Abstract:The neural basis of gustatory perception， as a convergence point of cognitive neuroscience and sensory science， is increasingly gaining scholarly attention. This review summarized the latest research advances in the application of neuroimaging techniques to the field of gustatory decoding， delving into how the brain relied on its intricate neural networks to process gustatory information and transition from sensory input to complex cognitive functions. Electroencephalography (EEG) captured the immediate electrophysiological responses of the brain to gustatory stimuli with its high temporal resolution， while functional magnetic resonance imaging (fMRI) mapped the hemodynamic responses of the brain to gustatory stimuli with its high spatial resolution. Additionally， functional near-infrared spectroscopy (fNIRS) technology， with its low sensitivity to motion artifacts and good temporal resolution， provided a new perspective for monitoring taste processing under natural behavioral conditions. This review synthesized the neural network structures of gustatory perception revealed by these techniques and discussed their potential applications in enhancing our understanding of the mechanisms of gustatory perception and in the diagnosis and treatment of related diseases.

Abstract:In recent years， the issue of excessive sugar intake has intensified globally. To address the growing demand for sugar reduction among consumers， it is crucial to gain a deeper understanding of the interactions between sweetness and other basic taste components (sour， bitter， salty) within food matrices and their potential mechanisms. This article summarized the fundamental interaction patterns of sweetness with other basic tastes in aqueous solutions， comprehensively reviewed and discussed the application studies of binary taste mixtures in real systems， and explored the potential mechanisms of binary taste interactions from chemical， physiological， and neurological perspectives. This provided scientific evidence and innovative ideas for developing low-sugar， healthy， and uniquely flavored food and beverage formulations.

Abstract:To effectively address health issues caused by excessive sugar intake， it is crucial to explore the selection preferences and perception mechanisms of sweeteners. This study used Drosophila melanogaster (black-bellied Drosophila) as a model organism to investigate the specificity of sweet taste perception receptor mechanisms by assessing Drosophila' preferences for caloric sugars (sucrose， fructose， glucose) and non-caloric sugar substitutes (sorbitol). The results showed that， compared to sorbitol， caloric sugars stimulated female Drosophila to lay more eggs and exhibited significant oviposition site preferences. Considering the sweet taste receptor Gr5a， it was found that this receptor played a critical role in the perception and behavioral regulation of low-concentration sweet substrates. In high-concentration sweet substrates， even when the function of Gr5a was impaired， fruit flies could still perform limited oviposition， suggesting the presence of other compensatory perception mechanisms. These diverse perception mechanisms enabled animals to more effectively select foods that meet their needs in their environment， optimizing nutritional choices. This study revealed the perceptual and behavioral response mechanisms of Drosophila in a complex sugar environment， providing scientific evidence for the application of sugar substitutes in food and offering new perspectives and theoretical support for broader sugar reduction strategies and healthy eating research.

Abstract:The three microalgal proteins - Spirulina platensis protein(SPP)， Chlorella pyrenoidosa protein (CPP)， and Nannochloropsis oculata protein (NOP) were isolated， and their emulsifying properties and interfacial characteristics were examined across pH values of 1， 3， 5， 7， and 9. Emphasis was placed on comparing and evaluating the stability， rheology， and morphology of DHA algal oil emulsions that were stabilized by SPP， CPP， and NOP. Results indicated that near their respective isoelectric points (pH 3)， minimal solubility， emulsifying activity， emulsion stability， and maximal hydrophobicity were exhibited by SPP， CPP， and NOP. Higher solubility and emulsion stability were shown by NOP and SPP compared to CPP， whereas superior emulsifying activity， especially for NOP， was exhibited by NOP and CPP. Nanoemulsions were prepared by sonication， using pH 7 microalgal protein solutions as the continuous phase and 10% DHA algal oil as the dispersed phase， revealing a distinct water-in-oil structure observed via microscopic and SEM imaging. Successful encapsulation of DHA algal oil within all three microalgal proteins was confirmed by XRD and FTIR， with DSC and TGA results demonstrating good thermal stability. Among them， NOP-stabilized emulsions exhibited the smallest average particle size， most uniform dispersion， superior rheological properties， apparent viscosity， and storage stability compared to CPP and SPP， indicating potential applications as high-quality plant protein emulsifiers.

