Abstract:China has become the largest country of agricultural products production with the increase of the total output of fresh agricultural products year by year. To realize the transformation from a large agricultural country to an agricultural power， the development and application of green preservation technology in the supply chain is one of the key contents. Based on the development and challenges of agricultural product supply chain， the application and research progress of new food technologies in the green preservation of fresh agricultural product supply chain including sorting， preservation， packaging， traceability， etc.， are reviewed， and the main research directions for future development are proposed in this paper. The aim of this review is to promote the application and development of green preservation technology in modern agricultural supply chain.

Abstract:The intestinal microbial metabolism of procyanidin B1 was explored by using porcine caecal microorganisms through static culture in vitro. Under anaerobic operating conditions， firstly， we obtained the intestinal microorganisms from the cecal lumen of freshly slaughtered pigs， which required for the incubation model， then incubated the procyanidin B1 in prepared the culture medium， and collected the incubation solution at 0， 2， 4， 6， 10， 18 h， Use UHPLC-TOF-MS/MS to detect metabolites at different time points， and use non-targeted metabolomics analysis methods to determine differential metabolites in the metabolic process of procyanidin B1， and analyze metabolic pathway of procyanidin B1. Results showed: 21 kinds of metabolites were screened and identified. The metabolism of procyanidin B1 by the intestinal flora was fairly rapid， and it was exhausted at 6 h； the metabolites catechins and 5-(3'，4'-dihydroxyphenyl)-γ-valerolactone was produced in large quantities between 2-4 h； Phenylpropionic acid and benzoic acid were the main metabolites， which reach a peak at 6 h and continued producing between 4-18 h. Analyze the metabolic pathways of procyanidin B1 based on the results above. We believed that procyanidin B1 can be metabolized through three pathways， namely: the flavan bond breaks， the lower structure forms catechins， and the catechins further open the C ring to form catechins. C-ring-opening product； the lower structural unit of procyanidin B1 undergoes cleavage of the A ring to form phenyl-γ-valerolactone； the cleavage of the upper structural unit of procyanidin B1 directly forms phenolic acids.

Abstract:Lactobacillus bulgaricus is the main strain of fermented dairy products， but it is often subjected to various environmental stresses. For revealing the anti-stress protection mechanism， the Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 was used to determine the sublethal and minimum lethal conditions of bacterial cells under different environmental stresses (acid， salt， bile salt， oxygen， and cold). By comparing the survival rate of bacterial cells treated with sublethal conditions of different environmental stresses， the cross protective effects of bacterial cells under multiple stress environments were studied. According to the transcriptomics sequencing results of ATCC 11842 strain under acid stress and acid-cold stress， 11 genes related to sugar metabolism， amino acid metabolism， transport system， molecular chaperone， and stress were selected， and the RT-qPCR technology was used to analyze the expression changes of these genes at the transcription level under different environmental stresses. The results show that: ATCC 11842 strain can significantly improve the survival rate under the minimum lethal conditions after pretreatment with acid stress and oxygen stress sublethal conditions(pH 4.8，40 min；15 mmol/L H2O₂，1 h). Among the 11 genes that respond to acid stress in the ATCC 11842 strain， 10 genes were found to also respond to other different environmental stresses. The expression of LDB_RS02110， LDB-RS00810， LDB_RS04920， LDB_RS05285， LDB_RS00230， LDB_RS06340， LDB_RS05615， LDB-RS01180， LDB_RS06995 and LDB_RS03130 were significantly up-regulated and down-regulated.

Abstract:Phosphatase is a key enzyme involved in the degradation of inosinic acid(IMP) in aquatic products. Acid phosphatase from sea bass(Lateolabrax japonicus) liver was used as the research object. Through homologous modeling， molecular docking and other means， ACP inhibitors were selected from traditional Chinese medicine compounds and their inhibition mechanism was studied. The results showed that benzoic acid， quercetin， hexadecanoic acid and dihydroresveratrol have strong inhibitory effect on phosphatase activity. The results showed that hydrogen bond and van der Waals force were the main driving forces for the combination of hexadecanoic acid and ACP， which results in the decrease of the fluorescence intensity， the red shift of the maximum emission wavelength of ACP. The combination of hexadecanoic acid with the active center of ACP changed the two-dimensional and three-dimensional structure of ACP， reduced the contact between ACP and inosinic acid (IMP)， and delays the degradation of IMP.

Abstract:Objective: To study effects of Hippophae rhamnoides polysaccharides(SBP-3) on proliferation， apoptosis， invasion of Hep-G2 cells through p38 pathway. Methods: The proliferation of Hep-G2 cells was detected by CCK-8 method. The apoptosis of Hep-G2 cells was detected by flow cytometry. The migration and invasion of Hep-G2 cells were detected by scratch test and Transwell method. The effect of seabuckthorn polysaccharide on Hep-G2 cells was investigated by Western blot. Results: After 48 hours of SBP-3 treatment， the inhibition rate of each group(125， 250， 500， 1 000 μg/mL)was significantly increased (P<0.05)， and the highest inhibition rate was 60.43% at the concentration of 1 000 μg/mL. Apoptosis of Hep-G2 cells could be induced in each dose group(125， 250， 500 μg/mL) (P<0.01)， and the apoptosis rate gradually increased with the increase of SBP-3 concentration. At the same time， SBP-3 can weeken the invasion and migration ability of cells(P<0.01)， inhibit MMP-2 and MMP-9 protein expression (P<0.01)in p38 signaling pathway. Conclusion: SBP-3 can inhibit the proliferation， apoptosis， migration and invasion of Hep-G2 cells. It is speculated that SBP-3 can further inhibit the expression of MMP-2 and MMP-9 by down regulating the activity of p38MAPK signaling pathway.

