 139-146.   doi: 10.13386/j.issn1002-0306.2022090058
Abstract(35) HTML(9) PDF(9)
This study was aimed at optimization of the fermentation conditions for agarase production by Sphingomonas sp.Q2 which was isolated from Gracilaria and characterization of its enzymatic properties and degradation products. The optimum fermentation conditions were determined by response surface analysis. The agarase was purified by (NH4)2SO4 precipitation and column separation and its enzymatic properties was investigated. The results indicated that the optimal culture medium components for agarase production were agar 4.42 g/L, K2HPO4 1.30 g/L, NaCl 10.51 g/L. The highest enzyme activity of 1085.71 U/mL was obtained ,which was 1.58 times compared with the initial activity. The crude enzyme was purified 7 times with 112048.82 U/mg of enzyme activity. The recovery rate of agarase was 48.04%. The enzyme had optimal temperature and pH of 40 ℃ and 6.5, respectively. The enzyme activity remained above 90% when stored at the optimum temperature for 8 h. The capital hydrolysates were identified as neoagarotetraose by MS and 13C-NMR. The agarase showed a good thermal stability and high stability, which laid the foundation for the development and application of functional oligosaccharides agar.
Optimization of Oligosaccharide Preparation Process and Physiological Activity Analysis of Konjac Crude Powder
ZHANG Wei, SUN Nan, ZHANG Yuyao, WU Xiaoya, ZHAO Yu, ZHANG Bingqian, ZHANG Baoshan
2023, 44(18): 147-155.   doi: 10.13386/j.issn1002-0306.2022100174
Abstract(23) HTML(4) PDF(3)
In this paper, konjac powde were hydrolyzed by Bacillus licheniformis to prepare oligosaccharides. The effects of concentration of konjac powder, inoculum amount of strain, bacteriolysis temperature and hydrolysis time on hydrolysis rate of konjac powder were determined by single factor tests. The antioxidant activity of konjac powder oligosaccharides was evaluated with the scavenging ability of ·OH, ·O2· and DPPH· as indexes. The prebiotic activity of konjac powder oligosaccharides was investigated by in vitro fermentation test. The results showed that the optimal hydrolysis process parameters was as follows: concentration of konjac powder 20 g/L, inoculation capacity 1×107 CFU/g, hydrolysis temperature 43.6 ℃, hydrolysis time 10.2 h. Under the optimal conditions, the hydrolysis rate of konjac powder was 39.06%±0.12%, and the yield of KGOS was 66.72%. With the prolongation of hydrolysis time, the viscosity of solution decreased from 2430.33 mPa·s to 18.06 mPa·s. When the concentration of konjac powder was 10 mg/mL, the clearance rates of ·OH, ·O2 and DPPH· were 61.47%, 34.60% and 81.43%, respectively. The OD600 of KGOS, glucose and konjac powder on the proliferation of Lactobacillus plantarum, Lactobacillus brevity and Lactobacillus casei in vitro were 0.775, 1.371, 0.236, 0.791, 1.339, 0.224 and 0.916, 1.336, 0.243, respectively. The results provide a theoretical basis for the further processing and utilization of oligosaccharides in konjac powder.
Effects of Lactic Acid Bacteria Fermentation on Hypoglycemic and Antioxidant Activities of Goat Yoghurt in Vitro
ZHANG Hui, SUN Xiaochen, XIAYIDAN Maimaiti, LIU Xiaoli, FAN Linlin, XIA Xiudong, WANG Ying
2023, 44(18): 156-163.   doi: 10.13386/j.issn1002-0306.2022100176
Abstract(35) HTML(6) PDF(2)
Objective: The effects of lactic acid bacteria on the hypoglycemic and antioxidant activities of fermented goat milk were studied. Methods: Three lactic acid bacteria with hypoglycemic and antioxidant functions preserved in the laboratory and commercial yoghurt starters Lactobacillus bulgaricus (LB) and Streptococcus thermophiles (ST) were used as strain starters. The goat milk was fermented by single strain fermentation and mixed fermentation with commercial starters. The antioxidant and hypoglycemic functions of goat yoghurt fermented by different lactic acid bacteria were analyzed in vitro. Results: The results showed that in vitro antioxidant and hypoglycemic activities of goat milk fermented by single and mixed fermentation were improved. The goat yoghurt fermented by Pediococcus acidilactici GC215 had the highest DPPH clearance rate and reducing activity, which were 87.35% and 359.17 μmmoL/L L-cysteine reduction equivalent respectively. And its PTIO free radical clearance rate was 11.25%. Compared with unfermented goat milk, the inhibition rate of α-glucosidase activity of goat milk fermented by Liquorilactobacillus mali L31 increased by 44.08%. The goat yoghurt fermented by Lactobacillus brevis PC-2 mixed with LB and ST had the highest inhibition on α-amylase activity, which the activity inhibition rate was 82.30%. Conclusion: Functional lactic acid bacteria fermentation of goat milk could improve the antioxidant and hypoglycemic activities of goat yogurt in vitro. The research results would provide reliable strain resources for functional fermentation of goat milk and a new direction for the development of functional products of goat milk at the same time.
Effects of Phenyllactic Acid on Listeria monocytogenes Biofilms
JIANG Congyi, KANG Rui, YU Tao, JIANG Xiaobing
2023, 44(18): 164-172.   doi: 10.13386/j.issn1002-0306.2022100239
Abstract(27) HTML(6) PDF(2)
To investigate the effect of phenyllactic acid (PLA) on Listeria monocytogenes biofilms, crystal violet method was used to measure the biomass of L. monocytogenes biofilms, and inverted microscope and scanning electron microscope were used to observe the structure of L. monocytogenes biofilms, the content of extracellular polysaccharide, extracellular protein and extracellular DNA in biofilm was measured by phenol-sulfuric acid method, Folin-phenol method and diphenylamine method, respectively. The effect of PLA on the transcription of genes associated with biofilm formation of L. monocytogenes was detected by real-time quantitative PCR. The results showed that the minimum inhibitory concentration values of PLA against eight L. monocytogenes strains were 6 mg/mL. PLA inhibited L. monocytogenes biofilm formation by reducing the synthesis of extracellular polysaccharides and extracellular proteins. For mature biofilms of L. monocytogenes, PLA destroyed the biofilm structure and reduced the biofilm biomass by reducing the amount of extracellular polysaccharides and extracellular proteins. PLA also inhibited the swarming motility of L. monocytogenes. The transcription levels of quorum sensing system agr in L. monocytogenes were significantly (P<0.05) decreased in the presence of PLA. As a natural antimicrobial compound, PLA had the potential application to control food contamination by L. monocytogenes and its biofilms.
Design, Expression and Evaluation of Bacteriostatic Activity of Hybrid Antimicrobial Peptide NK-LPd
LIU Ziqi, LIU Zhengyu, GUO Yinhong, WANG Hongfei, YAO Bo
2023, 44(18): 173-180.   doi: 10.13386/j.issn1002-0306.2022100277
Abstract(24) HTML(12) PDF(1)
Objective: To reveal the bacteriostatic activity of hybrid antimicrobial peptide NK-LPd, and discuss its further exploitation potential. Methods: Two glycines were utilized as the linker to connect the active fragments of NK-lysin and Piscidin, and the physicochemical properties and functional structures of the hybrid antimicrobial peptides were predicted by bioinformatics. The hybrid antimicrobial peptide NK-LPd gene was optimized according to Pichia pastoris codon preference principle. The optimized gene was amplified by gene splicing via overlap extension polymerase chain reaction (gene splicing by overlap extension polymerase chain reaction, SOE-PCR) and inserted into the secretory expression vector pPIC9K. The recombinant plasmid was chemically transformed into P. pastoris KM71 competent cells. The recombinant expression was induced by 0.5% methanol as the inducer, which products were purified by affinity purification and its activity was evaluated. Results: KM71/pPIC9K-NK-LPd was successfully constructed. After expression for 5 days, an expression product with a relative molecular mass of about 6 kDa was obtained in the supernatant, which was in line with the expected size. Bacteriostatic activity experiments showed that NK-LPd had strong bacteriostatic activity against Gram-negative and Gram-positive bacteria. Compared with the parent peptides, the bacteriostatic activity of NK-LPd was significantly enhanced. Conclusion: The hybrid antimicrobial peptide NK-LPd was designed and expressed in P. pastoris KM71, and its bacteriostatic activity was superior to that of the parent peptides. This study could provide technical reference for the design and production of novel hybrid antimicrobial peptides.
Effects of Bifidobacterium animalis subsp. lactis Combined with Traditional Starter Culture on the Quality Characteristics of Fermented Cow Milk and Yak Milk
PAN Kun, CHEN Hanshuanglu, ZHOU Haidong, LIAO Binxu, LI Qiaoyan, TANG Shanhu, LI Sining, LIU Liang
2023, 44(18): 181-192.   doi: 10.13386/j.issn1002-0306.2022110167
Abstract(19) HTML(6) PDF(3)
To evaluate the effects of different starter cultures and different fermentation substrates on the quality of fermented milk, the samples were prepared with Bifidobacterium animalis subsp. lactis (Ba) in co-cultures with traditional yogurt starter cultures (SL), and the acidification profile, viable bacteria count, water-holding capacity, proteolytic activity, rheological property, physical stability, microstructure, volatiles and sensory characteristic of fermented cow milk, fermented yak milk and fermented milk mixtures of cow to yak milk ratios of 1:1 were investigated. The results showed that for the same fermentation substrates, Ba-SL significantly improved the acidification property and viable bacteria count of fermented milk (P<0.05), and increased the proteolytic activity of fermented cow milk, yak milk and mixed milk at the first day by 0.026, 0.025 and 0.016 compared with SL alone, respectively. Furthermore, Ba-SL improved the gel network structure, volatiles, and sensory quality of fermented milk. However, the co-cultures of Ba-SL had no significant effect on the physical stability of fermented milk (P>0.05). Ba-SL significantly enhanced the water-holding capacity of fermented cow milk and fermented mixed milk (P<0.05), and there was a higher water-holding capacity in fermented mixed milk in comparison to fermented cow milk and fermented yak milk during the whole refrigeration period, with the largest values of water-holding capacity being 45.68% on the 7 d. SL starter in conjunction with Ba increased the viscoelasticity of fermented yak milk, but decreased the viscoelasticity of fermented cow milk and fermented mixed milk compared to the single-culture of SL. For the same starter cultures, the acidification property, viable bacteria count, physical stability, and sensory score of fermented cow milk were significantly higher than those of the other groups (P<0.05), and the viscoelasticity of fermented yak milk was the highest among the fermented milk. The water-holding capacity of fermented mixed milk was significantly higher than those of the other groups throughout the refrigeration period (P<0.05), and the gel network structure and key volatiles of fermented mixed milk was the densest and more diverse among the three fermented milk, while the proteolytic activity of fermented mixed milk was between fermented cow milk and fermented yak milk. This study suggested that Ba in co-culture with SL could improve the quality of fermented milk, and both of cow milk and mixtures of cow and yak milk were more suitable to prepare fermented milk compared to yak milk.
