Abstract:Pickering emulsions stbilied by sohid nanoparticls have become a hot topie in maleriak chemistry as an ef ficient system for biocatalytic reactions. This system has many advantages， such as high catalytic efficiency and easy re-covery of enzymes and carriers， and has received attention from food researchers in recent years. Based on the related research on biocatalytic reaction systems of Pickering emulsions in inorganic and organic synthesis fields, this paper re-views the advances in the design of particle emulsifiers， catalytic reaction systems， and reactor engineering in three as-pects，and summarizes the application of Pickering emulsion biocatalysis in the food field. The aim is to provide theoreti-cal support and inspiration for promoting the green, efficient, and sustainable development of the food industry.

Abstract:β-glucan has a variety of physiological activities and good physiological functions. Dictyophora indusiata (Vent. Pers.) Fisch. contains lots of β-glucan， while its structure and solution properties are not understood clearly. In this paper， a water-soluble polysaccharide (DIPP) was extracted from D. indusiata. The physicochemical properties， structure and solution properties of DIPP were characterized by acid hydrolysis， infrared spectrum， methylation， scanning electron microscope (SEM)， high performance size exclusion chromatography multiangle laser light scattering (HPSEC-MALLS) and rheometer. The results showed that the weight average molecular mass of DIPP was 2.8×106 u， and only glucose was detected. The sugar residues were T-Glap (29.8%)， 1，3-Glcp (42.6%) and 1，3，6-Glcp (27.8%). The infrared spectrum showed that DIPP contained β-configuration. In dilute solution， DIPP had high intrinsic viscosity ([η]=1 094.3 mL/g). The DIPP solution (0.5%) showed high viscosity and gel properties. In conclusion， DIPP is a β-glucan with high viscosity. The results of this study can provide structure basis for the polysaccharide functional activity research and product development.

Abstract:In order to evaluate the effect of the interface structure on the stability and bioaccessibility of lutein nanostructured lipid carriers (Lutein-NLCs)， whey protein isolate and Tween 80 were applied to design Lutein-NLCs with single-layer， double-layer and complex interface structures. The basic properties， interface adsorption characteristics， bioaccessibility as well as stability of Lutein-NLCs with differen interface structures were investigated. The results showed that the particle sizes of Lutein-NLCs were in the rage of 127.60-180.86 nm. The maximum encapsulation efficiency of Lutein-NLCs could reach 97.78%， and lutein bioaccessibility of Lutein-NLCs with differen interface structures was significantly higher than that of ordinary nanoemulsions (P<0.05). Additionally， lutein bioaccessibility of Lutein-NLCs with single interface structure was significantly higher than that of composite interface and double interface structures (P<0.05). The release rate of lutein in of Lutein-NLCs with three types of interface structures was significantly lower than that of ordinary nanoemulsions. Furthermore， the sustained-release effect of Lutein-NLCs with composite interface and double-interface structures is more significant compared to single-interface Lutein-NLCs. During storage， Lutein-NLCs could increase the lutein retention rate， and the retention rate of Lutein-NLCs with composite interface was the highest， which was 12.06 times that of control group.

Abstract:Protein self-assembly to form amyloid fibril aggregates is an important means to improve and broaden the functional properties of food proteins. In this study， we investigated the functional properties of protein structure evolution， viscosity and thermal properties during the self-assembly of rice glutelin amyloid fibril aggregates (RAFA) formed by heating at pH 2.0 and 85 °C for different times， and their digestive behaviors in vitro digestion simulation. The results showed that at pH 2.0 and 85 ℃， the high molecular weight subunits of natural rice glutelin were gradually hydrolyzed into small molecular peptides below 12 ku， and the β-sheet structure content of RAFA increased from (22.76 ± 0.49)% at 0 h to (32.11 ± 0.52)% at the peak 6 h with the extension of heating time， indicating that the formation of RAFA is a protein hydrolysis followed by peptide reorganization aggregation process. In addition， RAFA showed high thermal stability， with the Tmax value of the exothermic peak increasing from (70.34 ± 0.51)℃ at 0 h to (174.55 ± 0.34)℃ at 4 h of peak. The TEM results of in vitro digestion showed the same trend of fiber digestion for 6 h and 10 h of heat treatment. After 60 min of pepsin digestion， a part of long fibers with branched shape was enzymatically dissolved into short fibers， while larger aggregate particles were observed； with the reduction of fiber structure after pancreatic enzyme action， large aggregate particles were enzymatically dissolved into small aggregate particles， so RAFA exhibited pepsin resistance. This study provides a theoretical basis for the construction of novel foods using protein fiber aggregates.

Abstract:The effects of gallic acid， coumaric acid， protocatechuic acid， vanillic acid and syringic acid on the clearance of sodium nitrite and the blocking rate of nitrosamine synthesis were studied. The operating conditions of phenolic acid were optimized by single factor (phenolic acid concentration， reaction time， pH) and orthogonal experiment. The results showed that when the phenolic acid concentration was 2.5/3.0 mg/mL， the reaction time was 90 min and the pH was 3.0/3.2， the five phenolic acids had better scavenging effects on sodium nitrite， and the scavenging rates were more than 75%， among which the highest scavenging rate of syringic acid was 97%， followed by gallic acid (94%). When the phenolic acid concentration was 3.0 mg/mL， the reaction time was 60 min and the pH was 2.8/3.0/3.2， the five phenolic acids had a strong ability to block the synthesis of nitrosamine， and the blocking rates were more than 50%. Among them， the blocking effects of syringic acid and gallic acid were still the best， 97% and 93% respectively. This study provides a theoretical basis for the better application of phenolic acid in meat processing.

Abstract:This study aims to isolate lactic acid bacteria with high-yield conjugated linoleic acid from Chinese paocai and baby feces， and then conduct functional and safety evaluations. 27 strains with CLA conversion rate greater than 8% were initially screened by ultraviolet spectrophotometry， identifying and classifying its CLA isomer composition by GC-Q-TOFMS. 8 lactic acid bacteria strains with more than 10% conversion rate of CLA and the mass concentrations of c9， t11-CLA， t10， c12-CLA isomers in the fermentation broth were higher than 20 μg/mL were obtained. The 8 strains were further evaluated characteristics such as self-aggregation， hydrophobicity， adhesion performance， gastrointestinal tolerance， antibacterial activity， and safety. The results showed that Lactobacillus plantarum NCU001044 and NCU006007 performed well overall， with self-agglutination rate of more than 60%， moderate hydrophobicity， and the adhesion rates were 8.81% and 9.10%， respectively. Their survival rates were 95.68% and 84.63% at pH 2.5 acidic conditions， and survival rates were higher than 65% in 0.3% bile salts. In terms of safety， the two strains are neutrally sensitive or sensitive to penicillin， benzamicin， tetracycline， and erythromycin and had no hemolytic activity. In this study， two Lactobacillus plantarum stains were screened with high biotransformation ability of beneficial CLA isomers and great probiotics potential. They have good ability to colonize the gastrointestinal tract， as well as acid and bile salt tolerance， besides show high inhibitory effect on pathogenic bacteria， which could be further used in the development of fermentation products and functional probiotics.