Abstract:In this paper， PCR technology was used to carry out targeted mutation of single-stranded monellin (MNEI)， and the constructed recombinant plasmid pET15b-MNEI double-site mutant was transformed into Escherichia coli BL21-codonPlus(DE3)-RIL for recombinant expression of heterologous protein. The target proteins were purified by nickel column affinity chromatography and collected by molecular sieve. The dialysis of the proteins was carried out using distilled water in a dialysis bag with a interception volume of 3.5 ku. The sweet threshold of the target proteins obtained by dialysis was determined by double-blind sensory evaluation. The secondary structure and thermal stability of the protein mutants were determined by circular dichrometry. The results showed that three double-site mutants E2M/E50N， E2Q/E50N and E2A/E50N were successfully constructed， and the mutant E2Q/E50N was successfully expressed and purified. Compared with wild-type MNEI control， the sweet threshold of the mutant E2Q/E50N was 0.64 μg/mL， and the sweetness was nearly doubled； the Tm value was 78 ℃， the thermal stability was improved by 4 ℃. These results could provide theoretical basis and technical support for the production and application of sweet protein monellin in food， beverage and pharmaceutical industries.

Abstract:In order to explore the characteristics of extracellular proteases from large edible and medicinal fungi， proteases were isolated and purified from corn gliadin fermented by Armillaria mellea and purified by saturated ammonium sulfate precipitation crude enzyme solution， DEAE Sepharose Fast Flow anion chromatography column and Sephadex G-50 chromatography column. The results showed that the molecular weight of the protease was 18.4 ku， the optimum temperature of the protease was 60 ℃， it had good stability at 40-60 ℃， the enzyme activity was the highest when the pH value was 8， the stability range of pH was 6-8； Mn2+ could obviously promote the enzyme， ethylenediamine tetraacetic acid (EDTA) could obviously inhibit the neutral protease， and the Michaelis constant Km was 3.786 mg/mL. The results provided a theoretical basis for the research and application of proteases derived from large edible and medicinal fungi， and put forward new ideas for the research and development of enzyme preparations from large fungi.

Abstract:Four protein fractions of foxtail millet were gradually removed from the whole flour system according to their solubility， and the changes in the structure and pasting properties of the residues were investigated by scanning electron microscopy (SEM)， low-field nuclear magnetic resonance (LF-NMR)， Fourier infrared spectroscopy and rapid viscosity analyzer (RVA). The protein fraction-starch blends were also constructed for reverse validation. Overall， prolamin greatly affected the pasting properties of starch， followed by glutelin， while albumin and globulin showed less impact on it. SEM results showed that prolamin did not connect or encapsulate the starch granules， suggesting that it did not constitute a physical barrier to the pasting of starch； while， glutelin tightly surrounded and connected the starch granules. Combining the results of RVA and LF-NMR， as well as the characteristics of protein fractions， it was believed that prolamin induced a hydrophobic effect which further increased the mobility of water molecules， thus promoting the water absorption， swelling and pasting properties of starch. However， glutelin decreased the peak viscosity and breakdown value， and increased the pasting time of starch， indicating that it had a limiting effect on starch pasting.

