Abstract:The host's immune system， metabolism， and other physiological and pathological states are all influenced by the structure and function of the gut microbiota. Machine learning and deep learning have been used in recent years to explore the potential intervention targets of the gut microbiota， and the technology of developing microbiota-directed food (MDF) and regulating gut microbiota composition in a targeted way to improve human health has gradually advanced. In order to offer a fresh perspective on potential intervention target exploration of gut microbiota in the future and the development of MDF， this article introduced the application of artificial intelligence in the exploration of gut microbiota intervention targets and summarized the development process of MDF and their applications in various aspects such as malnutrition and blood sugar management.

Abstract:Lactobacillus casei Zhang is a probiotic lactic acid bacteria strain with excellent properties screened by our research team. It is difficult to distinguish Lactobacillus casei from its relative's species by traditional methods， and the systematic classification of Lactobacillus has recently been updated， resulting in the need to reconfirm the taxonomic status of Zhang. In this study， the taxonomic status， antibiotic resistance genes， virulence genes， and environmental resistance genes of Zhang were characterized using comparative genomics， and the bacteriocin gene cluster and potential probiotic genes carried on the genome of this strain were explored. The comparative genome's results showed that average nucleotide identity value between Zhang and Lacticaseibacillus paracasei ATCC 25302T was 98.49%. The taxonomic status of Zhang was confirmed as Lacticaseibacillus paracasei by comparison with taxonomic database and phylogenetic analysis. Zhang's genome does not contain antibiotic resistance genes， virulence genes， or environmental resistance genes. Carnocin-related bacteriocin gene cluster include core peptide， LanT transport and guided cleavage， and immune or transport functions were annotated on Zhang's genome. In addition， Zhang's genome encodes potential probiotic genes such as glutathione synthesis， riboflavin synthesis， adhesion factors， and exopolysaccharides secreted. This study updated the taxonomic status of Zhang as Lacticaseibacillus paracasei， revealed that it does not contain antibiotic resistance genes， virulence genes， or environmental resistance genes， and annotated several potential probiotic genes， providing data reference for further development and industrialization of this strain.

Abstract:A strain of lactic acid bacteria which produce antibacterial active substances was isolated and sifted from Tibetan cheese. After eliminating the interference of organic acids and hydrogen peroxide， the fermentation supernatant of the bacteria still had obvious antibacterial activity. After the fermentation supernatant was treated with pepsin， proteinase K and trypsin， its antibacterial activity was lost， indicating that the antibacterial substance in the metabolite of the bacteria had protein properties， and it was preliminarily determined to be a bacteriocin. It was identified as Lactobacillus plantarum by morphological observation， physiological and biochemical analysis and homology analysis of 16S rDNA gene sequence， named Lactobacillus plantarum ZFM804. The bacteriocin was preliminarily purified by macroporous resin (XAD-16) chromatography， strong cation exchange chromatography and RP-HPLC three-step method. The molecular mass of the bacteriocin was determined 15 ku approximately by SDS-PAGE. The analysis of physical and chemical properties showed that the bacteriocin had good acid-base stability: had bacteriostatic activity in the range of pH 3~11； good thermal stability: 100 ℃ treatment for 30 min still had obvious bacteriostatic activity， and could be degraded by proteases in human body. The results of the antibacterial spectrum assay showed that the bacteriocin had inhibitory effects on both gram-positive and gram-negative bacteria， and was a broad-spectrum bacteriocin.

Abstract:Acid phosphatase(ACP) is a key enzyme involved in the degradation of flavorful substances inosinic acid (IMP). Therefore， inhibition of ACP is very important to maintain the flavor of aquatic products during storage. This study investigated the interaction and inhibitory mechanisms of epicatechin (EC) on ACP by UV-Vis absorption spectroscopy， fluorescence spectroscopy， circular dichroism and molecular docking. The results showed that EC could effectively inhibit ACP activity， and the IC50 value was 0.184 mmol/L. It was reversible inhibitor of ACP， and the inhibition mechanism was the un-competitive type by kinetic analysis. The inhibition constant (Ki) was 1.025 mmol/L when the concentration of EC was 0.1 mmol/L. The fluorescence of ACP was quenched by the interaction with EC and the quenching mode was dynamic quenching. The binding constant (Ka) of ACP was 1.455×105 L/mol after adding EC at 298 K. The interaction of ACP with EC was driven by hydrogen bonds and van der Waals forces. EC altered the secondary structure of ACP， resulting in an increase in α-helix and a decrease in β-folding， β-turning and random coil. This study provides a new idea to inhibit the degradation of IMP in aquatic products during storage.

Abstract:Active peptides or food enzymes with natural antioxidant function are green， safe and reliable， and have attracted wide interest as green and multifunctional food additives. Hexose oxidase (HOX)， a D-hexose:O₂ 1-oxidoreductase， and has the functions of deoxygenation， acidification and improving protein crosslinking. In order to optimize the expression strategies of hexose oxidase in Pichia pastoris， different genotype host strains， different gene expression modes and different gene copy number in transformants were systematically compared. The transformants with different genotypes were obtained by the newly established three-step screening method， and their enzyme activities by fermentation were compared. The results showed that Muts host with slow methanol metabolism generated higher HOX activity； inducible expression by methanol was better than constitutive expression by GAP promoter； higher gene copy number of HOX gene generated higher enzyme activity. Although these factors related to gene expression in P. pastoris had been optimized， the HOX activity was still in a low level， and the maximum activity produced by KCX56 strain was 4.92×10-2 U/mL， which contained six gene copy number. The purification of recombinant HOX showed that there were three recombinant proteins with the molecular weight of 62， 40 ku and 29 ku， respectively. They should be protoenzyme of hexose oxidase and two subunits formed by proteolytic cleavage. Among them， the proportion of protoenzyme with low activity was much higher than other two， which may be one of the reasons for the low fermentation activity by these recombinant strains. The study of enzymatic characteristics showed that the optimum conditions for the recombinant HOX were 50-60 ℃ and pH 4.0， and it can maintain 50% activity at room temperature (20 ℃). Under low temperature (20-60 ℃) and acidic conditions (pH 3.0-6.0)， HOX activity can be stably maintained， so it is an antioxidant enzyme with good acid resistance， meaning that HOX is suitable for the preservation and antioxidant application for acidic foods.

Abstract:Objective: The sequence characteristics and gene expression pattern of CsrA， an important post-transcriptional regulatory protein， in Shewanella putrefaciens from aquatic products were investigated in this study. Method: The csrA gene of S. putrefaciens was cloned， and the structural characteristics and interaction protein network of CsrA were analyzed by bioinformatics methods. Moreover， the expression characteristics of csrA gene in response to cold， heat， high salt， starvation， ethanol and quorum sensing signal molecules were analyzed by real-time PCR. Results: CsrA is a highly conserved hydrophilic protein with nine phosphorylation sites， consisting of two α-helixes and five β-sheet， and active structure exists as a dimer. CsrA was predicted to interact with proteins that involved in protein synthesis， flagellar assembly and movement， biofilm formation， and quorum sensing regulation. In addition， csrA gene expression was significantly induced at 4 ℃ for 5 h， while immediately induced at 45 ℃ for 1 h. High salt concentration significantly induced csrA gene expression. The expression of csrA gene increased gradually in nutrient deficiency medium， which was significantly higher than that in the control group at 5 h. The expression of csrA gene was continuously up-regulated in the 5% ethanol group， while 10% ethanol reduced the expression of csrA. Quorum-sensing signal molecules induced the up-regulated expression of csrA gene. Therefore， CsrA is closely related to the spoilage caused by S. putrefaciens and plays an important role in its response to different environmental conditions， which can provide reference for further analysis of the biological function of CsrA.