Abstract:In this study， 16 strains of Lactobacillus were analyzed for their antibacterial ability against pathogenic bacteria Staphylococcus aureus， Salmonella typhimurium and Escherichia coli， adhesion and intervention of pathogenic bacteria to Caco-2 cells， resistance to acid and bile salt stress and regulatory activity to immune cells. The results showed that the diameter of inhibition zone corresponding to the cell-free supernatant of L. plantarum KLDS 1.0328 was more than 15 mm. Using Lactobacillus rhamnosus LGG as control， six Lactobacillus strains with stronger or equivalent adhesion ability to Caco-2 cells in vitro were screened. Four strains with strong inhibitory ability to Caco-2 cells were further screened based on the competition， exclusion and displacement tests. The inhibition rates of L. plantarum KLDS 1.0328 for competition of S. typhimurium was (72.52 ± 4.94)%. Additionally， it is confirmed that L. plantarum KLDS 1.0328 has strong tolerance to acids and bile salts， has a good regulatory effect on immune cell activity， and has the potential for further development and application in food industry.

Abstract:Inflammatory mediator (NO) and proinflammatory factors (IL-1β、TNF-α and IL-6) were utilized to evaluate the anti-inflammatory activity of galactooligosaccharide (GOS) in vitro by LPS-induced RAW264.7 macrophages. Moreover， the structure-activity relationship of this bio-activity was also explored from the perspective of the degree of polymerizations. The results showed that GOS could significantly reduce the secretion of inflammatory mediator (NO) and proinflammatory factors (IL-1β、TNF- α and IL-6)， implying that GOS had the excellent anti-inflammatory capacity. Besides， the in vitro anti-inflammatory activities of GOS with different degrees of polymerization indicated that there are significant differences in the ability to regulate the secretion of proinflammatory cytokines and inflammatory mediators. In conclusion， GOS with higher degree of polymerization showed stronger anti-inflammatory activity in vitro.

Abstract:In this paper， Dendrobium huoshanense was used as raw material to study the changes of active components (total phenols， total flavonoids， and total acids) and in vitro antioxidant properties (ABTS radical scavenging capacity and hydroxyl radical scavenging capacity) during fermentation. The correlation between the changes of active components and in vitro antioxidant properties was determined by Spearman analysis. The oxidative stress model was constructed with WRL-68 human normal hepatocytes to explore the changes of cell-related antioxidant enzyme activities before and after fermentation. The results showed that the contents of total phenols and flavonoids of Dendrobium huoshanense enzyme increased by 35.5% (P < 0.05) and 49.1% (P < 0.05)， and the scavenging capacity of ABTS· and ·OH increased by 31.1% and 26.3%， respectively. The former was positively correlated with the contents of total phenols (P < 0.01) and total acids(P < 0.05)， while the latter was positively correlated with the contents of total acids (P < 0.01) and total flavonoids (P < 0.01). The oxidative stress model of WRL-68 cells was constructed with hydrogen peroxide. In the enzyme group， the level of intracellular reactive oxygen species (ROS) decreased significantly， and the activities of related antioxidant enzymes catalase (CAT)， glutathione peroxidase (GSH-Px)， and superoxide dismutase (SOD) increased. Conclusion: the active components and antioxidant capacity of Dendrobium huoshanense before and after fermentation were significantly improved， and the improvement of antioxidant capacity was significantly positively correlated with the increase of phenolic acids and flavonoids during fermentation. After fermentation， WRL-68 cells had a stronger protective ability against oxidative stress than before fermentation.

Abstract:In this paper， the anti-tumor activities of different flavonoids from Youzao jujube were studied by cell proliferation， cell migration and cell apoptosis. All five flavonoids had inhibitory effect on cell growth of pancreatic cancer cell BXPC-3， colon cancer cell HT-29 and lung adenocarcinoma cell A549. Among the flavonoids， Quercetin had the most obvious inhibitory effect on BXPC-3 and HT-29， with inhibition rates 79.08% and 89.09%， respectively. Hyperoside had the most obvious inhibitory effect on A549， and the inhibitory rate was 74.32%. Quercetin had a strong inhibition on migration of BXPC-3， but no obvious effect on HT-29 and A549. TUNEL staining was used to access cell apoptosis. Results suggest that the inhibitory effect of of flavonoids of Youzao jujube may be mediated by cell apoptosis.

Abstract:Firstly， whey protein isolate (WPI) was hydrolyzed by trypsin at constant conditions (i.e.， pH 8.5， 37 °C， enzyme/substrate ratio: 0.5%， 5 h) to prepare whey protein hydrolysates (WPH). Secondly， this study evaluated the influence of milieu conditions on emulsifying properties of WPH. Namely， pH values (3-7) and ionic strength (0.1 mol/L and 1 mol/L) by means of the addition with different salts (NaCl， KCl， CaCl2， MgCl2) were combined with heat treatment of WPH prior emulsification. For emulsion characterization， particle size distributions were measured by laser diffraction， emulsion stability was evaluated by STEP technique， and mass spectrometry was used to identify individual precipitated peptides due to heat treatment or the changes of milieu conditions. It was found that the charge-shielding effect caused by the increase in ionic strength at pH3 led to significant emulsion flocculation， while the effect of ionic strength on the emulsification characteristics of WPH at pH7 was insignificant. In addition， at the isoelectric point of WPH (pH4)， heat treatment significantly improved the emulsification characteristics of WPH， especially for the sample group with the addition of CaCl2. Combining the composition of the precipitated peptides at different environmental conditions and the corresponding emulsification characteristics， f(41-60)， f(71-91)， and f(78-101) released from β-Lg are believed to make an important contribution to the emulsification characteristics of WPH.