Abstract:In order to develop flour food with low digestibility and study the effect of Quercus variabilis Bl. acorn shell extract on wheat starch properties. Quercus variabilis Bl. acorn shell was taken as raw materials in this study， and extracted by ultrasonic assisted ethanol extraction. Subsequently， the functional components of the ethanol extract were analyzed by HRLC-MS， and its effects were determined on the gelatinization properties， gel properties and digestion properties of wheat starch by comparative test and in vitro simulated digestion test. The results showed that the yield of ethanol extract was 2.40%， Quercus variabilis Bl. acorn shell， in which the total phenol content was 102.87 mg GAE/g and the total flavonoid content was 41.72 mg RE/g. By HRLC-MS， 34 components were detected， including polyphenols， flavonoids， terpenes， organic acids and other active components. The ethanol extract could significantly reduce the gelatinization viscosity and thermal stability of wheat starch， as well as some gel properties (i.e. elasticity， hardness， chewiness， and viscosity)， made surface rougher and the organizational structure looser， and inhibit the aging of wheat starch gel. After the addition of 15% ethanol extract of Quercus variabilis Bl. acorn shell， the digestibility reduced by 38.16% by 20 min of in vitro simulated digestion. Conclusion: The ethanol extract of Quercus variabilis Bl. acorn shell contains abundant functional components， which could change the gelatinization properties and gel structure of wheat starch， reduce the digestibility of wheat starch， and could be combined with wheat starch to develop low-digestibility flour products.

Abstract:In the study， a model of HeLa cells protected by Lactiplantibacillus plantarum CY1-2 against 2，2'-azobis[2-methylpropiona midine] dihydrochloride (ABAP) damage was established. The antioxidant mechanism of L. plantarum CY1-2 was investigated using cell proliferation test， morphological observation and western blot analysis. The results showed that the cell protective model conditions were as follows: 108 CFU/mL of L. plantarum CY1-2 protected cells for 3 h， and then 110 mmol/L of ABAP damaged cells for 3 h. Under this model condition， both the cell and the cell-free extract of L. plantarum CY1-2 could effectively improve the viability of HeLa cells， and the cell survival rate increased by 9.41% and 25.71%， respectively. Meanwhile， microscopic observation showed that compared with the injured group， HeLa cells protected by the cell-free extract of L. plantarum CY1-2 were large and plump， with clear edges and good extensiability. Western blot analysis indicated that， compared with the injured group， the cell-free extract of L. plantarum CY1-2 could positively regulate the expression of kelch-like ECH-associated protein 1 (Keap1)， nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1) proteins in HeLa cells， resulting in increasing by 18%， 47% and 58% respectively. L. plantarum CY1-2 protects HeLa cells from oxidative damage by activating Keap1-Nrf2-ARE signaling pathway to improve its antioxidant capacity. This study was expected to provide a theoretical basis for the development of lactic acid bacteria antioxidants.

Abstract:In this study， to illustrate the specific regulation targets and pathways of glycerol monolaurate (GML) on lipid metabolism， GML was used to treat hyperlipidemia model of liver tumor cells HepG2 induced by oleic acid， and explore the regulation effects of GML on lipid metabolism of liver cells and its potential targets and mechanisms based on bioinformatics prediction and transcriptome sequencing analysis. Bioinformatics analysis showed that the GO and KEGG enrichment analysis of potential GML targets obtained 519 and 144 signal pathways (P<0.05)， respectively. Molecular docking supported that GML might regulate lipid metabolism through regulating ALB， AKT1， EGFR and other core target proteins. The results of cell experiment showed that the level of lipid accumulation in the cell group treated with GML was improved compared with the high-fat control group. A total of 2 879 differentially expressed genes were screened by transcriptome analysis， with 1 363 up-regulated and 1 516 down-regulated genes， respectively. According to the enrichment analysis of KEGG signal pathway， HIF-1α pathway and fatty acid oxidative catabolism pathway were significantly enriched. The gene transcription expression levels of important proteins CPT1B， FABP1 in the pathway were up-regulated to 1.79 times and 2.81 times in the GML treatment group compared with those in the high-fat group， respectively， and the expression levels of main downstream regulation genes of HIF-1α were significantly increased (P＜0.05)， indicating that GML intervention improved the oxidative stress of high-fat cells through regulation of HIF-1α pathway， and improved the lipid metabolism disorder in high-fat cells mediated by fatty acid degradation pathway. This study provides a theoretical reference for the research on the regulation and mechanisms of functional lipid components in improving lipid metabolism disorder induced by high-fat diet.