Abstract:The aim of this study was to explore the inhibitory mechanism of solid-state fermented Chinese alcoholic beverage Luzhou-flavor baijiu(NX) and Maotai-flavor baijiu(JX) on the cell proliferation of hepatoma cell line HepG2. CCK-8 (Cell Counting Kit 8) method was used to evaluate the cell proliferation of HepG2. The activity of alcohol dehydrogenase (ADH)， catalase (CAT)， xanthine oxidase (XOD) and the contents of reactive oxygen species (ROS) and nitric oxide (NO) were detected by kit to evaluate the oxidative stress response. The gene expression level of Nuclear factor erythroid 2-related factor 2(NRF2) and NAD(P)H quinone oxidoreductase 1(NQO1) was measured by real-time quantitative PCR (qRT-PCR). Results: Compared with 100 mmol/L ethanol， NX and JX significantly inhibited HepG2 proliferation. JX (6.25-100 mmol/L) had a higher promoting effect than NX on regulation of the XOD and CAT. However， NX (6.25-100 mmol/L) significantly enhanced the production of NO than JX. Both NX and JX(100 mmol/L) decreased the gene expression of NRF2 and NQO1 in HepG2. Treatment with the antioxidant N-acetylcysteine (NAC) abolished the inhibition of cell proliferation and the down-regulation of NRF2 and NQO1 induced by both JX and NX. Conclusion: Both Luzhou-flavor and Maotai-flavor baijiu may inhibit the proliferation of hepatoma cell line HepG2 through oxidative stress.

Abstract:The purpose of the present study was to investigate the antibacterial stability of eight monoalkyl phenol flavorants， which were listed in the positive list of Chinese food additive use standard (GB 2760-2014)， against four food-related microorganisms. Influences of temperature， ultraviolet radiation and pH value on antimicrobial stability of eight monoalkyl phenol flavorants were investigated by double dilution method. The results indicated that 2-ethylphenol， 4-ethylphenol， 2-isopropylphenol and 2-propylphenol among the eight monoalkyl phenols had better antibacterial stabilities after they were heated for 20 min under 80， 110， 121 ℃， respectively； minimal inhibitory concentration (MIC) ranges of two ethylphenols and two propylphenols to four test bacterium were 0.195-0.781 mg/mL and 0.098-0.391 mg/mL. m-Cresol， 2-propylphenol， 2-isopropylphenol and 4-propylphenol showed better inhibitory stability after ultraviolet irradiation for 20， 40， 60 min， and their MIC ranges to four test bacterium were 0.781-1.563 mg/mL， 0.098-0.391 mg/mL， 0.195-0.391 mg/mL and 0.195-0.391 mg/mL， respectively. When the pH value deviate from 7， the antibacterial activities of most of the eight phenols increased， and their MICs to four test bacterium reduced to half of the original values.

Abstract:In order to study the antibacterial effect of curcumin combined with phloretin against Escherichia coli and explore the antibacterial mechanism， the sub-inhibitory concentrations of curcumin and phloretin were determined by the micro broth dilution method. The effects of each drug on the growth curve， extracellular nucleic acid protein， lactate dehydrogenase (LDH)， alkaline phosphatase (AKP) and total protein content of Escherichia coli were determined by bacterial culture at sub-inhibitory concentration doses. The Oxford cup method was used to analyze the combined antibacterial effect of curcumin and phloretin at the sub-inhibitory concentration of each drug. These results showed that: 1) Curcumin and phloretin had a significant inhibitory effect on the growth of Escherichia coli when both concentrations were 250 μg/mL， and this concentration was determined as the sub-inhibitory concentration of curcumin and phloretin. 2) The combined action of curcumin and phloretin at sub-inhibitory concentrations could effectively inhibit the growth of Escherichia coli， and the antibacterial effect was better than that of curcumin and phloretin alone(P<0.05). 3) The combined use of curcumin and phloretin at sub-inhibitory concentrations has a strong destructive effect on the cell wall and cell membrane of Escherichia coli， resulting in the increase of nucleic acid， protein and AKP index in the supernatant of bacterial liquid. At the same time， the combined use of sub-inhibitory concentrations of curcumin and phloretin reduced the expression of total proteins (including LDH) in bacteria， and the effect was significantly better than that of curcumin and phloretin alone (P<0.05). It can be seen that the antibacterial effect of curcumin and phloretin is better than that of curcumin and phloretin alone.

Abstract:Using rye bran as raw material， dietary fiber was prepared by enzymatic method， and the structure， monosaccharide and phenolic composition and functional properties of the two dietary fibers were determined respectively. The results showed that the surface of soluble dietary fiber (SDF) was loose， which was mainly composed of arabinose (68%)， galactose (13.1%) and xylose (12.2%). The surface of insoluble dietary fiber (IDF) was porous and irregular， which was mainly composed of xylose (54%) and arabinose (38.3%). Both dietary fibers had infrared characteristic absorption peaks of sugars. The crystallinity of IDF was higher than that of SDF， and the structure was more regular. SDF showed better water absorption (2.19 g/g)， cholesterol adsorption capacity (2.09 mg/g，pH=7) and nitrite adsorption capacity (327 μg/g，pH=2). The composition and content of phenolic substances in IDF were significantly higher than that in SDF (P < 0.05). The phenolic substances of IDF and SDF were mainly bound ferulic acid.

Abstract:The purpose of this experiment was to study the effect of rice protein on the physicochemical properties of rice starch before and after glutaminase (TG) catalyzed cross-linking. The functional properties and structural characteristics of starch blending systems were analyzed by technical means such as RVA， and the formation of starch-protein composite systems could be promoted under hydrothermal conditions. The results showed that the protein had a significant effect on the structure， digestibility and other functional properties of starch under the catalysis of TG enzyme， and the interaction force between rice protein and starch under the catalysis of TG enzyme was further enhanced. The expansion coefficient decreased from 13.24 g/g to a minimum of 7.02 g/g， and its amylose overflow decreased by 38.7%； with the participation of TG enzyme， the stability of the short-range ordered structure of starch was gradually enhanced with the increase of protein content. The protein with the addition amount of 10% has a better effect on reducing the digestibility of starch under the catalysis of TG enzyme； before and after the action of TG enzyme， the protein has little effect on the thermal properties of starch， but its gelatinization characteristics parameters were significantly reduced， and the viscosity also significantly decreased； TG enzyme catalyzed protein to make starch granule network structure more dense and aggregated. The above results indicated that the modification effect of TG enzyme catalyzed cross-linked protein on starch was more significant.

Abstract:In order to investigate the effects of rice flour on the physical properties of wheat flour dough， six varieties of Heilongjiang japonica rice mixed with high gluten wheat flour were prepared， and the mixed flour dough was subjected to multi-faceted analysis of texture properties analysis(TPA)， stress relaxation analysis， and large deformation mechanical analysis such as gluten strength. The results showed that， with the increases of rice flour content， the hardness， elasticity and cohesion of rice-high gluten wheat mixed flour increased， while the adhesion and resilience decreased. The stress relaxation time of all groups except Longdao 9 showed an overall upward trend， which increased by 2.01， 2.23， 4.08， 2.06 s， and 3.3 s， respectively. With the increase of rice flour addition ratio， the stretch value and rebound value of the mixed flour dough decrease， and the strength of the dough increases. Because Longdao 9 is glutinous rice， the stretch value and rebound value increase， and the strength decreases.

