Abstract:This article reviews the development journey of intelligent grain processing equipment and introduces the specific application practice of intelligence in grain processing equipment. The intelligent development of grain processing has gone through four important stages: Connect， monitor， assist， and self-optimize. Each stage marks a significant advancement in technology and a profound impact on applications. In the connect stage， the automation of the equipment in the factory and the collection of production data were achieved， which initially improved the production efficiency and management transparency. In the monitor stage， data-driven optimization and optimization suggestions are generated through the data in-depth analysis in the production process， which help to better improve production efficiency and product quality. In the assist stage， based on data analysis and decision-making， it guides the automatic adjustment of equipment， achieve the closed-loop control for important functions， which reduces manual intervention， significantly improves production efficiency and ensures product quality. In the self-optimize stage， AI technology and machine learning algorithms are integrated to achieve the decision-making and optimal control of the equipment automatically， which reflect the intelligence is truly reached. At present， there are good practices in the first three stages of intelligent development of grain processing， such as automatic continuous ship unloader and intelligent grinding system in the data connection stage. Production monitoring stage of the error and downtime analysis system， temperature and vibration management system， etc. The color loop control and bran starch loop control in the data feedback adjustment stage have brought great influence in the industry. In the future， with the continuous innovation of grain processing equipment technology， AI， big data， IoT and other technologies will continue to develop and practice and grain processing intelligence will usher in a broader development prospect.

Abstract:In the context of the globalization of food manufacturing and supply， establishing and practicing the big food concept， constructing diversified food supply and efficient comprehensive utilization system is the basic guarantee of stable and safe food supplying. Storage and packaging technology and equipment play an important role in improving food quality and efficiency. Emerging technologies such as intelligent perception， wireless positioning and remote control promote the upgrading of food storage， artificial intelligence， nanomaterials and biotechnology promote the intelligent green of food packaging， and support the high-quality development of food manufacturing combined with high-end equipment of food storage and packaging intelligence. This paper analyzes the development trend of food storage and packaging technology and equipment industry， summarizes the research progress of key technologies and equipment of intelligent storage and packaging， highlights the core issues of the development of intelligent storage， intelligent packaging and high-end equipment， and finally expounds the development trend of key technologies and equipment of storage and packaging. Guided by the national strategic planning， with high-end equipment for food storage and packaging as the engine， with technological innovation， green development and cross-border integration to form new quality productivity to drive the high-quality development of food manufacturing.

Abstract:Streptococcus thermophilus is often used as a starter culture in the production of fermented dairy products. In this study， S. thermophilus IMAU80809 was selected as the research object and subjected to mutagenesis treatment with nitrosoguanidine (NTG). Through the determination of enzyme activities related to galactose metabolism and gene sequence alignment analysis， a mutant strain capable of efficiently metabolizing galactose， S. thermophilus IMAU80809Y， was screened out. On this basis， fermented milk of S. thermophilus IMAU80809 and its mutant strain was prepared， and the changes in pH value， titratable acidity， viscosity， water-holding capacity， viable cell count， and key metabolites were analyzed in detail. The results showed that compared with the wild type strain， the curdling time of the mutant strain's fermented milk was shortened to 7 h. The activities of β-galactosidase and galactokinase increased by 76.16% and 21.13% respectively. While the activities of pyruvate kinase and glucokinase decreased by 46.89% and 18.83% respectively. In addition， the metabolic amounts of lactose and galactose by the mutant strain increased by 0.599 g/100 g and 0.208 g/100 g respectively. These results indicate that the ability of the mutant strain to metabolize lactose and galactose was significantly higher than that of the wild-type strain. This study provides a theoretical basis for the production of low-galactose fermented dairy products.

Abstract:To investigate the potential of walnut dietary fiber to promote the growth of Lactobacilli， various mass concentrations of dietary fiber (0.1 to 3.2 g/L) were added to MRS medium. The effects of walnut dietary fiber on the growth of ten strains of Lactobacilli were compared， and the optimal 'fiber + strain' combination was selected based on promotion rate to evaluate the proliferation effects. The results showed that walnut insoluble fiber only promoted the growth of Lactiplantibacillus plantarum by up to 9.95%， while inhibiting the growth of the other nine strains. In contrast， walnut soluble fiber exhibited the highest promotion rate for Ligilactobacillus salivarius at 44.34%， followed by Lactiplantibacillus plantarum (16.14%) and Lacticaseibacillus casei (11.23%). The effect of walnut soluble fiber on the proliferation of Ligilactobacillus salivarius were as follows: walnut soluble fiber significantly increased the biomass， viable count， non-specific adhesion ability (P<0.05). At a fiber concentration of 3.2 g/L， the biomass and viable count increased by 2.86 times and 7.28 times， respectively， and the surface hydrophobicity increased by 8.81%. Additionally， it significantly promoted the formation of biofilm (P<0.05)， increased sugar utilization， and reduced the pH value of the fermentation broth (P<0.05). At 3.2 g/L fiber addition， the pH value of the fermentation broth reached its lowest point at 3.74. Furthermore， walnut soluble fiber significantly increased the activities of β-galactosidase and lactate dehydrogenase in Ligilactobacillus salivarius (P<0.05). Conclusion: walnut soluble fiber promotes the proliferation of Ligilactobacillus salivarius by increasing the activities of β-galactosidase and lactate dehydrogenase， and is beneficial to promoting its adhesion and biofilm formation. These findings provide a theoretical reference for the use of walnut dietary fiber as a new type of prebiotics， and offer new ideas for its comprehensive development and utilization.

Abstract:Superoxide dismutase is a cellular antioxidant with promising applications in food， cosmetic and pharmaceutical industries. In this study， based on the codon preference and efficient expression pattern of Pichia pastoris， the superoxide dismutase afSOD gene from Aspergillus fumigatus was optimized to reduce the GC content from 59% to 41%， and the CAI value was optimized from 0.69 to 0.96， and the gene sequence identity before and after the optimization was 73.8%. The recombinant strain induced an enzyme activity of up to 213.78 U/mL for 72 h. The recombinant enzyme AfSOD had the highest catalytic activity at pH 8.0 and 40 ℃， and was stable in a neutral environment and at 40-50 ℃. The promotion of the enzyme activity by the metal ion Cu2+ was particularly significant， with 5 mmol/L of Cu2+ increasing the enzyme activity by 80%， whereas Fe2+ showed a significant inhibitory effect. The recombinant enzyme AfSOD showed a significant scavenging effect on DPPH and hydroxyl radicals up to (97.65±1.46)% and (89.48±2.53)%. In addition， the efficient expression of recombinant enzyme AfSOD significantly enhanced the tolerance of yeast strains to temperature， osmotic pressure， salt， acetic acid and ethanol. This study not only provides some technical support for the efficient preparation of superoxide dismutase， but also provides theoretical support for the enhancement of yeast production tolerance.

Abstract:Low methoxyl amide pectin (LMAP) are widely used in the food industry and many gel foods contain saccharides. Previous research has revealed that the degree and type of polymerization of these saccharides molecules affect pectin gel characteristics， but systematic investigations are missing. This study investigates the LMAP commonly used in industrial production. Methods such as texture analysis， rheology， low-field nuclear magnetic resonance， and electron microscopy were employed to explore the effects of adding different types and degrees of molecules saccharides at pectin mass concentration 0.8-1.2 g/L， pH 2.5-5.5， and calcium ion concentration (R value of 0.8-1.2) on the gelation process， gel strength， moisture state， and microstructure of pectin gels. Simultaneously， the potential mechanisms by which saccharides molecules of different degrees and types alter the gelation behavior were investigated. The results indicated that the addition of different types of sugars can increase the gel strength of pectin to some extent， and the gel strength increases correspondingly with the increase in saccharides polymerization degree. When the pectin mass concentration was in the range of 0.8-1.2 g/L， the gel strength of pectin gels containing 10% polyglucose was significantly higher than that of other types of sugars， ranging from 1.53 to 2.08 times higher than the group without added saccharides. Under different R values (Ca2+ concentration)， the gel strength of pectin gels with added polyglucose samples was also significantly higher compared to those with other types of saccharides. At pH 3.5， the sample with added glucose exhibited the highest gel strength， which was 1.28 times higher than the group without added saccharides. This study elucidated the effects of eight types of saccharides molecules on the gelation properties of pectin， providing theoretical guidance for the preparation of related gel-based food products.