Abstract:In this study， the samples of crude polysaccharides were prepared from 8 kinds of fermented bean flour by Lactobacillus casei， and the yield， structural characteristics and antioxidant activities of these crude polysaccharides were compared and analyzed. The results showed that the yields of crude polysaccharides were between 1.07% and 11.42%， and the yield of crude polysaccharides from fermented red bean flour showed the highest value (11.42%). All of the crude polysaccharides contained uronic acid， and the uronic acid in crude polysaccharides from fermented kidney bean flour showed the highest content 7.46%. The molecular weight of main polysaccharides was between 0.35-36.67 ku， and the crude polysaccharides from fermented mung bean flour contained the most types of polysaccharide molecules. The crude polysaccharides were composed of mannose， glucuronic acid， glucose， galactose， xylose and arabinose with different contents. The apparent form of crude polysaccharides was flaky， loose and irregular， and the crude polysaccharide from fermented mung bean flour showed the highest degree of looseness. The infrared spectra of crude polysaccharides from 8 kinds of fermented bean flour was consistent with the characteristic absorption of polysaccharide compounds. The crude polysaccharides from 8 kinds of fermented bean flour showed different antioxidant activities: the IC50 values for scavenging DPPH radical of fermented lentil and crude mung bean polysaccharides were 0.07 mg/mL and 0.98 mg/mL， respectively， the crude polysaccharides from fermented lentil flour had the best scavenging effect on DPPH radical. The IC50 value for scavenging ABTS radical cation of crude polysaccharides from fermented mung bean flour was 0.67 mg/mL， which showed the best scavenging ability for ABTS radical cation and crude polysaccharides from mung bean flour also showed the highest reduction ability to iron ions. Compared with the crude polysaccharides from 8 kinds of fermented bean flour by Lactobacillus casei， the crude polysaccharides from fermented mung bean flour showed the best antioxidant activity. It provided an important theoretical basis for the nutritional evaluation of fermented bean foods by Lactobacillus casei.

Abstract:In this work， neohesperidin (NH) and whey protein (WP) complex (NH-WP) was prepared to explore the possibility of enhancing the antioxidant activity of whey protein (WP). The non-covalent interaction mechanism of NH with WP was studied in terms of fluorescence spectroscopy， synchronous fluorescence spectroscopy， thermodynamic analysis and molecular docking simulation. The antioxidant activity of NH-WP was also analyzed by a series of common used methods. The results showed that the endogenous fluorescence of WP could be statically quenched by NH， which changed the microenvironment of aromatic amino acids in WP. Non-covalent interactions between NH and WP lead to the formation of NH-WP complexes， characterized by a negative ΔG， positive ΔS， and positive ΔH， suggesting an endothermic and spontaneous process primarily driven by hydrophobic forces. There was only one binding site between them and the complex was formed by combining them at a ratio of 1∶1. In addition， the antioxidant activity of NH-WP complex was lower than that of free NH at the same concentration， but higher than that of the pure protein， what's more， the antioxidant activity of WP exhibited dose-dependent effect with the increase of NH addition， suggesting that the introducing of NH could effectively improve the antioxidant activity of WP. This research could enrich the theoretical basis of the interaction between WP and polyphenols， and provide good reference basis for improving functional properties of proteins as well as widening the application of NH and WP in the field of food and medicine.

