Abstract:Fruits and vegetables are an important part of the human diet. The health effects of fruits and vegetables are closely related to human health. Polysaccharides are the main active components of fruits and vegetables， and immune regulation is their main effect. It is of great significance to clarify the immunomodulatory activity and mechanism of fruit and vegetable polysaccharides. This article reviewd the structural characteristics of fruit and vegetable polysaccharides， and their immunomodulatory effect and mechanism. The future research direction of the structure analysis of fruit and vegetable polysaccharides and their structure-activity relationship about immunomodulatory， and their mechanism were also prospected.

Abstract:In order to explore the anti-oxidation and hypoglycemic activity of millet， the DPPH· scavenging capacity and total antioxidant capacity of four different extracts， extracts digestive solution and sediment digestive solution of millet were determined. The glucose uptake levels on PA-induced insulin-resistant HepG2 cells （IR-HepG2） were detected. The results showed that the water extract and ethanol extract had higher antioxidant activity， and their antioxidant capacity decreased after simulated digestion in vitro （the total antioxidant capacity decreased by 50.00% and 54.55%， respectively）. Unlike the antioxidant results， the water extract and the ethanol extract （20， 40 μg/mL） had no significant effect on the improvement of IR-HepG2 insulin resistance. The n-butanol extract （40， 80 μg/mL） and n-hexane extract （20， 40， 80 μg/mL） all significantly increased the glucose uptake of IR-HepG2. After digestion， the ethanol extract significantly improved insulin resistance， but n-butanol and n-hexane extracts had no effect on insulin resistance. The glucose uptake was enhanced by n-hexane sediment digestive solution， n-butanol sediment digestive solution， water sediment digestive solution and millet digestive solution. However， ethanol sediment digestive solution did not improve insulin resistance， indicating that the hypoglycemic effect of millet was mainly concentrated in ethanol extract.

Abstract:In order to improve the utilization rate and nutritional value of oat bran， with oat bran coarse powder as raw material， and the effects of micronization on the nutritional， functional and antioxidant properties of oat bran were explored. The results showed that with the decrease of bran size， the fat content of oat bran increased significantly （P < 0.05）， the polysaccharide content increased first and then decreased， the polyphenol content increased first and then decreased， and there were significant differences among the groups， and the dietary fiber content decreased significantly （P < 0.05）. With the decrease of the grain size of oat bran， the total antioxidant capacity of oat bran increased gradually， while the scavenging rate of hydroxyl radical and TBA value decreased gradually. The scavenging rate of DPPH radical and ABTS radical reached the maximum when oat bran was 74 μm （200 mesh）， which was 92.1% and 71.88%， respectively. The inhibition rate of linoleic acid peroxidation was the strongest. Correlation analysis showed that there was a great correlation between total phenolics， dietary fiber and antioxidant indexes， and the correlation coefficients were greater than 0.71. Polysaccharides， total phenolics and dietary fiber may be important functional components of oat bran with antioxidant capacity.

Abstract:The purpose of the research was to develop functional products derived from immature persimmon and improved its application value. Using the immature persimmon as test material， a comprehensive method combined by water extraction， gelatin precipitation process and organic solvent extraction was used to extract and separate the persimmon extracts， then three separated components F1， F2 and F3 were obtained. The components of tannin were identified by ultraviolet spectrum， infrared spectrum and HPLC analysis， as well as their antioxidative activity， antibacterial activity and anticancer activity in vitro were also evaluated. The results revealed that the separated components F1， F2 and F3 had similar absorption characteristics with tannins， and the molecular structures were highly similar， all containing -OH， aromatic ring skeleton， C=C， C-H structure. F1 contained 240.9 mg/g gallic acid and four unknown ingredients， F2 contained 270 mg/g protocatechin and two unknown ingredients， and F3 contained 37.8 mg/g ferulic acid and four unknown ingredients. DPPH radical scavenging ability was F1>F3>VC>F2， ABTS radical scavenging ability was F1>VC>F3>F2， hydroxyl radical scavenging ability was VC>F1>F3>F2， and total reducing capacity was VC>F3>F2>F1， indicating that F1， F2 and F3 all had strong antioxidative properties. Three components had different degrees of inhibition on Staphylococcus aureus， E. coli， Shigella， Salmonella， and Sakazakii， meanwhile， the antibacterial ability was F1>sodium benzoate>F3>F2. Both F2 and F3 had no inhibitory properties on tumor cell proliferation， and only F1 had a certain inhibitory effect on the proliferation of human liver cancer cells HepG2 and human gastric cancer cells MKN-45 in vitro. Conclusion： Immature persimmon tannin had the potential to be developed into natural antioxidants， preservatives and anti-cancer drugs.

Abstract:There is a big difference in the hypoglycemic activity in vitro between polysaccharides by Inonotus obliquus from submerged fermentation and fruit body. In order to improve the activity of the former， this study explored the glucose consumption of HepG2 cells and insulin-resistant HepG2 cells added with extracellular polysaccharides from Inonotus obliquus by submerged fermentation under different stimulating factors. The results showed that polysaccharides obtained by adding stimulating factors could promote the glucose consumption of cells， and different stimulating factors had different effects of promoting hypoglycemic activity in vitro. To be specific， 160 μg/mL birch extract， 40 μg/mL VB6， 80 μg/mL VB1 and betulin group fermented polysaccharides could significantly increase the glucose consumption of IR-HepG2 cells for 48 h， and the effect was better than the non-stimulating factor group. Among them， thepromotion effect of VB6 was the most significant， which was 66.80% higher than that of the non-stimulating factor group， and significantly higher than that of the positive control group （P<0.01）. Therefore， the paper proved that the birch indeed contained stimulating factors that could promote the production of active polysaccharides from the fruit bodies of Inonotus obliquus， and further proved that the betulin， VB1 and VB6 in the birch extract could improve the hypoglycemic activity of the polysaccharide produced by the liquid submerged culture of Inonotus obliquus.