Abstract:Objective: To investigate the anti-depression mechanisms of fish oil by using network pharmacology. Methods: The targets for the treatment of depression with fish oil were obtained from databases such as the PharmMapper， SwissTargetPrediction， DrugBank， GeneCards， and Disgenet. The potential targets protein interaction network was analyzed using String website and Cytoscape software. Enrichment analysis of potential target proteins was performed using the DAVID 6.8 database. Additionally， a visual network diagram of the component-target pathway was created using Cytoscape software. Results: Fish oil exhibited anti-depression effects mainly through EPA and DHA. A total of 115 relevant targets for the treatment of depression were identified， including MAPK3， MAPK1， CASP3， PPARG， PPARA， PTGS2， DRD2， among others. These main targets play an anti-depressant role via regulating signal pathways， such as serotonergic synapse， PPAR signaling pathway， arachidonic acid metabolism， neuroactive ligand-receptor interaction and influencing biological processes， such as response to drug， steroid hormone mediated signaling pathway， oxidation-reduction process. Conclusion: Fish oil treatment for depression is characterized by its action on multiple targets and pathways， potentially involving the serotonergic synapse， PPAR signaling pathway， neuroactive ligand-receptor interaction， and arachidonic acid metabolism pathways to exert its anti-depressant effects.

Abstract:In order to investigate the effect of complex probiotics on immune function of cyclophosphamide-induced immunosuppression model mice， BALB/c mice were randomly divided into blank group and model group (perfused with normal saline)， positive control group [perfused with levamisole hydrochloride (LEV， 10 mg/kg)]， and low-dose， medium-dose， high-dose experimental group (perfused with 2.5×106， 5×106， 1×107 CFU/0.4 mL composite probiotics) for 28 days. The viscera index， cellular immune function， humoral immune function， percentage of splenic lymphocyte subsets， serum immunoglobulin and cytokine levels were determined. The results showed that， compared with model group， the thymus index of mice in each dose group was significantly increased (P<0.01)， and that in the low， medium and high dose groups was increased by 58.92%， 67.86% and 80.36%. The degree of delayed type allergic reaction increased (P<0.01) 20.34%， 27.12% and 67.80% in low， medium and high dose groups. Serum hemolysin levels were increased in both groups (P<0.05)， and and were significantly increased in medium dose and high dose groups (P<0.01)， by 31.25% and 40.23%， respectively. The percentages of CD3+， CD4+CD8- and CD4-CD8+ in splenic lymphocytes increased in low， medium and high dose groups (P<0.05)， and CD3+ was the most significant (P<0.01)， while those in low， medium and high dose groups increased by 33.17%， 42.63% and 54.65%， respectively. The proportion of natural killer (NK) cells in high-dose group was significantly increased by 56.50% (P<0.01)， and serum levels of immunoglobulin IgA， IgG， IL-2 and TNF-α were increased (P<0.05). In conclusion， compound probiotics could significantly improve the immunity of CTX mice， providing an important reference for the development of health food to enhance the immunity.

Abstract:The digestive properties of garlic polysaccharides were evaluated by simulating digestion in vitro and their effects on the immune function and intestinal flora of healthy mice were investigated. The results showed that garlic polysaccharides exhibited good anti-digestive properties, and approximately 93% of garlic polysaccharides could not hydrolyzed after oral and gastrointestinal digestion and were utilized by microorganisms. The results of animal experiments showed that garlic polysaccharides could promote the growth and development of mouse spleen, and significantly promote the levels of IgA (34.56%)， IgM (39.56%) and IgG (106.22%) in serum as well as SIgA (61.54%) in feces. It also improved the intestinal environment of mice， including promoting the proliferation of beneficial bacteria(such as Bifidobacterium and Lactobacillus)， inhibiting the growth of harmful bacteria， and increasing the levels of acetic acid and propionic acid. This result demonstrated that garlic polysaccharides could act as prebiotics and enhance the immune function of the body.

Abstract:The purpose of this study was to evaluate the immunomodulatory properties of chicken soup， chicken meat and their complexes. Gushi chicken(two year) was used as raw material to prepare chicken soup powder and chicken meat powder， respectively， and their amino acid compositions were determined. Chicken soup， chicken meat and their complexes were given to immunosuppressive mice induced by intraperitoneal injection of cyclophosphamide. The body weight， immune organ index， cytokines， immunoglobulins， spleen immunohistochemical analysis and histopathology of the mice were measured. The effects of immune chicken meat and their complexes on the above indicators were analyzed from the aspects of cellular immunity and humoral immunity. The results showed that chicken soup， chicken meat and their complexes improved the immune capacity of immunosuppressed mice. Chicken soup significantly increased the blood hemoglobin content [(133.33±4.07) g/L]， serum IgA content [(341.99±17.89) pg/mL] and serum IgG content [(1 988.75±96.56) pg/mL] of immunosuppressed mice. Compared with chicken soup， the expression of CD4+ on spleen cell surface was significantly increased. Their complex could increase thymus index [(1.62±0.47) mg/g]， improve spleen and ileum tissue injury， stimulate interferon-γ secretion [(1 355.83±71.73) pg/mL]， and restore Th1/Th2 balance. Conclusion: This study showed that chicken soup， chicken meat and their complexes had an improvement on the immune regulation function of immunosuppressed mice， and the comprehensive effect of chicken soup was better than that of chicken.

Abstract:Objective: In this study， the effects of different dietary fatty acid composition on liver glucose level were discussed based on the interaction of insulin and iron metabolism. Methods: Sixty 21-day-old clean male SD rats were randomly divided into: control group， 15% SO group， 15% PO group (lard)， 15% OO group (olive oil)， 15% FO group (fish oil)， and 1∶1 SO∶FO group. Firstly， the fatty acid compositions of oils were determined by gas chromatography， and then the contents of glucose and insulin in liver were measured after 13 weeks of intervention with different oils. The contents of hemoglobin， serum iron， ferritin in liver were also detected， and the iron deposition in liver tissue was observed by prussian blue staining. The key genes expressions of iron metabolism in rat liver was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The n-6 unsaturated fat acid content in SO was 46.37%， the n-3 unsaturated fat acid content in FO was 37.55%， the saturated fat acid content in PO was 24.78%， and the monounsaturated fatty acid content in OO was 36.39%. There were no significant differences in the contents of glucose in the liver of rats in each group. The level of hepatic insulin in the rats of 1∶1 SO∶FO group was significantly lower than that in the control group and the 15% SO group (P < 0.05). There were no significant differences in hemoglobin and ferritin among all the groups， but the serum iron content in 15% SO group was the highest and significantly higher than that in the control group and 1∶1 SO∶FO group (P < 0.05). Compared with the control group， the iron content in liver of 15% PO group was significantly higher (P < 0.05)， and prussian blue staining results showed that brown particles increased in 15% SO group and 15% PO group. The expression of hepcidin (Hep) gene decreased significantly in 15% SO group and 15% PO group (P < 0.05)； the expression of ferroportin 1 (FPN 1) gene in 15% SO group and 15% PO group was significantly lower than those in other high-fat groups (P < 0.05). Compared with the control group， the expression of divalent metal transporter 1 (DMT-1) gene in 15% FO group was significantly higher (P < 0.05). Compared with the control group， the expression of transferrin receptor-2 (TfR-2) gene in 15% PO group decreased significantly (P < 0.05). Conclusion: Compared with 15% SO， 15% 1∶1 SO∶FO could inhibit the increase of serum iron level and liver iron deposition， and then resist the decrease of insulin sensitivity； 15% OO and 15% FO had no remarkable effect on liver iron deposition， while 15% PO could cause liver iron deposition. Overall， appropriate supplementation of fish oil can improve liver glucose and iron metabolism.