Abstract:In this study， sodium pyrophosphate (SPP) was used to modify Chinese soft-shelled turtle gelatin (CTG). The effects of phosphorylation modification on color， gel properties， rheological properties， structure and Pickering emulsion stability of CTG were studied. The results showed that phosphorylation significantly reduced the brightness of CTG and made it more yellow. Modification with low concentration of SPP (40∶1) improved the gel properties of CTG， but had no significant effect on its rheological properties. The gel strength was increased to 252 g and the gelling time was reduced to 96 s. With the increase of SPP concentration， the gel strength， viscosity， gelling and melting temperature of CTG decreased to 196 g， 25 mPa·s， 18.6 ℃ and 27.5 ℃， respectively. But its shear resistance increased. The structural analysis showed that SPP modification made phosphate group covalently bind with CTG， increased the molecular weight of CTG， changed the content of α and β chains， secondary as well as tertiary structures of CTG. The microstructure revealed the change in gel network of CTG after modification. SPP modification improved the emulsifying properties of CTG， reduced the droplet size of Pickering emulsion stabilized by CTG， and made it show a better droplet state. The emulsion stabilized by CTG/40∶2 had the smallest droplet， which decreased to (4.13±2.47) μm. While the emulsion stabilized by CTG/40∶6 had better creaming and droplet stability， its stratification began on day 5， and it had lowest CI value of 11.2% after 28 days of storage. This study can provide theoretical and technical reference for the development of new aquatic food gelatin with excellent properties.

Abstract:Selenium-enriched Hypsizygus marmoreus mycelium polysaccharide (Se-HMP) and H. marmoreus mycelium polysaccharide (HMP) were prepared from the powder of H. marmoreus before and after selenium-enriched fermentation， respectively， and then investigated their physical and chemical properties， microscopic morphology， chemical bonding mode and immune activity. The properties were conducted by uronic acid content determination， Congo red test， Fourier transform infrared spectroscopy and electron microscope. The immune activity was evaluated by means of proliferative activity， phagocytic activity and cytokine content using mouse macrophage RAW264.7 model. The results indicated that the yield of crude polysaccharide from selenium-enriched H. marmoreus was (22.90±1.62)%， which was 1.99 times that of H. marmoreus without selenium-enrichment. The content of uronic acid in Se-HMP was (15.60±1.46)%， which was significantly higher than that in HMP (P<0.05). Both Se-HMP and HMP have no triple helix structure， but their micromorphology is quite different. Polysaccharides in SE-HMP are bound with selenium in the form of Se=O bond and O-SE-O bond. In the range of 0.05-1.00 mg/mL， Se-HMP increased the proliferative activity of RAW264.7 cells and significantly promoted the secretion of NO and TNF-α (P<0.05) in comparison with HMP， but their ability to up-regulate IL-6 level was similar. In addition， both Se-HMP in low mass concentration (≤0.25 mg/mL) and HMP in high mass concentration (≥0.50 mg/mL) can promote phagocytosis of macrophages. Therefore， Se-HMP has higher immune activity in comparison with HMP， which may be due to the organic binding of polysaccharide and selenium and the higher content of uronic acid in Se-HMP.

Abstract:Silver carp (Hypophthalmichthys molitrix) was used as a raw material. The effects of four kinds of polysaccharide (0-1%) on the structure and emulsification properties of myosin-polysaccharide complexes were determined after the addition of chitosan， ι-carrageenan， κ-carrageenan and λ-carrageenan， respectively. Ultraviolet-visible spectrophotometer， fluorescence spectrometer， Fourier infrared spectrometer， nanoparticle zetasizer and contact Angle analyzer were used to analyze the structural and functional characteristics of myosin treated by four kinds of polysaccharides. The results showed that the turbidity increased with the increase of polysaccharide content. When the polysaccharide content was 1.00%， the turbidity of myosin-polysaccharide complexes after addition of chitosan， ι-carrageenan， κ-carrageenan and λ-carrageenan increased from 0.22 to 0.30， 0.28， 0.34 and 0.40， respectively， and the surface hydrophobicity also increased. The α-helix and β-sheet of myosin interconverted with β-turn after treating with four kinds of polysaccharides. The contact angle of myosin decreased from 125.43 and 129.08 to 98.53 and 116.25， respectively， with the increase of chitosan and λ-carrageenan addition. When κ-carrageenan content was greater than 0.5%， the contact angle of myosin increased and the addition of ι-carrageenan possessed the same change trend， indicating that the macromolecules formed by myosin and polysaccharides might be rearranged to change the hydrophobic region in the interior. The emulsifying stability of myosin treated with four kinds of polysaccharides reached the peak at the content of 0.5%. Meanwhile， the emulsifying stability of myosin treated with κ-carrageenan was high compared to the others. These results indicate that proper amount of polysaccharide can improve the emulsification stability of silver carp myosin， providing a theoretical basis for the application of polysaccharide-myosin emulsions.

Abstract:Resveratrol's disadvantages such as low water solubility and instability limit its bioavailability. The encapsulation properties and in vitro digestion forms of four protein nanoparticles were explored to investigate their effects on resveratrol bioaccessibility. The results showed that resveratrol and various proteins mainly bound by hydrophobic interaction and were encapsulated in an amorphous state. Zein nanoparticles (ZRNP) and sodium caseinate nanoparticles (CRNP) have an encapsulation efficiency of more than 80% due to their good hydrophobicity. During in vitro simulated digestion， ZRNP aggregation reduced the resveratrol release rate to (33.95±0.98)%. Whey protein isolate nanoparticles (WRNP) have strong anti-digestion ability， resulting in the release rate of free amino acids was only (22.84±1.40)%. CRNP and soy protein isolate nanoparticles (SRNP) can significantly improve the in vitro bioaccessibility of free resveratrol by more than 50%. Combined with encapsulation properties and forms of action during in vitro digestion， CRNP is expected to improve its bioaccessibility as an encapsulation carrier for resveratrol. This study provides a theoretical basis for improving the bioavailability of hydrophobic polyphenols and their further application in food and oral drugs.

Abstract:Graptopetalum paraguayense is an edible succulent with multiple physiological properties. In this study， hyperuricemia (HUA) mouse model was established using hyperuricemia diet (containing 20% yeast extract and 4% potassium oxyazinate)， and the effects of Graptopetalum paraguayense juice/ crude polysaccharide on serum uric acid and gut microbiota in HUA mice were investigated. The results showed that the serum uric acid content of HUA mice was decreased significantly (P<0.05)， as evidenced by 14.76% and 29.83% reduction after Graptopetalum paraguayense juice/crude polysaccharide treatment. Moreover， the blood urea nitrogen content of HUA mice was also decreased 22.56% and 18.05%， respectively. Additionally， Graptopetalum paraguayense juice/ crude polysaccharide could also attenuate the glomerulus tumidness， renal tubule epithelial cell atrophy and inflammatory cell infiltration of HUA mice； it also inhibited the expression of URAT1 and GLUT9， promoted the expression of ABCG2， thereby promoting the excretion of uric acid. Moreover， Graptopetalum paraguayense juice/crude polysaccharide decreased the abundances of Desulfovibrionaceae unclassified and Desulfovibrio， and increased the abundances of beneficial bacteria including Muribaculum， Alloprevotella and Bacteroides. These results of our study are conducive to the development and utilization of Graptopetalum paraguayense， and also can provide theoretical reference for the development of Graptopetalum paraguayense related uric acid lowering functional food.