Abstract:In order to explore the digestive characteristics of soy hull polysaccharide in gastrointestinal tract， the results show that: the total sugar and uronic acid content of soy hull polysaccharide did not change significantly from oral to small intestine during simulated digestion， its content fluctuated between 126 mg and 29 mg， however， the total sugar content began to decrease at 12 h of fermentation in the large intestine stage and significantly decreased to (71.02 ± 0.45) mg after 48 h of fermentation， the content of reducing sugar increased from (18.04 ± 0.15) mg to (81.13 ± 0.36) mg after digestion， and finally decreased to (51.55 ± 1.31) mg in the subsequent fermentation stage； the absolute value of the potential increased from 3.46 mV to 20.10 mV in the digestion stage and decreased significantly in the large intestine stage. After 48 h of fermentation， the absolute value of the potential changed to 15.26 mV； the particle size showed an obvious downward trend during the whole digestion stage， and the pH value did not change significantly during the oral to small intestinal stages， and decreased from 7.92 to 5.93 in the large intestine stage； the viscosity of digestive juice showed a decreasing trend.

Abstract:The antioxidant activity and structural changes of kidney bean protein hydrolysates during different digestive periods were analyzed by using kidney bean protein as raw material through gastrointestinal simulation model. The results showed that the solubility and hydrolysis degree of kidney bean protein were significantly increased after digestion with gastrointestinal protease. Compared with gastric digestion， the proteolysis degree of kidney bean was increased by 120.27% and the solubility was decreased by 3.46% in gastrointestinal digestion. It was found by electrophoresis pattern and antioxidant activity analysis. After intestinal digestion， the protein subunit hydrolysis was enhanced with the continued action of trypsin， resulting in an increase in low-molecular weight peptides. The subunit bands with molecular weight <14.4 ku were significantly deepened. Compared with simulated gastric digestion， the antioxidant capacity of hydrolysates was significantly enhanced. Total antioxidant capacity， Fe reduction capacity and ABTS clearance rate were increased by 25.31%， 85.76% and 53.80%， respectively. To classify hydrolysates by ultrafiltration， which are produced by the continuous digestion of the gastrointestinal tract respectively for 0.5， 2 and 3 hours. With the prolonging of digestion time， the hydrolysates showed strong antioxidant capacity due to the increase of digestible products with molecular weight less than 10 ku. Fourier transform infrared spectroscopy (FTIR) analysis showed that the hydrolysis of pepsin unfolds the protein structure. The relatively compact β-fold in spatial structure is broken and transformed into a looser β-corner. The stable structure of kidney bean protein was restored after intestinal digestion， and the β-fold increased from 34.63% to 41.29%. The contents of sulfhydryl group， total sulfhydryl group and total sulfur-containing amino acids in gastrointestinal digestions decreased continuously with increasing degree of hydrolysis. After intestinal digestion， the content of exposed sulfhydryl group， total sulfhydryl group and total sulfur-containing amino acids decreased to (4.94±0.23) μmol/g， (6.14±0.20) μmol/g and 2.08 μg/g， respectively. SEM scanning analysis showed that flocculent aggregation occurred during hydrolysis of kidney bean protein. After simulated digestion through the intestines compared to gastric digestion. The order of the protein microstructure was increased and the surface of the digested product was fine and granular.

Abstract:Chitosan is a kind of macromolecular polymer with rich source， which has a wide range of application value in many fields， such as chemical industry， food， biology and so on. However， it needs to be degraded into small molecular oligosaccharides to give full play to its activity. As the advantages of enzymatic degradation of chitosan are more and more obvious compared with other methods， the exploration of new stable and efficient chitosanase has attracted the attention of the majority of researchers. According to the chitosanase's amino acid sequence of Bacillus nakamurai in genebank database， we designed the corresponding coding gene and expressed and purified the recombinant protein by E.coli prokaryotic expression system. The results of enzymatic properties showed that the optimum temperature was 37 ℃ and the relative enzyme activity was still 50% after 30 min treatment at 46 ℃， and the optimum pH was 4.5， and 60% relative enzyme activity could be maintained after 60 min treatment at pH 2.5. Ag+ and Hg+ completely inhibited the enzyme activity. Mn2+， Mg2+ and Ca2+ promoted the enzyme activity， while K+， Na+ and EDTA had no obvious effect on the enzyme activity. In this study， the enzymatic properties of chitosanase from B. nakamurai were studied for the first time， which expanded the resources of chitosanase library and provided theoretical basis for the subsequent research and practical application of the enzyme.

Abstract:The dietary fiber in mung bean skin was used as an experimental object in this experiment. In order to improve functional properties of dietary fiber in mung bean skin， we examined the effect of extrusion and/or enzymatic hydrolysis treatment on water holding capacity， oil holding capacity， swelling capacity， cation exchange capacity， glucose adsorption capacity and cholesterol adsorption capacity of skin dietary fiber in mung bean. We also investigated the effect on structural properties of dietary fiber in mung bean skin by scanning electron microscope， X-ray diffraction and Fourier transform infrared spectroscopy. The results showed that the combined treatment could more significantly modify the properties of dietary fiber in mung bean skin than either treatment alone. Compared with the dietary fiber in mung bean skin before and after modification， the water holding capacity， oil holding capacity， swelling capacity， cation exchange capacity and glucose adsorption capacity were enhanced by 1.46， 1.15， 1.87， 6.98 and 1.66 times in the combined treatment group， respectively. The cholesterol adsorption capacity was (2.38±0.05) mg/(mL·g) at pH 2， and (3.45±0.12) mg/(mL·g) at pH 7. The results of scanning electron microscope analysis indicated that the surface structure of dietary fiber in mung bean skin after combined treatment was loose， and more wrinkles and porous characteristics appeared. X-ray diffraction and Fourier transform infrared spectroscopy analysis indicated that the relative crystallinity of dietary fiber in mung bean skin after combined treatment was the lowest， and some cellulose components were redistributed to transform into soluble dietary fiber (SDF). Therefore， extrusion combined with enzymatic hydrolysis treatment can be used as a better method to modify dietary fiber， providing theoretical basis for improving the utilization rate of dietary fiber in mung bean skin and further exploiting its nutritional value.