Abstract:Adlay seed (Coix lacrymajobi L.) is the mature seed kernel of adlay， a gramineous plant， with a protein content of 12.2% to 16.7%， rich in glutamine， leucine and proline， and easily absorbed by the body. Despite its nutritional balance and healing properties， adlay seed remains an underutilized grain due to its difficult-to-cook characteristics. Extrusion technology integrates mixing， stirring， crushing， heating， sterilization， puffing and forming into one， resulting in a product with not only a higher degree of pasting but also a short production cycle and low cost， which facilitates the consumption of adlay seed and indirectly promotes the economic growth of the adlay seed consumption industry. Some studies have shown that changes in the secondary， tertiary and quaternary structure of proteins depend on high temp-induced cross-link aggregation and high shear-induced mechanical unfolding， so extrusion treatments could have an impact on the structure and properties of proteins. For example， extrusion treatment could induce partial breakage of the hydrogen and disulfide bonds between protein molecules， causing denaturation of proteins， which in turn has an impact on solubility， emulsification and digestibility of proteins， providing new ideas for obtaining a wide range of adlay seed protein products. However， most of the research on the extrusion processing of adlay seed has focused on the effect of extrusion treatment on the starch properties of different varieties of adlay seed， while the extrusion processing of adlay seed protein is less. In addition， in order to enrich and develop the research system of adlay seed protein modification， it is necessary to further explore the influence of extrusion treatment on the structure and properties of adlay seed protein components. Therefore， in this study， defatted adlay seed powder was used as the raw material for extrusion and the Osborne classification method was used to separate and extract albumin， globulin， prolamin and glutenin to investigate the effects of extrusion treatment on the structural and functional properties of the four protein fractions. The results showed that the particle size of all four protein fractions decreased significantly after extrusion， and the particle size curves of globulin， prolamin and glutenin showed a multi-peaked distribution. After extrusion， the free sulfhydryl content of the albumin， globulin and glutenin decreased by 72.37%， 40.64% and 51.71%， respectively. And the maximum fluorescence absorption wavelength of these protein fractions was blue-shifted， and the subunit types and molecular weight were also significantly reduced， but there was no significant change in the prolamin. With the exception of globulin， the content of ordered structures， i.e.， α-helix and β-sheet， in the secondary structure of all three protein fractions was significantly reduced after extrusion(P < 0.05). The water- and oil-holding properties of the albumin， globulin and glutenin were significantly increased (P < 0.05). In conclusion， the structural properties of albumin， globulin and glutenin were significantly changed after extrusion， but the prolamin had higher structural stability and resistance to thermal shear. The results could provide theoretical support for the industrial preparation of adlay seed protein fractions and their application in a variety of food formulations.

Abstract:Functional and nutritional compounds have been increased during the germination of the brown foxtail millet. However， the characteristic smell is also produced， and affects the quality of the germinated brown foxtail millet. To control and improve the quality of the germinated brown foxtail millet， the origins of the volatiles must be known. Two cultivars of the brown foxtail millet， Jigu 39 and Jichuang 1， were used for 24 h germination. The volatiles were detected using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that 5 aldehydes， 2 ketones， and 2 esters were mainly produced after 12 h germination， whereas 10 alkanes and 4 alkenes were mainly produced at 0-12 h germination of the brown foxtail millet. The volatiles were mainly produced by the enzymatic oxidation of the fatty acids. The palmitic acid， stearic acid， oleic acid， linoleic acid， and linolenic acid were increased first and then decreased. The model experiment showed that the nonanal and decanal were enzymically formed by oleic acid， 3-octen-2-one and (E)-2-octenal were enzymically formed by linoleic acid， and dodecane and nonanal were enzymatically formed by linolenic acid.

Abstract:Catechol is a major cell growth inhibitor in lignocellulose hydrolysate， with strong toxicity， and can inhibit the growth and fermentation performance of Saccharomyces cerevisiae during subsequent alcohol fermentation. The effects of catechol on the physical and chemical properties of Saccharomyces cerevisiae GGSF 16 were studied. The results showed that when the concentration of catechol was 1.2 g/L， the growth and metabolism of Saccharomyces cerevisiae cells were significantly inhibited， resulting in slower glucose consumption time and longer ethanol fermentation cycle， and lower ethanol production rate. The membrane permeability of yeast cells was significantly changed， and the content of nucleic acid and protein in the cells was 2.50 and 2.01 times higher than that in the control group. The content of trehalose， a stress metabolite in cells， increased significantly by 2.89 times. In addition， in order to resist the oxidative damage of cells， the content of intracellular GSH decreased significantly by 70.63%. Scanning electron microscope showed that after treatment with catechol， the cell wall and cell membrane of smooth and full yeast cells were damaged， and there were cavities， a large number of torn fragments and adhesion between them. The cells lost their protective effect and died. This study preliminarily clarified the damage and toxicity mechanism of phenols on Saccharomyces cerevisiae， and provided a reference for further revealing the inhibitory effect of lignocellulose hydrolysate on Saccharomyces cerevisiae.

Abstract:In this paper， Bacillus subtilis spores were treated with 0.8 g/L and 1.6 g/L tea polyphenols at different temperatures， and the inactivating effect of tea polyphenols combined with heat treatments on Bacillus subtilis spores was determined by plate counting method. The effect of tea polyphenol combined with heat on the energy metabolism of Bacillus subtilis was analyzed by measuring the activity of adenosine triphosphate (ATP) enzymes and tricarboxylic acid metabolizing enzymes (succinate dehydrogenase (SDH) and malate dehydrogenase (MDH)). The results showed that tea polyphenols combined with heat had a significant synergistic effect on Bacillus subtilis spores， and the inactivating effect was more pronounced as the concentration and temperature increased. After 1.6 g/L tea polyphenol combined with 100 °C treatment of spores， the total number of colonies decreased by 2.45 lg(CFU/mL)， nucleic acid leakage and conductivity increased significantly (P < 0.05)， OD260nm increased from 0.05 to 1.08， and conductivity increased from 6.61 ms/cm to 71.46 ms/cm， indicating that the treatment could disrupt the cell membrane of Bacillus subtilis spores. Scanning electron microscopy revealed that the morphology of Bacillus subtilis spores subjected to the tea polyphenol combined with heat treatment was wrinkled and depressed， and their ATP， SDH and MDH activities were significantly reduced (P < 0.05)， as shown by a decrease of 0.16 U/mg in ATPase activity， 5.3 U/mg in SDH enzyme activity and 18.7 U/mg in MDH enzyme activity， indicating that the tea polyphenol combined with heat treatment could well disrupt the energy metabolism of Bacillus subtilis spores. In conclusion， tea polyphenol combined with heat treatment can disrupt the cell structure of Bacillus subtilis spores， and at the same time inhibit the activity of related enzymes in the respiratory metabolic pathway， which affects the normal growth of the bacterium and eventually leads to its death.