Abstract:Objective: To investigate the effects of brown rice dietary fiber on lipid metabolism in high-fat diet mice. Methods: Thirty C57BL/6J male mice were selected and randomly divided into control group， high-fat diet group and brown rice dietary fiber group according to body weight， with 10 mice in each group. Body weight was measured and food intake was recorded weekly. At 14 weeks， body fat distribution， blood lipid metabolism related indicators of mice were measured， adipose histological changes in liver and epididymis were observed， and colon contents were collected for intestinal flora and bile acids metabolomics analysis. Results: Brown rice dietary fiber reduced the body weight and inhibited the increase in body weight of high-fat diet mice (P < 0.05)； the levels of triglycerides and lipopolysaccharides in the blood of mice were significantly reduced (P < 0.05). In addition， body fat percentage， epididymal adipocyte size， liver fat volume and vacuole number were all reduced in mice. The results of intestinal flora analysis showed that brown rice dietary fiber intervention increased intestinal Ace and Chao1 indices in high-fat diet mice (P < 0.05). At the phylum level， brown rice dietary fiber increased the relative abundance of Bacteroidota， and decreased Desulfobacterota abundance and the ratio of Firmicutes to Bacteroidota (F/B) (P < 0.05). At the genus level， brown rice dietary fiber promoted the relative abundance of the beneficial bacterium Faecalibaculum and reduced the relative abundance of Romboutsia， Lactobacillus， Enterococcus， and Streptococcus (P < 0.05). Bile acid metabolomics results showed that brown rice dietary fiber increased overall bile acids levels and decreased the ratio of 12?琢-OH to non-12?琢-OH bile acids (P < 0.05). The levels of non-12?琢-OH bile acids such as taurine chenodeoxycholic acid， lithocholic acid， hyodeoxycholic acid， and β-ursodeoxycholic acid were significantly elevated (P < 0.05). Conclusion: Brown rice dietary fiber can effectively improve high-fat diet-induced lipid metabolism disorders by regulating the intestinal flora and non-12?琢-OH bile acids levels in mice.

Abstract:Objective: To investigate the intervention effects of slowly digestible starch noodle， acarbose and white kidney bean extract on non-obese diabetic mice induced by streptozotocin (STZ). Methods: A slowly digestible starch noodle with calcium alginate/glucomannan/cornstarch microstructure was studied. The development of in vitro digestion experiments and the characterization of scanning electron microscopy showed that the slowly digestible starch noodle was successfully constructed. The postprandial blood glucose response curve of slowly digestible starch noodles was explored by establishing an animal experimental model of non-obese diabetic mice. Slowly digestible starch noodle， acarbose and white kidney bean extract were used to intervene diabetic mice in different ways for 4 weeks. Fasting blood glucose and body weight of mice in each group were monitored weekly. After 4 weeks of intervention， serum indexes such as FINS， ALT， AST， Urea， CREA， CHOL， TG， HDL-C and LDL-C were measured. At the same time， the histological characteristics of the liver and kidney of each group of mice were observed. Results: Acarbose and slowly digestible starch noodle had a significant effect on glycemic control in diabetic mice (P<0.05)， which could significantly lower blood glucose levels and significantly improve insulin resistance and insulin sensitivity in diabetic mice. However， the side effects of acarbose can result in liver damage in diabetic mice， which is reflected in the significant height of the liver function indicators alanine aminotransferase (ALT) and aspartate transaminase (AST) (P<0.05) and significant liver lesions in liver pathological sections. At the same time， after the intervention of slowly digestible starch noodle in diabetic mice， alanine aminotransferase， aspartate transaminase， urea， creatinine， total cholesterol， triglycerides， high density lipid-cholesterol and low density lipid-cholesterol were closer to normal mice， or there was no significant difference (P>0.05). Compared with acarbose and slowly digestible starch noodle， the intervention effect of white kidney bean extract was worse in different indexes (P<0.05). Conclusion: Slowly digestible starch noodle has a good intervention effect on non-obese diabetic mice， and has no side effects on mice.

Abstract:Purpose: To explore the effect of soybean hull polysaccharides on the growth and adhesion of probiotics. Methods: The absorbance of OD600nm， growth time and pH value were explored to analyze the proliferation capacity of Lactobacillus paracasei 6244. A mouse intestinal probiotic adhesion model was established to study the effects of soybean hull polysaccharides on the adhesion capacity of Lactobacillus paracasei 6244 from measuring the changes of auto-aggregation， co-aggregation， hydrophobicity and intestinal microenvironment. The results showed that 0.5 mg/mL C-ASP and HW-ASP significantly accelerated the growth rate of Lactobacillus paracasei 6244， shortened the growth time to 4.08 h and 4.69 h， respectively， but had no significant effect on the acid-producing capacity of Lactobacillus paracei 62445. In addition， C-ASP can significantly improve the surface hydrophobicity and co-aggregation of Lactobacillus paracasei 6244， promoted the secretion of exopolysaccharides， surface proteins and other adhesins and intestinal mucus， and increased the colonization of Lactobacillus paracasei 6244 in different intestinal tissue， especially in the jejunum and ileum segments， the adhesion rate of Lactobacillus paracasei 6244 increased by more than 32%. Conclusion: Soybean hull polysaccharide can promote the proliferation and adhesion of intestinal probiotics， which is conducive to the active role of intestinal probiotics and the improvement of intestinal microenvironment.

Abstract:Juncao Ganoderma lucidum， which is cultivated with Juncao instead of wood chips， has a wide range of bioactivities and has been shown to have a strong in vitro immune effect. Cyclophosphamide， as an alkylating antitumor agent， is also a typical immunosuppressant that causes immune damage to the body. In the present study， cyclophosphamide-induced immunocompromise model in mice was investigated by gavage of 100 mg/(kg·d) Juncao Ganoderma lucidum alcohol to study the improvement of immune injury in mice. The results showed that JGEH significantly (P < 0.05) increased body weight (6.32%)， organ indices (thymus 38.50%， spleen 71.32%， liver 1.27%， and kidney indices 11.48%)， carbon contouring capacity (41.50%)， and the degree of delayed metamorphosis (59.50%) in mice. In addition， JGEH significantly (P < 0.05) increased immunoglobulin and anti-inflammatory factors， such as IgG (27.73%)， IgA (26.51%)， IgM (23.41%)， and IL-10 (41.98%)， and decreased inflammatory cytokines， such as TNF-α (17.40%)， IFN-γ (17.49%)， and IL-6 (42.33%)， in serum， and significantly (P < 0.05) increased leukocytes (41.23%)， erythrocytes (18.91%)， hemoglobin (42.32%)， platelets (40.29%)， and percentage of lymphocytes (159.94%) in whole blood of mice. Research ideas for the development of alcoholic extracts of the mycorrhizal Juncao Ganoderma lucidum.