Abstract:Staphylococcus carnosus is a food microorganism widely used in fermented meat products. However， the growth and metabolism mechanism of staphylococcus carnosus in fermented meat products is still unknown at present， which is closely bound up to the difficulty in plasmid transformation and the inability to establish a mature molecular biological system in genetic engineering operations. Staphylococcus carnosus has a thick and dense rigid cell wall and a restrictive modification (RM) system， causing poor reproducibility and inefficient of electrical conversion. In this study， the effects of shock buffer， electric field intensity， plasmid concentration， recovery medium， plasmid modification and heat treatment of competent cells on the electrical conversion efficiency of Staphylococcus carnosus pCA44 were studied， and the electrical conversion scheme was optimized. The results showed that: The competent cells were washed with 10% glycerol and 0.5 mol/L mannitol， 500 ng/100 μL plasmid modified by Escherichia coli DC10B was added， the competent cells were treated at 56 ℃ for 2 min， electric field intensity was 10 kV/cm， the mixture of plasmid and cell was shocked， and RGM2 containing 0.5 mol/L mannitol was added immediately after electric shock， which obtained the highest transformation efficiency， reaching 6.26×105 CFU/μg， and all the randomly selected transformants were positive for PCR verification. The electrical transfer scheme obtained in this study significantly improved the electric shock conversion efficiency of Staphylococcus carnosus pCA44， which could provide technical support for the analysis of its fermentation and metabolism mechanism， and provide reference for other staphylococcus strains with RM system barrier in the future.

Abstract:In order to obtain a high-yield fermentation strain of 2，3，5，6-tetramethylpyrazine (TTMP)， Bacillus velezensis CS1.11 screened from moromi was mutated by ultraviolet radiation. The diameter of casein plate hydrolysis ring and the intensity of acetoin color reaction were used as indicators for preliminary screening. The solid-state fermentation of TTMP from steamed soybean meal and roasted wheat was rescreened， and three mutant strains were obtained. Study on protease， amylase activity as well as acetoin synthesis ability showed that two mutant strains CS1.11-32 and CS1.11-33 were better than another， and their TTMP accumulation increased by 47.64% and 78.89%， respectively， compared with the original strain， which were suitable for soy sauce fermentation. The effects of roasted wheat addition amount， water addition amount， inoculation amount， fermentation temperature， and stirring times on the accumulation of TTMP were studied and CS1.11-33 showed better TTMP accumulation ability compared with CS1.11-32. The optimal fermentation conditions for solid-state fermentation of CS1.11-33 to accumulate TTMP were obtained by response surface methodology as follows: Roasted wheat addition of 44%， water addition of 29%， fermentation temperature of 37 ℃， inoculation amount of 8%， and no stirring during fermentation. Under these conditions， the maximum accumulation of TTMP reached 1 895.08 mg/kg dry basis， 2.6 times that before optimization. Breeding and fermentation research of Bacillus velezensis TTMP high-yield strain in moromi will lay the foundation for increasing TTMP concentration in soy sauce， rapidly enhancing Jiang-flavor， and promoting the functional application of TTMP.

Abstract:This study was aimed to investigate the effects of different Lactobacillus and fermentation conditions on the enrichment of polyphenols in whole grain black barley， in which No.1 Lactobacillus hilgardii (DSMZ 20051)， No.2 Lactobacillus fermentum (DSMZ 20052)， No.3 Lactobacillus diolivorans (DSMZ 14421) and No.4 strains Lactobacillus kisonensis (JCM15041) were used in the fermentation. The results showed that different fermentation strains had significant effects on polyphenols enrichment of black barley (P<0.05). The polyphenols enrichment effect of No.4 strains Lactobacillus kisonensis(JCM15041) was better than other three strains. The optimal fermentation conditions were established as follows via single factor and orthogonal experiments: solid-liquid ratio 1∶5， inoculum volume of No.4 strains 3%， fermentation time 24 h， fermentation temperature 30 ℃. Under these optimized conditions， the polyphenols content reached (0.88±0.016) mg/g， which was 1.05 times higher than that of unfermented black barley. Some of polyphenols compounds such as bergenin， cinnamic acid， maltol， catechin， genkwanin， trans-coumaric acid， caffeic acid， anthocyanidin， and ferulic acid were identified in the extract of black barley fermentation broth by using the targeted metabolomics analysis of UPLC-Q-TOF-MSE， which were 3.82， 7.95， 1.38， 0.21， 0.43， 1.40， 0.37， 0.36 times and 0.33 times higher than that of unfermented black barley(P<0.05). Additionally， syringic acid and veratric acid were only detected in fermented black barley. In conclusion， fermentation of black barley with Lactobacillus kisonensis (JCM15041) could effectively enrich polyphenols， which can be used for the preparation of functional whole grain food material.

Abstract:In order to investigate the structural and functional changes of the complex formed by the interaction of vitexin and mung bean protein(VT-MBP) at different temperatures during mung bean food processing. The effects of heating temperature on the macromolecular structure of vitexin-mungbean protein complexes (VT-MBP) was investigated by Fourier infrared spectroscopy， scanning electron microscopy， fluorescence spectroscopy， and SDS-PAGE. The changes on the functional properties such as solubility， emulsification， foaming， and antioxidant properties of VT-MBP were analyzed under different temperatures. The results showed that: Heating temperature changed the molecular structure of VT-MBP， and the content of α-helix and β-sheet in the secondary structure of VT-MBP decreased with the increase of temperature. Fluorescence spectroscopic results revealed that the interaction mechanism of VT and MBP was static quenching and binding through non-covalent hydrophobic interaction. In addition， VT-MBP had good emulsification， foaming and foam stability when the heating temperature was 90 ℃. Conclusion: The heating temperature has a significant impact on the structure and functionality of VT-MBP. The present results provide a theoretical basis for determining the optimal processing temperature of mung bean food and developing functional mung bean protein beverages.

Abstract:This study aimed to investigate effects of dry salt-curing processing on content and composition, antioxidant activity and bioaccessibility of polyphenolic compounds in Sanhua Plum (Prunus salcina LindI.). The free and bound phenols in Sanhua plum were 14.81 mg GAE/g DW and 9.25 mg GAE/g DW, respectively, and salting process significantly reduced 65.90% the free phenol contents, significantly increased 45.84% the bound phenol contents. Salt-curing caused a significant decrease in free phenolic content whereas a significant increase in bound form. The concentration and distribution of individual phenolic compounds in Sanhua plum were changed by salt-curing processing. The concentration of epicatechin, quercitrin, quercetin-hexoside and procyanidin B2 was decreased, while 4-hydroxybenzoic acid, chlorogenic acid and cryptochlorogenic acid contents were increased after salt-curing. DPPH· and ABTS+· antioxidant activities of free phenolics were decreased, while DPPH· antioxidant activities of bound phenolics were increased by dry salt-curing processing. The phenolic bioavailability of fresh and salt-cured plums was 49.50% and 34.80%, respectively. The obtained data provides a theoretical basis for the processing of preserved fruits products.