Abstract:In order to explore the role of pmrA gene in acid tolerance resistance and biofilm formation of Salmonella typhimurium(S. typhimurium) induced after acid stress. Measuring the growth curve， acid tolerance response， and biofilm formation ability of the wild-type (WT) strain of S. typhimurium and pmrA deletion mutant strain (ΔpmrA) to preliminarily confirm whether acid stress and the lack of pmrA affect the biofilm formation ability of S. typhimurium. Further determined the strain characteristics of WT and ΔpmrA such as swimming ability， surface hydrophobic ability and self-aggregation. At the same time， metabolic activity， extracellular polymeric substance (EPS) content and biofilm microstructure of the biofilm formation also should be analyzed to explore the mechanism of pmrA deletion on the biofilm formation ability of acid stressed S. typhimurium. The result: After acid stress， the acid tolerance of ΔpmrA was 53.92 % of WT. On the 4th day of biofilm culture， the biofilm formation of ΔpmrA was only 54.68% of WT. The swimming ability and hydrophobicity of ΔpmrA were 35.20% and 59.10% of WT， respectively. After acid stress， the biofilm metabolic activity and the extracellular polymeric substances content of ΔpmrA were increased to a certain extent compared with those which had not experienced， however， they were dramatically lower than those of the WT strain(P<0.05). In the meantime， the three-dimensional structure of the biofilm of the ΔpmrA was still relatively scattered and the number of living cells in the membrane were prominently less than the WT strain (P<0.05). Conclusion: pmrA gene was closely associated with S. Typhimurium， especially in acid tolerance response and biofilm formation.

Abstract:Objective: This study aimed to uncover antimicrobial activity and mechanism of LG-EO on Vibrio parahaemolyticus(VP). Methods: The antimicrobial activity and possible mechanism of LG-EO on VP were investigated through MIC(minimum inhibitory concentration)， time-kill assay， AKP (alkaline phosphatase) activity in supernatant， leakage of electrical conductivity(EC) and protein， cells morphology， membrane potential， respiratory chain dehydrogenase activity and intracellular DNA content and structure. Results: The MIC of LG-EO against three VP strains was about 80 μg/mL to 120 μg/mL， and the killing efficacy enhanced with increasing concentration at 80-280 μg/mL and extension of treated time. Treatment with 240 μg/mL LG-EO for 10 min resulted in no viable bacterial count of all three VP strains (detection limit 1lg CFU/mL). Treated with LG-EO above MIC， the integrity of the cell wall and membrane was disrupted， leading to a rise in AKP activity， protein content and conductivity in the supernatant and changes in cellular ultrastructure. In the VP strains treated LG-EO， cell membrane potential reduced， and activities of respiratory chain dehydrogenases and ATPases decreased， indicating the energy metabolism of VP was interrupted. Moreover， LG-EO could interact with bacterial DNA via intercalation， to disturb the normal cellular functions. Conclusion: LG-EO showed strong antimicrobial effect against VP by disrupting cell wall and membrane， interfering with cellular energy metabolism， causing DNA loss or denaturation. Thus， LG-EO is expected to be an alternative for novel multifunctional food additive with bacteriostatic action in aquatic food industries.

Abstract:In this research， the effects of different doses of blueberry and red cabbage anthocyanin on weight， exercise exploration， cognitive memory and other aspects of mice were studied by constructing D-galactose-induced aging mice model. The results showed that 120 mg/(kg·d) of blueberry anthocyanin and 60 mg/(kg·d) of purple cabbage could significantly improve the learning and memory ability of aging mice， significantly increase the activities of SOD and GSH-PX in serum and brain of aging mice (P<0.05) and inhibit the production of lipofuscin.

Abstract:Objective: This study aims to analyze the reasons why freeze-drying affects the survival of Lactobacillus paracasei PC-01 cells from the perspective of proteome. Method: Set different fermentation temperatures to 32.5 ℃ and 37 ℃， respectively， high-density fermentation of Lactobacillus paracasei PC-01 and freeze-drying， taking samples before and after freeze-drying， using TMT technology for protein quantitative determination， KEGG function annotation and enrichment analysis were performed on the identified differential proteins， and the mechanism of the differential expression of the proteins on the survival of the bacteria in the two experimental groups was studied. Result: The experimental results showed that the number of viable bacteria before and after freeze-drying of the high-density fermentation of Lactobacillus paracasei PC-01 at 32.5 ℃ was significantly higher than that of the 37 ℃ experimental group. The study found that the up-regulated proteins were concentrated in carbohydrate metabolism and membrane transport. In terms of pathways， the proteins with large differences before and after freeze-drying are aldehyde ketone reductase， 4-oxalocrotonic acid tautomerase， dipeptidase， GNAT family N-acetyltransferase， phosphoribosylglycinamide formyl proteins such as transferase. Conclusion: The development of this research has enabled us to understand the changes in the internal molecules of Lactobacillus paracasei PC-01 before and after freeze-drying. According to the functions of key differential proteins， freeze-drying mainly affects freezing resistance， membrane transport capacity and cell metabolism. The cells of Lactobacillus paracasei PC-01 strain survived. This can provide a reference for the industrial production of Lactobacillus paracasei PC-01.

Abstract:Bitter pyroglutamate peptide pGlu-LFNPSTNPWHSP(PGP) is one of the crucial compounds in Huangjiu. In this paper， six proteases were screened to degrade bitter peptide PGP in the simulated Huangjiu， and the degradation rate of PGP combined with effect on the quality of Huangjiu was studied to evaluate potential application of different proteases in reducing the bitterness of Huangjiu. Results showed different proteases had great differences in the degradation of bitter peptides， among them， flavor protease， papain and acid protease had better degradation effects， reaching 95.7%， 79.8% and 24.7%， respectively. Then three effective proteases were applied to commercially Huangjiu， flavor protease had the best effect on reducing bitterness， degradation of PGP reaching 25.2%， and bitterness intensity from 7.2 to 5.8， while volatile compounds had no significant effect. Using ultra-performance liquid chromatography-quadrupole-time-of-flight-MS(UPLC-QTOF-MS)， results showed that the flavor protease was a multi-site enzymatic hydrolysis， which could enzymatically hydrolyze PGP to form tryptophan (W) and pyroglutamate leucine (pGlu-L) and other small molecule amino acids and peptide fragments. This study revealed new insights into reducing bitterness of Huangjiu， which may offer a possibility to reduce the bitterness and improve the quality of Huangjiu.