Abstract:In this experiment， soluble dietary fiber (SDF) was extracted from millet by enzymatic method. The oil holding capacity， solubility and adsorption of cholesterol and NO₂- of SDF were determined， and the monosaccharide composition and molecular weight of SDF were studied. At the same time， the effects of SDF on the growth of Lactobacillus plantarum， Lactobacillus rhamnosus， Lactobacillus fermentans， Lactobacillus acidophilus， Bifidobacterium brevis， Escherichia coli and Staphylococcus aureus were analyzed. The results showed that the oil holding capacity and solubility of SDF were 4.05 g/g and 1.78 g/100mL. When pH was 2.0， the adsorption capacity of SDF for cholesterol and NO₂- was 16.22 μg/g and 6.97 μg/g respectively. At pH 7.0， the adsorption capacity of SDF for cholesterol and NO₂- was 26.31 μg/g and 2.77 μg/g respectively. Infrared spectrum analysis showed that SDF had typical polysaccharide characteristics. Chromatography showed that SDF was a heteropolysaccharide with a molecular weight of 1 784 u. SDF was composed of fucose， arabinose， galactose， glucose， mannose and glucuronic acid with a molar ratio of 0.02 ∶ 0.27 ∶ 0.26 ∶ 98.34 ∶ 0.95 ∶0.15， respectively. In the range of 5~20 mg/mL， SDF showed significant promoting effects on Lactobacillus plantarum， Lactobacillus rhanosus， Lactobacillus fermentans， Lactobacillus acidophilus， and Bifidobacterium brevis， and showed significant inhibitory effects on Escherichia coli and Staphylococcus aureus in a concentration dependent manner. In addition， SDF added to the medium significantly reduced pH compared to the control， which was conducive to the growth and reproduction of beneficial microorganisms in the gut. The results of this experiment can provide a theoretical basis for further study of SDF and development and utilization of millet resources.

Abstract:Enzymatic soybean protein and phospholipids as the main materials， building a sports nutrition food system， through conductance， potential， particle size， SDS-PAGE electrophoresis， ISO-DALT two-dimensional electrophoresis and microscopic observation， the droplet characteristics of aggregates and their composite emulsions and protein subunit changes were systematically studied. The results showed that pepsin could only degrade soybean protein to a limited extent， and the protein subunits were not changed significantly after enzymatic hydrolysis for 30 minutes； when enzymatic hydrolysis of soybean protein (enzymatic hydrolysis for 30 minutes) and phospholipid with the mass ratio of 5∶1， their aggregates had better droplet characteristics (P<0.05)； when the aggregates were prepared with this ratio as the wall material， it was found that the oil phase and water phase ratio of 1∶3 can be formed the more ideal oil-in-water emulsification system (P<0.05)； Compared with the enzymatic soybean protein emulsion， the composite emulsion droplets had a higher average particle size and potential (P<0.05). In the process of in vitro gastric digestion， the droplet characteristics (conductivity， potential and average particle size) of the composite emulsion were significantly higher than that of the enzymatic protein emulsion(P<0.05)， and the protein degradation rate was greater than that of the enzymatic protein emulsion， and all subunits except β subunit could be degraded. Therefore， it was deduced that there was a droplet “self-assembly” process in the in vitro gastric digestion of the composite emulsion， which will help the expansion of application in sports nutrition food for the soybean protein-food-emulsification system， and provide certain theoretical support for clarifying the mechanism of its digestion and absorption.

Abstract:In this study， tape 2 diabetic mellitus(T2DM) were given high fat diet with 10% highland barley and 5%， 10%， 20% germinated highland barley respectively to study the activities of highland barley and germinal highland barley in lowering blood glucose and blood lipid. The results showed that 5%， 10% and 20% germinated highland barley can reduce the fasting plasma glucose， insulin level and insulin sensitive index， serum total cholesterol and low density lipoprotein levels and the content of apolipoprotein B， improve the content of apolipoprotein A and the activity of lecithin cholesterol acyltransferase， to alleviate the glucose and lipid metabolism disorder in T2DM.

Abstract:Mulberry is known as ‘the best health fruit in the 21st century’， however it is not resistant to storage and is extremely perishable. In the research and development of new probiotic fermented mulberry juice functional products， there is a lack of special strains. The black pearl mulberries are used as raw materials， and 12 new probiotic lactic acid bacteria isolated and identified from natural fermented foods are used as test strains. By comparing the acid production characteristics and growth ability of the test strains in the preliminary mulberry juice medium， the test strains were preliminarily screened； the sensory quality of the optimized mulberry juice culture medium was evaluated by the preliminary screening strain， and the strains were re-screened； the quality of the pure-bred fermented mulberry juice products of the re-screened strains was analyzed and evaluated. We studied the laxative effect of pure-bred fermented mulberry juice products on test mice. The results showed that: after preliminary screening and re-screening， a new probiotic suitable for fermenting mulberry juice， namely Lactobacillus plantarum P17， was obtained； the pure-bred fermented mulberry juice product of P17 strain was uniform and stable in tissue. Rich fruity aroma and fermented aroma， physical， chemical and nutrient composition comply with relevant national and industry standards， and the content of live probiotic bacteria reaches 8.7×108 CFU/mL and is rich in polyphenols (199.59 g/kg ± 0.12 g/kg) and anthocyanins (29.12 mg/L ± 0.06 mg/L). Its shelf life is 25 days in 4 ℃， and the number of viable probiotic bacteria is still 9.5×107 CFU/mL； P17 pure-bred fermented mulberry juice product shortened defecation time， promoted small intestinal movement and content discharge in constipation model mice and improves the constipation of mice.

Abstract:Mung bean is a kind of legume that is often eaten in Asian， especially Chinese. Previous studies have shown that mung bean has a variety of health benefits. However， the single method of mung bean consumption limits the increase in its consumption. This research aims to develop dried noodles with high mung bean content， good processing quality and good edible quality. In order to explore the impact of three pretreatment methods of crushing， superfine crushing， and extrusion on the quality of mung bean dough with an added amount of 4%~50%， rapidly viscosity analyzer， the mixing tester and the texture analyzer were used to measure the starch gelatinization characteristics， dough rheological characteristics and texture characteristics of flour， respectively. The results show that superfine pulverization and extrusion can improve the quality of noodles. This research expands the edible method of mung bean and provides a theoretical basis for the production of industrialized mung bean noodles.