Abstract:Objective: To investigate the protective effect of sulforaphane (SFN) against titanium dioxide nanoparticles (TiO₂ Nps)-induced liver injury in mice. Methods: Fifty 6-week-old male C57BL/6J mice were randomly divided into a control group (NC)， a TiO₂ Nps model group (100 mg/kg)， a TiO₂ Nps+low-dose SFN administration group (0.5 mg/kg)， a TiO₂ Nps+medium-dose SFN administration group (1 mg/kg)， a TiO₂ Nps+high-dose SFN administration group (2 mg/kg)， and 10 in each group. Blood was collected from the orbits after 9 weeks， and the livers of the mice were retained. The serum levels of ALT and AST， oxidative stress and inflammation were detected in the liver tissues of mice. HE staining was used to observe the histopathological and morphological changes in the liver tissues of mice， and immunohistochemistry staining was used to detect the expression of F4/80 proteins in the livers of mice. Protein immunoblotting was used to detect the expression levels of OGG1， NF-κb， ERK and p-ERK proteins. Results: Compared with the control group， the serum levels of AST and ALT were significantly increased in the model group (P<0.01)； compared with the model group， each SFN administration group significantly reduced the serum levels of ALT， AST and TBIL (P<0.01)； significantly increased the GSH/GSSG ratio of the liver tissues as well as the level of SOD (P<0.01)； and significantly reduced the level of MDA in the liver tissues of the mice (P<0.05， P<0.01). Real-time quantitative PCR results showed that compared with the model group， the mRNA levels of IL-6 and TNF-α were significantly reduced in the SFN medium- and high-dose administration group (P<0.05， P<0.01). Western blotting results showed that compared with the model group， the protein expression levels of NF-κb， p-ERK and ERK were significantly down-regulated in the administration group (P<0.05， P<0.01). HE staining results showed that compared with the model group， the administration group had HE staining results showed that the vacuolization degree of hepatocytes in the administered group was improved compared with that in the model group. Immunohistochemical staining showed that F4/80 expression was reduced in the administered group compared with the model group. Conclusion: SFN was able to attenuate TiO₂ Nps-induced changes in liver injury， oxidative stress and inflammatory indexes in mice， suggesting that SFN could alleviate TiO₂ Nps-induced oxidative stress and inflammatory responses and might act through the NF-κb-ERK/p-ERK pathway.

Abstract:In order to improve the enrichment of γ-aminobutyric acid (GABA)， the effects of germinating temperature， germinating time， hot air drying temperature， ultrasonic， ozone， freezing and high temperature and pressure stress on GABA content in germinated brown rice were studied. The results showed that germinating temperature， germinating time and hot air drying temperature had significant effects on GABA content during brown rice germinating， and the influencing degree of each factor was: germinating time > hot air drying temperature > germinating temperature. The optimum conditions for the preparation of high GABA content are: germination temperature 31 ℃， germination time 40 h， hot air drying temperature 50 ℃， GABA content was 21.43 mg/100 g. In the middle and late stages of germination (18-40 h)， brown rice was treated with 15 g of ozone stress. At the middle stage of germination (12-30 h)， 30 kHz ultrasonic stress was treated for 20 min. Freeze brown rice for 9 h after germination. After germination， brown rice was sterilized at 120 ℃ for 30 min. The GABA content of germinated brown rice was all significantly increased.

Abstract:Lutein is a carotenoid which has high antioxidant activity and remarkable protection function on the eye. Unfortunately， it is difficult to play the role as an effective functional component because of its instability， poor solubility in water， and low intestinal absorption rate. In this work， zein was glycosylated with chitosan oligosaccharide by the Maillard reaction to prepare zein/chitosan oligosaccharide (COS) conjugates (MDZ) to improve the encapsulation and delivery properties to lutein. Optimum preparation process conditions and characterization of lutein-loaded MDZ nanoparticles (MDZ-LUT) were investigated. The results revealed that the optimal preparation conditions were: the mass concentration of lutein was 100 μg/mL， the mass ratio of zein to COS was 1 ∶ 3， temperature was 91 ℃， and the time was 92.30 min， the encapsulation rate of MDZ-LUT reached (88.79±0.37)%. The MDZ-LUT had a smaller particle size (310.73±5.31) nm， and better polydispersity (polydispersion index PDI 0.23±0.02). The results of FTIR suggested that lutein could be combined and encapsulated better by Maillard-modified zein. Furthermore， the simulated gastrointestinal digestion and antioxidant results showed that the digestive stability and free radical scavenging activity capacity of lutein in MDZ-LUT increased significantly. These findings indicated that the zein/COS nanoparticles obtained by the Maillard reaction might be an efficient and promising delivery system to encapsulate and protect bioactive lutein compounds.

Abstract:Comparison of the structural properties of resistant japonica starch prepared using various physical methods provides a theoretical foundation for industrial production. The resistant japonica starch (denoted as HMT-JS， PT-JS， and UT-JS， respectively) was prepared by the heat moisture method， the heat pressure method， and the ultrasonic method using japonica starch as raw material. The optimal preparation conditions were determined by single-factor tests， and the structure and properties of the resistant japonica starch under the optimal process conditions were investigated. The results showed that the optimum conditions for the preparation of resistant japonica rice starch by different physical methods were as follows: HMT-JS: moisture content of 20%， heat moisture time of 6 h， heat moisture temperature of 110 ℃， resistant starch content of 24.31%； PT-JS: starch emulsion mass fraction of 30%， heat pressure time of 30 min， heat pressure temperature of 110 ℃， resistant starch content of 16.68%； UT-JS: starch emulsion mass fraction of 30%， ultrasonic time 20 min， ultrasonic temperature 30 ℃， resistant starch content of 15.02%. Compared with japonica starch， the solubility and swelling power of the three resistant starches were reduced， the thermal stability was significantly improved， and they were less likely to regenerate， and the freeze-thaw stability also changed to different degrees； the rheological results showed that japonica starch and the three resistant starches were weak gel systems and pseudoplastic fluids； the surface of the three resistant starch granules became rough and adhered， and the relative crystallinity and short-range orderliness increased. The results of in vitro digestion tests showed that within the same hydrolysis time， the hydrolysis rate of the three resistant starches was lower than that of japonica rice starch， with HMT-JS having the lowest glycaemic index of 74.45%. The results of the study provide a reference for the development of deep processing products of japonica starch.

Abstract:In order to improve the utilization and stability of loquat flower polyphenols， pectin， sodium alginate and chitosan were used as composite wall materials to prepare loquat flower polyphenols microcapsules. The preparation process of loquat polyphenol microcapsules was optimized by single-factor test and response surface analysis， and the apparent properties， in vitro slow release effect and stability of the microcapsules were evaluated. The results showed that the loquat polyphenol enriched by macroporous resin had higher polyphenol content and biological activity， and was used as the core material of this experiment. The best preparation process of pectin assisted embedding for microcapsules was as follows: pectin to core material mass ratio 1∶2， sodium alginate mass fraction 2.0%， chitosan mass fraction 0.19%， calcium chloride mass fraction 1.5%， pH 5.9. Under these conditions， the embedding rate of microcapsules was (86.98±0.25)%， the drug loading was (38.24±0.49)%， the average particle size was (4.92±0.74) μm， and the shape was nearly spherical. After 6 h of simulated gastroenteric fluid digestion， the cumulative release rate of microcapsules in stomach and intestinal fluid was 19.59% and 82.53%， respectively. In addition， the temperature stability and light stability of loquat flower polyphenols were improved after microencapsulation. The microcapsules prepared by this process can improve the slow-release and stability of loquat flower polyphenols， and improve the utilization rate of loquat flower polyphenols.

Abstract:Ponkan peel is rich in glycoside flavones and polymethoxylated flavones. To utilize adequately the two flavone， the synchronized extraction from ponkan peel was carried out， whose technology was optimized by single factor and orthogonal test， based on the the extraction rate of main flavonoid monomer of ponkan peel. The obtained crude extract was purified by the macroporous resin column chromatography. The results showed that the optimized extracting technology was a concentration of 60% ethanol， solid-liquid ratio (g/mL) of 1∶40， extracting temperature of 75 ℃ and extracting time of 110 min， by which the total extracting ratio of seven flavones was (72.63±1.53) mg/g. Through the single factor experiment， the better purified conditions by the macroporous resin column chromatography were a loading sample volumn of 170 mL， loading sample mass concentration of 2.5 g/L in 30% ethanol solution， flow rate of 1 mL/min and elution concentration of 80% ethanol， under which the contents of hesperiding， nobiletin and tangeretin in purified extract were 4.6， 2.3， 1.45 folds of those of crude extract. Conclusion: The glycoside flavones and polymethoxylated flavones in ponkan peel were extracted synchronously at a higher extracting ratio， whose contents were enhanced further by the following purification by the macroporous resin column chromatography. The research results can provide the evidence and reference for the extraction of multiple flavones and comprehensive utilization of ponkan peel.