Vertical Distribution and Enrichment Culture of Bacteria in the Acetic Acid Fermentation Stage of Zhenjiang Aromatic Vinegar
CUI Yunlai, ZHANG Hui, LI Yulong, LUO Shaobo, NING Xueyue, TIAN Jiabei, HAN Dong
2023, 44(18): 193-199.   doi: 10.13386/j.issn1002-0306.2022110197
Abstract(28) HTML(4) PDF(1)
The taste and flavor of fermented vinegars are closely related to the fermentation microorganisms. In order to investigate the vertical distribution of bacterial community in the acetic acid fermentation stage of Zhenjiang aromatic vinegar, and to investigate the enrichment effect of different media on the culturable bacteria from Cupei. In this study, the bacterial diversity of Cupei and enriched culture samples were determined by high-throughput sequencing. The results showed that the number of OTUs in the surface, middle and bottom Cupei samples were 66, 76 and 111, respectively. The dominant bacterium in the surface layer was Acetobacter, while the dominant bacterium in the middle and bottom layers was Lactobacillus. The richness and diversity of bacterial flora became more abundant and diverse with the depth of fermentation. Meanwhile, high-throughput sequencing after enrichment showed that the oligotrophic medium enriched higher bacterial diversity than the nutrient-rich medium. This study revealed that there were differences in bacterial diversity in different depths of Cupei. And it also proposed an oligotrophic medium for bacterial isolation to make isolation of fermentation microorganisms from Cupei more efficient.
Investigation on the Transport Mechanism of Penicillium expansum MFS Protein Based on Molecular Dynamics Simulation
YANG Qi, WANG Yanling
2023, 44(18): 200-208.   doi: 10.13386/j.issn1002-0306.2022110341
Abstract(34) HTML(11) PDF(3)
The Penicillium expansum produces a toxic secondary metabolite, patulin. The PatC gene encodes the MFS transport protein, and transports the patulin precursor substance to the extracellular space, ultimately forming PAT. This has high reference value in the prevention of patulin. In order to study the transport mechanism of the PatC, the spatial structure of the PatC was predicted by using bioinformatics methods, and the interaction site and possible mechanism of E-ascladiol and the PatC were analyzed by molecular docking and molecular dynamics simulation. The results showed that the gene encoded 546 amino acids, containing 14 transmembrane helix and MFS functional domains. The molecular docking results showed that the protein had 4 binding sites with the E-ascladiol, namely SER353, TYR336, PRO339, and PRO188. Molecular dynamics simulations of 200 ns were performed for the Wild protein complex system and the P188A mutant system. The results showed that the small molecule substrate and the PatC were tightly bound, and that the protein's flexibility changed strongly after forming a complex in the Pro188~Ser197aa and Gly231~Val241aa regions. It could be inferred that these two regions might have functional sites. By analyzing the parameter data of the P188A mutant system, it could be predicted that PRO188 was an important target of the PatC protein, which could provide a basis for subsequent molecular experiments. The results of the research could lay the foundation for exploring the transport mechanism of patulin, and provide new strategies for the prevention of apple rot.
Establishment and Application of Rapid Detection Method for Polymyxin Resistance Gene mcr-1 Based on RPA-LFD Method
JIAO Xue, DONG Yuzhi, WANG Jingwen, LÜ Chenze, FANG Jiehong, JIANG Han
2023, 44(18): 209-216.   doi: 10.13386/j.issn1002-0306.2022120034
Abstract(43) HTML(18) PDF(5)
Objective: To develop a rapid, efficient and visual method for the detection of bacterial colistin resistance gene mcr-1, so as to provide the basis and convenience for the development of its detection at the grassroots level. Methods: Using recombinase polymerase amplification combined with a lateral flow dipstick (RPA-LFD) assay, supplemented by a hand-held colloidal gold reader. According to the conserved sequence of the mcr-1 gene, a pair of specific RPA primers were designed and synthesized. Through the optimization of the reaction conditions and system, as well as the specificity test, sensitivity test, simulated food sample test and actual sample test, the RPA-LFD assay for visual and quantitative detection of bacterial colistin resistance gene mcr-1 was successfully established. Results: When the primer concentration was 400 nmol/L and the primer ratio was 1:1, the optimal reaction conditions of this method are Mg2+ concentration 14.0 mmol/L, reaction temperature 37 ℃ and reaction time 20 min. The sensitivity was good, the standard curve equation was y=0.117x+0.051, the quantification limit was 101~108 copies/μL, and the detection limit was 101 copies/μL, which was an order of magnitude lower than the PCR method and the detection result of the simulated sample was consistent with the PCR method. Carrying status of colistin resistance gene mcr-1 in each 15 pork samples, chicken samples, pig farm environmental samples, broiler farm environmental samples, Escherichia coli isolates and Enterobacter campylobacter isolates were analyzed by the established RPA-LFD assay. The detection rate of positive samples by RPA-LFD assay was consistent with that of conventional PCR method, and a total of 9 mcr-1 gene positive samples were detected. RPA-LFD quantitative analysis showed that the concentration of mcr-1 gene in positive samples was between 4.5×102~8.6×104 copies/µL. Conclition: The RPA-LFD detection method of the bacterial colistin resistance gene mcr-1 established in this study had strong specificity, high sensitivity, and simple operation, and could be widely used in grassroots inspections.
Processing Technology
Optimization of Coffee Micro-water Degumming Process Based on Principal Component Analysis
LI Xuerui, YAN Jing, LIU Xiuwei, WU Xinyi, YANG Taixian, PAN Jun, ZHU Zhiyan, TIAN Hao, LI Hong
2023, 44(18): 217-224.   doi: 10.13386/j.issn1002-0306.2022100096
Abstract(38) HTML(22) PDF(4)
To optimize the micro-water degumming process, this study investigated the effects of different processing techniques including mechanical peeling degumming+sun drying (A), mechanical peeling degumming+heat pump drying (B), manual peeling+heat pump drying (C), mechanical peeling degumming+water soaking degumming+heat pump drying (D), and manual peeling+water soaking degumming+heat pump drying (E) on the content of aroma precursors (protein and crude fat), taste-producing substances (caffeine, chlorogenic acid and caffeic acid), and volatile substances in green coffee beans. The results showed that compared to the manual peeling degumming+heat pump treatment group, the mechanical peeling degumming+heat pump drying group exhibited a significantly increased chlorogenic acid and caffeic acid contents in raw coffee beans, a significantly decreased (P<0.05) protein content with the increase in pectin residue (P<0.05). The content of crude fat and caffeic acid in raw coffee beans significantly higher in the mechanical peeling degumming+water soaking degumming+heat pump drying treatment group than in the mechanical peeling degumming+heat pump drying treatment group (P<0.05). Chlorogenic acid and caffeic acid contents in raw coffee beans were significantly higher in the mechanical peeling degumming+heat pump drying treatment group than in the mechanical peeling degumming+sun-drying treatment group (P<0.05). The contents of protein, crude fat, and caffeine in green coffee beans were lower in manual peeling+heat pump drying (C) and manual peeling+water soaking degumming+heat pump drying (E). The protein content in green coffee beans was the highest (13.71%) in mechanical peeling degumming+water soaking degumming+heat pump drying(D), and its crude fat content was only second (9.84%) to mechanical peeling degumming+sun drying (A). According to the overall score of quality indicators from high to low, the 5 treatment groups were ranked as D>B>A>E>C. The PCA score plot grouped samples B and D into one quadrant, and the samples in other treatment groups were located in different quadrants, which indicated a relatively small difference in the quality of raw coffee beans between the mechanical peeling degumming+heat pump drying group and mechanical peeling degumming+water soaking degumming+heat pump drying treatment group, while the difference in quality of raw coffee beans among the other treatment groups was dramatic. The analysis results of the relative content of volatile substances showed that raw coffee beans in the manual peeling+water soaking degumming+heat pump drying treatment group contained more main flavor compounds such as n-octadecane (4.80 µg/g), damascenone (1.85 µg/g), dibutyl phthalate (20.28 µg/g) than those in the mechanical peeling degumming+water soaking degumming+heat pump drying treatment group (1.63, 0.94, 4.07 µg/g), and compounds in raw coffee beans exhibited an overall decreasing trend with decreasing pectin residues. Taken together, rich flavor could be obtained from green coffee beans by taking advantage of pectin, and the optimal comprehensive quality could be obtained from the micro-water degumming process, namely, mechanical peeling degumming+water soaking degumming+heat pump drying. The findings would provide new perspectives for the processing of the Yunnan fine coffee beans and fermented flavor coffee beans.