Abstract:Six strains of lactic acid bacteria were used for Pueraria lobata enzymes pure fermentation. After fermentation， the number of viable bacteria count， pH values， total acidity， reducing sugar content， and total phenols content of Pueraria lobata enzymes were determined. Two in vitro antioxidant activity determination methods (ABTS and FRAP) were used to evaluate the antioxidant capacity of fermented Pueraria lobata enzymes. The contents of major isoflavones such as puerarin and major organic acids such as lactic acid in Pueraria Lobata enzymes were determined by high performance liquid chromatography. A principal component analysis (PCA) method was used to fit the overall data and establish a comprehensive evaluation model to select the strains suitable for fermentation of Pueraria Lobata enzymes. The results showed that the fermented Pueraria lobata enzymes all had a viable count of 8.0 lg (CFU/mL) and the pH value decreased to below 3.60. The reducing sugar content decreased from 9.1% to 17.9% after fermentation， and the total acid content reached up to 8.47 g/1 000 g. The composition and content of organic acids changed significantly. The total phenols content of Pueraria lobata enzymes did not change significantly after fermentation， and the in vitro antioxidant activity was effectively maintained. In addition， the contents of daidzein and genistein increased up to 40.7% and 39.9% after fermentation. The PCA results showed that cumulative variance contribution rate of the first three principal components was 85.9%， which could reflect the quality of the fermented enzyme comprehensively. Lactobacillus delbrueckii subsp. bulgaricus GIM1.155(1.825 points)， Lactobacillus acidophilus GIM1.321(1.174 points) and Lactiplantibacillus plantarum R4 (0.621 points) ranked high in the overall evaluation score， indicating that they performed better in terms of growth， metabolism and functions. Compared with pure fermentation， the quality of Pueraria lobata enzymes prepared using these three strains as a mixed starter culture was improved. The results of the study can provide a theoretical reference for the mixed culture fermentation of Pueraria lobata enzymes.

Abstract:To investigate the effects of different fermentation strategies of Schizosaccharomyce spomb S17 and Torulaspora delbrueckii R86 on the physicochemical indexes， color and aroma quality of Cabernet Sauvignon rosé wine， and to lay the theoretical foundation for the enhancement of wine quality by adopting non-Saccharomyces enological yeasts. In this study， Cabernet Sauvignon from XiGe winery in Ningxia were used as the test material， and a strategy of simultaneous and sequential inoculation of two strains was designed to make rosé wine， with commercial Saccharomyces cerevisiae CECA fermented alone as the control. After vinification， the basic physicochemical indexes， color and aroma components of the wine samples were analyzed， and the aroma characteristics were quantitatively characterized by sensory tasting. Results indicated that the volatile acid content of the wine samples co-fermented with S17 and R68(0.29 g/L) was much lower than that of the treatment groups fermented with S17 alone (0.81 g/L) and fermented with S17 followed by R68 (0.78 g/L)； the malic acid content (0.62 g/L) was lower than that of R68 alone (0.85 g/L) and fermented with R68 followed by S17 (0.71 g/L). The three mixed fermentation strategies displayed higher levels of anthocyanin and pyruvic acid and a body rich in color， which enhanced the stability of the wine color. The wine samples co-fermented with S17 and R68 showed outstanding ester content (21 525.60 μg/L) and increased the content of volatile compounds such as alloysol， limonene， n-octanal and phenylethylaldehyde. In conclusion， co-inoculation of S. pombe and T. delbrueckii has the potential to reduce volatile acids， enhance the fruitiness and aromatic complexity of the wine， and contribute to improving the color quality of the wine.

Abstract:To explore the properties of active peptide in hairy tofu of fermented soybean curd，the process conditions， isolation and purification， antioxidant ability in vitro and amino acid composition of bioactive peptides in hairy tofu of fermented soybean curd were studied. The results showed that the highest content of bioactive peptide was from alkaline protease hydrolysis on the single enzyme method. The content of bioactive peptide from alkaline protease enzymolysis extraction was (69.441 ± 1.033) mg/g and 66.07% higher than that without alkaline protease， under the optimal extraction process conditions on response surface methodology as follows: material to liquid ratio 1∶50(g/mL)， enzyme amount 2 500 U/g， enzymolysis temperature 50.78 ℃， enzymatic hydrolysis pH 5.5， enzymolysis time 2.08 h. The total reducing force， the clearance of the ABTS， DPPH and hydroxyl radicals of the bioactive peptide from alkaline protease enzymolysis extraction were increased by 37.80%， 22.91%， 31.75% and 62.46% than that without alkaline protease， respectively. The bioactive peptide extraction with molecular <3 ku and 3-10 ku were sieved by ultrafiltration， than the same concentration enzyme lysates with out ultrafiltration， the clearance of the ABTS radicals increased by 145.26% and 74.71% and clearance of the DPPH radicals increased by 93.41% and 72.44% than the same concentration with out ultrafiltration. The amino acid composition of bioactive peptide extraction with alkaline protease under the optimal process were standard AA accounted to 73.01%， essential AA accounted to 37.74%， flavor AA accounted to 17.39% and officinal AA accounted to 43.67%. Luo's hairy toufu in Chengkan village of Huizhou district was an excellent source of food origin bioactive peptides with good antioxidant， nutritional and medicinal health functions， so it had great value in development and utilization.

Abstract:Glutinous rice and japonica rice were selected as the raw materials. In addition， Lactobacillus acidophilus HSP001， Lactobacillus sakei HSP002 and their compound strains were used as starters to investigate effects of Lactic acid bacteria (LAB) fermentation on the physicochemical characteristics of mixed rice flour and the quality of rice cakes. The results showed that， LAB fermentation significantly improved the water-holding capacity of mixed rice flour. Furthermore， the mixed rice flour fermented by Lactobacillus sakei HSP002 exhibited excellent pasting properties due to the highest trough viscosity (1 295 cP)， the lowest breakdown value (394 cP)， and the largest final viscosity (1 295 cP). In the dynamic rheological characteristics study， the mixed rice dough prepared using Lactobacillus acidophilus HSP001 possessed good viscoelasticity， which was attributed to the largest storage modulus (G') and loss modulus (G'')， and the samllest tangent value (tan δ). In terms of texture and cooking properties of rice cakes， the rice cakes prepared using Lactobacillus acidophilus HSP001 owned the lowest hardness and chewability， the best cohesiveness， and the least cooking loss rate. Moreover， the rice cakes prepared using compound starter presented good sensory quality. Compared with rice cakes prepared using a single strain， the types and contents of aldehydes and ester in rice cakes prepared using compound starter increased， and the products had a unique fermentation flavor. These results provide a reference for the research and production of traditional rice-based fermented foods.