Abstract:Lack of network structure of rice protein， resulting in a lack of network structure in the rice protein， which limits the application of rice as a gluten-free raw material in food. In this experiment， whey protein isolate and soybean protein isolate were added to rice flour for extrusion treatment， and then the network structure and functional properties of protein components in mixed rice flour were investigated to explore the effects of double protein cooperative extrusion technology. The results showed that extrusion would decrease free sulfhydryl group content in double protein mixed rice flour by 65.8%， and the content of total sulfhydryl and disulfide bonds increased slightly； the average particle size of protein aggregates increased from 43.8 nm to 164 nm； the characteristic absorption peaks of functional groups of rice flour protein shifted， and the contents of α-helix and β-sheet of ordered structure increased slightly； the maximum fluorescence absorption wavelength of rice flour protein shifted to red， the chromophore in the environment increased， and the rice flour protein partially unfolded； the results of the microstructure showed that the rice flour protein exhibited a cross-linked network structure； the solubility of rice flour protein decreased by 61.57%， and increased its water-holding capacity， foaming capacity， foam stability and emulsifying activity by 142.52%， 15%， 20.51%， and 227.27%， respectively. Therefore， the double protein cooperative extrusion technology improved the network structure of rice protein and changed the functional characteristics of rice protein.

Abstract:This study investigated the effects of ultrasound-assisted enzymatic hydrolysis on mung bean proteins to enhance peptide yield， antioxidant capacity， and promote the application of plant proteins in food. To investigate the effects of sonication alone and ultrasound-enzymatic treatment on the structural properties of mung bean protein (MBP)， as well as their influence on the structure and antioxidant activity of mung bean peptides. Results showed that using an ultrasound power of 400 W， ultrasound time of 15 min， alkaline protease， and enzymatic hydrolysis for 4 h significantly improved the yield， nitrogen solubility index， hydrolysis degree， and antioxidant activity of mung bean peptides. Compared to enzymatic products without ultrasound treatment， these parameters were increased by 17.8%， 11.1%， 5.8%， and 14.7%， respectively. This indicates that ultrasonic pretreatment effectively enhanced enzymatic efficiency and the activity of mung bean protein. Structural analysis revealed that the high shear， mechanical energy， and cavitation effects generated by ultrasound pretreatment altered the molecular conformation of mung bean protein. Specifically， the ultrasound-assisted enzymatic treatment group exhibited a decrease in α-helix and β-sheet content， an increase in β-turn and irregular curling in the secondary structure， an 89% reduction in average particle size， a 4.4-fold increase in ζ-potential value， and a significant decrease in protein particle. The molecular mass of the ultrasound-assisted enzymatic products was significantly lower than that of the single enzymatic products. These findings suggest that this method is an effective approach to enhance the utilization of mung bean protein. Furthermore， the results of this study provide a theoretical foundation for the application of mung bean protein in food processing.

Abstract:In order to reduce the oil absorption of mung bean starch (MBS) on the basis of maintaining its crispy characteristics， this paper used mung bean starch (MBS) as raw material to investigate the effects of freeze-thawed (FT) and ultrasonically-assisted freeze-thawed (U-FT) treatments on the effects of freeze-thawed (FT) and ultrasonic-assisted freeze-thawed (U-FT) treatments on the oil-absorption characteristics and structural properties of mung bean starch. The influence of ultrasound-assisted freeze-thawed treatment on the changes of oil absorption and structural properties of MBS was evaluated by analyzing the oil absorption rate， adsorption properties， particle size distribution， contact angle， functional groups， crystalline properties， thermal properties and microstructure. The results showed that both FT-MBS and U-FT-MBS decreased the oil absorption of starch， in which ultrasonic power of 180 W and two freeze-thaw cycles resulted in a significant decrease in the oil absorption of MBS (P<0.05) and a remarkable increase in the water absorption of starch (P<0.05). And the total oil adsorption rate of MBS obtained from both treatments reduced by 5.51% and 10.25% respectively in starch-oil simulated frying system compared to the original starch. The results of structural characterization revealed that FT-MBS had a rough surface and a denser structure； U-FT-MBS particles had larger and irregular shapes， and the changes in the moiety and rough surface altered the starch's oleophobicity. The two treatments resulted in a decrease in the specific surface area of the MBS particles and an enlarged average particle size， which resulted in an increase in the oleophobicity of the starch granules and a decrease in the degree of crystallinity by 3.61% and 6.54%， respectively. Taken together， the modified treatments reduced the oil absorption of MBS before and after frying. A significant reduction in oil absorption was observed for U-FT-MBS， which was attributed to the fact that this treatment enhanced the interaction between MBS and water molecules， altered the short-range ordered structure of starch， delayed the pasting process， and reduced the decomposition of the starch structure during deep-frying， which in turn inhibited the penetration of oil.

Abstract:Objective: To improve the gel properties of sturgeon surimi and promote the development of high-quality sturgeon surimi products. The effect of ultrasonic treatment on gel properties of sturgeon surimi was studied. Methods: In this study， the optimal conditions for the preparation of sturgeon surimi heat-induced gel (SHG) by ultrasonic treatment were obtained through response surface experiment， in which gel strength was the main evaluation index， and ultrasonic time， ultrasonic power， and NaCl mass fraction were the evaluation factors. The effects of ultrasonic treatment on the heat-induced gel properties of sturgeon surimi were evaluated by analyzing the changes in relevant parameters， such as gel strength， whiteness， water retention， water distribution， and microstructure. The structural characteristics of sturgeon surimi gel protein were analyzed by analyzing secondary structure， total sulfhydryl group (T-SH)， and surface hydrophobicity (H0). The optimal conditions of ultrasonic treatment were an ultrasonic time of 40 min， ultrasonic power of 180 W， and NaCl mass fraction 3%. The heat-induced gel strength of sturgeon surimi prepared under these conditions was the highest， reaching 657.00 g·cm. This data was generally consistent with the theoretical value predicted by the response surface model (660.40 g·cm). The results showed that ultrasonic treatment could improve the gel properties， whiteness， and water retention of SHG. In addition， ultrasonic treatment could promote the transformation of α-helix and random curling to pleated sheet and β-turning， promote the unfolding of the myofibrillar protein， reduce T-SH content， and promote the cross-linking of proteins. Conclusion: Ultrasonic treatment could improve the gel strength， texture properties， whiteness， and water retention of sturgeon surimi heat-induced gel， and promote the cross-linking of sturgeon myofibrillar proteins， which was conducive to the formation of more uniform and dense gel structure. This study provides a technical means to improve the gel properties of sturgeon surimi.

Abstract:Study the effects of different combinations of fermentation agents on the changes of physicochemical indexes and antioxidant function of fermented pufferfish. Pediococcus pentosaceus， Lactobacillus plantarum and Staphylococcus xylosus were used as fermenting agents to ferment pufferfish. Comparative analysis of different combination fermenting agents before and after fermented. Results showed that used a combination of three kinds of starter was superior to other starter groups. The pH value was 5.04， total acidity was 6.02 mL/10 g and amino acid nitrogen content was 0.72%， free fatty acid content was 147.54 μmol/g， neutral protease activity was 506.82 U/g and hydroxy free radical scavenging activity was 47.52 U/mg， and Anti-superoxide anion activity was 477.16 U/g. The fermentation of pufferfish sausage with different kinds of fermentation agents can not only get high quality fermentation product， but also promote the development of fermentation process.