Abstract:In this research， the effects of different sterilization temperatures on color and related chemical substances in lotus rhizome juice were studied， and the correlation between color parameters and chemical substances was analyzed to determine the relationship with them. The results showed that the values of a， b， ?驻E and A420nm increased， the contents of reducing sugar and 5-hydroxymethylfurfural increased， and the contents of ascorbic acid， total phenol， threonine， serine， methionine， histidine and proline decreased. Compared with sterilization at 101， 111 ℃ and 121 ℃， sterilization at 81 ℃ and 91 ℃ had little effect on the color and chemical substances of lotus rhizome juice. 5-Hydroxymethylfurfural， ascorbic acid and reducing sugar were significantly correlated with ?驻E and A420nm， among which 5-hydroxymethylfurfural had the strongest correlation with ?驻E， and the coefficient reached 0.940， indicating that 5-hydroxymethylfurfural was the main factor causing the color change of lotus rhizome juice before and after sterilization. 5-Hydroxymethylfurfural was significantly related to ascorbic acid， reducing sugar， threonine and methionine. It could be inferred that the production of 5-hydroxymethylfurfural was mainly related to the oxidative decomposition of ascorbic acid and the Maillard reaction of threonine， methionine and reducing sugar.

Abstract:In this study， the enzymatic hydrolysis preparation of flavor peptide from Stropharia rugosoannulata were optimized by using response surface methodology based on the taste characteristics and peptide yield. The optimal process parameters were as follows， the hydrolysis time was 51.62 min， the addition amount of alkaline protease was 0.99% (enzyme activity， 200 000 U/g)， the hydrolysis temperature was 42.03 ℃， and the substrate mass concentration was 48.45 g/L. Based on the optimal parameters of conventional enzymatic hydrolysis process， the peptide was prepared by simultaneous ultrasound-assisted enzymatic hydrolysis. The peptide content in the samples(469.21 mg/g dry weight) at 30 min treatment of the plate ultrasound-assisted enzymatic hydrolysis could reach the peptide yield under the optimal conditions of conventional enzymatic hydrolysis， and the preparation time of the base material was significantly reduced； the peptide yield (492.87 mg/g dry weight) at 40 min treatment of ultrasound-assisted enzyme hydrolysis was 6.5% higher than that of conventional enzyme hydrolysis. The peptides prepared by simultaneous ultrasound-assisted enzymatic hydrolysis had better savory and umami taste characteristics， which were enhanced by 1.1-1.8 times and 1.1-1.3 times， respectively， compared with the peptide prepared by conventional enzymatic hydrolysis. The peptide-rich samples showed superior angiotensin-I converting enzyme (ACE) inhibitory activity with 50% inhibitory concentration (IC50) of 0.071， 0.074， 0.122 mg/mL and 0.123 mg/mL. By analyzing the sequence of the flavor peptide， it was found that the peptide showed salty and umami taste when the aspartic acid (D)， valine acid (V)， glutamic acid (E)， leucine acid (L)， glycine acid (G)， arginine acid (R)， proline acid (P)， and alanine acid (A) in the combination of DD， VV， EL， VG， VE， RP， RA， RV or VR were present in the peptide sequence. The high proportion of these amino acids' combination in the peptides might be the main reason for the salty and umami taste characteristics of the samples. The mechanism of in vitro ACE inhibitory activity of the flavor peptide was predicted by molecular docking technique， and the flavor peptides could form hydrogen bond interaction with the amino acid residues of ACE active pocket， which might be the main reason for the ACE inhibitory effect of the flavor peptides. The study can provide a theoretical basis for the preparation and application of the flavor-active peptide of mushroom， and provide a reference for the preparation of salt-reducing and umami-enhancing condiments， functional foods， or food additives.

Abstract:Corn oil is one of the most phytosterol rich vegetable oils. Containing a certain amount of wax， which affects the sensory and transparency of edible corn oil. In this study， the wax ester of bleached corn oil was removed by dry method， the influence of dewaxing process on wax content， phytosterol content and mobility were also investigated. And on the basis of single factor test， the preparation process of dewaxed corn oil was optimized by response surface analysis. The response surface methodology results showed that optimal solution was as follow: 62 h crystallization time， 3.5 ℃ crystallization temperature， 1.4 ℃/min cooling rate. Under these conditions， the content of wax， ester sterol and total sterol in corn oil were 34.75 mg/kg， 842.52 mg/100 g and 1 110.61 mg/100 g， respectively. It provides a theoretical reference for producing edible corn oil rich in phytosterols in the dewaxing process.

Abstract:The flavor compounds in six strawberry flavors were determined by headspace solid-phase microextraction (SPME) combined with gas-mass spectrometry (GC-MS)， and one strawberry flavor was selected to study its volatilization during the processing and storage of modified milk. The influence rules of sexual components were compared and analyzed when they were added to water and milk. Samples were taken at three process points before homogenization， after homogenization and after sterilization(137 ℃， 4 s) for SPME-GC-MS detection， and the samples stored at room temperature for days 0， 15， 43， 98 and 198 were tested. Three main volatile compounds， ethyl butyrate， ethyl 2-methylbutyrate and ethyl hexanoate in the No. 5 strawberry flavor， were selected and added to the milk according to their respective proportions in the strawberry flavor， and their individual changes were studied. The results showed that the contents of ethyl butyrate， ethyl 2-methyl butyrate and ethyl hexanoate decreased by 28.92%， 35.92% and 29.91%， respectively， after sterilization compared with those before homogenization. On the 198th day of storage， compared with the 0th day， the content of some volatile compounds in the strawberry flavor in milk and water increased significantly (P<0.05). The results of this study showed that heat treatment and storage time had a great influence on the volatile components in strawberry flavor.

Abstract:The ultrasonic assisted ethanol ammonium sulfate aqueous two-phase extraction method was used to optimize the extraction process of flavonoids from celery leaves by response surface methodology(RSM) and BP neural network. The effects of four main factors on the extraction rate of total flavonoids were studied. The central composite design experiment was adopted. The data sample output from response surface was used as the input sample of BP neural network， and the characteristics of its interactive algorithm were used to optimize the fitting， so as to achieve the purpose of optimizing the extraction process by combining BP neural network with response surface. The results showed that under the conditions of ultrasonic time of 52.25 min， ultrasonic temperature of 52.5 ℃， solid-liquid ratio of 1 ∶ 44 and ethanol content of 61.47%， the extraction rate of total flavonoids from celery leaves could reach 6.62%. Total flavonoids from celery leaves had scavenging effects on DPPH·， ·OH and ·O₂-， and the maximum scavenging rates were 88.2%， 86.1% and 84.3%， respectively. It could be used as a kind of bacterial inhibitor. The content of luteolin and apigenin in the sample extract was relatively high by LC-MS analysis.