Abstract:Polygonatum kingianum， belong to the genus Polygonatum (Liliaceae)， mainly distributed in subtropical in the southwest of China， including Guizhou， Sichuan， and Yunnan. The dried rhizomes of P. kingianum have been used as a famous homologous plant of medicine and food for thousands of years. The paper was investigated the antioxidant activities and cell protective effects of Polygonatum kingianum. Using D101 macroporous resin， the methanol extract was eluted by different volume fraction of methanol water (20%， 40%， 60%， 80%， 100%) to obtain the different polar samples. The contents of total phenolic (TPC) and total flavonoids (TFC) in different polar samples were determined. The antioxidant activities were evaluated by 2，2-diphenyl-1-picryhydrazyl (DPPH) and 2，2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods. Furthermore， the cytoprotective effects of different polar samples were performed on hydrogen peroxide (H2O₂)-induced oxidative stress in HepG2 cells. The intracellular ROS production， the content of lipid peroxides (MDA) and the activity of enzymes (superoxide dismutase (SOD)， glutathione peroxidase (GSH-px)) were measured. Principal component analysis (PCA) was used to analyze the correlations among the TPC and TFC， antioxidant activities (DPPH and ABTS)， the contents of intracellular ROS and MDA， and the activities of intracellular oxidase (SOD， GSH-px). The results showed that the antioxidant capacities of different polar samples were positively correlated with TPC and TFC. The antioxidant capacity of the sample increased with the increasing of total phenolic and flavonoids content. The TPC of the 40% and 60% methanol samples were (40.27±0.59) mg GAE/g extract and (51.34±2.08) mg GAE/g extract， respectively. While TFC were (23.95±1.73) mg RE/g extract and (24.97±2.75) mg RE/g extract， respectively. The 40% and 60% methanol samples exhibited the highest phenolic and flavonoid contents， and displayed significantly free radical scavenging activities in vitro. Additionally， these samples markedly inhibited intracellular ROS production， enhanced SOD and GSH-px levels， and reduced MDA content. In conclusion， different polar samples of P. kingianum had certain antioxidant activities and cell protective effects， and 40% and 60% methanol samples displayed the best antioxidant activities and cell protective effects.

Abstract:Grape seed polyphenols were extracted from Cabernet Sauvignon grape seeds after winemaking. The static and dynamic adsorption-desorption capacity of AB-8 macroporous adsorption resin on grape seed polyphenols was studied， and the technological conditions suitable for the separation and purification of grape seed polyphenols were selected. On this basis， human fecal fermentation model was constructed in vitro to explore the effects of different concentrations of grape seed polyphenols on intestinal flora. The results showed that the optimal process conditions for purification of grape seed polyphenols by AB-8 macroporous adsorption resin were as follows: Loading mass concentration 8 mg/mL， ethanol volume fraction 80%， loading flow rate 2 mL/min， elution flow rate 1 mL/min. Under these purification conditions， the purity of polyphenols increased from 32.16% to 80.35%. Gut microbes sequencing results showed that the grape seed polyphenols concentration changes will not significantly affect the intestinal bacteria (P>0.05)， and will significantly influence the diversity of intestinal flora(P<0.05). At phylum level， after 24 h of fermentation， compared with blank control group (CK)， the relative abundance of Proteobacteria and Actinomycetes was increased in groups with different concentrations of phenol， while the relative abundance of Bacteroidetes and Firmicutes was decreased. However， F/B values in low concentration group (LG)， medium concentration group (MG) and high concentration group (HG) were decreased by 8.21%， 39.81% and 57.49%， respectively. At the genus level， the change of polyphenol concentration can affect the growth and proliferation of different intestinal flora， which could be shown as promoting or inhibiting the flora with the increase of the concentration， such as increasing the relative abundance of Escherichia/Shigella， Klebsiella， Lactobacillus， Bifidobacterium， Streptococcus and reducing the relative abundance of Bacteroides， Clostridium XlVa， Enterococcus， Bilophila and other bacterial genera. Concentration effects were observed with changes in polyphenol mass concentration， and different fermentation time had obvious fluctuation. Therefore， different mass concentrations of grape seed polyphenols could improve the intestinal environment by regulating different bacterial community composition， and the low mass concentration group (LG， 4 mg/mL) had the best effect.