Optimization of the Vacuum Frying Process of Pork Belly Slices by Response Surface Methodology and Principal Component Analysis
HUANG Ruihan, PAN Hongjie, YANG Shuang, XU Qinglian, XING Yage
2023, 44(18): 225-234.   doi: 10.13386/j.issn1002-0306.2022100227
Abstract(53) HTML(13) PDF(13)
To improve the production process of meat products in the industrialization of Sichuan cuisine, this study was conducted to investigate the effects of different vacuum frying temperature, frying time and slice thickness on moisture content, color, texture characteristics and sensory scores of pork belly slices, and to optimize the vacuum frying process conditions of pork belly slices using response surface combined with principal component analysis based on single-factor experiments and correlation analysis. The results showed that moisture content, a* value, b* value, hardness, and chewiness were more strongly correlated with 3 factors, namely, frying temperature, frying time, and slice thickness. The cumulative contribution rate of the first two principal components extracted in the principal component analysis was 82.822%, which could evaluate the quality of vacuum-fried pork belly slices to a certain extent. An optimal vacuum frying process for pork belly slices was achieved, where frying temperature 100 ℃, frying time 3 min, and slice thickness 3 mm. In this case, the standardized comprehensive score of pork belly slices was 0.931, and a standard deviation from the predicted value was 0.5%, indicating that the model could better predict the standardized comprehensive score of vacuum-fried pork belly slices. This process would provide a feasible method and a certain theoretical reference for the production of meat products in the industrialization of Sichuan cuisine.
Process Optimization and Characteristic Analysis of Sea Buckthorn Juice Deacidification by Compound Lactic Acid Bacteria Fermentation
NING Zhixue, ZHU Libin, ZHU Dan, NIU Guangcai, WEI Wenyi, XU Ruihang
2023, 44(18): 235-243.   doi: 10.13386/j.issn1002-0306.2022100232
Abstract(9) HTML(4) PDF(2)
In order to study the effect of compound lactic acid bacteria fermentation on reducing acid of sea buckthorn juice, the Oenococcus oeni and Lactobacillus brevis were used to ferment sea buckthorn juice. With the total acid degradation rate as the index, the fermentation process of sea buckthorn juice was optimized by single factor experiment and response surface experiment, and the changes of flavonoids, polyphenols, total acid, pH, total soluble solids (TSS), reducing sugar, organic acid and antioxidant activity during fermentation were studied. The results showed that the optimal fermentation conditions were as follows: The ratio of Oenococcus oeni to Lactobacillus brevis was 1:1, the initial pH was 3.7, fermentation temperature was 31 ℃, fermentation time was 18 h, inoculation amount was 5%. Under these conditions, the total acid degradation rate reached 38.52%. At this time, the contents of flavonoids, polyphenols, total acid, pH and TSS were significantly different from those before fermentation (P<0.05). The contents of flavonoids and polyphenols in sea buckthorn fermentation broth increased by 44.74% and 22.22%, respectively, compared with those before fermentation. The pH increased from 3.71 to 3.85, the total acid content decreased from 8.49 g/L to 5.22 g/L, the TSS content decreased by 20.29%, and the reducing sugar content did not change significantly (P>0.05). The content of malic acid in fermentation broth decreased significantly (P<0.05), the degradation rate was 94.59%, and the content of lactic acid increased significantly (P<0.05), reached 10.37 mg/mL. The changes of quinic acid, ascorbic acid, tartaric acid, oxalic acid and citric acid were not significant (P>0.05). The maximum values of DPPH and ABTS+ free radical scavenging rate and ferric reducing antioxidant power (FRAP) of sea buckthorn juice after lactic acid fermentation reached 78.20%, 64.48% and 1.1626 mmol/L, respectively. Therefore, the sea buckthorn juice fermented by compound lactic acid bacteria could effectively reduce its acidity and improve its quality and antioxidant activity, which would provide a theoretical basis for the development of acid-reducing technology and related products.
Extraction Process Optimization and Antioxidant Activity of Total Flavonoids from Haloragis micrantha (Thunb.) R. Brown.
XIA Yuhong, LIU Ying, ZHOU Ming, ZHU Zhenxin, LU Yue, LIU Hongcun, MENG Juan, GONG Zhiqiang, YANG Lifang
2023, 44(18): 244-250.   doi: 10.13386/j.issn1002-0306.2022100235
Abstract(44) HTML(19) PDF(4)
The objective of this study was to optimize the extraction process of total flavonoids from Haloragis micrantha (Thunb.) R. Brown. and explore its antioxidant activity. With the yield of total flavonoids as an evaluation index, single factor tests were used to investigate the effects of ethanol volume fraction, solid-liquid ratio, ultrasonic temperature and extraction time on the total flavonoids content of Haloragis micrantha (Thunb.) R. Brown., and the Box-Behnken method was used to optimize the extraction process. The scavenging ability and total reducing power of total flavonoids of Haloragis micrantha (Thunb.) R. Brown. to DPPH and ABTS+ free radicals were detected. The results showed that optimum extraction process was ethanol volume fraction of 76.15%, liquid to material ratio of 1:39.66 g/mL, ultrasonic time of 41.14 min. The yield of total flavonoids from Haloragis micrantha (Thunb.) R. Brown. was 28.61±0.05 mg/g. The total flavonoids of Haloragis micrantha (Thunb.) R. Brown. could effectively scavenge DPPH and ABTS+ free radicals. Within a certain range, the scavenging ability increased with the increasing of mass concentration, and the total flavonoids of Haloragis micrantha (Thunb.) R. Brown. had high reducing power and better antioxidant activity. The total flavonoids of Haloragis micrantha (Thunb.) R. Brown. had the strongest ability to scavenge ABTS+ free radicals. When the concentration of total flavonoids was 3 mg/mL, the clearance rate of ABTS+ were 98.28%, which was equivalent to 3 mg/mL vitamin C (clearance rate was 99.81%). This process would be simple and feasible, and the extracted total flavonoids have good antioxidant activity.
Ultrasound-Assisted Extraction and Analysis of Antioxidation and Hypolipidemia Activities of Polysaccharides from Lilium brownii var. viridulum
WANG Weizhen, YANG Panpan, TI Yongrui, TANG Yuchao, XU Leifeng, WU Xuewei, SONG Zihan, MING Jun
2023, 44(18): 251-257.   doi: 10.13386/j.issn1002-0306.2022100237
Abstract(23) HTML(13) PDF(4)
Lilium brownii var. viridulum is one of the main traditional edible and medicinal lily in China. This study aimed to explore the extraction technology, physicochemical properties and functional activity of polysaccharide from Lilium brownii var. viridulum, used Lilium brownii var. viridulum scales as materials, polysaccharide yield as the index, solid-liquid ratio, extraction time and extraction temperature as factors to optimize the extraction process of lily polysaccharide. Then the polysaccharide was purified through removing protein. The physicochemical properties of the polysaccharides were analyzed, and the antioxidant and lipid-lowering abilities were measured in vitro. The results showed that the optimal extraction conditions were the material to liquid ratio 1:20 g/mL, extraction time 20 min, extraction temperature 75℃, and polysaccharide yield was 11.98%. The contents of total sugar, uronic acid and protein of crude polysaccharide were 58.46%, 8.06% and 10.85%, respectively. After deproteinization, the contents of total sugar and uronic acid of polysaccharide were increased to 84.78% and 15.41%, respectively, and the content of protein was reduced to 4.73%. The scavenging rates of 10 mg/mL deproteinized polysaccharide for DPPH and ABTS+ free radicals were 8.75% and 38.59%, respectively, which were lower than those of control VC. The inhibition rate of deproteinized polysaccharide for pancreatic lipase was 85.78%, which was higher than that of the control orlistat, indicating good inhibit pancreatic lipase effect in vitro. These results would provide a basis for further study on the structure-activity relationship and development of potential functional food, and provide theoretical reference for the application of lily.
Optimization of Extraction Process and Purification of Flavonoids from Peony Seed Meal by Membrane Method
ZOU Ping, XU Ying, CHEN Wentao, ZHANG Yingyang, XU Rong
2023, 44(18): 258-267.   doi: 10.13386/j.issn1002-0306.2022100241
Abstract(20) HTML(14) PDF(2)
In this study, the flavonoids in peony seed meal were separated and purified by microfiltration-nanofiltration secondary membrane separation method. The effects of material-liquid ratio, extraction temperature, ethanol volume fraction and extraction time on the extraction amount of total flavonoids were investigated by single-factor experiments, and the extraction process was optimized and validated by response surface methodology on the basis of single factors. Eight types of microfiltration membranes, including polyvinylidene fluoride (PVDF), polyethersulfone (PES), polytetrafluoroethylene (PTFE), polypropylene (PP), mixed cellulose (MCE), polyacrylonitrile (PAN), aqueous acetate (CA) and polyamide (PA), were selected for the primary separation of PSMF extracts. The nanofiltration membranes were homemade organosilicon/PA composite membranes in the laboratory. The results showed that the optimum extraction conditions for PSMF were 1:15 g/mL, 50 ℃, 70% ethanol volume fraction, 30 min, (240.28±2.25) μg/mL of PSMF extraction amount. The PA membrane had a better separation effect, and the composite membrane had a better purification effect on PSMF, and the water solubility of flavonoids was increased to more than 90% after separation. After calcination at 800 ℃, the residual mass of the raw material solution was 1.43% and that of the PA membrane separation was 0.76%, and the BTESE/PA composite membrane was reduced to 0.26%, with fewer impurities and higher purity. Comparing its antioxidant activity before and after separation, the ·OH, DPPH· scavenging rate and reducing power were improved after separation, and the O2· scavenging rate decreased from 79.94% to 64.82%. In this study, the active components in peony seed meal were analyzed. PSMF would be a novel phytoflavonoid resource with rich composition and certain research space.