Abstract:The natural drying process of chili peppers in Xinjiang Gobi Desert includes six steps which are hanging and drying， harvesting， spreading and drying， piling， sweating， bagging and transportation. However， the natural drying process is based on experience without technical protocol and theoretical guidance， in order that dried chili peppers are easy to be fragile and moldy. Therefore， it is necessary to monitor the natural drying process of chili peppers in Xinjiang Gobi Desert and develop its technical protocol， so as to standardize the natural drying process， ensure the safety and the quality of dried chili peppers. This study followed the natural drying process of three common varieties of chili peppers which were Honglong 18， Honglong 23 and Pepper Tiepi， and monitored the environmental temperature， humidity， wind speed， dry basis water content， water activity， color difference and moldy rate of drying chili peppers， and established a mathematical model of natural drying process of chili peppers in Xinjiang Gobi Desert. The natural drying process of chili peppers in Xinjiang Gobi Desert was in accordance with the Logarithmic drying model. Combined with the actual experience， this study regulated that the dry basis water content of peppers was about 1.0 g/g and 0.16 g/g when they were piled-up and at the end of natural drying. The determination of the dry base water content of chili peppers at the beginning of piling and the end of drying could provide a theoretical basis for the development of the technical protocol. In addition， this study found that mechanically harvested peppers were more damaged and more prone to mold in the natural drying process. Therefore， reducing the mechanical damage of peppers and standardizing the natural drying process were conducive to improving drying efficiency， ensuring the safety of dried peppers， and promoting the high-quality development of the dried chili pepper industry.

Abstract:In order to improve the hot-air drying efficiency and product quality， the drying characteristics and quality changes of Huangshan stinky mandarin fish were investigated at different drying temperatures (55， 65， 75， 85 ℃ and 95 ℃). The results showed that the effective moisture diffusion coefficient (Deff) of stinky mandarin fish ranged from 2.8848×10-10 m2/s to 8.8663×10-10 m2/s in the range of 55-95 ℃. The higher temperature led to higher effective water diffusion coefficient， and its diffusion activation energy (Ea) was 27.9370 kJ/mol. The data fitting result showed that Page model could accurately describe the water migration during hot-air drying of stinky mandarin fish. Drying temperature had significant effect on the quality of stinky mandarin fish. When the temperature was 75 ℃， the fish rehydration ratio was the largest at 3.03±0.13， the peptide content was the highest at (3.79±0.25) g/100 g， and with the most significant antioxidant effect. The texture characterization and overall quality of 75 ℃ were relatively better. This research preliminarily revealed the correlation between drying characteristics and quality of stinky mandarin fish， which could provide theoretical reference for the optimization of quality control during the drying process of Huangshan stinky mandarin fish.

Abstract:Extruded instant porridge is produced by controlling the amount of water added and the speed of screw separately. By measuring the physical and chemical properties， sensory quality and texture characteristics of instant porridge， the influence of different control conditions on the quality of instant porridge were analyzed. The results showed that with the increase of screw speed， the water solubility index(WSI)， water absorption index(WAI) and sensory quality increased， while the hardness， viscosity， chewiness and resilience of instant porridge decreased. With the increase of water addition， WAI， WSI and sensory quality decreased， which resulted of hardness， stickiness， chewiness and resilience increased. Screw speed was positively correlated with WSI， WAI and sensory quality， and negatively correlated with texture characteristics. Water addition amount was negatively correlated with WSI， WAI and sensory quality， and positively correlated with texture characteristics. High screw speed and low water addition amount were beneficial to improve the quality of instant porridge. The screw speed of 250 r/min and water addition amount of 15% had the best effect on the quality of extruded instant porridge.

Abstract:This paper studied the effects of controlled atmosphere(CA) with different CO₂ ratios (4% CO₂， 8% CO₂， 12% CO₂) on the appearance quality and chlorophyll degradation of Brassica chinensis L. under the condition of 4% O₂. The results showed that CA could effectively delay the yellowing of Brassica chinensis L.， reduce the weight loss rate and effectively maintain the appearance quality of Brassica chinensis L. Compared with the control group stored in the air environment， CA could significantly delay the degradation of chlorophyll a/b in Brassica chinensis L. On the 12th day of storage， the chlorophyll a/b content in the 4% CO₂ treatment group was 48.20 μg/g FW and 40.45 μg/g FW. 4 days before storage， the activity of chlase and MD was inhibited by CA， the activity of chlase in 4% CO₂ treatment group was 23.09 U/g FW， and MD was 43.03% lower than that in control group. At the later stage of storage， 4% CO₂ treatment effectively delayed the increase of the activity of PPH and Chl-POX， which were 5.49 U/g FWand 1.90 U/g FW. In general， the CA condition of 4% O₂ + 4% CO₂ seemed to be optimal for Brassica chinensis L. storage.

Abstract:In this work， the wolfberry filling was produced as the research object， and the changes of moisture， color， texture， microorganisms and other quality indicators of wolfberry fillings during storage were detected and a shelf-life prediction model was established. The results showed that the hardness， moisture content， total colonies number， and mold number of the wolfberry fillings were increased gradually while the L value and a value were decreased gradually with the prolonged storage time no matter under 4， 25 or 37 ℃ conditions. In general， the slowest rate of deterioration of the wolfberry fillings was observed under storage 25 ℃. On the basis of correlation analysis， the total number of colonies was chosen as the quality indicator that reflecting the shelf life of wolfberry fillings， the growth kinetic model of the total colonies number under different temperature conditions and the kinetic model that changes with the storage temperature were established. The accuracy factors， deviations， and root mean square error of the kinetic model were 0.995-1.099， 1.071-1.189 and 0.03-0.07， respectively. Finally， the microbial prediction model was established and verified. The relative error between the predicted value and the actual value was from -1.77% to 26.76%， which indicated that the model could predict the shelf life of wolfberry fillings effectively. The technical support could be provided for the wolfberry fillings storage according to this research.

Abstract:In order to study the metabolic components of Camellia oleifera kernels， and metabolites difference in seed kernel in Camellia drupifera and Camellia oleifera were explored at the same time， then antioxidant activity of kernels oils in Camellia drupifera and Camellia oleifera were detected. Broadly targeted metabolomics based on ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was used to detect differential metabolites between Camellia drupifera and Camellia oleifera. The metabolites in the kernels of two Camellia species were compared via cluster analysis， correlation analysis and orthogonal partial least squares discriminant analysis (OPLS-DA). Finally， the seed kernel oil was extracted by Soxhlet extraction method， and the difference in antioxidant activity of the oil was compared. The results showed that 25 metabolites Camellia drupifera owned and 16 metabolites Camellia oleifera owned were filtered in the 536 metabolites belonging to 11 classes detected in the kernels of two Camellia species. 197 differential metabolites were filtered among the whole 536 metabolites， and made up 36.75%. Amond them， 103 metabolites were expressed higher in Camellia drupifera than Camellia oleifera， which made up 52.28% in total differentially expressed metabolites； 94 metabolites were expressed in lower levels than Camellia oleifera， which made up 47.72% of 197 differential metabolites； These 197 metabolites differentially expressed in two Camellia species mainly participated in 20 pathways， flavonoid biosynthesis， phenylpropanoid biosynthesis， tyrosine metabolism and anthocyanin biosynthesis were the pathways occupying top 4 differential metabolites， and there were 7 metabolites (3.55%)， 5 metabolites (2.54%)， 4 metabolites (2.03%) and 4 metabolites (2.03%)， respectively. The variety and content of flavonoids and lipids in Camellia drupifera were more abundant than Camellia oleifera. The antioxidant activity tests showed that the DPPH free radical scavenging rate of Camellia drupifera seed oil was slightly higher than that of Camellia oleifera when the oil mass concentration was greater than 6.0 mg/mL， and when the oil mass concentration exceeded 0.4 mg/mL， the hydroxyl clearance rate of Camellia drupifera was slightly higher than that of Camellia oleifera. The seed kernels of Camellia drupifera were rich in flavonoids and phenolic acid compounds， and the types and content of lipids are more abundant than those in Camellia oleifera seed kernels. The difference expression metabolites of seed kernels may be the key factor affecting the composition and antioxidant activity of the two types of Camellia oil.