Abstract:Objective： Lactobacillus paracasei is a kind of lactic acid bacteria with potential probiotic function， it has a vast theoretical basis and extensive application scenarios. In this study， Lactobacillus paracasei PC-01 isolated from sour yak milk of Longren Township， Dangxiong County， Lhasa， Tibet， was used as the research object to evaluate its potential probiotic characteristics and safety. Methods： The survival rate of Lactobacillus paracasei PC-01 was 88.60% after cultured in simulated artificial gastrointestinal fluid for 11 h. The delay time of bile salt tolerance was 0.34 h. The safety evaluation results showed that the strain was sensitive to six antibiotics， and resistant to vancomycin and clindamycin. Hemolysis test was negative and animal experiments further confirmed that Lactobacillus paracasei PC-01 had no side effects. Conclusion： Lactobacillus paracasei PC-01 has potential probiotic properties and safety， which provides a reference for its wide application.

Abstract:Objectives： In order to investigate the mechanism of different inhibitory effects of chitosan on some microorganisms. Methods： The minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） of chitosan were determined， and the relative conductivity， dissolved OD260nm value， dehydrogenase and β-galactosidase activity were measured. Results： The results showed that the MIC of chitosan to Lactobacillus plantarum， Escherichia coli and Saccharomyces ellipsoideus were 0.2， 2， 0.4 mg/L， MBC were 0.8， 16 mg/L and 3.2 mg/L， respectively. 4MIC chitosan significantly increased the relative conductivity and OD260nm value of all microorganisms. MIC chitosan treatments increased the relative conductivity of all microorganisms and OD260nm value of S. ellipsoideus significantly， but the OD260nm value of E. coli decreased， and no significant difference was found in L. plantarum at 0.5 h， but its increased significantly at 9 h. Chitosan significantly inhibited the dehydrogenase of L. plantarum and S. ellipsoideus， but had no significant effect on E. coli. The inhibition effect of chitosan on β- galactosidase was weaker than that of dehydrogenase. Conclusions： Chitosan was easy to pass through the cell wall of L. plantarum and S. ellipsoideus， also damage cell membrane of S. ellipsoideus. But it was difficult to pass through E. coli cell wall. The difference of antibacterial activity of chitosan might be related to the barrier ability of cell wall and resisting destruction of cell membrane to chitosan.

Abstract:In order to find a safe and effective control method of Shigella flexneri， the study investigated the inhibitory effect of protocatechuicaldehyde （PC） against S. flexneri and its possible mechanism. The minimum inhibitory concentration （MIC）， the minimum bactericidal concentration （MBC） of PC against S. flexneri were determined. Besides， cell morphology potential， the changes of intracellular ATP concentration， membrane potential， the effects on synthesis and destruction of protein as well as the growth curve were also measured to investigate the possible antimicrobial mechanism of PC against S. flexneri. The results showed that the MIC of PC against S. flexneri was 0.5 mg/mL and the MBC was 4.0 mg/mL. Field emission scanning electron microscopy showed that the morphology of S. flexneri was damaged， while PC treated cells were wrinkled and shriveled. In addition， PC affected the cell membrane permeability of S. flexneri， with mass concentration of 2×MIC and 4×MIC reduced the intracellular ATP concentration， cells treated with PC showed hyperpolarized cell membranes. It also destroyed cell proteins and inhibits cell protein synthesis. Moreover， after treatment with PC， the growth retardation period of S. flexneri was prolonged and the specific growth rate was reduced. In conclusion， PC has good antimicrobial activity against S. flexneri， it has the potential to be used in food industry as a natural and safe bacteriostatic substance.

Abstract:In this study， three lactic acid bacteria （LAB） with antimicrobial activity against common food-borne pathogens （Staphylococcus aureus， Listeria monocytogenes and Bacillus cereus） were obtained from goat milk， and their antimicrobial properties and potential probiotic characteristics were described. Those strains were identified as Enterococcus faecalis （termed as DH9003 and DH9012） and Lactococcus lactis （termed as DH9011）， and their antimicrobial products showed typical bacteriocin traits， such as being of heat-stable and proteinase nature. Bacteriostatic activity of concentrated bacteriocin produced by those LAB was found at low mass concentration （MIC50 and 4MIC50）， while complete inhibition activity against Lis. monocytogenes was found from two En. faecalis strains （DH9003 and DH9012） at high mass concentration （16MIC50）. Besides of that， all those LAB were of no-hemolytic activity， sensitivity to ampicillin （50 mg/mL） and streptomycin sulfate （100 mg/mL）， and resistance to bile， artificial simulated intestinal tract and gastric juice at different pH level （2.5， 3.0， 3.5）， β-galactosidase activity. In addition， all those LAB present auto-aggregating phenotype with ranged from 30%-55%. DH9003 and DH9012 showed good co-aggregation ability with Lis. monocytogenes and E.coli （52.6%， 63.2% and 68.5%， 57.6%， respectively）， while less co-aggregation ability between DH9011 and Lis. monocytogenes was obtained as 15.6%， and no co-aggregation with E.coli. The results in our study demonstrated that all those LAB were of strong antimicrobial activity， tolerance to bile and simulated gastrointestinal environments， adhesion ability， safe characteristics. Therefore， those LAB are considered as potential probiotic candidates with huge application values.

Abstract:Purpose： To investigate the protective effects of Wickerhamomyces anomalus QF-1-1 against lead toxicity in rats. Methods： Rats were randomly divided into low and high dose lead-poisoning model group， low and high dose of intervention group， blank control group. The lead-poisoning model group were given 1 mg/mL and 4 mg/mL lead acetate water for free drink and were fed normal diet while the intervention group were given 1 mg/mL and 4 mg/mL lead acetate water for free drink and were fed a diet containing Wickerhamomyces anomalus QF-1-1 powder， the control group were given distilled water for free drink and were fed normal diet. The experiment lasted for 7 weeks， during which the lead content in the feces of each group was measured regularly. After 7 week of feeding， the body mass， organ indexes， lead content in the blood， liver， kidney， brain of rats were tested. Paraffin sections of liver， kidney and brain tissue were prepared for observation of histopathological changes by hematoxylin and eosin staining. Results： After 7 weeks of feeding， the lead-poisoning model was constructed successfully， low dose lead-poisoning model group reached moderate lead poisoning， high dose lead-poisoning model group reached severe lead poisoning， and significant pathological tissue damage occurred in liver， kidney and brain. Compared with the model group， the liver and kidney indexes， lead content in the blood， liver， kidney， brain were decreased and lead content in the feces of intervention group were increased significantly. Moreover， the pathological changes of liver， kidney and brain tissues were improved. Conclusions： Wickerhamomyces anomalus QF-1-1 can alleviate damages to body caused by Pb， especially for moderate lead poisoning.