Abstract:Low field nuclear magnetic resonance (LF-NMR) was used to detect the relaxation time and proportion of water in different binding states in frozen cooked noodles， and the effects of cooking time and frozen storage time on water state and distribution of noodles before and after recooking were analyzed. The results showed that the water in frozen cooked noodles existed in three binding states: strong bound water(T21，0.20-0.69 ms. A21，3.97%-11.14%)， weak bound water(T22，1.44-3.77 ms. A22，5.87%-15.24%)and free water(T23，33.36-67.20 ms. A23，73.62%-89.68%). The bonding of water and macromolecular substances in noodles decreased， the water holding capacity of noodles decreased， the difference between water content in the center and edge of noodles gradually decreased， and the water gradient gradually decreased during frozen storage of 120 days. In addition， the water content between center and edge still shower significant difference for precooked noodles of 7 min and 9 min storaged till 28 days(P＜0.05)， But the water gradient disappeared for precooked noodles cooking for 11 minutes. Properly shortening the precooking time of noodles could prolong the retention time of noodle water gradient during frozen storage， and then improve the quality of frozen cooked noodles. The study will provide theoretical guidance for quality improvement of frozen cooked noodles during processing and logistics.

Abstract:In this study， the best solid adsorbent for decolorization was first determined by single-factor test， and then the effects of decolorization temperature， solid adsorbent addition and decolorization time on the decolorization rate of fish oil were investigated. On this basis， the Box-Behnken(BB) experimental design was used to optimize the decolorization conditions of fish oil， and the results of the BB test were analyzed by response surface methodology (RSM) and artificial neural network (ANN). The results showed that the activated white clay had the best decolorization effect， and the decolorization rate tended to increase and then decrease with the increase of decolorization temperature， solid adsorbent addition and decolorization time； the correlation coefficient r， determination coefficient R2， root mean square error RMSE and mean square error MSE values of RSM and ANN models were 0.9647， 0.9307， 1.1000， 1.2100 and compared with the RSM model， the ANN model fits better and has less error between the measured and predicted values， so it is more suitable as a prediction model for the decolorization rate of fish oil. Therefore， the RSM and ANN models were selected to jointly optimize the fish oil decolorization process. Firstly， the optimal decolorization conditions were selected by the RSM model， with decolorization temperature of 93.79 °C， solid adsorbent addition of 4.80%， and decolorization time of 9.69 min. Subsequently， the above conditions were brought into the ANN model， and the maximum decolorization rate of fish oil was finally obtained as 99.53%. The results of this study showed that the RSM-ANN model has strong accuracy and applicability， which provides a new idea for process optimization in food research.

Abstract:Zein/ pectin composite colloidal particles were prepared by anti-solvent combined with heat treatment， which were further used to construct cinnamon essential oil-encapsulated Pickering emulsion by high-speed homogeneous emulsification. The effect of zein/pectin mass ratio， pH value and the proportion of oil phase on the ζ-potential， average particle size， particle size distribution (PSD) and encapsulation efficiency of the emulsion were investigated， and the response surface methodology (RSM) was used to optimize the preparation process. The RSM results showed that the proportion of oil phase was a critical factor affecting Pickering emulsion and the interaction between pH value and the proportion of oil phase was the most significant. When zein/pectin mass ratio was 10 ∶ 4，pH value was 3 and proportion of oil phase was 50%， the comprehensive score of the emulsion could reach 85.52. Under the above optimized conditions， the encapsulation efficiency， average particle size， PSD and ζ-potential of Pickering emulsion were(82.14 ± 4.86)%， (15.69 ± 0.17) μm， (1.277 ± 0.011) μm， and (-30.75 ± 1.63) mV， respectively. The experimental results provide an experimental reference for the preparation of Pickering emulsion containing plant essential oils.

Abstract:In this study， egg white protein gel particles were used as an emulsifier to prepare Pickering emulsion. The effects of oil phase ratio and particles concentration on egg white protein Pickering emulsion (EWP-PE) were studied. Loaded with β-carotene， the thermal stability and storage stability of the emulsion were studied. The results showed that: 1) When the content of egg white protein was 4% and the oil phase ratio was 40%， the particle size of EWP-PE was 47.37 μm， the Zeta- potential value was -30.3 mV and the emulsion index was 14.2%. At this condition， the EWP-PE had good stability. 2) When EWP-PE was loaded with β-carotene， its particle size increased significantly with temperature increasing (P<0.05). At 80 ℃， the retention rate of β-carotene in emulsion still maintained 65.8%. After 15 days of storage， the retention rate of β-carotene in EWP-PE was 42.8%， which was significantly higher than that in oil phase (27.5%). In conclusion， EWP-PE loaded with β-carotene showed good thermal stability and storage stability. This study provided reference data for the application of β-carotene in food field.

Abstract:To investigate the effect of high CO₂ stress on cell wall metabolism of Actinidia arguta. Based on the ‘Longcheng NO. 2’ as the experimental material， the air-regulated element A (CK2) and air-regulated element B (TR) are respectively pasted， and the air-regulated element CK1 is not pasted， research during the high concentration of CO₂ stress on frozen fruit peel strength， cell wall polysaccharides， cell wall degradation enzymes and reactive oxygen species (ROS)， the microstructure of fruit peel in different treatment groups was analyzed on day 60. The results showed that the suitable storage environment (O₂ content 17.00%-20.92%， CO₂ content 1.63%-2.78%) was formed in CK2 group during cold storage. TR group formed a high concentration of CO₂ stress storage environment (O₂ content is 11.22%-15.55%， CO₂ content is 9.00%-11.93%). Compared with CK1 and CK2， TR group could inhibit the decrease of peel strength， affect the normal decrease of propectin， cellulose and hemicellulose contents， inhibit the increase of water-soluble pectin， and decrease the activities of polygalacturonase (PG)， cellulase (CX)， β -galactosidase (β-Gal) and amylase. The activity of superoxide anion (O₂·-)， content of hydrogen peroxide (H2O₂)， malondialdehyde (MDA) and relative electrical conductivity were increased. At the same time， the structure of pericarp cells was seriously damaged， the epidermis was rough and disorderly， the cell gap was enlarged， and the tissue contour was blurred and disordered. Further analysis showed that the CO₂ content in the TR group exceeded the tolerance threshold during storage， which resulted in the slow decline of fruit rigidity and hardness， affected the process of post-ripening， inhibited the metabolic transformation of cell wall polysaccharide， the accumulation of free radicals in the tissue membrane lipid peroxidation， damaged cell structure， and lost commercial property.