Abstract:Objective: To explored the microbial diversity and community structure of traditional fermented raw cheese of yak milk in Tashkorghan Pamirs Xinjiang. Methods: 6 raw cheese samples were collected from different herdsmen's families. The microbial diversity was analyzed by high-throughput sequencing technology. At the same time， the traditional yak milk fermented cheese samples were selected and isolated by pure culture. The species of bacteria and yeast were identified by traditional classification， 16S rDNA sequencing and 26S rDNA D1/D2 spacer sequencing. Results: The optimized sequence 945 432 was obtained by sequencing the V3-V4 region of 16S rDNA gene. The optimized sequence 1 302 962 was obtained by sequencing the its region of fungi. At the genus level， Lactobacillus and Streptococcus belonging to Firmicutes were the dominant bacterium， Kluyveromyces， Torulaspora， Issatchenkia and unclassified dipodascacease belonging to Ascomycotea were the dominant fungi. According to PCoA analysis， the community structure of the six samples had both similarities and differences. 52 strains of bacteria were isolated on MRS and MC medium and 46 strains of yeast were isolated on YGC medium. Through the analysis of bacterial 16S rDNA sequence and fungal 26S rDNA D1/D2 compartment sequence， 52 strains of bacteria were classified into 7 genera and 11 species. They were Enterococcus durans， Enterococcus faecium， Bacillus tropicus， Bacillus cereus， Bacillus paramycoides， Pseudomonas helleri， Lactobacillus paracasei， Lactobacillus gallinarum， Enterobacter hormaechei， Streptomyces microflavus and Staphylococcus epidermidis. 46 yeast strains were classified into 8 genera and 9 species. They were Yarrowia lipolytica， Candida zeylanoides， Pichia fermentans， Pichia kudriavzevii， Guehomyces pullulans， Wickerhamomyces anomalus， Kluyveromyces marxianus， Issatchenkia orientalis and Saccharomyces cerevisiae. In this study， the microbial resources in traditional fermented dairy products in Tashkoghan Pamirs were analyzed for the first time. There is diversity of microorganisms in yak milk fermented milk products in this area. Further in-depth research and excavate are needed.

Abstract:The standardization of paocai quality depends on the microbial community structure in the fermentation process. In this study， high-throughput sequencing technology was used to study the dynamic changes of bacterial community structure composition， detect the dynamic changes of physical and chemical factors， reveal the correlation between them， and carry out functional prediction and metabolic pathway analysis. The results showed that: Simpson index in S1 stage was significantly higher than that in S2 and S3 stage， while Shannon index was significantly lower than that in S2 and S3 stage (P<0.05)， indicating that the diversity of bacterial community was low in the early fermentation stage. The bacterial species detected from 9 samples of paocai belong to 6 phylum， 9 classes， 29 orders， 47 families， 59 genera， 83 species. Firmicutes and Proteobacteria were the dominant phyla in paocai fermentation. The dominant genera were Pseudomonas， Lactobacillus， Enterobacteriaceae and Lactococcus. The relative abundance of Firmicutes was 10.61%， 64.83% and 77.51% at the beginning， middle and end of fermentation respectively， while Proteobacteria decreased from 84.18% to 17.91%， and Pseudomonas decreased from 33.19% at the beginning of fermentation. The relative abundance of Lactobacillus increased rapidly from less than 1% to 67.65% in the end fermentation period. L. curvatus was the main Lactobacillus in the middle fermentation period， L. plantarum was the main Lactobacillus in the late fermentation period. Correlation analysis and Redundancy analysis showed that titratable acid and nitrite were the main driving factors of bacterial community structure change， and had the greatest influence on bacterial community composition. Nitrite was positively correlated with the community at the early fermentation stage， amino acid ammonia mainly affected the community at the middle fermentation stage， soluble protein and TTA had a greater impact on the community structure at the late fermentation stage. Titratable acids were significantly positively correlated with Lactobacillus and negatively correlated with Pseudomonas. The acidic environment created by lactic acid bacteria through lactic acid fermentation could significantly inhibit the growth of Pseudomonas and other harmful microorganisms. In this study， the community composition and differences of naturally fermented paocai in different stages were elucidated， and the driving factors affecting its composition were explained， which provided help for the production of paocai.

Abstract:Objective: To reveal the changes of fungal community structure and diversity in walnut the potential health threats during natural mildew through studying the fungal infection process of walnut during natural mildew. Methods: The fungal ITS rDNA of fresh walnut kernel samples with different mildew time was sequenced by Illumina Miseq high-throughput sequencing technique， and the changes of fungal community composition and diversity in the process of fresh walnut kernel mildew were analyzed. Results: Ascomycota is the main fungal species in the mildew process of walnut samples， with a relative abundance of 27.41%-99.98%， followed by Basidiomycota with a relative abundance of 0.01%-32.56%. At the fungal level， it was found that the main dominant populations in the mildew process were Fusarium， Alternaria， Gibberella and Aspergillus. The mildew process of walnut in a week can be divided into three periods: Period Ⅰ (0-2 days)， Period Ⅱ (3-4 days) and Period Ⅲ (5-7 days). In stages of Period Ⅰ and Period Ⅱ， Fusarium was the dominant genus， and the main fungus that change significantly among other periods were Fusarium， Aspergillus， Alternaria， Gibberella and Penicillium. Conclusion: The changes of fungal microbial community during mildew of walnut could be divided into three periods， during which the fungal diversity showed a downward trend， and there were a variety of harmful pathogens， such as Fusarium and Aspergillus， etc.， which might cause potential safety risks if not handled properly.

Abstract:The gas chromatography-ion mobility spectrometry(GC-IMS) was used to determine the volatile organic compounds(VOCs) of rape flower honey from 10 geographical origin in China， 67 characteristic components were selected from a wide range of VOCs signal data by two-dimensional differential spectrum method. Principal component analysis (PCA) and partial least squares discriminant analysis(PLS-DA) were performed on 10 geographical origin rape flower honey samples from the untargeted perspective of differentiated VOCs distribution profile. Based on PLS-DA， the discrimination model of rape flower honey geographical origin was established. The result showed that the predictive power (Q2) and goodness of fit(R2) parameters of the cross validation were 0.959 and 0.987， respectively. The permutation showed that it did not overfitting， and the identification model was robust and effective， which could effectively identify rape flower honey from 10 geographical origin. At the same time， 21 characteristic markers that played a key role in effectively distinguishing rape flower honey geographical origin were further screened out by variable importance for the projection (VIP) values. In this study， GC-IMS technology and PLS-DA theory and method were introduced to achieve accurate identification of rape flower honey samples from different geographical origin， which provided a new technical strategy for honey origin tracing.