Abstract:Objective： To explore the regulatory effect of whey protein and pea protein on mice with intestinal flora disorder， and to reveal the application potential of whey protein and pea protein in regulating intestinal flora disorder. Methods： By infusing lincomycin hydrochloride into mice to establish a model of intestinal flora disorder， intervene in gavage protein samples from model mice， after the intervention， the content of Enterococci， Escherichia coli， Lactobacillus， and Bifidobacterium in the contents of the cecum of the mice was detected， and the colonization resistance of the intestinal microorganisms of the mice was evaluated. Bacterial genomic DNA were collected from fresh feces of each group of mice for 16S rDNA sequencing analysis to evaluate the effect of different samples on the intestinal flora. Results： Compared with the model group， the colonization resistance and species richness of intestinal flora of mice were improved in each treatment group， changed the composition structure of the bacterial community， reduced the number of pathogenic bacteria， promoted the proliferation of beneficial or neutral bacteria， and improved the functional gene composition of the bacterial community. The species composition and functional gene composition of the intestinal flora of mice in each treatment group tended to be at the level of the blank group. Conclusion： Whey protein， pea protein， and pea hydrolyzed protein-peptide can regulate the structure of intestinal flora and improve the disorder of intestinal flora caused by antibiotics.

Abstract:Foxtail millet （FM） is usually eaten after cooking in daily life， however， studies about the structural and functional properties changes of the main storage protein prolamin in FM before and after cooking are limited. In this study， the prolamins from uncooked and cooked FM were extracted respectively， and the structural and functional changes of which were compared. Scanning electron microscopy results showed that the structure of prolamin from cooked FM was different from that from uncooked FM， as evidenced by occurrence of protein body cross-linking between each other and the changes in protein shape from circular to irregular. The differential scanning calorimetry results further confirmed that the denaturation temperature of prolamin in cooked FM was increased， thus demonstrating that the structure of which tended to be stable. In addition， the amino acid content of prolamin in cooked FM was significantly higher than that in uncooked foxtail millet. Moreover， the secondary structure analysis revealed that part of β-fold was converted to α-helix in prolamin from cooked FM， which indicated that its structure became stable. Furthermore， solubility of prolamin in cooked FM was decreased when compared with prolamin in uncooked FM. Taken together， significant structural and functional changes occurred in FM prolamin after cooking.

Abstract:The objective of this study was to investigate the effects of soaking water ratio and drying methods on the water absorption， color and total phenolic content of peach gum during the commercialization of peach gum. Results showed that the water absorption of peach gum could reach up to 26 times of its original weight. The average content of total phenol in unsoaked peach gum was 2.49 times than that of the sample after soaking. The average content of total phenol in the sample after vacuum freeze-drying under different ratios was 1.14 times than that of the sample after heat pump drying. There was a significant color difference （P<0.05） between the soaked sample and the unsoaked sample， moreover， the color saturation， brightness and b* value were significantly increased （P<0.05）. Besides， the color difference of the sample after vacuum freeze-drying was lower than that of the sample after heat pump drying. The results of correlation analysis showed that the total phenolic content was positively correlated with L* value （P<0.01）， and negatively correlated with △E value（P<0.05）. In this study， it was clear that the color saturation and brightness of peach gum were significantly improved during the process of soaking， except lightness. Vacuum freeze-drying could reduce the chromatic aberration of the sample while retaining the content of phenolic substances in peach gum.

Abstract:The fruit will be crushed， collided， and damaged due to vibration during transportation， and these damages will affect the quality of the fruit during storage. In this paper， the length of the vibration time was used as a variable to study the effect of different vibration time on the changes of carbon dioxide concentration and quality of Myrica during storage. Research results showed that vibration would increase the respiratory strength of Myrica and increase the carbon dioxide concentration in the package. The quality of Myrica treated with 12 hours of vibration in terms of firmness， anthocyanins， vitamin C， and total antioxidant properties were lower than the quality of other Myrica treatments. Correlation analysis showed that the concentration of carbon dioxide in the Myrica packaging was strongly negatively correlated with vitamin C， total antioxidant capacity， and firmness， and was generally negatively correlated with titratable acids and anthocyanins， and weakly correlated with soluble solids. The concentration of carbon dioxide in the Myrica packaging could reflect the quality of Myrica to a certain extent in the process of logistics storage. Using multiple linear regression equations， the shelf life prediction model constructed with the above-mentioned quality indicators of Myrica can better predict the storage time of Myrica after different vibration time treatments.

Abstract:Using iobaric tags for relative and absolute quantification（iTRAQ） technology， the expression of differential proteins in muscular of Solenocera melantho stored in constant temperature and conventional frozen storage group for 30， 60 and 90 days was studied， and the distribution and function of differential protein and the quality change mechanism of Solenocera melantho during frozen storage were explored. The results showed that there were 79， 105 and 125 differential proteins in the constant temperature frozen storage group， and 100， 125 and 141 differential proteins in the conventional frozen storage group， respectively， compared with fresh Solenocera melantho. Two freshness indicator proteins， including myosin heavy chain and sarcoplasmic calcium-binding protein were screened out based on the test results.

Abstract:Based on the minimum inhibitory concentration（MIC） of phillyrin and the synergistic antibacterial effect with Nisin， potassium sorbate and sodium nitrite， this study explored the antibacterial effects on Staphylococcus aureus， Escherichia coli， Salmonella and Bacillus subtilis. Besides， the best compounding antibacterial scheme were verified in the preservation of minced meat. The test results showed that the combined use of phillyrin and sodium nitrite had the lowest compound inhibitory index（FICI） for the four tested bacteria， and the FICI values for Staphylococcus aureus， E. coli， Salmonella and Bacillus subtilis were 0.19， 0.38， 0.57 and 0.63， respectively， the antibacterial effects on the four test bacteria are all synergistic effects or additive effects. The pH of the minced meat of the experimental group added with the compound antibacterial agent increased by 0.49%， the control group increased by 1.80%； the total number of colonies in the minced meat of the experimental group increased by 88.09%， the control group increased by 214.29%； the TBARS value of the minced meat of the experimental group increased by 90.63%， and the control group increased 200%， so the compound antibacterial agent can inhibit the bacterial growth in minced meat， slow down the oxidation of minced meat， and have a certain protective effect on the color of minced meat.