Abstract:Objective: To determine the optimal dose of high energy electron beam irradiation to treat the Cucurbita pepo L. subsp. Pepo and improve its storage characteristics. Method: This experiment irradiated the two sides of Cucurbita pepo L. subsp. Pepo with high energy electron beams at doses of 0.3， 0.4 kGy and 0.5 kGy respectively. Results: 0.4 kGy high energy electron beam irradiation can reduce the rotting rate of Cucurbita pepo L. subsp. Pepo by 16.18%， its total phenol content remained at a high level， the soluble solid content decreased， and the accumulation of malondialdehyde decreased. And the respiratory intensity， weight loss rate， color saturation， titratable acid and peroxidase activity were not significantly different from the control melon (P>0.05). At this dose， the peak activity of superoxide dismutase was 1.14 times that of the control melon， and the ultrastructure of the melon silk cell was complete. When stored for 120 days， the brittleness， trigonelline content and phenylalanine ammonia-lyase activity were 1.58， 3.34 times and 1.84 times higher than those of the control melon， respectively. Conclusion: So 0.4 kGy irradiated Cucurbita pepo L. subsp. Pepo two sides is the suitable radiation dose， it is expected to be used for the storage and preservation of Cucurbita pepo L. subsp. Pepo.

Abstract:Different lighting time affects the content of bioactive substances in postharvest kale sprouts. The contents of glucosinolates， vitamin C， total polyphenols， chlorophyll， carotenoids， and total antioxidant capacity in Chinese kale sprouts were analyzed during postharvest storage at room temperature after different treatments including shading treatment group (0 h light / 24 h darkness， 8 h light / 16 h darkness and 12 h light / 12 h darkness) and supplementary light treatment group (24 h light / 0 h darkness)， and the natural photoperiod (16 h light / 8 h darkness) was used as control. The results showed that total glucosinolates content in shading treatment T1 (0 h light / 24 h dark) increased significantly by 27.96% and 19.73% respectively when stored for 2 d and 3 d compared with the control， and the shading treatment T2 (8 h light / 16 h dark) increased remarkably by 27.70% and 10.88%， respectively. In addition， shading treatment effectively maintained the contents of chlorophyll and carotenoids in Chinese kale sprouts during storage. The postharvest light time had no significant effect on the total polyphenol content and antioxidant capacity. The research results provide a theoretical basis for setting the light time reasonably to postpone the decrease of Chinese kale sprouts after harvest， which is potential in maintaining the quality of Chinese kale sprouts during the postharvest period.

Abstract:In order to investigate the effect of exogenous chlorogenic acid on apple gray mold resistance and its own chlorogenic acid synthesis， Fuji apple was treated with 300 μg/mL chlorogenic acid solution for 30 min， and then inoculated with gray mold after 1 d， and treated with water as the control group (CK)， the spot diameter and incidence were counted， and the changes in gene expression and enzyme activity of enzymes related to chlorogenic acid synthesis were determined. The results showed that after treatment with 300 μg/mL chlorogenic acid， the activities of PALC4H and 4CL， the key enzymes upstream of the phenolpropane metabolic pathway， increased significantly， and the corresponding gene expressions all reached the peak after 6 h of inoculation with gray mold， which were 10， 5 times and 2.5 times of the CK group， respectively. Meanwhile， the gene expression of the downstream synthesis gene hydroxycinnamic acid-CoA acid ester/ quinic acid hydroxycinnamic acid transferase (HCT/HQT) reached a peak at 48 h in the treated group， which was about 3 times higher than that in the CK group， and there were two higher gene expressions at 6 h and 12 h in the treated group for coumaric acid 3'-hydroxylase (C3H)， which were about 3 times and 5 times higher than that in the CK group， respectively， stimulating chlorogenic acid synthesis This stimulated the increase of chlorogenic acid synthesis， which induced the increase of fruit resistance， effectively reduced the incidence of apple gray mold and slowed down the expansion of spots. Conclusion: Exogenous chlorogenic acid treatment can induce the response of enzymes of the phenolpropane metabolic pathway， increase the level of chlorogenic acid in apples， and effectively suppress apple gray mold.

Abstract:To clarify the residue characteristics of ametryn in the growth cycle of corn， and comprehensively evaluate its long-term dietary risk to Chinese residents， an efficient and sensitive analytical method was developed for ametryn in corn， corn stover， sweet corn and sweet corn stover in the study. The samples were extracted with acetonitrile， purified by dispersive solid phase extraction (d-SPE)， and determined by gas chromatography-mass spectrometry (GC-MS). The mean recoveries and relative standard deviations were 82.0%-108.0% and 1.3%-14.4%， respectively， and the limit of quantitation was up to 0.001 mg/kg. Ametryn can be stored stably for 280 d in corn， corn stover， sweet corn and sweet corn stover at -20 ℃ under dark， and the average degradation rates were -1.3%-18.9%. The residues of ametryn in corn stover and sweet corn stover were significantly higher than those in corn and sweet corn stover (P < 0.05). The supervised trials median residue (STMRs) and the highest residues (HRs) of ametryn in four corn products were 0.003-0.066 and 0.009-0.254 mg/kg， respectively. The chronic dietary risk (ADI%) of ametryn in registered crops (corn， sugarcane and pineapple) was 0.09%-1.18%. The ADI% of ametryn in urban areas were significantly higher than that in rural areas， and the ADI% of ametryn in female were significantly higher than that in male. The children aged 2-6 years suffered the highest exposure of ametryn (ADI%， 0.83%-1.18%). Although ametryn have an acceptable dietary risk for Chinese consumers， it's necessary to continuously pay attention to the increasing risks caused by the bioaccumulation， especially for children. Meanwhile， the high potential exposure risk of ametryn from corn stover should be alerted in forage or agricultural applications.

Abstract:Objective: Through high-throughput sequencing， the bacterial distribution characteristics of Lingnan mulberry fruit wine with different natural fermentation cycles were explored， so as to improve the food safety and quality of fermented fruit wine products. Methods: A 6-month short-term fermented mulberry new wine (STF) and an 18-month long-term fermented mulberry aged wine (LTF) from the Chuangxian Fruit Mulberry Picking Garden in Yonghe Town， Guangzhou， Lingnan Province were collected， and the total biological DNA of the whole fermentation liquid was extracted， and the 16S rRNA bacterial conserved region amplification， purification and sequencing analysis were performed， and the sequencing data were further processed by professional biological analysis software， including species annotation， cluster analysis， potential biological function prediction analysis， diversity analysis， etc. Results: The average number of bacterial tags for new wine and aging wine were 126 126 and 127 401 respectively， and the average number of OTUs were 746 and 789 respectively by high-throughput sequencing. After species annotation， 10 main phyla are Proteobacteria， Bacteroidetes， Firmicutes， Cyanobacteria， Actinobacteria， Epsilonbacteraeota， Acidobacteria， Planctomycetes， Gemmatimonadetes and Chloroflexi. Sediminibacterium， Reyranella， Curvibacter， Streptococcus， Acinetobacter， Bradyrhizobium， Ralstonia， Burkholderia-Caballeronia-Paraburkholderia， Bacteroides and Actinobacteria are mainly genus. Sediminibacterium in new wine was significantly higher than that of aged wine (P<0.05)， and Acinetobacter was significantly lower than that of aged wine (P<0.05). Conclusion: Lingnan mulberry fruit wine bacteria with different fermentation cycles have different richness of microbial community diversity and differentiated bacterial community composition. The functional prediction analysis shows that the LTF sample flora is related to immune diseases， cardiovascular diseases， development， signaling molecules and interactions. The increase indicates that the fermentation time of mulberry fruit wine is too long， which increases the food safety risk of the product.