Abstract:Two-dimensional correlation NIR spectroscopy was combined with discriminant analysis (DA) method for the identification of aged vinegar samples of different vinegar ages. A total of 100 aged vinegar samples of five different vinegar ages were selected， and the 1D NIR spectra of all samples were collected at room temperature. The two-dimensional correlation synchronous spectra and asynchronous spectra of each sample in the wavelength range of 1 001-1 830 nm were constructed with the age of vinegar as the external disturbance factor， and the spectral characteristics of the two-dimensional correlation spectra of the samples were analyzed. Based on the diagonal data (autocorrelation spectrum) of the two-dimensional correlation synchronous spectra， a discriminant analysis model was established for the old aged vinegar samples with different vinegar ages， and the identification accuracy of the model calibration set was 97.3% and that of the prediction set was 96%. The results showed that the proposed method could provide more spectral feature information with vinegar age， and provide a classification model with higher accuracy for the rapid identification of aged vinegar.

Abstract:Objective: In order to provide insight to food sources basis of equol， the content of equol in stinky tofu and its influencing factors was studied. Method: This study was to investigate the equol in 4 representative brands of stinky tofu and 8 others fermented soybean products on the domestic market by RP-HPLC， Spearman's correlation was used to analyze the relationship between the equol and soy isoflavones and physicochemical indexes， and the effects of stinky tofu brine and brine soaking and frying on the content of equol in Changsha stinky tofu were also investigated. Results: The equol was only detected in 4 kinds of stinky tofu， and the contents ranged between 11.93-24.33 μg/g dry matter， with the Changsha HSJD stinky tofu being the highest content (24.33 μg/g dry matter)， and 8 others fermented soybean products without equol. A significant positive correlation between equol and daidzein and genistein(Spearman's r was 0.335 and 0.411， respectively， P<0.05)， and pH (Spearman's r was 0.539， P<0.01)， a negative correlation between equol and chlorides， amino acid nitrogen and total acid content (Spearman's r was -0.463， -0.506， and -0.674， respectively， P<0.01). Our research revealed that the equol was detected in Changsha HSJD stinky tofu fermentated for 2 years (called STB2) or 1 year (called STB1) and added bean cured， the content was 309.62， 168.31 μg/g dry matter， respectively. There were no equol in Changsha HSJD stinky tofu without bean cured(called STB3). ST5 was soaked in STB1 and ST6 was soaked in STB2， and then their equol content were 24.33 μg/g dry matter and 38.31 μg/g dry matter， respectively. There were no equol in Changsha HSJD stinky tofu was soaked in Cold boiled water and STB3. The content of equol was significantly decreased(P<0.05) after the Changsha HSJD stinky tofu is fried， the ST5 decreased from 24.33 μg/g dry matter from to 9.84 μg/g dry matter and that of ST6 from 38.31 μg/g dry matter from to 10.27 μg/g dry matter. Conclusion: A kind of food with good source of equol was Stinky tofu. The content of equol in stinky tofu was affected by the technology of soaking brine and fryin.

Abstract:In order to deeply reveal the correlation between the porridge eating quality， kernel sensory quality and nutrients of milled foxtail millet， this study collected 49 commercial yellow millets from major producing provinces across China， and comprehensively analyzed the eating quality of millet porridge， sensory quality and nutrient contents of millet kernel and their correlations. The results showed that the color， homogeneity and odor of the millet kernel were the key factors affecting the color and taste of its corresponding porridge； while the homogeneity and palatability of millet porridge could not be directly indicated from the sensory score of millet kernel. The color of millet porridge was significantly negatively correlated with fatty acid value and vitamin B1 content. The homogeneity of porridge was significantly negatively correlated with the contents of insoluble dietary fiber and vitamin B1. The taste of porridge was significantly negatively correlated with the contents of crude protein， crude fat， insoluble dietary fiber， most vitamins and amino acids and fatty acid values. The palatability of porridge was significantly positively correlated with the amylose content， and significantly negatively correlated with the contents of most other nutrients. The color and homogeneity of millet kernel were significantly negatively correlated with vitamin B1 content； millet kernel integrity was significantly positively correlated with the content of most nutrients， but significantly negatively correlated with amylose content. The odor of millet kernel was significantly positively correlated with the contents of soluble dietary fiber and total dietary fiber. Milled foxtail millet with good color， homogeneity and odor has better color and taste in its corresponding porridge， while millet with good integrity has higher nutritional value.

Abstract:Functional dyspepsia(FD) is a functional gastrointestinal disease， but its etiology and pathogenesis have not been fully elucidated. Studies have shown that there is a correlation between the composition of intestinal flora and FD， and the disturbance of gastrointestinal flora may be one of the main mechanisms of FD. At present， the treatment of functional dyspepsia is limited， and there are safety problems. A class of active bacteria known as probiotics can control the body's gastrointestinal homeostasis， nutritional digestion and absorption， and energy balance when taken in certain dosages. Therefore， it has potential advantages to alleviate FD by regulating intestinal flora by probiotics， targeting intestinal microorganisms. This paper summarized the research progress of probiotics in improving functional dyspepsia by regulating intestinal flora， so as to provide reference basis for probiotics to improve FD.

Abstract:With the increasing population and serious challenges in food production mode and consumption， plant-based meat substitutes industry development is of great importance to effectively alleviate animal meat shortage due to the increasing population， improve resident nutritional health， and reduce environmental pollution， and will be a new pioneer in carbon peaks and carbon neutralization. Health is the leading reason for consumer choice of plant-based meat substitutes， which can be up to 30% protein (3 times that of pork)， a nutritionally healthy food with high protein and low fat. However， there are still some differences in nutrition between plant-based meat substitutes and animal meat， such as B vitamins， selenium， manganese and other micronutrients. The zinc， iron and other vitamins need further equalization and enhancement， the characteristics of digestion and absorption are not clear. In this paper， the current states of industrial development of plant-based meat substitutes were outlined， and strategies for improvement of nutritional quality of plant-based meat substitutes by analyzing the nutritional quality of plant-based meat substitutes and its influencing factors were proposed， to provide references for the evaluation and improvement of nutritional quality of plant-based meat substitutes.

Abstract:Milled foxtail millet is an important food crop in China， which is mainly eaten by porridge and cooked foxtail millet. It is of great significance to systematically analyze the cooking and edible quality of milled foxtail millet and its formation mechanism. Starch and protein are the two main components in milled foxtail millet， which are closely related to its cooking and edible quality. In this paper， the research progress of the effects of the content， composition and structure of starch and protein in millet， as well as the protein-starch interaction on the cooking and edible quality of milled foxtail millet were summarized and analyzed. The purpose of this research is to provide a theoretical reference for evaluating and improving the edible quality of milled foxtail millet.

Abstract:Sourdough fermentation affects the rheological， sensory and shelf-life attributes of baked goods， and can effectively improve the functional， nutritional and application quality of baked goods. Sourdough fermentation plays a positive role in extending the shelf life of baked goods， improving flavor， delaying bread aging， reducing glycemic index， increasing mineral bioavailability， and reducing gluten content. At the same time， sourdough fermentation could reduce salt content in foods to prevent hypertension， improve irritable bowel syndrome， and promote synthesis/release of bioactive compounds (especially phenolic compounds). Sourdough fermentation also has great application advantages in increasing the development potential of non-traditional food products (such as beans) and milling by-products (bran and germ). The above will provide new ideas for the application development， quality improvement and research of functional properties of sourdough products.