Abstract:Wheat bran had negative effects on the quality of whole wheat dough and semi-dried noodles. In order to improve the quality of whole wheat dough and semi-dried whole wheat noodles (SWWN)， fermentation of bran was applied in this study. The effects of different bran pre-fermentation methods (including unfermented， nature fermented， liquor koji fermented， yeast fermented， and liquor koji and yeast fermented methods) on the moisture distribution and dynamic rheological properties of whole wheat dough， and the eating quality of SWWN were studied in this paper. In the analysis of low-field nuclear magnetic resonance (LF-NMR)， the T21 value increased and the T22 value decreased in the whole wheat dough made with pre-fermented bran. It was possible that the water in the whole wheat dough migrated from the bran to the protein and starch. In the dynamic rheology experiment， the elastic modulus G′ and viscosity modulus G″ of the whole wheat dough decreased in the liquor koji and yeast fermentation groups. In the liquor koji and yeast fermentation group， the water absorption of SWWN increased during cooking， and the hardness and gumminess decreased. The external appearance and microstructure observation showed that the internal structure of SWWN became loose in liquor koji and yeast group. The irregular pores were observed in the cross-section of SWWN， which improved the eating quality of SWWN. At the same time， after fermentation by liquor koji and yeast， the content of phytic acid reduced， and the content of polyphenols increased， which improved the nutritional value of SWWN.

Abstract:In order to explore whether soybean protein isolate(SPI) and soybean polysaccharide(SSP) system had inhibitory effect on the bitter taste of stevioside (STE)， this paper took the quality scores of SPI， SSP and STE as factors and sensory comprehensive score as indicators to study the inhibitory effect of SPI-SSP composite system on STE. The results showed that: When the mass fraction of SPI is 1.0% and the mass fraction of SSP is 0.3%， the mass fraction of STE can reach 0.5%， and the inhibition effect of emulsion is better than that of aqueous solution. Further pain suppression effect of interfacial tension， the optimum emulsion system of the indices such as particle size， Zeta potential and stability test， that with the increase of mass fraction of SPI， the interfacial tension values presented a significant decline， shows that soybean protein isolated polysaccharide-stevia glycoside in oil-water interface combination form relatively stable interfacial film. In conclusion， when the mass fraction of STE and SSP in the composite emulsion is 0.5% and 0.3%， the SPI mass fraction higher than 1.0% can form a relatively stable O/W emulsion without adverse bitter taste.

Abstract:Frozen cooked noodles (FCNs)， as a convenient food， can be frozen and stored for a long time. In this paper， FCNs using low gluten wheat flour were investigated as a possible replacement and strengthening of gluten by curdlan. A systematic analysis of the structure， chewiness， and moisture variations of the FCNs was carried out by means of pressed slice observation， texture determination， and NMR， respectively. The results showed that the cooking caused a decrease in the stability of the internal structure of FCNs and a decrease in firmness and tackiness. Compared to the control (0.0%)， the addition of 0.5% curdlan resulted in a homogeneous and compact internal structure of FCNs， and significantly increased the firmness (63.75-75.87 g) and viscosity (1.22-1.41 g·sec) of FCNs after cooking (7 min). In addition， the addition of 0.5% curdlan reduced the time for water to reach the center of the noodles from 5 min to 3 min and the free water content from 91.957% to 91.220%. The addition of 0.5% curdlan significantly inhibited the destruction of the internal homogeneity of FCNs using low gluten wheat flour during the cooking process， and reduced the decrease of the firmness and toughness of FCNs during the cooking process， which is of positive significance for the application and promotion of curdlan.

Abstract:It was studied the physicochemical properties of pre-heating treatment grain flours and in-vitro digestibility of grain starch. By analyzing the gelatinization property， swelling power， water absorption and starch composition of oat， foxtail millet and corn flours were heated by steam and baking. Results showed that: Heat treatment caused a significant decrease in the gelatinization temperature of oat flour and a significant increase of millet and corn flour(P<0.05). Heat treatment caused a significant increase in the setback of oat and millet flour and a significant decrease of corn flour (P<0.05). Heat treatment significantly decreased the peak viscosity and breakdown of corn flour(P<0.05). Different heat treatments had different trends in the effects of peak viscosity and breakdown of oat and millet flour. The swelling power of oat flour， when heated by steam and baking， decreased by 32% and 12%， respectively， and the water absorption index increased by more than 20%. But heat treatment made millet and corn flour change less. Heat treatment reduced the water solubility index of three kinds of cereal flour by 28% to 55%. The fast-digestible starch was decreased by 10% to 20%， but the slow-digestible starch was increased by 3% to 30%， and the resistant starch was increased about 20%. The oat starch composition was most affected by heat treatment. The particle diameters of oat， millet and corn starch were about 5， 10 and 15 μm respectively. After heat treatment， the starch of oat， millet and corn were agglomerated and bonded， especially oat starch. The physical and chemical properties of grain flours were affected by appropriate pre-heat treatment， then improved the processing properties. The starch composition was changed by heat treatment， reduced digestibility， and improved the functional properties.

Abstract:Hairtail is one of the most popular marine fish. Since the outbreak of COVID-19， severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has been detected in numerous imported hairtails in China， posing significant health risks. Electron beam (E-beam) irradiation is an efficient and rapid method of inactivating microorganisms. Previous work found that specific doses of E-beam irradiation can inactivate SARS-CoV-2 in cold-chain seafood. The article studied the effects of 2， 4， 7， 10 kGy of E-beam irradiation on the nutritional， physical， storage， and sensory quality of imported hairtail. The results showed that 4-10 kGy E-beam irradiation significantly reduced the vitamin A content of hairtail while significantly increasing its hardness， elasticity， adhesiveness， and chewiness. The dose of 10 kGy irradiation significantly decreased the total volatile base nitrogen (TVB-N) content of hairtail. It was shown that 2-10 kGy E-beam irradiation had no effect on the sensory quality of hairtail. In conclusion， a dose of 2 kGy was recommended in consideration of the keeping safety and quality in hairtail.