Abstract:In recent years， the problem of antibiotic residues in food is one of the food safety problems that people are concerned about. To determine the residue of semicarbazide (SEM) in crayfish， this study provides a method for the determination of SEM residues in crayfish based on Excitation-emission matrix fluorescence combined with chemometrics. After simple pretreatment， the sample was derivatized with 2-hydroxy-1-naphthylaldehyde and SEM to produce 2-hydroxy-naphthylaldehyde nitrofuran metabolites derivative (SEM-HN) with fluorescence properties. The fluorescence spectrometer collects the fluorescence spectra of the sample to obtain the three-dimensional fluorescence data matrix. After the blank sample was deducted， the excitation-emission matrix fluorescence data matrix was analyzed using PARAFAC and ATLD in chemometrics. Both algorithms can get better quantitative analysis results. In order to evaluate the accuracy of the two algorithms， the quality factors were calculated: sensitivity (SEN)， selectivity (SEL)， detection limit (LOD) and predicted root mean square error (RMSEP). The results show that the accuracy of the two algorithms is good. In order to further verify the performance of PARAFAC and ATLD， EJCR test analysis is used. The results show that ATLD algorithm is better than PARAFAC algorithm. Excitation-emission matrix fluorescence combined with ATLD algorithm can quickly determine SEM residues in crayfish.

Abstract:In recent years， the incidence rate of Type 2 diabetes mellitus (T2DM) has been increasing. In 2019， there were about 417 million T2DM patients worldwide and 104 million in China， which has been a threat to human health and quality of life. The main symptom of T2DM is insulin resistance (IR) that the body cannot respond normally to insulin. Excessive intake of high fat diet (HFD) is the major incentive of IR. Many studies have proved that HFD can lead to intestinal micro-ecological imbalance， which in turn induces the IR of metabolic tissues. Researches have shown that the intestinal micro-ecology mainly controls the body's glucose and lipid metabolism by regulating the body's energy metabolism and inflammation. Further research suggests that bile acid metabolism disorder caused by intestinal micro-ecological imbalance is also another important cause of insulin resistance in the body. Therefore， this article will review the interactions among high-fat diet， intestinal flora and insulin resistance from different aspects， such as high-fat diet and insulin resistance， intestinal flora and insulin resistance， and the‘gut microbiota-bile acid-insulin resistance’. Although there is no evidence to confirm the causal relationship of‘high-fat diet-intestinal flora-bile acid’ in the occurrence and development of insulin resistance， but the mutual regulations between intestinal flora and bile acid metabolism provide enlightenment for insulin resistance， prevention and treatment of T2DM.

Abstract:Anthocyanin is a natural edible functional pigment widely found in flowers， vegetables and fruits. It has various physiological activities and has a positive effect on human health. The latest in vivo and in vitro experimental studies show that anthocyanins can also regulate uric acid metabolism， which provides a new direction for its diversified development. This article systematically summarizes the structure， component analysis， physiological function and uric acid synthesis and metabolism process of anthocyanins， and explored the mechanism of anthocyanins regulation of uric acid metabolism， so as to provide reference for the research and development of healthy food and disease regulation.

Abstract:Alternaria toxins， as the secondary metabolites produced by Alternaria species， are widely contaminated in crops and agricultural products such as cereals， fruits， vegetables， nuts， oil crops， etc.， which shows different degrees of acute toxicity， genetic toxicity， reproductive and developmental toxicity to humans and animals. However， the available studies of its contamination level， dietary exposure and toxic effects are still relatively limited and short of systematization， which making it difficult to carry out a comprehensive risk assessment. Therefore， this review systematically demonstrated the contamination status and toxicological profiles of typical alternaria toxins， aiming to provide a more comprehensive and systematic theoretical basis for the further assessment of exposure level of alternaria toxins， comprehensive safety evaluation， and scientific formulation of limit standards and regulations.

Abstract:ε-Poly-L-lysine (ε-PL) is a new natural food preservative approved by our country since 2014. It has attracted extensive attention from the food industry due to its excellent characteristics， such as wide antibacterial spectrum， good water solubility， high safety， high temperature resistance and good stability. Thus， ε-PL has become a key natural food preservative instead of chemical food preservatives. This review is firstly introduced ε-PL's physicochemical and biological properties and microbial production methods. Then， the worldwide achievements of ε-PL's antimicrobial mechanisms and applications in food industry in recent decade years are systematically reviewed. Finally， the future research on ε-PL is prospected based on the analysis of the application bottleneck of ε-PL in food industry. It is expected that this review provide references for the wide use of ε-PL in China's food industry.

Abstract:Shellfish processing products tastes delicious and has high nutritional value， which is deeply loved by consumers. However， the fishy odor of shellfish and its products can also affects the taste and sales of products. Therefore， a deeper understanding of the formation and regulation of fishy taste substances will promote the development of shellfish processing industry to a certain extent. In this paper， the research progress of main fishy odor compounds and their formation mechanism in shellfish in recent years were reviewed， aiming to provide theoretical basis for the regulation of fishy odor compounds in aquatic food and the improvement of flavor quality， which is of great significance for the innovation and enrichment of basic theories of aquatic product processing.

Abstract:Green vegetables refer to a group of vegetables that are green in appearance because of their high chlorophyll content. Due to the combined action of enzymes and microorganisms can cause vegetable chlorosis， sensory deterioration， and even decay， resulting in a lot of waste， it is of great importance to study the preservation and green protection technique for postharvest storage of vegetables. In this paper， the mechanisms of chlorosis and decay of green vegetables， the effects of non-thermal physical， chemical， biological and their combination on the quality of vegetables are reviewed. The problems of these technologies are expounded， and the research prospects are prospected.