Preparation of Glycosylated Walnut Protein Isolate-Inulin Conjugate and Analysis of Its Properties
CHEN Yu, CAO Shinuo, SHEN Yijie, LI Chang, DU Jian, WANG Fengjun
2023, 44(18): 268-275.   doi: 10.13386/j.issn1002-0306.2022110144
Abstract(20) HTML(9) PDF(2)
To improve the solubility of the walnut protein, it was modified through glycosylation. The preparation process of the walnut protein isolate-inulin conjugate was optimized by single-factor and response surface tests. To determine the structural and functional properties of walnut isolated proteins-inulin conjugate, infrared spectra, endogenous fluorescence spectra, solubility and emulsification properties were studied. Results showed that when the reaction temperature was 89 ℃, the reaction time was 75 min, the mass ratio of protein to sugar was 1:2, and the walnut protein isolate-inulin conjugate could reach a maximum solubility of 83%, which was 47% higher than that of walnut isolated protein. Fourier infrared spectroscopy and fluorescence spectroscopy analyses showed that the walnut isolated protein and inulin were joined by covalent bonding, that their shape changed from scattered small granular particles into a sheet structure, and that their fluorescence intensity remarkably reduced. Compared with walnut isolate protein, the foamability and foam stability of walnut protein isolate-inulin conjugate increased by 49% and 23%, respectively, and the emulsification index increased by 17%. These results indicate that protein modification through glycosylation improved the structure and properties of the products. This paper would provide a new method for the processing and utilisation of walnut isolate protein and broadening the field of walnut protein processing and utilization.
Optimization of the Formulation and Process of Sweet Potato Leaf Jelly by Response Surface Methodology
GAO Xueli, GU Qianqian, LI Guanghui, WANG Yonghui, HE Shenghua, HUANG Jihong, GUO Weiyun
2023, 44(18): 276-282.   doi: 10.13386/j.issn1002-0306.2022110222
Abstract(39) HTML(11) PDF(12)
To research the effect of sweet potato leaf extract on the comprehensive quality of starch jelly, this study investigated the impact of several factors, including sodium carbonate, white granulated sugar, sweet potato leaf extract, sweet potato starch, and steaming time, on the sensory quality and texture characteristics of sweet potato leaf jelly, which was made using sweet potato leaf and sweet potato starch as the main ingredients. Response surface optimization experiments were conducted, using elasticity as the response value, to determine the optimal formula and process parameters for sweet potato leaf jelly. The optimal formula for sweet potato leaf jelly was: Sweet potato leaf extract 40 mL/100 g, white granulated sugar 1 g/100 g, sweet potato starch 19 g/100 g, purified water 40 mL/100 g. The raw materials were thoroughly mixed and steamed for 8 minutes, and then cooled. The resulting product had a green color, uniform texture, and a unique sweet potato leaf aroma, and the elasticity was verified to be 6.19. This study would provide a technical support for expanding the application of sweet potato leaf and improving the comprehensive value of the sweet potato industry.
Compound Enzyme Extraction of Platycodon grandiflorum Polysaccharides and Its Structure and Antioxidant Activity Characterization
LI Wei, FANG Leilei, ZHANG Yanqing, XIE Junbo
2023, 44(18): 283-291.   doi: 10.13386/j.issn1002-0306.2022120100
Abstract(30) HTML(9) PDF(3)
Objective: Optimize the extraction process of Platycodon grandiflorum polysaccharides by compound enzyme method, and preliminarily analyze its structure and in vitro antioxidant activity. Methods: Response surface methodology was used to optimize the extraction conditions with the extraction rate of polysaccharides as the index and the addition amount of enzymes, solid-liquid ratio, enzymolysis time and enzymolysis temperature as the factors. The molecular weight and monosaccharide composition of purified polysaccharides were analyzed by high performance liquid chromatography (HPLC), the glycosidic bonds and surface morphology of purified polysaccharides were analyzed by nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM), respectively, and the free radical scavenging ability and reducing power of purified polysaccharides were evaluated. Results: The optimum extraction conditions were as follows, the addition of cellulase, pectinase and papain was 2%, the enzymolysis time was 90 min, the solid-liquid ratio was 1:30 g/mL, the enzymolysis temperature was 50 ℃. Under these conditions, the actual extraction rate of polysaccharides was 9.01%±0.07%, and the purity of polysaccharides was 92%±0.76%. The purified polysaccharides component PGP-W-1 (6.2 kDa) was composed of mannose, rhamnose, glucose, galactose, xylose, and arabinose with a molar ratio of 4.9:4.3:7.9:7.8:4.8:18.6. NMR spectrum showed that PGP-W-1 was pyranose ring with α- and β-glycoside bond. The IC50 values of the PGP-W-1 on DPPH free radicals, ABTS+ free radicals and hydroxyl free radicals were 2.14, 2.25, and 0.78 mg/mL, respectively. Conclusion: The optimized extraction process of Platycodon grandiflorum polysaccharide was feasible with high extraction efficiency and showed excellent antioxidant activity in vitro.
Preparation of Resistant Starch by Ultrasonic Annealing Method and Its Physicochemical Properties
ZENG Xurui, LIU Liangzhong, QI Ting, ZHU Zhe
2023, 44(18): 292-299.   doi: 10.13386/j.issn1002-0306.2022120135
Abstract(21) HTML(13) PDF(1)
In order to optimize the process conditions for the preparation of waxy rice resistant starch by ultrasonic annealing method, this study took the content of resistant starch as an index, and based on the single factor experiment, the response surface analysis method was used to explore the effects of water content, ultrasonic time, annealing temperature and annealing time on the content of resistant starch, and the physicochemical properties of the prepared resistant starch were analyzed. The results showed that the optimum conditions were as follows: Water content 68%, ultrasonic time 23 min, annealing temperature 55 ℃, annealing time 25 h. Under these conditions, the content of resistant starch was 45.61%±0.95%. Compared with original starch, the transparency of waxy rice resistant starch increased by 38.19%, and the solubility at 90 ℃ increased from 6.03% to 52.45%, while the swelling power decreased from 41.04 g/g to 6.38 g/g. Under scanning electron microscope, the surface morphology of resistant starch changed significantly, which showed that it was a rough structure with many holes. Fourier infrared spectroscopy showed that ultrasonic annealing promoted the generation of short-range ordered structures of starch. Differential scanning calorimetry analysis showed that the enthalpy of resistant starch increased by 5.05 J/g after ultrasonic annealing, and X-ray diffraction analysis displayed that the crystalline shape was changed and the crystallinity of resistant starch was improved. This study provided a reference for the industrial production of waxy rice resistant starch.
Screening of α-Glucosidase Inhibitory Peptides from Tea Leaves using Ultrafiltration Affinity Combined with Liquid Chromatography-Mass Spectrometry and Molecular Docking Technology
ZAN Lixia, WANG Weiwei, ZHANG Wenyi, LI Xinsheng, CHEN Xiaohua, YAN Fei, FU Jing
2023, 44(18): 300-306.   doi: 10.13386/j.issn1002-0306.2023030066
Abstract(23) HTML(9) PDF(1)
Objective: To screen for tea peptides with inhibitory activity against α-glucosidase. Methods: The response surface method was used to optimize the preparation process of tea peptides. Affinity ultrafiltration was used to isolate tea peptides that bind with α-glucosidase, and liquid chromatography-mass spectrometry was used to determine the sequence of the isolated peptides. Virtual screening was performed using bioinformatics methods. Results: The optimal preparation process of tea leaf enzymatic hydrolysis products was alkaline protease hydrolysis temperature of 50 ℃, enzymatic hydrolysis time of 3 h, and a liquid-to-solid ratio of 10:1 (mL/g). The α-glucosidase inhibitory rate was 57.29%. From this, 624 peptide segments were identified, and LIGF was selected for its α-glucosidase inhibitory activity. At a concentration of 5 mg/mL, LIGF exhibited a maximum inhibition rate of 88.13% against α-glucosidase and an IC50 value of 1.22 mg/mL. Molecular docking showed that LIGF could form 5 hydrogen bonds with α-glucosidase, and the binding energy was −3.51 kJ, indicating a high affinity, stability and ability to bind to α-glucosidase. Conclusion: LIGF had potential value as a therapeutic drug for type II diabetes.
Analysis and Determination
Online Identification and Constitutive Relationship Analysis of Antioxidant Components in Jerusalem Artichoke
ZHANG Zhiyi, BAI Ruoxi, ZONG Aizhen, ZHANG Minmin, ZHENG Zhenjia, ZHANG Bin
2023, 44(18): 307-312.   doi: 10.13386/j.issn1002-0306.2022080031
Abstract(35) HTML(7) PDF(3)
In this study, a new method based on the HPLC online scavenging diphenyl-1-picrylhydrazyl (DPPH) radical activity and Q-TOF/MS for the rapid screening and identification of caffeoylquinic acids in Jerusalem artichoke, and its antioxidant activity was evaluated. The mobile phase was acetonitrile-0.1% formic acid aqueous solution (gradient elution), and the samples were separated by C18 column. The samples were mixed with DPPH radical solution in PEEK tube and then entered UV detector, the detection wavelength were 280 and 517 nm, and the online screening of caffeoylquinic acid components was realized by the negative peak generated at 517 nm. Results showed that, under the negative ion mode, according to the precise molecular weight combined with the standards, five antioxidant compounds were screened from the Jerusalem artichoke, including chlorogenic acid, caffeic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid. The free radical scavenging rate of each component to DPPH, ABTS+ and superoxide anion was in the range of 54.63%~95.43%, 8.32%~69.63%, 27.37%~51.40%, and were positively correlated with the concentration. In this study, the caffeoylquinic acids in Jerusalem artichoke were rapidly identified and their antioxidant activities were explored, which provided a scientific basis for the development and utilization of caffeoylquinic acids in Jerusalem artichoke.