Abstract:To comparative analysis of the glyceride composition of sea buckthorn oil， this study examined the potential of lipidomics based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry （UPLC-QTOF-MS）. There were 92 diglycerides and triglycerides had been selected by the analysis of genuine sea buckthorn oil and its adulterants oil （exemplified by sunflower seed oil， rapeseed oil and soybean oil）. Among them， 16 were diglycerides and 76 were triglycerides. The cluster differentiation and prediction of samples was carried out by chemometrics analysis， like principal component analysis（PCA）， orthogonal partial least squares discrimination analysis （OPLS-DA） and so on. The results showed that the model established by this method had good explanatory ability and predictive ability. It can be used to distinguish sea buckthorn oil， sunflower seed oil， rapeseed oil and soybean oil and can provide experience for the identification of high-value edible oil.

Abstract:In order to excavate the exploitation utilization value of Brassica rapa L. ssp. rapa resources， this study analyzed the nutrient composition and amino acid composition of 50 Brassica rapa L. ssp. rapa resources by using atomic absorption spectrophotometry and automatic amino acid analyzer. The results showed that the content of mineral elements of 50 Brassica rapa L. ssp. rapa resources were different， which calcium （Ca）， maghesium （Mg） and potassium （K） were the main element. The total mineral element content of G2 and T11 resources was the highest. Analysis of amino acids showed that G4 recourse had the highest content of total amino acids， essential amino acids in children， essential amino acids， non-essential amino acids， flavor amino acids， sweet amino acids， medicinal amino acids and sulfur-containing amino acids， and 1408 had the highest content of aromatic amino acid （1.09 g/100 g DW）. Amino acid content analysis of Brassica rapa L. ssp. rapa resources showed that the average content of glutamate was the highest （3.35 g/100 g DW） and the content of cystine was the least（0.01 g/100 g DW）. The principal components analysis showed that the five principal components contained most of the information of all tested traits （81.807%）. Clustering analysis revealed that 50 species of turnip resources could be classified into 4 groups at 5 genetic clusters： Group 1 possessed the lowest selenium （Se） content （0.058 mg/kg） and the lowest average amino acid content （9.72 g/100 g DW）. Group 2 possessed the lowest average iron （Fe） content （47.08 mg/kg） and the highest average methionine content. Group 3 possessed the middle and lower levels of mineral elements and amino acids. Group 4 possessed the highest average of mineral elements and amino acids indicating that the better exploitation utilization value. Comprehensive analysis of all detected components， four excellent Brassica rapa L. ssp. rapa germplasm resources （G2， G4， T11 and 1408） were selected for further study.

Abstract:Objective： Explore the nutritional function and mechanism of Dioscorea opposita thunb. Methods： The chemical components and potential targets of Dioscorea opposita thumb were obtained from the database analysis of the Chinese medicine system pharmacology analysis platform （TCMSP）. The Cytoscape platform was used to construct a Dioscorea opposita thumb-compound-target network， and topological analysis identified the potential important compounds. Using the String database to analyze the protein interaction network of the potential targets of Dioscorea opposita thumb， then screened out the potential pivotal target proteins for the function of Dioscorea opposita thumb. KEGG functional enrichment of potential targets was analyzed by R software to find out the key metabolic pathways to function. Results： The Dioscorea opposita thumb-compound-target network was constructed， and 11 important chemical components related to nutritional pharmacological functions were screened out such as glycine， alanine and stigmasterol. The protein interaction network found 11 key target proteins such as catalase （CAT） and interleukin 6 （IL6）. KEGG pathway enrichment results indicated that Dioscorea opposita thumb might play a nutritive pharmacological function by systematically regulating multiple key metabolic pathways of neuroactive ligand receptor interaction， carbon metabolism， and amino acid biosynthesis. Conclusion： The results provided a scientific basis for the positioning of Dioscorea opposita thumb nutritional pharmacological function， also provided a new method for the systematic elucidation of the mechanism of medicine and food homologous food.

Abstract:Attenuated total reflection-Fourier mid-infrared spectroscopy（ATR-FTIR） and competitive adaptive weighted sampling（CARS）， combined with physical and chemical analysis， were established to quickly determine the content of water soluble protein and total sugar in royal jelly. Based on the CARS method， Savitzky-Golay smoothing and first-order derivatives were used to preprocess the original spectrum， and 84 characteristic wavelength points were selected. The model has the best prediction effect on water soluble proteins. The correlation coefficients of the correction set and the verification set are 0.9631 and 0.9771， respectively， RMSECV and RMSEP are 0.0913 and 0.0754， respectively. The PLS quantitative model of total sugar screened 111 characteristic wavelength points and subjected to Savitzky-Golay smoothing and second-order derivative processing. The results were the best. The correlation coefficients of the correction set and the verification set were 0.9750 and 0.9850， and the RMSECV and RMSEP were only 0.4485 and 0.4244， the modeling effect was good. It can be seen that based on the CARS method for screening characteristic wavelengths， it is feasible to use ATR-FTIR and partial least squares to quickly detect the content of water-soluble protein and total sugar in royal jelly， and the established quantitative model has good robustness and high prediction accuracy.

Abstract:To realize the rapid prediction of total volatile basic nitrogen （TVB-N） content in mutton， near-infrared spectroscopy technology and computer vision technology were employed to obtain the spectral information and image characteristic parameters， and least squares support vector machine （LSSVM） prediction model for TVB-N content was established based on fused spectra and image information. Spectral information in the range of 320-1 100 nm and image information of 73 mutton samples storage at 4 ℃ from 1 to 15 days were collected， and the TVB-N contents in samples were determined referring to the national standard method. Then the spectral characteristic information was extracted using competitive adaptive reweighted sampling algorithm， and the color and texture features were extracted as the image characteristic information. Finally， spectral information and image information were fused using feature layer fusion method， and LSSVM models were established based on three kinds of characteristics information， respectively. The results showed that the model based on fused spectra and image information yielded better prediction performance than that based on spectral information or image information merely， with correlation coefficient in the prediction set of 0.930， the standard analysis error of 1.873 mg/100 g， and relative percent deviation of 2.635. The results indicated that the feasibility of the prediction for TVB-N content in mutton based on spectra and image information. It provided an effective method for quantitative， rapid， nondestructive and accurate prediction of TVB-N content in mutton samples.