Abstract:The red swamp crawfish preboiled were placed in the plastic box filled with water， then the boxes with crawfish were vacuumed， followed that the crawfish were frozen in the ice locker at -20， -40， and -55 ℃， respectively. After the center temperature of which were -15 ℃， the frozen crawfish in boxes were stored at -20 and -40 ℃ for 24 weeks. Juice leakage， water holding capacity (WHC)， shearing force， pH value， TVB-N value， moisture state， and myofibrillar microstructure were measured to investigate the changes in quality attributes of red swamp crawfish during freezing storage， and the effect of frozen and freezing storage temperatures on quality attributes. The results showed that， compared with -20 ℃， muscle fibers of red swamp crayfish frozen at -40 ℃ and -55 ℃ are more slightly damaged， and the crayfish meat has higher juice leakage， lower shearing force， pH value， and TVB-N value and WHC. Compared with -40 ℃， the muscle fibers of red swamp crayfish stored at -20 ℃ has weaker integrity， and the muscle structure is changed from compact to loose. In addition， the crayfish meat has higher juice leakage， shearing force， pH value， and TVB-N value as well as lower WHC and percentage of bound water and immobilized water. These results indicate that the quality attributes of red swamp crayfish were affected by frozen and freezing storage temperatures， which may provide scientific guidance for the supply of red swamp crayfish throughout the year.

Abstract:In this paper， the changes of cell wall components and cell wall structure of Zizyphus jujuba mill cv Lingwuchangzao during storage at 4 ℃ for 25 days were studied， and the effects of secondary structure changes in cell wall pectin polysaccharide on pectin components and cell wall structure were analyzed by Fourier transform infrared spectroscopy. The results showed that within 25 days of postharvest storage， with the extension of storage time， the hardness of fruit decreased continuously， and the hardness at the end of storage was 84.77% of that at the beginning of storage. The content of soluble solids showed an "inverted V" trend and reached the highest value (27.07%) on the 7th day of storage. In the extracted pectin components， the content of water-soluble pectin is increasing continuously， and the correlation analysis shows that the hardness is significantly correlated with soluble solids and water-soluble pectin， and the correlation coefficients are 0.9638 and -0.8862 respectively. Fourier transform infrared spectroscopy analysis showed that with the extension of storage time， the esterification degree of pectin decreased and the peak of pyranoside bond in pectin shifted， which may be related to the softening of jujube fruit. The results of scanning electron microscopy showed that the cell wall structure of Lingwu long jujube. changed from compact honeycomb structure to loose void structure during storage， which may be closely related to the formation of water-soluble pectin in pectin components. This change resulted in the hardness decrease of Lingwu long jujube. The softening phenomenon of Lingwu long jujube.

Abstract:Chilling injury is a physiological disease of yellow peach fruit during low temperature storage. In this paper， yellow peach was treated by 1-methylcyclopropene (1-MCP) and ethylene adsorbent (EA)， and the effects of 1-MCP-EA and 1-MCP on chilling injury (CI) and sugar metabolism were studied. Yellow peach was stored at 4 ℃ for 28 days， compared with the control and 1-MCP， 1-MCP-EA treatment could better maintain fruit hardness， soluble solid content (SSC) and reduce chilling injury browning. The results showed that 1-MCP-EA and 1-MCP treatment could reduce the decrease of sucrose content and the increase of fructose and glucose content， and inhibit the increase of acid invertase (AI) and neutral invertase (NI) activities. 1-MCP-EA treatment could effectively inhibit the increase of sucrose synthase (SS) activity and the decrease of sucrose phosphate synthase (SPS) activity in yellow peach fruit. Therefore， 1-MCP-EA treatment had better effect on inhibiting chilling injury and maintaining nutritional quality in yellow peach.

Abstract:A THz time-domain spectroscopy (THz-TDS) technology with transmission mode combined with principle component analysis (PCA) was established to identify and detect the three nereistoxin-related pesticide (cartap， bensultap and monosultap) residues in rice powder. The characteristic absorption peaks of cartap， bensultap and monosultap were obtained in the matrix of polyethylene and served as the basis for both discrimination and detection， and the THz absorbance of cartap， bensultap and monosultap in the matrix of rice powder was analyzed by PCA. A good linear relationship was observed between the absorbance of cartap， bensultap and monosultap (at the characteristic absorption peaks of 1.95， 1.19 and 1.70 THz， respectively) and corresponding quality score over the range of 0.002%-16.667% with a correlation coefficient over 0.9599. Three nereistoxin-related pesticides at the adding quality score of 0.002% could be successfully discriminated with the help of PCA. The results showed that the proposed method was sample and fast for the discrimination and detection of nereistoxin-related pesticide residues in the matrix of rice， which could provide experimental basis for the application of THz-TDS technology in agricultural products monitoring.

Abstract:Fatty acids (FAs) composition pattern， i.e. FAs fingerprints， of milk and dairy products is not only determined or affected by milk animal's species and breeds， natural geographical and climate environmental origin， also correlated to feeding pattern of milk animal， quality of raw milk， product type， product standard and processing parameters， etc.， artificial and industrial factors. To date， the concept of "industrial fingerprint" of dairy products has not been proposed， and lacks systematic studies. A total of 200 Holstein cow (cow)， Yak and Goat raw milk， Ultra high temperature (UHT) milk and milk powder samples were collected， and FAs were detected by gas chromatography method. According to the following five categories/aspects of industrial factors such as ①product type， ②UHT treatment， ③producer/brand， ④liquid milk series， and ⑤feeding pattern of cow， significant of differences of each single FA and overall differences of FAs data set were tested and compared， and principal component analysis(PCA) was conducted to observe the natural clustering of sample sets by their FAs fingerprints. As the results， most FA showed significant differences in each study aspects， but no significant differences were observed on general mean of overall FAs by block designed analysis on variance and paired t test， traditional statistics could not distinguish the complex overall changes of FAs pattern. PCA showed that the natural clustering of milk samples were consistent with processing methods， brands， series， and feeding patterns， proving that these various industrial factors could cause characteristic and patterned changes on FAs fingerprints of dairy products. Conversely， it is feasible and promising to establish FAs fingerprint model to distinguish the producing and processing methods， producer and brand of milk products， product series and so on， integrity and authenticity of market dairy foods， and also facilitate and visualize massive data/multivariate evaluation on effectiveness of scientific feeding on milk animals and functional and peculiar dairy product development.