Determination of 10 Tetracycline Antibiotics in Fruit Products and Meat Sauce by QuEChERS with Ultra Performance Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry
GU Yue, TANG Huixin, LI Shuo, MA Ling, WANG Ke, YANG Lili
2023, 44(18): 313-320.   doi: 10.13386/j.issn1002-0306.2022100072
Abstract(30) HTML(21) PDF(2)
A method for the determination of 10 tetracycline antibiotics in fruit products and meat sauce was established by QuEChERS coupled with ultra performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-MS/MS). The optimal experimental conditions were determined by optimizing the mass spectrometric parameters, chromatographic conditions and pre-treatment techniques. The samples were extracted by 0.2% formic acid acetonitrile under ultrasonication, and then purified with PSA for fruit products and C18 for meat sauce. The target analytes were separated on a ZORBAX SB-Aq column (2.1 mm×150 mm, 3.5 μm), and detected by UPLC-MS/MS. The results demonstrated that the 10 tetracycline antibiotics showed good linearity in the respective linear range with the correlation coefficients (r) higher than 0.999. The limits of detection (S/N=3) were 0.09~3.92 μg/kg, and the limits of quantification (S/N=10) were 0.31~13.05 μg/kg. The average recoveries at three different spiked levels of 75, 300 and 750 μg/kg ranged from 70.0% to 101.0% with the relative standard deviation (RSD) of 1.0%~10.3% (n=7). The method is sensitive, simple and suitable for the rapid and simultaneous detection of 10 tetracycline antibiotics in fruit products and meat sauce.
Method Establishment for the Detection of Black Spot Disease on Winter Jujubes Based on Optical Properties
JIANG Mengwei, LAN Weijie, TU Kang, PENG Jing, BAI Bingyao, ZHANG Li, SONG Lijun, PAN Leiqing
2023, 44(18): 321-330.   doi: 10.13386/j.issn1002-0306.2022100082
Abstract(45) HTML(19) PDF(11)
The objective of this study is to investigate the variations of optical properties during the progression of black spot disease and select the characteristic wavelengths for disease detection. The optical absorption and scattering properties were measured on winter jujubes using a single integrating sphere detection system in the band range of 900~1650 nm combined with inverse adding-doubling (IAD) algorithm in this study. The characteristic wavelengths were obtained depending on the correlation analysis between optical properties absorption and physicochemical indicators. Finally, the effectiveness of characteristic wavelengths was verified using near-infrared spectroscopy. The results indicated that a* and weight loss increased with storage time, while L*, soluble solids content and chlorophyll showed a consistent decrease. Both the absorption coefficient (μa) and the reduced scattering coefficient (μs') of the winter jujubes showed a significant downward trend with the development of black spot disease. The μa and μs' curves were highly correlated with disease extent (spot area) and some quality indicators (weight loss, L*, a*, soluble solids content and chlorophyll) in the 1400~1650 and 900~1360 nm, respectively. The discriminant models built based on the 10 characteristic variables selected by optical properties performed best compared with the models based on full wavelengths and algorithm-based characteristic wavelengths, with an overall accuracy of 92.53% and 92.35% for the calibration and prediction set, respectively. This study demonstrated the potential of the short- and mid-wave infrared optical signal in the disease detection on winter jujubes and the effectiveness of characteristic wavelengths on the basis of optical properties.
Comprehensive Quality Evaluation of Roasted Kernels in Macadamia Nuts Based on Principal Component Analysis and Cluster Analysis
QIN Liyue, SHI Pingping, LI Ronghui, MA Feifei, HU Xin, HE Daiqin, SHEN Hui, SU Huosheng
2023, 44(18): 331-341.   doi: 10.13386/j.issn1002-0306.2022100124
Abstract(26) HTML(9) PDF(7)
To explore the quality evaluation indicators of roasted macadamia nut kernels and establish a quality evaluation system, 21 samples of macadamia nuts roasted by different temperature and time duration were selected to determine with 16 quality indicators which included in browning index, moisture, total phenolic content, ABTS+ free radical scavenging activity ratio, acid value, peroxide value, hardness, fracture force, shear force and 7 sensory evaluations. These 16 indicators were comprehensively explored by correlation analysis, principal component analysis and cluster analysis to screen the critical indicators of quality evaluation for roasted kernels in macadamia nuts. As indicated by the research findings, with the augment of roasting temperature and time duration, the indicators including moisture, hardness, fracture force, shear force and sensory evaluation of hardness exhibited downturn trends, but the browning index, acid value, peroxide value, and the sensory evaluation of color, aroma, sweetness, bitterness, crispness, overall preference took on an overall upward trend. Aside from that, the total phenolic content and ABTS+ free radical scavenging activity ratio displayed changing trends of initial augment and subsequent reduction. As demonstrated by the results of correlation analysis on 16 indicators, 11 pairs of indicators had remarkable correlation (P<0.05) and 66 pairs of indicators had extremely noticeable correlation (P<0.01). There was a striking positive correlation between browning index and color, aroma, crispness, bitterness in sensory evaluation and a marked positive correlation between moisture and hardness, fracture force, shear force. What’s more, overall preference was positively associated with browning index, total phenolic content and ABTS+ free radical scavenging ratio, and was negatively linked to hardness, fracture force and shearing force. Furthermore, overall preference was also positively associated with color, aroma, sweetness and crispness in sensory evaluation. The roasted kernels with 130 ℃/30 min obtained the highest comprehensive score in principal component analysis, which indicating the best comprehensive quality in all samples. Meanwhile, by combining with cluster analysis, moisture, browning index, hardness, ABTS+ free radical scavenging activity ratio, acid value and peroxide value were determined as the critical indicators to evaluate the quality of roasted kernels in macadamia nuts. The research findings in this paper would provide a certain theoretical basis and scientific reference for the quality evaluation and processing of roasted kernels in macadamia nuts.
Extraction of Volatile Compounds and Analysis of Aroma Characteristics in Fenggang Zinc-Selenium Tea
HE Ting, WU Qimei, XIANG Liping, FENG Hua
2023, 44(18): 342-351.   doi: 10.13386/j.issn1002-0306.2022100238
Abstract(24) HTML(9) PDF(4)
In order to explore the variation of volatile components of Fenggang zinc-selenium tea during the production process. The combination of headspace solid phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) was applied to detecte volatile components of Fenggang zinc-selenium tea during the production process, and optimize the extracting conditions. Principal component analysis and orthogonal partial least squares discriminant analysis were used to determine, distinguish and screen the volatile components of Fenggang zinc-selenium tea during the production process. The results showed that the best extraction process was as follows: Ratio of raw material to water was 1:6 (g/mL), extraction fiber 50/30 μm CAR/DVB/PDMS, extraction temperature at 90 ℃, extraction time for 70 min. A total of 91 volatile substances were identified by GC-MS that there were 37 kinds of common characteristic volatile components in the Fenggang zinc-selenium tea during the production process. Alcohols, ketones, esters and aldehydes were the main volatile components constituting the aroma of Fenggang zinc-selenium tea, among which alcohols were the most abundant and the highest content. Fenggang zinc-selenium tea could be divided into one category before processing and one category after processing by principal component analysis, and orthogonal partial least squares discriminant analysis showed that 15 volatile components contributed significantly to the odor of Fenggang zinc-selenium tea. Jasmonone, (S)-oxidized linalool, α-ionone, methyl salicylate, methyl heptenone, (E)-oxidized linalool, cedarol, β-cyclic citral, 2-pyrrol 6-trimethyl-6-vinyl tetrahydro-2H-furan-3-ol and methyl acetylsalicylate played an important role in the characteristic aroma quality of Fenggang zinc-selenium tea. This study can provide a theoretical basis for the production, processing, quality control of Fenggang zinc-selenium tea.
Analysis of Nutritional and Flavor Components of Ten Strains of Pleurotus pulmonarius
WANG Xiangfeng, ZHAO Wei, WANG Qiao, WANG Li
2023, 44(18): 352-360.   doi: 10.13386/j.issn1002-0306.2022100240
Abstract(38) HTML(10) PDF(2)
In this study, the nutritional and flavor components of the fruit bodies of 10 Pleurotus pulmonarius strains were analyzed and the results would provide a certain theoretical basis for the development, utilization and deep processing of Pleurotus pulmonarius. The apple sawdust and corn cob were used as substrates for cultivation of 10 strains of Pleurotus pulmonarius (5 strains collected in the field and 5 commercial cultivation strains), and the crude protein, total sugar, hydrolyzed amino acids, mineral elements, γ-aminobutyric acid and other nutrients as well as free amino acids and 5'-nucleotides and other flavor substances of their fruit bodies were determined. And then the protein nutrition were evaluated by comparative analysis of the amino acid score (AAS), chemical score (CS), amino acid ratio coefficient (RC), essential amino acid index (EAAI) and score ratio coefficient amino acid (SRCAA). The results showed that the crude protein in the fruit bodies of the 10 tested Pleurotus pulmonarius strains was between 30.00 and 36.07 g/100 g. The total sugar content was between 31.10% and 47.63%. The γ-aminobutyric acid content was between 249.64 and 485.34 mg/kg. The minerals were rich. And the essential amino acids were rich and balance, especially rich in lysine. The nutritional value of Pleurotus pulmonarius was closed to the nutritional level required by the human body, suggesting it was a good protein source and the nutritional value of the commercial strains were significant super to the wild ones. Comprehensive comparison of 10 test strains found that the index differences among 5 commercial cultivated strains were small and the quality was generally high, among which PL9 showed the best performance, and its protein nutritional value and EUC value were significantly higher than those of the other 4 strains. The difference among the 5 wild strains was significant, and some strains showed a high content of a single nutrient.
Identification of Malus toringoides (Rehd.) Hughes Teas with Different Processes Based on E-nose and GC-MS
YI Yuwen, HE Lian, DENG Jing, HU Jinxiang, PENG Yiqin, QIAO Mingfeng, CAI Xuemei, ZHU Kaixian, WU Huachang, LEI Min
2023, 44(18): 361-370.   doi: 10.13386/j.issn1002-0306.2022100266
Abstract(29) HTML(15) PDF(6)
The volatile substances among Malus toringoides (Rehd.) Hughes black tea, green tea and Kang brick tea were detected by electronic nose (E-nose), trap head space-gas chromatography-mass spectrometry (HS Trap GC-MS) and the differences of the volatile substances were analyzed by orthogonal partial least squares discriminant analysis (OPLS-DA), relative odor activity value (ROAV) and differential thermography in order to explore the odor differences of Malus toringoides (Rehd.) Hughes teas with three different processes. Result showed that E-nose could effectively distinguish three kinds of Malus toringoides (Rehd.) Hughes teas, and the prediction ability of the model established by E-nose combined with OPLS-DA was 95.70%. GC-MS analysis showed that aldehydes, esters and hydrocarbons were the main volatile substances, while alcohols were the main common volatile substances of black tea and green tea. The differences in the contents of aldehydes, esters, hydrocarbons and alcohols account for the variations in the aroma of Malus toringoides (Rehd.) Hughes teas produced by different processes. ROAV value combined with aroma type analysis showed that the volatile components of fruit aroma had a relatively large contribution to the formation of the odor of Malus toringoides (Rehd.). Isovaleraldehyde might be the key aroma substance to Malus toringoides (Rehd.) Hughes teas. Differential thermogram analysis showed that trimethoxyester, isovaleraldehyde and 2-ethylfuran were the main common volatile substances in Malus toringoides (Rehd.) Hughes teas.