Abstract:Colletotrichum capsici is one of the main pathomycete to the postharvest of pepper and destroying the quality shortens its storage period. The effects of storage at (28±1)°C and (90±5)% relative humidity on the metabolism of reactive oxygen species (ROS) in pepper were investigated by using green round pepper as the experimental material， scratching inoculated with C. capsici as the treatment group and scratching inoculated with sterile water as the control. The results showed that compared with the control group， the disease index of pepper inoculated with Colletotrichum capsici was significantly increased， and the disease index was as high as 3.97 (P<0.05) at 9 d. The cell membrane permeability， MDA content， total phenol and flavonoid accumulation of pepper after infection with C. capsici were 1.44， 5， 1.26， 1.24 times of the control group， respectively. The 'oxidative burst'--H2O₂ content and O₂- production rate increased in the early stage of storage， and the infection of C. capsici promoted the activities of PPO， POD， SOD and APX in pepper， and by 9 d of storage， the activities of PPO， SOD and APX were 22， 1.09 and 1.67 times higher than those of the control group， respectively. The activities of CAT and PAL increased first and then decreased， and PAL reached the peak on the 5th day， which was 1.506 times that of the control. Correlation analysis showed that O₂- production rate， PPO， POD， SOD and APX activities were significantly positively correlated with disease index (P<0.01). Combined with principal component analysis， it can be seen that pathogen infection activates the defense system of pepper， breaks the dynamic balance of redox in pepper， leads to the increase of ROS accumulation in the later stage of storage， which in turn causes serious damage to peppers' tissues， aging and rotting. Compared with scratch treatment， the infection of pepper anthracnose makes the oxidative damage of pepper more serious. This study elucidates the relationship between C. capsici and pepper active oxygen metabolism， and provides a theoretical basis for further research on the pathogenesis of pepper anthracnose and its prevention and control measures.

Abstract:Aiming at the problems of perishable， browning and nutrient loss of fresh-cut lily bulbs during storage， Lanzhou lily bulbs were stored with 5%， 10%， 15% and 20% CO₂ for 15 d at (4±1) ℃ and 5% O₂， respectively， to determine their appearance， flavor and nutritional quality. The results show that the treatment of lily bulbs with different concentrations of CO₂ has effects， among which 10% CO₂ treatment can effectively inhibit the browning of lily bulbs， maintain a low weight loss rate and a high fruit hardness， reduce the loss of flavor substances， and delay the loss of starch， sugar， soluble sugar and soluble solid (TSS). At 15 days of storage， the contents of total phenol， malondialdehyde (MDA) and peroxidase (POD) activity were 1.89 mg/g， 0.70 mmol/g and 3.90 U/(min·g)， respectively， which were significantly different from control group and other treatment groups (P<0.05). Although 5% CO₂ can reduce the Browning degree of lily， other indexes are worse than 10% CO₂ treatment group. Lilium bulbs treated with 15% CO₂ had serious loss of total phenol content and carbohydrate， and the degree of membrane lipid peroxidation was too high. The treated with 20% CO₂ was damaged by high concentration of CO₂， the degree of softening was more serious， and the contents of TSS， starch， MDA， total phenol and POD activity were significantly different from those treated with 10% CO₂ (P<0.05). The results showed that the most suitable concentration for storage and preservation of lily was 5% O₂ + 10% CO₂. This experiment provided a reference for the research and development of fresh-cut bulbs of lily.

Abstract:Pseudomonas and Aeromonas are the dominant spoilage bacteria in aquatic products， and their spoilage characteristics are regulated by quorum sensing system mediated by N-acyl homoserine lactone signaling molecules. In this study， salmon infected by Pseudomonas fluorescein alone or mixed with Aeromonas hydrophila were used as a model. The aerobic plate count (APC)， pH， water holding capacity (WHC)， thiobarbituric acid (TBA)， total volatatile basic nitrogen (TVB-N) and other indexes were used to evaluate the fresh-preserving effect of crude cell extract (CCE) from Bacillus cereus YF-2 with quorum quenching activity on refrigerated salmon. The results showed that the growth of P. fluorescens and A. hydrophila was not affected when the protein concentration of CCE from B. cereus YF-2 was 10-160 μg/mL. Treatment with 160 μg/mL of B. cereus YF-2 CCE could slow down the rise rate of the APC， pH， TBA and TVB-N， as well as the decline rate of WHC. Compared with salmon samples infected with P. fluorescens alone or mixed with A. hydrophila， adding B. cereus YF-2 CCE could prolong the storage period of salmon for 2 days and 4 days， respectively. This study was expected to provide a theoretical basis for the application of quorum quenching bacteria to control the spoilage of aquatic products and the development of new biological preservatives.

Abstract:Objective: Tetragenococcus halophilus is a kind of lactic acid bacteria， the high polymer exopolysaccharide produced by it has important application value. In order to explore the molecular mechanism of exopolysaccharide produced by Tetragenococcus halophilus， the whole genome of the strain was sequenced and analyzed， which provided a theoretical basis for the production and application of exopolysaccharide from Tetracococcus halophilus. Methods: The whole genome of Tetragenococcus halophilus CGMCC 3792 was sequenced by nanopore third-generation sequencing technology， and the gene prediction and functional annotation were performed by bioinformatics method. In addition， the genes related to the biosynthesis of exopolysaccharide were further explored， and the molecular mechanism of exopolysaccharide synthesis by Tetragenococcus halophilus CGMCC 3792 was analyzed deeply at the gene level. Results: The total length of the genome of Tetragenococcus halophilus CGMCC 3792 was 2 573 722 bp， encoding 2 633 genes. The biosynthesis pathway of exopolysaccharide was analyzed， and results showed that exopolysaccharide could be synthesized from mannose， fructose， maltose， glucose and cellobiose. Through genomic analysis， it was found that the genome contained a 15.4 kb exopolysaccharide gene cluster， including the regulating genes epsA and epsB， the chain length determining genes epsC and epsD， and two glycosyltransferase genes as well as the flippase encoding gene wzx. Conclusion: This study revealed the molecular mechanism of exopolysaccharide production by Tetragenococcus halophilus CGMCC 3792 at the gene level， which laid a foundation for its industrial application.

Abstract:In this paper， exogenous Saccharomyces cerevisiae was added to enhance the fermentation of Hongqu rice wine， and its effects on the formation of biogenic amines and volatile flavor components in Hongqu rice wine brewing， as well as the composition of brewing microbial communities were investigated. The results of physicochemical parameters and volatile components analysis showed that the enhanced fermentation with S. cerevisiae could effectively reduce the production of biogenic amines (with a reduction rate of up to 83.43%)， and completely inhibit the production of tyramine， significantly increase the content of characteristic ester aroma components such as methyl decanoate， ethyl octanoate， ethyl palmitate， ethyl stearate and ethyl 3-hydroxybutanoate， etc. in Hongqu rice wine， achieving a dual regulatory effect of 'amine reduction and flavor enhancement'. In addition， enhanced fermentation with S. cerevisiae effectively reduced the acidity of Hongqu rice wine by 75.24%. The results of microbial composition analysis based on high-throughput sequencing of 16S/ITS amplicons indicated that the enhanced fermentation with S. cerevisiae significantly reduced the relative abundance of potential amine producing bacteria such as Lactobacillus， Lactococcus， Weissella， Leuconostoc， Wickhamomyces and Sporobolomyces in Hongqu rice wine brewing， but increased the relative abundance of microorganisms such as Pseudomonas， Enterococcus， Kosakonia， Bacillus and Cronobacter. The results of flavor sensory evaluation showed that the acidity of Hongqu rice wine produced through S. cerevisiae-enhanced fermentation was moderate， the taste was more mellow and continuous， and the flavor and quality was significantly improved. This study reveals that S. cerevisiae-enhanced fermentation has positive impacts on the reduction of biogenic amines and the enhancement of characteristic aroma in Hongqu rice wine brewing. It also clarifies the regulatory effect of S. cerevisiae-enhanced fermentation on the composition of microbial communities in Hongqu rice wine brewing， and has certain reference value for improving the brewing technology of Hongqu rice wine. This study helps to improve the drinking safety and flavor quality of Hongqu rice wine， and also promotes the healthy and sustainable development of Chinese rice wine brewing industry.