Abstract:A method for the determination of perchlorate and chlorate in bovin milk and infant formula by high performance anion exchange chromatography-tandem mass spectrometry was developed. It was optimized about the protein precipitation reagent and the purification conditions of infant formula. The protein was precipitated by acetonitrile and the supernatant was purified by ion chromatographic pretreatment column. The separation was performed on a Dionex IonPac AS19 high performance anion column with gradient elution using potassium hydroxide eluent at the flow rate of 0.35 mL/min. The injection volume was 50 μL. The column temperature was 30 ℃. The results showed that the perchlorate and chlorate could be separated well under the experimental conditions and showed a good linear relationship with its corresponding quantitative ion peak area in a wide concentration range (R2>0.999). The limits of detection for perchlorate and chlorate were 7 ng/L and 1.7 ng/L， respectively， and the limits of quantification were 20 ng/L and 5 ng/L. The recoveries of milk and infant formula were 88.95%~102.33%， and the RSDs were 1.86%~3.21%. This method has the advantages of simple sample processing， low limit of detection， low limit of quantification， good stability， good repeatability and recovery， and could be widely used in the detection of milk and infant powder.

Abstract:In this study， the color of fifty Dianhong Gongou tea infusions was detected by using electronic eye technology， and the color quality of tea infusions was evaluated by combining with multivariate statistical analysis. The results showed that quality classification of high-quality (≥90 score) and non-high-quality(＜90 score) could be accurately judged based on partial least squares discriminant analysis (PLS-DA)， which had excellently interpretative and predictive ability (R2Y=0.988， Q2=0.981). The validation of the prediction set showed the reliability of the model， with an accuracy of 100%. Furthermore， the accurate prediction of quality scores of tea infusions' color was achieved based on the partial least square regression (PLSR) (calibration set: Rc=0.97， RMSEC=0.79， RPDc=4.15； prediction set: Rp=0.90， RMSEP=1.36， RPDp=2.15). The absolute error between the predicted value and the true value is within 2.3， and the relative error was within 2.7%. In summary， the Electronic eye technology can replace traditional sensory evaluation to achieve the speedy and accurate evaluation of color quality for Dianhong black tea.

Abstract:Tea residue contains high amount of protein， which can be cost-effectively extracted by alkali. However， the application of tea protein in food industry was limited due to its reaction with polyphenols or sugars. In this study， the physicochemical properties and bio-functionalities of the protein extract obtained from green tea residue were determined， and the emulsifying， foaming and antioxidant properties were improved by enzymatic method. The results showed that the protein content of the extract was 52%， and its isoelectric point (PI) was 3.6. The solubility， dispersibility， foaming and emulsifying properties of tea residue protein were positively correlated with the pH value of the solution； when the concentration of protein extract was 80 mg/mL， the inhibition of psychrophilic bacteria and Pseudomonas were 98% and 93% respectively. After pepsin treatment， the foaming ability of protein extract was 58.3 mL/g twice as that of the untreated sample， and the emulsifying ability was 100.0 mL/g four times as that of the untreated sample. After treatment with ViscozymeC L， the foaming ability of tea residue protein increased to 52.4 mL/g， the emulsifying ability decreased to 12.0 mL/g， while the antioxidant activity increased by about 50%. The results showed that the protein extracts from tea residue and their enzymatic hydrolysates had good functional properties and potential for the application in food industry.

Abstract:A chiral chromatographic method for the determination of calcium L-5-methyltetrahydrofolate (L-5-MTHF-Ca) was established， and the feasibility of the method was evaluated by methodology validation. Methods high performance liquid chromatography is used. The chromatographic column is CHIRALPAK HSA chiral column (4 mm×150 mm， 5 μm). The mobile phase is phosphate buffer solution ∶ acetonitrile (90 ∶ 10， V ∶ V). The flow rate is 0.6 mL/min. The injection volume is 5 μL. The column temperature is 30 ℃ and the detection wavelength is 280 nm. The results shows that the method could separate L-5-MTHF-Ca well， the resolution is 3.24， and the linear relationship is good in the concentration range of 0.016~0.100 mg/mL， the correlation coefficient is 0.9997， the detection limit and quantitation limit are 3.11 μg/mL and 4.98 μg/mL respectively， the precision is 0.38%， and the average recovery is 103.71%. System suitability test results are good， but L-5-MTHF-Ca will slowly degrade over time， so sample analysis as soon as possible. The method is simple， accurate and can be used for the determination of L-5-MTHF-Ca in various foods and health products.

Abstract:This paper used cellulase method to extract R-phycoerythrin and purified it. A fluorescence method for detecting the content of Cu2+ was established based on the fluorescence quenching of R-phythrocytin by Cu2+. The results of the study showed that the concentration of R-phycoerythrin extracted by the cellulase method was 43.64 mg/mL when the extraction temperature was 40 ℃， the extraction time was 5 hours， and the amount of enzyme was 2.5%. Purification of phycoerythrin by using 60% ammonium sulfate precipitation and DEAE Sepharose FF column to obtain pharmaceutical grade R-phycoerythrin with a purity of 2.1， and this R-phycoerythrin had good selectivity to Cu2+. The best detection conditions were R-phycoerythrin concentration 1.2 mg/mL， water bath temperature 30 ℃， reaction time 15 min， buffer pH 7.0. There was a good linear relationship between relative fluorescence intensity and Cu2+ concentration in the range of 0.5~50 μmol/L Cu2+， and the lowest detection limit (S/N=3) can reach 0.06308 μmol/L. This method was applied to the detection of Cu2+ content in actual samples， and the sample recovery rate was 94.50%~106.03%. This method has the advantages of green safety， short detection time， high sensitivity， good selectivity， Etc， and the detection of heavy metal Cu2+ content in aquatic products has broad application prospects.