Abstract:As a kind of indispensible microbe in cheese， lactic acid bacteria （LAB） can strenthen its flavour and nutrition， and its metabolites can benefit human health. For analyzing the diversity of the LAB in different areas， 14 samples of cheese were sequenced as the objects of this research by combining the LAB specific primers with PacBio SMRT sequencing technology. It was unraveled that 14 LAB genera and 65 LAB species have been detected in cheese samples. Among them， Lactococcus lactis （27.10%） and Streptococcus thermophiles （14.35%） were the dominant species， and there have been obvious differences showed in the structures of the communities of LAB in different samples. Principal coordinate analysis （PCoA） revealed that these samples were divided into three groups and each group has its own distinct LAB community. This possibly could be due to different sites， climate and raw materials of samples. In addition， there has been significant correlation among some low-abundance LAB species like Lactobacillus gallinarum， Lactobacillus plantarum as well as Lactobacillus delbrueckii. This research showed the complexity and diversity of the LAB communities in cheese and that geographical environment and climate had a significant impact on it. Thus， this study aimed to provide some references for the development of LAB resource by studying the diversity of LAB in cheese from different regions.

Abstract:The objective of this study was to elucidate composition of microbial community structure and analysis of its differences in Xinjiang Kazakh traditional air-dried meat. IlluminaMiSeq high-throughput sequencing technology was used to analyze the bacterial 16S rRNA V4-V5 region gene sequence in Xinjiang traditional air-dried meat samples. The results showed that a total of 1 788 749 valid gene sequence bands and 308 OTU were obtained from 26 samples in the three groups， of which the number of OTU shared by the three groups was 237 and the number of OTU shared by the 26 samples was only 13. The diversity analysis showed that there was a high degree of microbial community diversity in traditional air-dried meat. At the bacterial genus level， the genus Lycobacterium（30.76%） and Cyclosphaera （7.82%） were the dominant flora in the sample. In addition， Carnobacterium （2.59%）， Leuconostoc（2.20%）， Enterococcus （1.06%） and other lactic acid bacteria and micrococci （1.69%）， Staphylococcus （1.60%） were also detected. The research results have deepened understanding of the composition and diversity of bacteria communities in the traditional air-dried meat of the Kazakhs in Xinjiang. A large number of conditional pathogenic bacteria were contained in Xinjiang traditional air-dried meat， which seriously affected the safety of the air-dried meat.

Abstract:Objective： To study the discrepancy of gut microbiota between patients with hyperlipidemia and people without hyperlipidemia. Methods： Illumina HiSeq second-generation sequencing technology was used to analyze the gut microbiota composition and abundance， and the inverse probability of treatment weighting（IPTW） method was used to correct confounding factors. The discrepant gut microbiota of hyperlipidemia was screened by QIIME2 ANCOM， and the R Tax4Fun package was used for functional prediction. Results： There were 7 discrepant ASVs between the hyperlipidemia group and the non-hyperlipidemia group（ASV_232、ASV_63、ASV_173、ASV_46、ASV_393、ASV_283、ASV_41）.There was only one discrepant ASV between the TG group and the non-TG group（ASV_422）. There were 18 discrepant ASVs between the HDL-C group and the non-HDL-C group（ASV_9、ASV_15、ASV_28、ASV_36、ASV_50、ASV_56、ASV_80、ASV_99、ASV_153、ASV_45、ASV_636、ASV_243、ASV_109、ASV_516、ASV_13、ASV_74、ASV_96、ASV_259）. Functional prediction results showed that the functional composition of the sample in the hyperlipidemia group and the non-hyperlipidemia group was highly similar， and no significant difference was found. Most functional genes were related to energy metabolism. Conclusion： The discrepancy of gut microbiota between patients with hyperlipidemia and people without hyperlipidemia is Lachnospiraceae、 Ruminococcaceae at family level， Bifidobacterium， Faecalibacterium， Bacteroides， Ruminococcaceae_UCG-013， Agathobacter， Subdoligranulum， Lachnoclostridium， Lachnospiraceae_UCG-010 at genus level， functional prediction showed that carbohydrate metabolism and amino acid metabolism accounted for a large proportion.

Abstract:Qualitative and localized detection of oral probiotics in the host has great significance. In this study， a horizontal specific fluorescence in situ hybridization probe was designed to study the colonization of Lactobacillus rhamnosus in the host intestinal tract. Based on the genome sequences of L.rhamnosus Probio-M9 and other related species， the L. rhamnosus species-level specific probe （Probe-16S） and the L.rhamnosus Probio-M9 strain-level specific probe （Probe-SP） were designed. After these specific probes verified using 15 strains of Lactobacillus rhamnosus and 15 other probiotics of the genus， the L.rhamnosus Probio-M9 strain-level specific probe was examined its applicability both in vitro and in vivo by fluorescence in situ hybridization （FISH）. Finally， combining a fluorescent D-amino acid （FDAA）-based metabolic probe， the living cells of L.rhamnosus Probio-M9 were detected in the intestinal tract of rats. The strain-level FISH probe we designed could specifically identify the L.rhamnosus Probio-M9 from the gut microbiota. This method could combine with the FDAA probes to provide a reliable technic for further exploring the translocation of this probiotic strain in the host.