Rapid Detection of Three Foodborne Pathogenic Bacteria in School Catering by Isothermal Multiple Self-matching-initiated Amplification Technique
JIAO Qiang, CHEN Wansheng, ZHOU Nan, ZHANG Qingfa, LIU Zhiyong
2023, 44(18): 371-377.   doi: 10.13386/j.issn1002-0306.2022110196
Abstract(31) HTML(13) PDF(3)
Objective: In this paper, a detection method suitable for rapid identification of three pathogenic bacteria from food in the school catering was studied. Method: Based on isothermal multiple self-matching-initiated amplification technology (IMSA), strain-specific primers were designed for Salmonella invA gene, Escherichia coli O157:H7/NM rfbE gene and Listeria monocytogenes prfA gene to test the sensitivity, specificity, shortest enrichment time, and minimum detection limit of bacterial content. Food microbiology inspection according to National Food Safety Standards (GB/T 4789.4-2016, GB/T 4789.30-2016, GB/T 4789.36-2016) were the reference methods, and compared the consistency of the two methods. Result: The results showed that the sensitivity of our method to Salmonella, Escherichia coli O157:H7/NM and Listeria monocytogenes were 2.14×103, 2.79×103 and 3.62×103 CFU/mL respectively, the specificity was 100%, the shortest enrichment time of artificial contamination were 6, 8 and 8 hours respectively. The detection limits of the lowest bacteria content were 2.14, 2.79 and 3.62 CFU/25 g respectively, and the consistency of the results of 74 food samples using IMSA method and the reference method was 100%. Conclusion: IMSA technology of pathogenic bacteria detection in food had the advantage of having high sensitivity, strong specificity and accurate results, which could complete the detection of three pathogenic bacteria in food in a short time and was suitable for the rapid identification of pathogenic bacteria in school catering.
Study on Aroma Components in Different Types of Dark Tea Based on HS-SPME-GC-MS
DENG Jiantianye, YAN Meihong, SHANG Bohao, LI Yilong, XIAO Tian, ZHU Mingzhi, WANG Kunbo
2023, 44(18): 378-386.   doi: 10.13386/j.issn1002-0306.2022110337
Abstract(64) HTML(17) PDF(10)
Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and sensory evaluation were used to investigate the aroma characteristics of different dark tea products (Fu brick tea, Dark brick tea, Tibetan tea, Liupao tea, and Tianjian dark tea). Sensory evaluation results showed that the aroma characteristics of the five dark tea samples differed remarkably. Fungal and stale aromas were the major aroma profiles of Fu brick tea. Results showed that, Liupao tea had obvious persistent areca-like and stale aromas, Tibetan tea had a persistent stale aroma, and Dark brick tea exhibited a pure aroma feature. Furthermore, Tianjian dark tea showed a persistent smoked aroma. The following rank order of the score of the sensory evaluation in the five dark teas was observed: Tibetan tea (91.35) > Fu brick tea (90.15) > Dark brick tea (89.05) > Liupao tea (88.85) > Tianjian dark tea (86.33). A total of 56 volatile compounds were identified in the five dark teas. The composition and content of aroma components varied significantly among the different dark teas. Contents of the volatile compounds in the five dark teas with the following rank order: Fu brick tea (6355.30 μg/L) > Tibetan tea (5858.73 μg/L) > Dark brick tea (5789.71 μg/L) > Tianjian dark tea (4801.37 μg/L) > Liupao tea (3740.14 μg/L). Multivariate statistical analysis and odor activity values analyses showed that 1,2,3-trimethoxybenzene was the characteristic volatile component of the stale aroma of Tibetan tea. (E,E)-2, 4-decadienal, (E,E)-2, 4-nonadienal, citral I, citral II, hexanal, and methyl salicylate contributed to the fungal aroma of Fu brick tea, while 1,2,3-trimethoxybenzene was the key contributor to the stale aroma of Fu brick tea. In Liupao tea, (+)-cedrol was a major contributor to the areca-like aroma. (E,E)-2, 4-decadienal, (E,E)-2, 4-nonadienal, hexanal, and phytol were the main contributors to the pine-smoked aroma of Tianjian dark tea. The pure aroma of Dark brick tea was formed by the comprehensive action of many volatile components, including benzene ethanol, neroltertiary alcohol II, and oxidized linalool I. This study would provide a statistical basis for exploring the aroma quality of different types of dark teas.
Storage and Preservation
Effects of Different Storage Periods on the Shelf-life Quality of Fresh-cut Vegetable Yam and Iron Stick Yam
TIAN Tian, ZHAO Yaqi, WANG Qing, QIN Zhanjun, PAN Yuan, SHI Wenlin, ZUO Jinhua, YUAN Shuzhi, YUE Xiaozhen, FENG Bihong
2023, 44(18): 387-397.   doi: 10.13386/j.issn1002-0306.2022110189
Abstract(41) HTML(26) PDF(16)
In this study, the effects of storage at 4 ℃ for 0, 30 and 60 d on the phenolic content and browning key enzyme activities of fresh-cut yam during shelf life were investigated using 'Changshan fine hair yam' vegetable yam and 'Henan Wenxian' iron stick yam as test materials. The results showed that the browning index of both fresh-cut yams increased with the extension of shelf life, but with the extension of storage period, the browning index of vegetable yam was lower, while the browning index of iron stick yam was higher. At the 8th day of shelf period, the browning index of fresh-cut vegetable yam stored for 30 d was only 4.6% lower than that stored for 60 days, with no significant difference, while the browning index of fresh-cut iron stick yam for the same period was 8.4% lower than that stored for 60 days, and the difference was significant (P<0.05). Increase in respiration rate, ethylene release, lignin content, phenolics, chlorogenic acid, and browning key enzyme activities during the shelf life of fresh-cut iron stick yam as storage period and shelf life increased. However, the respiration rate and lignin content of fresh-cut yam decreased with the prolongation of storage period, the browning key enzyme activity showed a rising and then decreasing trend with the prolongation of storage period, and the phenolic substances increased in the late shelf stage, and other indicators were more consistent with the change pattern of iron stick yam. Further correlation analysis showed that the phenolic substances and enzyme activities in iron stick yam varied more with the storage time and were positively correlated with the browning index, while the browning index of vegetable yam varied with the storage time and was only positively correlated with the enzyme activity. In conclusion, vegetable yam was more suitable for fresh-cut processing, and the shelf-life of fresh-cut products can reach 8 days after 60 days of storage, while the shelf-life of fresh-cut product of iron stick yam was only 4 days after 60 d of storage.
Effect of Antimicrobial Peptide from Marine Microorganism on the Storage Quality of Freshly Squeezed Cucumber Juice
YAN Luqi, TAN Minghui, LI Kuntai
2023, 44(18): 398-406.   doi: 10.13386/j.issn1002-0306.2023020105
Abstract(28) HTML(5) PDF(4)
To investigate the effects of different concentrations of antimicrobial peptide from marine Bacillus subtilis on the quality changes of freshly squeezed cucumber juice during the storage period (5 d) at room temperature. Sensory evaluation, physicochemical analysis (pH, stability coefficient, total sugar content, total bacteria count), and electronic nose technique (principal component analysis, radar plot, corresponding values of primary flavor components sensors) were used to comprehensively evaluate the effect of freshness preservation. The results showed that the concentration of antimicrobial peptide was positively correlated with various physicochemical indexes. And 2×MIC concentration of antimicrobial peptide had the best effect, with the highest sensory score (7.03), pH (4.97), stability factor (32.86%), total sugar content (5.11 mg/mL), and the best antibacterial effect (0.88 log CFU/mL). Principal component analysis (PCA) showed that the flavor characteristics of cucumber juice in each antimicrobial peptide treatment group were similar, while the flavor characteristics of cucumber juice in the control group and the potassium sorbate treatment group were similar. The radar plot revealed that the flavor components of cucumber juice in each antimicrobial peptide treatment group increased at the later stage of storage (5th d), while the flavor components of cucumber juice in the control and potassium sorbate treatment groups remained unchanged basically during the storage period. The analysis of the response values of the flavor component sensors showed that the antibacterial peptide from Bacillus subtilis BBW1542 had a certain impact on the volatile flavor compounds in freshly squeezed cucumber juice. In conclusion, the preservation effect of antimicrobial peptide from B. subtilis BBW1542 was significantly better than that of the chemical preservative group (P<0.05). This study would provide a theoretical basis for the quality assurance of freshly squeezed cucumber juice in short-term storage and the development of marine microbial freshness preservatives.