Abstract:In recent years， demand for PUFAs-rich oils is increasing rapidly due to their nutritional value and health benefits. However， they are susceptible to certain factors， such as temperature， light and pH， to some extent. In order to prevent them from oxidation and degradation during food processing and storage， various microencapsulation strategies have been adopted to stabilize oils for better application in the food industry. In this review， the methods available for microencapsulation of PUFAs-rich oils are summarized， and the advantages and limitations of each method are compared. In addition， the research results of three kinds of wall materials and their microencapsulation of PUFAs-rich oil were summarized， and the different characteristics of PUFAs-rich oil microencapsulation applied to foods were analyzed. Finally， the development trend of oil microencapsulation rich in polyunsaturated fatty acids (PUFAs) was prospected， particularly with regard to the potential application of new green materials as wall materials.

Abstract:A rapid and accurate method for the determination of cyromazine residues in vegetables by composite solid-phase extraction and reversed phase ion-pair liquid chromatography(IS-RPLC) was established. The target was extracted by multiple ultrasonic extraction with ammonium bicarbonate solution， purified by composite solid-phase extraction column， and separated and determined by IS-RPLC. The calibration curve showed good linearity in the range of 0.1~2 μg/mL with the correlation coefficient greater than 0.998， and the limit of detection (LOD) of the method reaches 0.012 mg/kg， which can meet the regulatory and judgment requirements for the residue of cyromazine. Recovery experiments show that the recovery range is 77.7%~87.0%， and the relative standard deviation (RSD) is 1.6%~3.7%. The problems of low extraction recovery and difficult purification in the determination of cyromazine were effectively solved. The chromatographic peak shape of cyromazine which separated by C8 column combining with the ion-pair reagent was sharp and anti-interference.

Abstract:Objective: to determine the content of main components in germinating black highland barley from different areas and establish the corresponding fingerprint， so as to provide the basis for the formulation of quality standard of germinating black highland barley. Methods: the contents of GABA， ferulic acid and anthocyanin in germinating black highland barley powder were determined by HPLC； the contents of β - glucan were determined by UV spectrophotometry； the fingerprint similarity software and SPSS software were used for data analysis to establish the fingerprint common mode of germinating black highland barley， and the quality of 10 batches of samples was evaluated. Results: the contents of β - glucan， γ - aminobutyric acid， ferulic acid and anthocyanin in different batches of germinated highland barley powder were (68.35 ± 0.03) - (73.82 ± 0.02) mg/g， (6.56 ± 0.05) - (7.31 ± 0.03) mg/g， (0.15 ± 0.03) - (0.23 ± 0.01) mg/g and (0.86 ± 0.05) - (1.53 ± 0.03) mg/g， respectively. A total of 18 common peaks were demarcated in the HPLC fingerprint of budding black highland barley， and three active substances were identified. The fingerprint common mode of budding black highland barley was established， and the similarity value was above 0.902. The cluster analysis results divided 10 batches of budding black highland barley into two major categories， three main factors were selected by principal component analysis， and 10 batches of samples were comprehensively scored. Conclusion: the HPLC and UV methods established in this paper have good repeatability and stability， and the fingerprint can provide reference for the quality evaluation of different sprouting highland barley.

Abstract:A method was established to identify washed and sun-dried coffee comprehensively and accurately by screening differential components. High performance liquid chromatography(HPLC) of coffee samples were collected for multi-chemometrics analysis， and then the full raw signals and common peaks' area data that came from the two different processing types of coffee samples were divided into calibration set and test set respectively using the Kennard-Stone algorithm in the ratio of 7:3. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) models were established based on those data primitively. In the following work， the raw data were processed to optimize PLS-DA model by using the sole algorithm and combinatorial algorithm， such as variable importance in projection (VIP)， backward interval partial least squares (BiPLS)， successive projections algorithm (SPA)， uninformative variable elimination-partial least squares (UVE-PLS)， competitive adaptive reweighted sampling-partial least squares (CARS-PLS) separately， and BiPLS-VIP/CARS/SPA/UVE together. After that， the correlation coefficients ×100-1 of X-variables in the discriminant function of the optimum model were labeled on the chromatogram， which was used for screening quality markers between the two types of coffee， and the highest correlation component was qualitative analyzed. The results demonstrated that a qualified prediction model could not be established using the full raw signals to distinguish washed and sun-dried coffee， while the BiPLS algorithm at 90 intervals was the best optimum proposal among all kinds of algorithms， which had good discriminatory ability with an accuracy of 83.33%， a Q2 value of 0.813 and an root mean square error of cross validation (RMSEcv) value of 0.217. The qualitative results of the standards illustrated that chlorogenic acid is one of the important differential components of coffee with two different processing methods. Above all， compared to the traditional method of using the single or multiple compounds contents information as quality evaluation criteria， this identification method could dig out the differential components entirely and accurately， which providing a new thought with reference value for the product quality assessment comprehensive.

Abstract:Fruit ripening and quality formation is an important stage of plant fruits， which are regulated by many regulatory factors divided into positive regulatory factors and negative regulatory factors. In the past， the research on fruit ripening regulation mainly focused on the identification and functional analysis of positive regulatory factors， but now the negative regulatory factors related to fruit ripening have gradually attracted the attention of researchers. This review summarizes the negative regulatory factors related to fruit ripening and quality formation. According to the regulation mode to key genes related to ripening and quality formation， they can be divided into four categories including transcriptional repressors involved in transcriptional level regulation， negative regulatory factors involved in post transcriptional level， post-translational level regulation， and other negative regulatory factors， and we discuss and prospect the related follow-up research directions in this article.