Abstract:In this paper， using a Fourier transform near-infrared analyzer and an ultraviolet-visible spectrophotometer， with a commercial active beverage as a research object， a rapid quantitative detection study on the number of live lactic acid bacteria in live bacterial beverage was carried out. The original spectra of live bacterial beverages were subjected to Savitzky-Golay （SG） smoothing combined with first-order derivation （FD）， multivariate scattering correction （MSC） and orthogonal signal correction（OSC） pretreatment， and then using partial least squares to establish lactic acid bacteria a quantitative prediction model for the number of viable bacteria， and optimization and external verification of the optimal model. For the number of live lactic acid bacteria in live bacterial beverages， the PLS model established by Fourier transform near infrared spectroscopy with OSC pretreatment was the best. Using competitive adaptive weighting method （CARS） for wavelength screening and model optimization， the correction set correlation coefficient and root mean square error Rc was 0.9974， the RMSEC was 0.0211， the verification set correlation coefficient Rp was 0.9837， the root mean square error RMSEP was 0.0508. Finally， using the commercial samples that did not participate in the modeling， the optimized Fourier transform near infrared prediction model was externally verified. The correlation coefficient of the predicted value was 0.9068， and the root mean square error was 0.0108. The results showed that based on Fourier transform near infrared spectroscopy， the number of lactic acid bacteria in live bacterial beverages could be quickly and accurately detected， which provided a quick and convenient method for quality monitoring in the production and sales of live bacterial beverages.

Abstract:Objective： Extracellular polysaccharides（EPS）， as important secondary metabolites of lactic acid bacteria （LAB） play an important role in the production of fermented dairy products. Therefore， it is necessary to analyze the molecular mechanism of EPS production by lactic acid bacteria by bioinformatics in order to provide theoretical basis for the development and utilization of EPS. Methods：In this experiment， the second generation sequencing technology （Illumina Hiseq 4000） and Real-time fluorescent quantitative PCR（RT-qPCR） were used to sequence the genome of a strain of Streptococcus thermophilus IMAU20756 with high production of EPS from Mongolian yoghurt and quantitative analysis of eps gene expression at different time points. Results： The total genome length of the strain was 1 838 440 bp and GC contained 38.8%. In addition， it encoded 2 120 genes， including 1 962 functional genes， 36 tRNA， 515 pseudogenes， 1 tmRNA and 2 repetitive units. Among them， there are 12 genes related to EPS production. EpsA and epsB are regulatory genes， epsC and epsD determine the chain length of polysaccharides， eps1E， eps2E， epsG， epsF， epsH， epsI and epsJ are genes that encode glycosyltransferase， and epsK regulates the polymerization and output of polysaccharides. Conclusion： All the genes related to EPS biosynthesis could be expressed during fermentation， especially the gene expression of glycosyltransferase was the highest at 6 h of fermentation.

Abstract:Lead （Pb） and Cadmium （Cd） have emerged as major mussel pollutants in recent decades， thus the development of sensors capable of detecting both of Pb and Cd is of considerable interest. In this work， a bismuth film modified homemade electrode （HME） composed of ionic liquid/graphene composite （IL/GNs） was used as a working electrode for simultaneous detection of trace Pb2+ and Cd2+ in shellfish by differential pulse anodic stripping voltammetry （DPASV）. The best experimental parameters were optimized and set as follows： the mass concentration of Bi3+ at 500 μg/L， the enrich time of 420 s， enrich voltage at -1.1 V， stirring speed of 600 r/min， and HAc-NaAc buffer pH at 4.2. Under the optimal conditions， the DPASV peak currents showed good linear relationships with the mass concentrations of Pb2+ and Cd2+ in the same range of 1.0~45.0 μg/L and the detection limits for Pb2+ and Cd2+ were 0.5 μg/L and 0.8 μg/L， respectively. The analysis system was successfully applied to simultaneous detection of Pb2+ and Cd2+ contents in Scallop， Ostrea plicatula， Solen gouldi， Ruditapes philippinarum， and the results were comparable with those obtained from ICP-MS. The electrochemical sensor based on IL/GNS HME is easy to be operated and has high sensitivity toward sensing Pb2+ and Cd2+. It can be used for the rapid， accurate， and simultaneous detection of trace Pb2+ and Cd2+ in shellfish.

Abstract:Thai Hom Mali rice has good quality， high taste quality and nutritional value， which is loved by consumers all over the world. However， bad phenomena such as shoddy and adulteration often appear in the market. Establishing a rapid identification method of Thai Hom Mali rice is of great significance to promote the sustainable and healthy development of high-quality rice industry. In this study， based on the multi-source information fused by near infrared spectra and conventional indexes of Thai Hom Mali rice， the eigenvectors of the first derivative preprocessed near-infrared spectrum and the conventional index of 155 samples of Thai Hom Mali rice and 194 samples of Non-Thai Hom Mali rice were fused to form a 349 row and 14 column vector matrix， which was used as the input vector matrix of support vector machine classifier， and the fusion model of multi-source information was established. The identification results showed that the recognition rate of calibration set and verification set model was 100%， which solved the problem of low accuracy in the identification of Thai Hom Mali rice by common methods such as near infrared spectrum information， and realized the rapid and accurate qualitative identification of Thai Hom Mali rice. It has important application value in the identification of Thai Hom Mali rice adulteration.

Abstract:According to data released by the World Health Organization， ischemic heart disease， stroke， chronic obstructive pulmonary disease， Alzheimer's disease， tracheobronchial and lung cancer and diabetes are the top 6 causes of death in the world. This paper was based on 7 Economic Cooperation Organization（OECD） indicators related to non-medical determinants of health [Total fat supply （X1）， Total calorie supply （X2）， Total protein supply （X3）， Sugar supply （X4）， Vegetables supply （X5）， Fruits supply （X6） and Alcohol consumption （X7）] and 6 indicators related to health status [Ischemic heart diseases mortality （Y1）， Chronic obstructive Pulmonary diseases mortality （Y2）， Alzheimer's disease mortality （Y3）， Malignant neoplasms of trachea， bronchus， lung mortality （Y4）， Diabetes mellitus mortality （Y5）， Life expectancy （Y6）] from 2000 to 2013. Data from the top 10 countries in the OECD database were selected for multiple regression analysis using 6 indicators related to health status， including Y1， Y2， Y3， Y4， Y5 and Y6， and indicators related to non-medical determinants of health， including X1， X2， X3， X4， X5， X6 and X7. The results showed that the X7 was positively correlated with Y4 and negatively correlated with Y1 and Y5， and the coefficients were all greater than 1. It showed that alcohol consumption will increase the mortality rate of malignant neoplasms of trachea， bronchus， lung， but would significantly reduce the mortality rate of ischemic heart disease and Diabetes mellitus. X1 and X4 were significantly positively correlated with Y1， and the coefficients were both greater than 1， which indicating that total fat supply and sugar supply would increase the mortality rate of ischemic heart disease. Other health-related non-medical determinants， some of which were eliminated in stepwise regression， and the coefficients that were not eliminated were all less than 1， which had little influence on the change of Y value.