Preparation of Bleached Shellac/Sodium Alginate Composite Film and Its Application in Chilled Fresh Meat Preservation
YANG Jieru, LIU Haibo, ZHANG Wenwen, XING Shujie, ZHANG Jiayan, ZHANG Hong, ZHU Jing, LI Kun
2023, 44(18): 407-414.   doi: 10.13386/j.issn1002-0306.2023030313
Abstract(38) HTML(17) PDF(5)
In order to prepare a composite film with good mechanical properties and preservation properties, different bleached shellac/sodium alginate composite films were prepared by taking 1.5% sodium alginate as the base film solution, adding different concentrations of bleached shellac particle emulsion, and loading antioxidant tocopherol. Then the mechanical properties and permeability were compared, and the structure was characterized through FTIR spectroscopy analysis and SEM testing. The differences in preservation effects on cold fresh meat were also compared. The results showed that the composite film with 5% bleached shellac content had better properties, including mechanical properties, 37.37% reduction in transmittance and 43.00% increase in utraviolet ray barrier compared with PE film, and better CO2/O2 selectivity. And the microstructure characterization of the composite films were mutually confirmed with their performance. Using this film to pack chilled pork for preservation can effectively reduce the TVB-N content, drip loss, pH value and metmyoglobin content, and increase the shelf life to 9 days. This work has certain reference significance for the development of edible film and benefits for slowing down the spoilage of chilled pork during storage, protecting the color and taste of pork, and enhancing its nutritional value.
Nutrition and Healthcare
Effects of Tetrastigma hemsleyanum Superfine Powder on Intestinal Microflora in Rats with Alcohol-Induced Liver Injury
CHENG Xiaoyang, LIAO Ming, HE Quanguang, MO Caifeng, HUANG Maokang, HUANG Meihua
2023, 44(18): 415-424.   doi: 10.13386/j.issn1002-0306.2022090022
Abstract(33) HTML(21) PDF(1)
Objective: To investigate and reveal protective mechanism which the Tetrastigma hemsleyanum (SYQ) ultramicro powder alleviate alcohol-induced liver injury, and to provide a new research idea for clinical treatment of alcohol-induced liver injury. Methods: The rat model of alcoholic liver injury was established by continuous administration of alcohol for 8 weeks. At the same time, rats were given different doses SYQ ultramicro powder by intragastric to observe its protective effect on liver injury. Changes of ALT, AST, ALP and GSH, SOD, MDA were detected in serum and liver tissue, respectively. Pathological sections of liver tissue were used to observe the damage. Genomic DNA was extracted from feces and analyzed by 16S rDNA full-length sequencing. Results: Compared with the model group, medium and high doses of SYQ (0.5 and 1.0 g·kg−1) significantly (P<0.05) reduced the levels of ALT, AST ALP and MDA, increased the activities of SOD and GSH, and alleviated the liver lesions in rats. The pathological sections revealed that SYQ ultramicro powder dramatically alleviated liver cells swelling and steatosis, and these effectiveness were similar to the group of bifendate. Intestinal microflora analysis showed that the intestinal microflora structure significantly changed in rats with alcoholic liver injury. Compared with the model group, both SYQ and bifendate intervention improved the intestinal flora to a certain extent at phylum, genus and species level. SYQ effectively recovered the abundance of Prevotella, Lactobacillus_johnsonii, Raoultibacter_massiliensis altered by alcohol, and the effect of medium doses of SYQ was better than positive control group (P<0.05). Conclusion: The SYQ superfine powder had a significant protective effect on alcoholic-induced liver injury in rats, the mechanism may be related to its antioxidant stress and intestinal flora regulation.
Study on the Physicochemical Properties of Polysaccharide from Polygonatum sibiricum and Its Protective Effect on D-Galactose-Induced Oxidative Damage in Mice
LIU Wang, BAI Jinbo, ZHANG Wangjuan, LIU Chunyang, LI Muzi, ZHANG Jinhe, XU Guobing, XIE Songzi
2023, 44(18): 425-433.   doi: 10.13386/j.issn1002-0306.2022100250
Abstract(36) HTML(18) PDF(9)
In this study, a homogeneous polysaccharide fraction was extracted and purified from the rhizome of Polygonatum sibiricum, its physicochemical properties and protective effect against oxidative damage were analyzed, and its potential protective mechanism was initially explored. The homogeneous polysaccharide (PSP) was obtained by water extraction, alcohol precipitation, and separation on DEAE-52 cellulose and Sephadex G-100 columns. The phenol sulfate method, m-hydroxybiphenyl method, high performance gel permeation chromatography and Fourier infrared spectroscopy were used to analyze the physicochemical properties of PSP. The in vivo antioxidant effects of PSP were investigated in a mouse model of D-galactose induced oxidative damage. The results showed that the carbohydrate content of PSP was 94.42%±14.73% and its molecular weight was 5566.41 Da. PSP was also found to contain β-type furan or pyran fructose, as well as longer branched chains with more branches. Compared with the model group, the levels of SOD, GSH-Px and T-AOC significantly increased (P<0.05), and MDA levels significantly decreased (P<0.05) in serum, brain tissue and liver tissue of the PSP high dose groups, HE staining revealed that liver damage was significantly ameliorated and the expression of Nrf2 and HO-1 protein in the liver was significantly enhanced in the PSP-treated group (P<0.05). It could be concluded that PSP had a protective effect on oxidative damage in mice, and its protective mechanism might be related to the Nrf2/HO-1 signaling pathway.
Analysis on Food Patent Pattern of Amomum tsaoko Based on Baiten Patent Database
CHEN Zhenxia, WU Lianzhang, LI Yan, HU Xuan, YOU Shengjun, YU Shaohong, YUAN Chao, YANG Shaobing, YANG Yi, YU Fulai
2023, 44(18): 434-440.   doi: 10.13386/j.issn1002-0306.2022110164
Abstract(33) HTML(15) PDF(0)
The applied patents related to Amomum tsaoko food were searched through the Baiten database to understand the layout and development trends of the patents related to Amomum tsaoko food. And the patent analysis method was used to statistically analyze the whole profile of the patents, trends in applications and authorization, territory of applications, applicants, legal status and events, patent value and layout of technical applications. A total of 3225 invention patents of Amomum tsaoko food were searched, including 641 authorized patents and 281 valid patents, which were distributed in Anhui, Jiangsu and Sichuan, etc. The results showed that the research and development of Amomum tsaoko food field began to enter a mature and stable period in 2019, and the authorized patents began to decline from 2015. The majority of patent applicants were enterprises, but the patent invalidation rate was high. There was a lack of patents with technical content, and the market conversion rate of patent economy was low. From the perspective of technical layout, the current active technology of Amomum tsaoko food patent applied to meat products, condiments, bean products, aquatic products and vegetable products, the innovation of health food and its extracts was slightly weak. In terms of health food, Amomum tsaoko had high recognition and attention for its health care efficacy in enhancing immunity, strengthening spleen and appetizing, and lowering blood pressure. The distribution pattern of patents related to Amomum tsaoko food was comprehensively analyzed in this paper, providing reference for the subsequent research and development of Amomum tsaoko food, and helping the upgrading of Amomum tsaoko industry.
Analysis of Nutritional Components and Volatile Flavor Compounds in Common Edible Fungi
LI Na, LÜ Shuang, DONG Jianguo, LI Hongbo, ZHANG Ying, XU Dan, WU Yue, MO Haizhen
2023, 44(18): 441-448.   doi: 10.13386/j.issn1002-0306.2022110173
Abstract(52) HTML(22) PDF(16)
Edible fungi were rich in nutrients and were potential sources of high-quality protein. In this study, nutritional components such as moisture, ash, protein, total sugar and L-ergothione in 18 kinds of edible fungi were analyzed, and headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the fruit-body, mycelium and fermentation broth of 6 edible fungi (Lentinula edodes, Agaricus bisporus, Coprinus comatus, Pleurotus eryngii, Auricularia heimuer and Ganoderma lucidum). The results showed that the water content of 18 edible fungi ranged from 6.7 to 13.77 g/100 g, ash content from 2.24 to 10.9 g/100 g, fat content from 0.3 to 2.92 g/100 g and total sugar content from 2.11 to 10.5 g/100 g. The crude protein content of 18 edible fungi ranged from 7.88 to 35.87 g/100 g, among which the protein content of Agaricus bisporus was as high as 35.87 g/100 g. There was no significant difference in the content of other nutrients. The amino acids were rich and contained 8 kinds of essential amino acids necessary for human body. Principal component analysis showed that the amino acid composition ratio of Lentinula edodes, Auricularia heimuer, Grifola frondosa, Volvariella volvacea, and Flammulina velutipes was most similar to that of egg, but significantly different from that of meat, soybeans and wheat. The results of high performance liquid chromatography showed that Lentinula edodes was rich in ergothioneine, and the content was up to 336 mg/kg. The ergothioneine content of edible fungi such as Grifola frondosa, Morchella, Agaricus bisporus and Coprinus comatus were also higher than 100 mg/kg. A total of 34 volatile compounds, including aldehydes, ketones, esters, alcohols, phenols, ethers, alkanes and heterocyclic compounds, were identified by HS-SPME-GC-MS in 6 edible fungi. Ganoderma lucidum mycelium was rich in hexal, methylnonylketone, trans-2-octenal, 2-n-amylfuran, 2,4-nononadienal and other volatile compounds, which were significantly different from the other 17 samples. The flavor substances of the fermentation broth of the six edible fungi were similar, and all of them had special flavor substances such as ethyl heptanate and 18-crown-6. Pleurotus eryngii mycelium and the fruiting bodies of Ganoderma lucidum and Coprinus comatus contained butylated hydroxytoluene, methyl benzoate and other unique substances. This study provides data basis for the development of high value edible fungi by analyzing the nutritional components and flavor substances of common edible fungi.