Abstract:Young apple fruit wines were fermented with Saccharomyces cerevisiae and Lactobacillus plantarum in five ways: simultaneous inoculation fermentation (HF)， sequential fermentation 1 (SX-1)， sequential fermentation 2 (SX-2)， single strain fermentation (SY) and natural fermentation (NF)， in order to study the changes in reducing sugars， alcohol content， polyphenols， flavonoids and antioxidant capacity during the fermentation process， as well as to carry out organoleptic evaluations. The volatile flavor substances of five groups of fruit wines were determined using headspace solid phase microextraction combined with gas chromatogra phy-mass spectrometr (HS-SPME-GC-MS) technology. The results showed that during the fermentation process， the reducing sugar content of the five groups of fruit wines decreased and then stabilised； the alcohol content increased and then stabilised； and the polyphenols， flavonoids and antioxidant capacity increased and then decreased. A total of 76 aroma components were detected in the five groups of fruit wines， including 18 alcohols， 30 esters， 5 acids， 6 ketones and 2 aldehydes. Natural fermentation has the least amount of flavor substances， mixed-bacteria fermentation has the most， followed by single-strain fermentation. Natural fermentation is dominated by alcohols (58.53%)， esters (18.61%) and acids (12.64%)， and inoculated fermentation is dominated by alcohols (63.21%-68.81%) and esters (26.29%-28.56%). Compared to natural fermentation， inoculated fermented fruit wines are full-bodied and have higher sensory scores， and it contains more esters and alcohols. Conclusion: the HF group had the strongest ability to consume reducing sugars during fermentation， the highest polyphenol [(785.89±9.37)μg/mL] and flavonoid [(317.96±8.75)μg/mL] contents， as well as showing strong antioxidant capacity (85.06%-92.12%)， and the HF group had the highest sensory scores (90.05 points) and richer volatile flavor substances.

Abstract:In order to explore the difference and contribution of volatile substances in quality levels of strong-flavor Baijiu， sensory evaluation， gas chromatography-ion mobility spectrometry and chemometrics were used to detect and analyze the volatile substances in quality levels of strong-flavor Baijiu. Through GC-IMS detection， 41 variables that can characterize the difference of volatile substances in three grades of Baijiu were screened， including 13 esters， 8 alcohols， 6 ketones， 3 aldehydes and 4 other compounds. Principal component analysis and partial least squares discriminant analysis based on peak volume of 41 variables. The results showed that the cumulative contribution rate of the first two principal components of PCA reached 80.1%， which can effectively distinguish different quality levels of Baijiu samples. PLS-DA can screen 17 characteristic biomarkers based on variable importance projection， draw clustering heat maps for the above substances to distinguish the contribution of aroma substances to different Baijiu samples， and construct a K-nearest neighbor model， with a discrimination accuracy of 100%. This study can provide a theoretical basis for the rapid evaluation of the classification of strong-flavor Baijiu.

Abstract:In order to explore the complex microbial system and volatile flavor components in the traditional fermentation process of Sichuan Swiss Chard， high-throughput sequencing and bioinformatics related technologies were used to comprehensively analyze the microbial flora structure of the Swiss Chard and its relation among the microbial species. The types and contents of organic acids in the Swiss Chard were determined by liquid chromatography. At the same time， headspace solid phase microextraction (HS-SPME) and gas chromatography-time of flight mass spectrometry (GC-TOFMS) were used to systematically analyze the volatile flavor components of Sichuan Swiss Chard samples. The results showed that the main contributors to the flora were Lactobacillus， unclassified-Cyanobacteria， Halomonas and Lentilactobacillus. The Swiss Chard contain six organic acids including tartaric acid， lactic acid， acetic acid and so on. And the highest content of lactic acid was 470.50 mg/100 mL. The relative content of acids in volatile flavor substances was the highest， mainly acetic acid， followed by alcohols such as 2-octanol and esters such as ethyl lactate. This study clarified the correlation between the microbial community structure and the formation of flavor substances in Sichuan fermented kimchi， aiming to provide a theoretical basis for further improving the traditional fermented kimchi process and large-scale production of inoculation control.

Abstract:Purpose: To screen and identify immunologically active components in the hydrolysate of tuna protein. Method: Tuna protein was hydrolyzed using trypsin， and separation， purification， and identification were performed using a combination of Sephadex G-25 gel chromatography and liquid chromatography-mass spectrometry (LC-MS/MS). The evaluation criteria included the relative proliferation rate， phagocytic ability， nitric oxide(NO) production capacity， and cell cycle distribution of RAW264.7 cells. Components with strong immunological activity were selected， and their structures were identified. Results: After purification by Sephadex G-25 and Sephadex G-15 chromatography， the isolated FF1 fraction exhibited strong immunological activity， with a relative proliferation rate of 73.66%， phagocytic ability of 70.04%， and NO production capacity of 4.82 μmol/L in RAW264.7 cells. Conclusion: The FF1 fraction obtained after Sephadex G-15 separation demonstrated strong immunological activity， and two potential immunologically active peptide sequences were screened from this fraction， namely， Gly-Asp-Ala-Glu-Met-Glu-Ala-Tyr-Gly-Lys (GDAEMEAYGK) and Leu-Leu-Tyr-Gly-Gly-Ser-Val-Thr-Gln-Thr-Cys-Lys (LLYGGSVTQTCK). This study provides important theoretical references for the development and utilization of immunologically active peptides from tuna.

Abstract:Spoilage of cold meat during storage can cause huge economic losses to the industry， and it is crucial to establish a set of rapid test methods for meat freshness. In this paper， based on the loop-mediated isothermal amplification (LAMP) system successfully established in the previous stage， three application scenarios (testing laboratory， terminal market and home kitchen) were designed， and a total of 125 sets of samples were collected from 25 brands of chilled meats sold in the market to verify the accuracy of the LAMP system in monitoring the freshness of meat under multiple scenarios， by evaluating the organoleptic and bacterial counts. A total of 125 samples were collected from 25 brands of cold meat sold in the market. The results showed that after 3 days of storage at 4 ℃， the odor and viscosity scores of cold meat dropped below the threshold， and the total number of bacterial colonies reached 6.0-7.5 lg(CFU/g). The LAMP system could accurately monitor the freshness of meat in all three scenarios， with the spoiled meat samples showing a blue color and an absorbance value of more than 0.19， and fresh meat samples keeping a purple color and an absorbance value of less than 0.19. The LAMP system was also used in multiple scenarios to evaluate the freshness of meat. Meanwhile， comparing the results of multi-scenarios with the total colony count determination， the accuracy of spoilage monitoring can reach 100% for the experimental end of the test， 91.3% for the end-market end， and 100% for the home kitchen end. Therefore， this method has good accuracy in assessing the freshness of cold meat in different scenarios， and can realize the monitoring of meat freshness in multiple scenarios， with the feasibility of replacing the traditional detection methods.