Abstract:Food-grade Pickering emulsion is a new type of emulsion stabilized with natural food macromolecular solid particles instead of traditional surfactants. Pickering emulsion has the advantages of high stability， low production cost and environmental friendliness， which makes up for the disadvantages and deficiencies of traditional emulsion， such as poor stability， high production cost and potential safety hazards. It has a good prospect of development and application in the field of food， and it is a research hotspot at present. In this paper， the effects of different processing conditions such as particle conditions， drying， preparation and digestion on the stability of Pickering emulsions were systematically reviewed. The aim was to propose the future development direction of the research on the influence of different processing factors on the preparation of food grade Pickering emulsion， and provided support for the wider application of Pickering emulsion in the food field.

Abstract:Food-grade Pickering emulsions stabilized by edible solid particles have attracted more and more attention due to their wide application prospects in food and pharmaceutical industries. Compared to those emulsions fabricated by food materials such as protein particles and polysaccharide particles， Pickering emulsions stabilized by polyphenol-based particles can have both physical stability and bioactive abilities， which will be vital for exploiting functional foods. Based on the stabilization mechanism of Pickering emulsion， this review mainly elaborated the formation and effect of polyphenol-based particles in Pickering emulsions. Besides， the innovative applications of polyphenol emulsions were also discussed.

Abstract:In recent years， with the continuous enrichment of emulsion chamber structure types， emulsion-based embedding and loading technologies have become more efficient and durable. However， the more complex the emulsion chamber， the more factors affecting the interface structure， and the more difficult it is to maintain the stability of the system. In the process of emulsion construction， the influence of only one factor on its stability should not be considered simply， but the presupposition of preparation conditions should be carried out by integrating the structural characteristics of different chamber types. In this paper， the research progress of the chamber structure and interfacial stability of several typical emulsions was summarized， and the stability improvement of different types of emulsions was compared and analyzed to provide theoretical support for the development of new emulsion products.

Abstract:Type 2 diabetes is a metabolic disease characterized by hyperglycemia and disorder of glucose and lipid metabolism. In recent years， studies have found that some amino acids can be used as potential biomarkers of diabetes， such as branched-chain amino acids （BCAAs） and aromatic amino acids （AAAs） which can induce insulin resistance through the mammalian target of rapamycin complex 1 （mTORC1） signal pathway or by middle toxic metabolites accumulation. With the development of metabolomics research， it has been found that the different metabolites between type 2 diabetic animals and diabetic control animals tend to be enriched in amino acid metabolism pathways after polysaccharide intervention， but the specific mechanism is still unclear. Therefore， the mechanism analysis of polysaccharides improving diabetes by regulating amino acid metabolism may explore new strategies for the treatment of this disease.

Abstract:According to its water solubility， dietary fiber （DF） is divided into soluble dietary fiber （SDF） and insoluble dietary fiber （IDF）. In recent years， the incidence of hyperlipidemia continues to increase， seriously affecting people's life quality. More and more emerging evidence indicats that DF has a good regulating effect on lipid metabolism. However， these reports are mostly about the SDF. The role of IDF in regulating lipid metabolism has long been underestimated or neglected. This paper summarized the the regulation effectand mechanismof IDF in lipid metabolism， influencing factors and material basis of IDF regulating lipid metabolism. Furthermore， the existing problems and future key research directions of IDF industry were analyzed. This paper may provide a significant reference for the sustainable and healthy development of IDF industry.

Abstract:Clustered regularly interspaced short palindromic repeats（CRISPR） system and CRISPR-associated proteins （Cas） make up CRISPR-Cas system which is one part of the immune system exists in bacteria and archaea， and can defend against the invasion of foreign mobile genetic elements such as phages effectively. Studies have found this system can prevent foreign nucleic acids which carrying feature genes integrating into bacterial genome and has effect on regulating functional genes expression， it is essential for biological characteristics such as bacterial virulence， antibiotics resistance， and the ability of biofilm formation. This article analyzed the structure of CRISPR-Cas in the common foodborne pathogens， and reviewed the functional correlation between CRISPR-Cas system and bacterial virulence， antibiotics， biofilm formation and typing， provided a reference for subsequent functional research of CRISPR-Cas system and traceability and control of foodborne pathogens.

Abstract:Recently， the demand for dietary fiber with improved prebiotic properties is increasing. Pectin is the main source of soluble dietary fiber， which is relatively stable in gastrointestinal digestion stage. Its prebiotic effect depends on the usage of intestinal flora and the production of beneficial metabolites. Pectin is plant-derived heteropolysaccharide with the most complex structure， and confirming how the multi-scale structure characteristics of pectin that affects the intestinal fermentation behavior of the host is prerequisite for understanding its prebiotic effects. The present article reviewed the progress on the structure-activity relationship between bacterial fermentability and pectin structural characteristics， including structural properties such as esterification degree， molecular weight， and neutral sugar composition， etc. Besides， the existing problems and futures on this area were analyzed with the purpose of providing reference for basic research and application of pectin.

Abstract:In the process of traditional fermentation， abundant nutrients， open fermentation environment and traditional fermentation technology contributed to diverse and relatively stable microbial community ecosystem. Their growth， metabolism and interaction control the fermentation process and produce rich nutrients and unique flavor substances， which are the essence of traditional fermentation technology. There are many types of microbial interactions， including mutualism， favoritism and competition between fungi and fungi， fungi and bacteria， bacteria and bacteria， respectively. In recent years， with the wide application of high-throughput DNA sequencing technology and omics-based analytic technology， the understanding of microbial interactions in traditional fermentation processes has further deepened. This review summarized the microbial community structure from different traditional fermented foods and the state-of-the-art knowledge of microbial interactions in these fermentation processes， and especially focused on the molecular mechanism in typical microbial interactions.