Abstract:Inhibition and kinetics of α-amylase and α-glucosidase， as well as glucose uptake and consumption of human hepatoma HepG2 cell were investigated to assess the in vitro glucose-lowering effect of anthocyanin extract of Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruit (AECBF). The results showed that AECBF exhibited potently inhibitory effect on α-amylase and α-glucosidase， with IC50 value of 22.54 μg/mL and 3.51 μg/mL， respectively. The results of enzymatic inhibition kinetics indicated that both α-amylase and α-glucosidase gave a mixed-type inhibition， and competitive inhibition was predominant in α-amylase while uncompetitive inhibition in α-glucosidase. In addition， no obvious cytotoxicity of HepG2 was observed after treated with AECBF for 24 h， ranged from 0.1 μg/mL to 10 μg/mL (P＞0.05)， and glucose uptake and consumption of HepG2 cells were increased notably after treatment with 1 μg/mL to 5 μg/mL for 24 h (P＜0.05). Compared to normal control， AECBF-treated HepG2 cells gained the maximum glucose uptake and glucose consumption at 2 μg/mL and 5 μg/mL， respectively， corresponding to an increase by 72% and 44%， respectively. These results indicated that Chinese bayberry anthocyanin exhibits potent in vitro hypoglycemic activities.

Abstract:The antioxidant capacities and digestive enzyme inhibitory effects of free and bound phenolic extracts from Allium mongolicum Regel were studied through antioxidant and enzyme inhibition assays in vitro. The methods of Folin-Ciocalteu， NaNO₂-AlCl3 and vanillin-hydrochloric acid were used for the determination of total phenolics， flavonoids and condensed tannins， respectively. DPPH radical scavenging activity， ferric reducing antioxidant power(FRAP)， trolox equivalent antioxidant capacity (TEAC) and inhibitory effects on HO· mediated 2-deoxyribose degradation assays were used to comprehensively evaluate the antioxidant capacity. In vitro digestive enzyme inhibitory test assay was used to evaluate the inhibitory effects of polyphenol extracts from A. mongolicum Regel on α-glucosidase and pancreatic lipase. The content of total phenol， flavone and condensed tannin of polyphenol extracts from A. mongolicum Regel were in the range of 251.09-521.27 μg GAE/mg， 148.24-512.94 μg CAE/mg and 121.33-360.56 μg CAE/mg， respectively， and their contents varied from different origins. The DPPH radical scavenging activity， FRAP and TEAC of free phenolic extracts from A. mongolicum Regel were in the range of 175.02-248.81 μmol TE/g， 646.22-842.89 μmol Fe(II)/g and 54.95-87.95 μmol TE/g， respectively. The DPPH radical scavenging activity， FRAP and TEAC of bound phenolic extracts from A. mongolicum Regel were in the range of 447.14-623.95 μmol TE/g， 1 051.78-1 866.22 μmol Fe(II)/g and 441.17-714.50 μmol TE/g， respectively. The IC50 values of free phenolic extracts for the inhibition of non-site and site hydroxyl radical-mediated 2-deoxyribose degradation ranged from 1.14 to 2.27 mg/mL and 3.39 to 3.70 mg/mL respectively. The IC50 values of bound phenolic extracts for the inhibition of non-site and site hydroxyl radical-mediated 2-deoxyribose degradation ranged from 0.62 to 0.94 mg/mL and 2.80 to 3.99 mg/mL， respectively. In general， the antioxidant capacity of the bound phenolic extract was stronger than that of free phenolics. The free and bound phenolic extracts inhibited the pancreatic lipase and glucosidase in a mixed non-competitive manner， and the inhibitory effect of free phenolics was stronger than of bound phenolics. In terms of the phenolic content， antioxidant capacity and digestive enzyme inhibition activity， the comprehensive quality of the bound phenolic extract was better than that of free phenolics.