Abstract:Ochratoxin A (OTA) is a common mycotoxin that often contaminates food and causes different degrees of harm. In this study， a novel fluorescent aptamer sensor based on hybridization chain reaction (HCR) was developed for the rapid and sensitive detection of OTA in food products. Firstly， OTA binds to the aptamer and releases the trigger strand cDNA， which then triggers the HCR reaction between the hairpin HP1 and HP2， resulting in the formation of a G-quadruplex structure of G-quadruplex sequence in HP1， and at the same time， the N-quadruplex structure of G-quadruplex sequence in HP1. Sequence to form a G-quadruplex structure， while at the same time N-methylmesoporphyrin IX (NMM) dye is inserted into the G-quadruplex structure (G-quadruplex)， which significantly enhances the fluorescence signal. The enzyme-free and fluorescence-free quantitative detection of OTA was achieved by the change of fluorescence signal intensity. The results showed that the method was highly specific， and among the seven groups of tests， the results of the two groups containing OTA were positive， and the results of the other five groups without OTA were negative. The linear regression equation was Y = 0.71133lgCOTA+3.21383 with the correlation coefficient R2=0.9942， the linear range was 0.1 pg/mL - 5 ng/mL， and the limit of detection was 0.1 pg/mL. The recoveries of this method applied to the detection of artificially spiked samples of wheat， red wine and coffee were all in the range of 92%-97.88%， which were higher than those of the recoveries of the ELISA kits (90.5%-95.78%) indicated that the method was superior to the national standard method. Therefore， the novel fluorescent aptasensor developed in this study can realize the rapid， sensitive， specific and accurate detection of OTA in food， and also provides a new idea for the rapid detection of other toxins as well as other chemical contaminants affecting food safety.

Abstract:Salmonella is among the four leading culprits of diarrhoeal afflictions and poses a considerable risk to human health. Based on the various action modes and colour rendering principles of cresol red (CR) and hydroxynaphthol blue (HNB)， a colorimetric detection of Salmonella in food by doul-dye SRCA has been created. The first step involved designing the SRCA primers for the invA gene of Salmonella， followed by optimization of the double-dye addition to establish a doul-dye SRCA colorimetric method. The method underwent evaluation via specificity， sensitivity， and detection limit tests， and its practical application performance was assessed by detecting 60 actual samples. The study identified that the ideal concentration ratio of HNB/CR was 0.6， which equated to 75 μmol/L HNB and 125 μmol/L CR. The test yielded positive results for 8 Salmonella strains and negative results for other strains. The sensitivity of the method was 6.8 CFU/mL， which was 100 times higher than that of PCR (6.8×102 CFU/mL)， and the detection limit was 9.5 CFU/mL， which was 100 times lower than that of PCR (9.5×102 CFU/mL). Importantly， the sensitivity， specificity， accuracy of this method were 100%， 98.2%， and 98.3%. Therefore， the doul-dye SRCA colorimetric method can detect Salmonella quickly， specifically and accurately. On the one hand， the combination of two dyes produces a higher hue contrast and a wider range of color variation between negative (purple) and positive (green) samples than using a single dye. On the other hand， the colorimetric dyes can be pre-added to the reaction system， which can effectively avoid secondary pollution.

Abstract:The clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated (Cas) system has been widely used in the field of rapid detection for food safety， owing to its advantages of extremely high specificity， programmability and ease of operation. In recent years， the CRISPR/Cas-based biosensors have flourished and become a favored tool in the rapid detection area. In this paper， the mechanism of various Cas proteins， represented by Cas9， Cas12a， Cas13a and Cas14a， were discussed， and their application in the rapid detection of harmful substances in food (e.g.， foodborne pathogenic bacteria， heavy metals， pesticide residues and mycotoxins) was reviewed as well. Furthermore， current challenges and future perspectives of the CRISPR/Cas-based biosensors for food safety are emphasized. This review aims to provide useful information to help future development of novel CRISPR/Cas-based biosensors for food safety.

Abstract:Fatty acids are important factors involved in appetite regulation and energy homeostasis， including improving body composition， glucose homeostasis， blood lipid profile， and weight balance. The appetite promoting effect of fatty acids is mediated by a combination of central nervous system and gastrointestinal hormones. On the one hand， fatty acids participate in regulating appetite， feeding behavior， and energy homeostasis through complex neural networks composed of the appetite regulating center (hypothalamus) and other central nervous system regions (including the midbrain marginal dopamine system， striatum， amygdala， etc.). On the other hand， fatty acids transmit gastrointestinal signals to the central nervous system by stimulating the secretion of endocrine hormones such as leptin， insulin， and gastrin， forming the brain gut peptide axis to regulate appetite and feeding behavior. Different chain length fatty acids play different roles in the body， and these effects combine to have an overall impact on the appetite. This article reviews the regulatory mechanisms of fatty acids on appetite through central and peripheral pathways， with a focus on the various appetite regulatory effects and signaling pathways of different chain length fatty acids.

Abstract:Natural polysaccharides have shown the advantages of low cost， wide application， high biocompatibility and degradability. They can be used as nano delivery carriers of functional factors to improve the bioavailability and physicochemical stability of functional factors. In order to provide reference for the efficient preparation of polysaccharide based nanocarriers with biological functions. The origin of nanotechnology and the advantages of polysaccharide based nanocarriers were summarized， as well as the preparation methods， formation mechanism， structural characteristics， encapsulation efficiency， release rate of different types of polysaccharide based nanocarriers. The potential problems and application prospects of polysaccharide based nanocarriers were discussed in functional food research.

Abstract:Postbiotics can be defined as soluble metabolites released by food microorganisms during the growth and fermentation in culture medium， food， or gastrointestinal tract. It is rich in bioactive substances with different molecular weights. At present， the preparation and application of postbiotics have attracted much attention. Postbiotics of lactic acid bacteria is probably obtained using MRS medium and some byproducts of animals and plants (e.g. whey culture medium) are also used as culture medium to prepare postbiotics. The cell-free supernatant with large amounts of active substances can be obtained by post-treatments， such as centrifugation， filtration， cell disruption， and so on. Therefore， the biological activity of postbiotics can be influenced by the types of bacteria， culture conditions， preparation technology and analysis methods. Adding specific functional postbiotics to food can effectively improve food quality， which is the foundation and critical point to exert their active functions. The use of analytical procedures to detect the quantity and quality of postbiotics and the antagonistic molecules can help to study postbiotic metabolites derived from lactic acid bacteria. It also can clarify the beneficial effects of postbiotic substances on food. This article summarizes the preparation methods， chemical analysis techniques and factors affecting postbiotic activity of lactic acid bacteria. It can provide the theoretical references for the further research and development of postbiotic products， and also can maximize the effect of postbiotic activity.

Abstract:Osteopontin stands as one of the abundant functional proteins in human milk. It derived from various mammalian milks， including human milk， has been confirmed to exhibit positive effects on immune balance， intestinal health， and nervous system development in early life. Currently， commercially available milk osteopontin is mainly produced through the separation of bovine milk and has been approved for use in infant formula in some countries and regions. Based on the current scientific researches and applications of milk osteopontin， the relevant experts from clinical medicine， food science， nutrition， and industry representatives were organized by Chinese Institute of Food Science and Technology to form this evidence after literature retrieval， extensive discussions and seminars， which might enhance the scientific understanding of milk osteopontin among the food industry and promote its development in the food industry in our country.

Abstract:The dual demand for palatability and health has driven the development of sugar substitute products in recent years. D-allulose， as a low-calorie sugar substitute， has garnered increasing attention from the market and industry. In order to promote the scientific understanding of D-allulose within the industry and to foster innovative development of the D-allulose industry in China， this scientific consensus was carried out. The physicochemical properties， nutritional and health characteristics， and food safety， as well as the relevant regulations and application status in some countries were comprehensively analyzed through literature searches and symposiums， together with the opinions of relevant experts in the fields of food from researches and industries. D-allulose is a natural substance with sweet taste and has potential in industrial application. It is in low energy and does not raise blood sugar levels， making it feasible as substitute for sugars added in foods. At present， the industrial production of D-allulose is mainly adopted by biotransformation. The safety of D-allulose has been widely recognized， and many other countries have approved for its use in food， but it is still necessary to increase the scientific researches in terms of production and application and to enhance public awareness. This consensus provides important guidance for the scientific understanding of D-allulose.