Abstract:The addition of oil and fat can affect the quality of surimi and minced meat products. This effect mainly depends on the proportional relationship between oil， protein and moisture， as well as the type of oil and environmental factors such as pH. When the proportional relationship between oil， protein and moisture is appropriate， oil can usually improve the quality characteristics of meat products， such as brightness， water retention capacity and gel characteristics， and vice versa can reduce these characteristics. In addition， the use of vegetable oil instead of animal fat can reduce the content of saturated fatty acids in meat products and increase the content of unsaturated fatty acids. In the process of gelatinization with meat products， there are mainly two kinds of force relationship between oil and protein. The first is the interaction between the proteins that form the interface protein film by electrostatic attraction. The second is the interaction between the oil and the interface protein film. Finally， a fat-interface protein film-protein matrix emulsification system is formed. The type of oil and environmental factors such as pH affect the quality of meat products by changing the stability of emulsification system by affecting the formation of the force between oil and protein.

Abstract:As people keep paying attention to food health， quinoa has gradually become a new favorite on the table because of its balanced nutrition， and quinoa protein has received widespread attention because of its high protein content and ideal， balanced amino acid ratio. At the same time， quinoa protein is almost free of gliadin， which can meet the processing and nutritional needs of many different foods. In addition， the deep processing and modification of quinoa protein can further optimize the processing adaptability and product stability of quinoa protein， which is a necessary processing method for expanding the application market of quinoa protein. Therefore， this article focused on the characteristics and applications of natural quinoa protein， and the effect of modification on the properties of quinoa protein， in order to provide theoretical and technical reference for improving the processing adaptability of quinoa protein and quinoa protein-based food processing.

Abstract:Electric Field treatment is a food processing technique， which enables fast heat or mass transfer by inducing high current or high voltage. At present， electric field-based techniques are mainly used to inactivate enzymes in food and to improve the shelf life of food. However， they can also improve enzyme activity through electrochemical reaction and polarization effect. In this paper， the principle， advantages and disadvantages of the current electric field-based techniques were introduced， the research status of the electric field-based techniques in enzymatic reaction was summarized， the mechanism of the electric field affecting enzyme activity was presented， the key factors influencing the electric field passivation and the improvement of enzyme activity were discussed， and the application prospects of electric field in enzymatic reaction were prospected.

Abstract:In recent years， in order to solve the problem of drug resistance of pathogenic bacteria， a variety of new antimicrobial agents emerged. Among them， the antibacterial effect of silver nanoparticles （AgNPs） is quite outstanding， so it has been widely concerned. The antimicrobial activity of AgNPs involves complex biological processes such as biofilm， cell damage and gene expression. Oxidative stress reaction plays an important role in this biological process. Under the stress of AgNPs， excessive reactive oxygen species（ROS） is produced in microorganisms， which stimulates intracellular oxidative stress and causes the following three effects： destruction of cell wall， cell membrane and its contents； affecting oxidative stress related gene expression； changes in protein translation processes and metabolic pathways. Based on this， this paper introduced the generation of microbial oxidative stress under the stress of AgNPs， focusing on the influence mechanism of oxidative stress on microorganisms at the levels of cells， gene expression， transcriptome and proteome. This is helpful to further understand the role of oxidative stress in the antimicrobial mechanism of AgNPs.

Abstract:Nitrofurans are synthetic broad-spectrum antibiotics， including furazolidone， nitrofurantoin， furantoin， nitrofurazone and so on. Because of its low price and good antibacterial effect， it is widely used in the prevention and treatment of bacterial diseases in livestock and aquatic animals. However， nitrofurans have mutagenicity and carcinogenicity. Many countries have already banned the use of nitrofurans in animal food production， but the illegal use of nitrofurans is still widespread. Immunochromatography is a combination of chromatography and immunological reaction. Immunochromatography has been widely used in the detection of nitrofurans in food owing to its advantages of simple operation， low cost， high specificity and high sensitivity. In this paper， the basic principle of immunochromatography was summarized， and the application of immunochromatography with different labeling materials in the detection of nitrofurans in food was reviewed， and the future development trend was prospected.

Abstract:The abuse of antibiotics leads to the frequent emergence of multiple drug resistance， which brings new challenges to the medical environment. The exchange of genetic material between DNA in different organisms or cells promotes the exchange and recombination of genetic material， so that drug-resistant genes evolve to adapt to the new drug-resistant environment. Direct contact between humans and animals as well as some biological substances may cause rapid transmission of resistant bacteria between hosts. The early stage of infection is a period of high risk and can enter families and communities through close contact. There can also be indirect exposure to antibiotic-resistant bacteria and resistant genes in the food chain through contact or consumption of contaminated food. Resistant genes can spread throughout the food chain， remaining partially active in humans and animals and spreading as metabolites are released into new environments. Understanding the spread of drug resistance genes in the food chain， so as to carry out risk management， infection and other related safety problems play a crucial role. Monitoring systems at different levels and fields should be set up to monitor the production， circulation and use of antibiotics at all stages， and the information obtained in various fields should be combined to jointly deal with the spread of drug-resistant genes.

Abstract:The world is undergoing unseen changes in a century， which is putting forward new challenges to higher engineering education and new requirements for the training of engineering talents. Facing the future and industry demand， the engineering education will be continuously innovated. In this paper， the status of China's food industry and the talent problems， and the current situation of food talent training at home and abroad were reviewed， which indicated that the university should take the initiative to respond to these changes. Taking the College of Food Science and Engineering in Bohai University and Dalian Nationalities University as an example， a “five-in-one” outstanding new engineering talent training system was established by adhering to the guidance of ideological and political education， reforming the training mode， promoting scientific research regurgitation-feeding the teaching， deepening the integration of industry and education， and intensifying the integration of innovation and entrepreneurship education. The constructed training system has distinctly improved the quality of personnel training， engineering practice ability， and innovation ability of the students， and promoted the high quality development of higher engineering education in local universities. The study had great significance to the innovation of the construction ideas of first-class major， the connotative construction of food major， and the culture of engineering and technical talents with strong engineering practical and innovation abilities， and could adapt to the industrial transformation and upgrading.