Abstract:Endocrine disruptors (EDCs) in food are important risk factors for food safety. In particular， with the continuous development of the food packaging market， the migration of EDCs such as plasticizers or surfactants in food contact materials (FCMs) into food add the range of foodborne EDCs. Clarifying the toxic effects of foodborne EDCs is important for protecting food safety. In this paper， we systematically compiled and analyzed the current status of research on the toxic effects of foodborne EDCs from four aspects， including epidemiology， model organisms， alternative toxicology and computational toxicology， combined with metabolomics， transcriptomics and molecular biology. The application status， advantages， disadvantages and interconnections of different toxic effect evaluation techniques were discussed. Prospects for the application of different evaluation methods and techniques were proposed. The aim of this paper is to provide valuable information for the study of the toxic effects of foodborne EDCs.

Abstract:In recent years， the incidence of food allergy is increasing， which seriously affects the quality of life of many individuals and families. The regulatory effect and mechanism of nutrients on body metabolism have also been widely studied. More and more studies have explored the influence of nutrients on food allergy. This paper introduces the effects of vitamins， fatty acids， trace elements and dietary fiber in the diet of infants and mothers during the first 1 000 days of life on food allergy in infants and young children. This paper analyses the regulation of these nutrients on the immune system of infants and young children， then reduces the occurrence of food allergy， and aims at scientific and accurate dietary guidance for relieving food allergy of infants and young children.

Abstract:Spirulina (Arthrospira platensis)， a paragon of commercial applications of alga， has been widely cultivated as an economic product around the world. As one of the luminous energy transporters in a structure called phycobilisomes in cyanobacteria and microalgae， phycocyanin has been gaining attention as a natural blue colorant and a physiological active compound. Phycocyanin showed several health benefits such as anti-inflammatory， anti-tumor， anti-oxidant， and immunomodulatory， which have been fully tested， hence it is very promising for the application of phycocyanin in the area of drug delivery. However， purified phycocyanin is prone to precipitating and/or dissociating when dissolved in the water， and demonstrates high sensitivity to environmental stresses such as temperature， pH， light， and ion. In the field of colorant protection， researchers devoted themselves to the stability improvement of phycocyanin on the nanoscale such as nanoparticles and nanoemulsions， to keep its robustness in harsh conditions in food processings and storages. In the field of physiological activity maintenance， researchers hammered at bioaccessibility improvement of phycocyanin by adding oligosaccharides and/or preservatives， or modifying its molecular structure via physical methods and/or chemical methods， as well as forming various nanocarriers for phycocyanin delivery. In addition， phycocyanin， a fluorescent protein， has been employed as a shell material of nanoparticles， applied to the mediation of metal nanoparticles， utilized in the formation of fluorescent probes， and so on. In this paper， applications of phycocyanin were summarized， and prospects for its development were presented as well.

Abstract:Gel properties are one of the important determining factors for the quality and sensory properties of surimi products. Surimi is a typical multi-phase， multi-component food system. The interaction between the main components such as proteins， polysaccharides and lipids is the basis for the formation of surimi and ultimately determines the quality of the products. However， the interaction mechanism between the multiple components in the surimi mixed system and its effect on the quality of surimi products are still unclear. This constrains the processing technology， theoretical innovation and the healthy development of the industry for surimi products. In this paper， the effects of exogenous additives such as proteins， polysaccharides， lipids and polyphenols on the thermally induced gelation properties of surimi are reviewed based on the formation mechanism and influencing factors of surimi gels. The purpose is to analyze the interaction between the components in surimi products and their influence on gel characteristics. In this way， we provide a theoretical basis for the development of new surimi products and the regulation of gel quality.

Abstract:Pyrolisis of biomass result in smoke that can be condensed to be liquid smoke. Liquid smoke is a brown mixture， which contains phenols， aldehydes， ketones， acids， esters， etc. The flavor and color of liquid smoke can endow food with unique quality. Liquid smoke's basic ingredients are phenols， carbonyl compounds and organic acids， which have the function of antibacterial， anti-corrosion， anti-oxidation. The food of fluid smoking has unique flavor and can prolong their shelf life of products， so liquid smoke can be used in livestock products and aquatic products. The review summarizes the recent research progress in the main components， formation process， and application in food of liquid smoke. According to the characteristics of smoked food， the review can provide reference and basis for the development of compound liquid smoke with high color， flavor， antibacterial and antioxidant properties.

Abstract:Carotenoids are the most important nutrients in cereals and play an important role in human health. In this paper， the content of carotenoids in millet and cooking indexes were determined. The correlation between carotenoids content and cooking quality was found and summarized. In addition， the synthesis and distribution of carotenoids in grains， the absorption and utilization of carotenoids and their health effects were introduced. The problems in the research of carotenoids in grains were put forward， In order to provide reference for the efficient utilization of carotenoids in cereals.

Abstract:Mushroom is part of the most popular large fungi with rich nutritional value. However， there are many kinds of mushrooms， some of which contain mushroom toxin， which can lead to food poisoning incidents after people eat them by mistake. Depending on statistics， nearly 100 people die each year from ingesting wild poisonous mushrooms worldwide， among which China and Europe account for at least 50% of the deaths. Mushroom poisoning has become one of the most serious food safety problems in China， accounting for half of all food poisoning death. It is very important to study the sensitive and rapid detection technology of mushroom toxin for the identification of the source of food poisoning and the subsequent symptomatic treatment of the patients. In this paper， the types and properties of common toxic mushroom toxins were reviewed， and the detection methods of mushroom toxins such as chemical colorimetry， immunoassay and mass spectroscopy-chromatography were introduced， providing ideas for the development of a more convenient and rapid detection method for toxic mushroom.

Abstract:Under the guidance of ‘Greater Food’ approach， innovation of the food industry comes from the innovation of talents in the food field. On the basis of clarifying the development status of the food industry， this article proposes a training path for innovative talents in the food field in the new era. Firstly， by exploring the connotation of innovative talents in the new era， we will build an all-round innovation model. Secondly， through the full chain training of professional skills， the depth of education and training will be strengthened. Finally， through the multi-dimensional formation of knowledge system， the breadth of talent cultivation will be expanded.