Effect of Polygonatum sibiricum Extract in Improving the Organ Function of D-Galactose-induced Aging Mice and Its Mechanism
XIE Xiaofen, HU Guangxian, PAN Lu, WU Xuxian, ZHOU Dan, CHEN Jiuqiong, KUANG Menglan, YE Lan, QIN Zhen, XU Jianwei
2023, 44(18): 449-457.   doi: 10.13386/j.issn1002-0306.2022110220
Abstract(33) HTML(21) PDF(11)
Objective: The purpose of this study was to explore the protective effects of Polygonatum sibiricum extract (PSE) on the important organs of D-galactose (D-gal)-induced aging mice and its potential molecular mechanisms. Methods: The mice were randomly divided into five groups (n=10): control group, D-gal (500 mg/kg) group, low-PSE dose (0.5 g/kg) group, medium-PSE dose (1 g/kg) group, and high-PSE dose (2 g/kg) group. The organ indices (thymus, spleen, liver, and kidney) were detected. The levels of creatine kinase (CK), creatine kinase isoenzyme (CK-MB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), uric acid (UA), urea (UREA), creatinine (CREA), urea–creatinine ratio (BUN/Scr), and glomerular filtration rate (eGFR) in serum were measured. Pathological changes in the skin, liver, kidney, heart, brain, and lung of mice in different groups were analyzed by HE and Masson staining. The expressions of p53, p16, p21, RB, HO-1, Nrf2, and Keap1 mRNA in the liver, kidney, heart, and brain of each group of mice were detected by real-time PCR. Results: The thymus, spleen, liver, and kidney indices were increased in each PSE treatment group compared with those in the D-gal group (P<0.05). Moreover, in each treatment group, PSE decreased (P<0.05) the levels of CK, CK-MB, ALT, AST, ALP, UA, UREA, CREA, and BUN/Scr in mouse serum and increased the level of eGFR (P<0.05). HE and Masson staining showed that PSE could reduce the pathological damage caused by D-gal to the vital organs of mice. Compared with the blank group, the model group presented increased expression levels of p53, p16, p21, RB, and Keap1 mRNA in the liver, kidney, heart, and brain (P<0.05) and decreased HO-1 and Nrf2 mRNA (P<0.05). Compared with the D-gal group, mice in each PSE treatment group exhibited decreased mRNA levels of p53, p16, p21, RB, and Keap1 in the liver, kidney, heart, and brain tissues (P<0.05) and increased mRNA levels of HO-1 and Nrf2 (P<0.05). Conclusion: PSE has anti-aging effects, and its mechanism may be related to its inhibition of the p53/p21, p16-RB, and Keap1/Nrf2/HO-1 pathways.
Research Progress on Preparation of Marine Oligosaccharides by Enzymatic Method
YANG Zixiang, LI Jinmeng, SONG Kunyan, GE Fengru, YAN Feng, HUANG Bingbing, ZHANG Mengyan, WU Xiaodan, LIU Yuhuan, ZHENG Hongli
2023, 44(18): 458-467.   doi: 10.13386/j.issn1002-0306.2022100075
Abstract(32) HTML(10) PDF(4)
Marine oligosaccharides, which are prepared by degradation of marine polysaccharides, are carbohydrate compounds composed of two to ten monosaccharide residues. Compared with marine polysaccharides, marine oligosaccharides have several advantages, such as higher water solubility, stronger biological activity, and easier absorption by the body. Marine oligosaccharides have a series of physiological activities, such as anti-tumor, antioxidation, lowering cholesterol, and immunomodulation. They can be widely used in food, medicine, and other fields. This paper summaries marine polysaccharides, preparation of marine oligosaccharides from marine polysaccharides by enzymatic methods, and the catalytic mechanism of the enzymes. Furthermore, three major marine polysaccharides (alginate, chitosan, and xanthan) and the catalytic mechanism of the three enzymes (β-elimination mechanism of alginate lyase, replacement mechanism of chitosanase, and degradation mechanism of xanthan enzyme) are introduced. It is expected to provide a theoretical reference for preparation and application of marine oligosaccharides, deficiencies and potential for future research of preparation of marine oligosaccharides from marine polysaccharides by enzymatic methods are discussed.
Antimicrobial Effect of Plant Essential Oil Nanoemulsion Against Meat Spoilage Bacteria and Pathogenic Bacteria: A Review
GUO Wei, LIU Miaomiao, PAN Yue, FENG Mingxing, YAO Xianqi, ZHANG Huan, HUANG Junrong, CAO Yungang
2023, 44(18): 468-475.   doi: 10.13386/j.issn1002-0306.2022110175
Abstract(49) HTML(17) PDF(13)
Plant essential oil is a class of natural bacteriostatic agents that could effectively inhibit numerous meat spoilage and pathogenic bacteria, which has broad application prospects in the meat industry. As a nanoscale embedding system, nanoemulsion is efficient in improving the water solubility, stability and antibacterial activity of essential oil, and has become a research hotspot in the field of meat preservation. In this review, the construction methods (emulsification methods and emulsifiers), basic characteristics (stability and bioavailability) of plant essential oil nanoemulsion are introduced. The antibacterial activity and influencing factors (essential oil types, emulsification methods, emulsifiers, emulsion particle size and microbial species) of plant essential oil nanoemulsion were discussed. And the internal mechanism of plant essential oil nanoemulsion improving the antibacterial activity of pure essential oils through targeted binding, sustained release, and passive transportation were explored. The review may provide a theoretical reference for the further research, development and utilization of plant essential oil nanoemulsions in meat preservation field.
Research Progress on the Effect of Muscle Protein Degradation on the Quality of Fermented Meat Products
ZHENG Yun, ZHENG Shuang, ZHOU Tianshuo, BAO Wei, HAN Qi, LI Yanqing
2023, 44(18): 476-483.   doi: 10.13386/j.issn1002-0306.2022110202
Abstract(38) HTML(21) PDF(2)
The long-standing fermented meat products were deeply popular with consumers due to the distinctive flavor and long storage life. From the point of protein degradation in the process of fermentation of meat products and based on the recent researches of fermented meat products, this paper discusses the factors affecting the muscle protein degradation including the function of microbial proteases and endogenous enzymes, and the protein hydrolysis activity of core microorganism. The structure changes of muscle protein during fermentation are analyzed, including secondary and tertiary structure and functional properties of protein. This paper furthermore summarizes how the muscle protein degradation during fermentation improving the texture properties and flavor of the fermented meat products, and deterioration of products due to excessive protein degradation. Finally, the perspectives of the future researches are listed in order to provide some meaningful ideas for the intensive study of the fermentation control of meat products.
Application of Droplet Microfluidic Technology Combined with Nucleic Acid Amplification in the Detection of Foodborne Pathogens
ZHANG Mengyu, PENG Jiayi, WEI Jinyuan, YANG Jingxian, ZHONG Qingping
2023, 44(18): 484-491.   doi: 10.13386/j.issn1002-0306.2022110323
Abstract(58) HTML(28) PDF(12)
Foodborne pathogen is an important factor affecting food safety. With the biotechnology development and the improved requirements for food safety, the detection methods of foodborne pathogens are constantly updated and improved. By microfluidic technology, the processes of sample pretreatment, separation and detection are integrated on a tiny chip, and a variety of functions are completed. As an important branch, droplet microfluidic technology can be used for high-throughput detection with the dispersed microdroplets formed by two insoluble liquids. In this paper, according to the different ways of nucleic acid amplification, the characteristics of droplet microfluidic-digital polymerase chain reaction, droplet microfluidic-digital loop-mediated isothermal amplification, and droplet microfluidic-digital recombinase polymerase amplification are compared and summarized. The applications of these methods in the detections of foodborne pathogens are also presented. In addition, the future developments of these technologies are prospected. The intelligent, continuous, precise and miniaturized rapid detections of foodborne pathogens are realized by droplet microfluidic technology combined with digital nucleic acid amplification. This paper would provide references for the development of the technology in the field of rapid detection of foodborne pathogens.
Advances in Immunomodulatory Peptides of Animal Protein Origin
LIANG Yongyi, WANG Hong, BAI Weidong, XIAO Gengsheng, ZENG Xiaofang
2023, 44(18): 492-501.   doi: 10.13386/j.issn1002-0306.2022120041
Abstract(54) HTML(8) PDF(11)
Animals have long been a rich and invaluable source of bioactive peptides, of which animal protein-derived immunomodulatory peptides have the advantages of high safety, low allergenicity and low cost, and play an irreplaceable role in human health and disease prevention. The immunomodulatory activities of peptides are related to amino acid composition, sequence and peptide chain length. In recent years, many new advances have been made around the study of immunomodulatory components and bioactivities related to animal protein sources, but few teams have introduced and summarized the immunomodulatory peptides in detail. In this review, the structure-effect relationships and mechanism of action of animal protein-derived immunomodulatory peptides in recent years are reviewed, the characteristics of immunomodulatory peptides from different animal protein sources are summarized, and the future research and development trend of animal protein-derived immunomodulatory peptides are prospected, which might contribute to further research and development of animal protein-derived immunomodulatory peptides.
Progress in Carbohydrate Quality Indicators and Factors Influencing Glycemic Index
XU Yao, LIU Xiaofeng, YANG Yuexin, ZHU Jing
2023, 44(18): 502-509.   doi: 10.13386/j.issn1002-0306.2023050117
Abstract(21) HTML(7) PDF(5)
Carbohydrates play a crucial role in the development of chronic diseases, and although research in this area is expanding, the precise definition of carbohydrate quality remains unclear. Currently, commonly utilized indicators encompass dietary fiber content, whole grain intake, free sugars intake and the glycemic index (GI). High-quality carbohydrate foods typically exhibit high dietary fiber content, consist of whole grain components, contain low levels of free sugars, and possess a low GI. The GI, in particular, directly influences the human blood sugar response and serves as a vital measure for describing carbohydrate quality. This article provides a comprehensive overview of the factors that influence the GI, focusing on three aspects: digestion and absorption, processing methods, and starch composition and structure. It further examines the GI values of various food sources. The rate of digestion and absorption, as well as diverse processing methods, can influence the GI. Additionally, the composition and structure of starch directly affect the GI. Amylose and amylopectin exhibit dissimilar structural compositions, with amylopectin containing more amylase binding sites than amylose, leading to a higher digestion rate. Consequently, foods with elevated amylose content tend to have relatively low GI values. Additionally, starch can be categorized into three types (A-type, B-type, and C-type) based on the crystal form of amylopectin present in the starch. Among these types, A-type starch is the most readily digestible, while B-type and C-type starch exhibit low GI characteristics due to their reduced digestibility. By studying the microstructure of starch, researchers can gain valuable insights into the influencing factors of the GI, thereby introducing a fresh perspective to the assessment of food carbohydrate quality.