Abstract:In order to improve the freeze-dried survival rate of Lactobacillus fermentum BLHN3， the effect of cryoprotectant on the freeze-dried resistance of Lactobacillus fermentum BLHN3 and the storage stability of freeze-dried Lactobacillus powder were investigated. The experimental results showed that the survival rate of Lactobacillus fermentum BLHN3 was the highest with 3% L-glutamate +5% maltose +5% skim milk， and the number of viable count reached 1.48×1011 CFU/g. Scanning electron microscopy showed that cryoprotectants could maintain the integrity of the cell membrane of Lactobacillus after freeze-dried. The FTIR results showed that the cryoprotectant could reduce the damage of freeze-dried cells by binding with the cells. The activities of lactate dehydrogenase (LDH) and ATPase were significantly increased， but the pyruvate kinase (PK) activity was not significantly different after freeze-dried. In addition， the accelerated storage test showed that low temperature storage was an effective method for the preservation of powder. Conclusion: Lactobacillus fermentum BLHN3 could be prepared into a high activity freeze-dried starter with 3% L-glutamate sodium， 5% maltose， 5% skim milk as cryoprotectants.

Abstract:Pseudomonas fluorescens is a dominant spoilage bacterium commonly found in fresh aquatic products， and its spoilage ability is regulated by a quorum -sensing system of N-homoserine lactones (AHLs). Based on the quorum-sensing quenching activity， the type of quenching activity substance from strain YF-2 was analyzed using heat inactivation and acid sensitivity tests. The results showed that strain YF-2 had a significant quenching effect on P. fluorescens AHLs， with a degradation rate of 100%. Its quenching active substance existed in the crude cell extract (CCE)， which was preliminarily identified as acyltransferase or oxidoreductase by heat inactivation and acid sensitivity assays. The degradation of C4-HSL， C6-HSL and C8-HSL treated by the CCE at protein concentrations of 20， 40 μg/mL and 80 μg/mL ranged from 52.8% to 100%， and the inhibition and clearance rate of P. fluorescens biofilms ranged from 25.84% to 56.63% and 26.12% to 59.35%， respectively. In addition， the confocal laser scanning microscopy showed that the CCE reduced the thickness of P. fluorescens biofilm and disrupted the biofilm structure. Meanwhile， Bacillus cereus was recognized as the source of strain YF-2. The application of B. cereus to control the spoilage bacterium P. fluorescens in aquatic goods will have a theoretical foundation thanks to this study.

Abstract:To mitigate the growth of antibiotic resistance in Staphylococcus aureus due to the misuse of antibiotics， this study aimed to identify natural and safe antimicrobial substances as alternatives to traditional antibiotic treatments for Staphylococcus aureus infections. Six Bacillus strains (Bacillus velezensis SN-20， Bacillus amyloliquefaciens SN-31， Bacillus amyloliquefaciens SN-34， Bacillus amyloliquefaciens SN-36， Bacillus subtilis SN-43， and Bacillus amyloliquefaciens SN-46) were selected for thin-layer chromatography analysis， lipopeptide stability testing， and determination of the antimicrobial mechanism of lipopeptides. The results indicated that these six Bacillus strains could produce lipopeptides such as surfactin， fengycin， and iturin. Among them， the crude lipopeptide extracts from Bacillus velezensis SN-20 and Bacillus amyloliquefaciens SN-46 exhibited significant inhibitory effects on Staphylococcus aureus， with inhibition zone diameters exceeding 12.5 mm and minimum inhibitory concentrations (MIC) of 1.25 mg/mL and 2.5 mg/mL， respectively. The lipopeptides produced by these two Bacillus strains maintained their antimicrobial activity at pH value of 3 and 11， at a temperature of 100 ℃， and after treatment with protease K， demonstrating their excellent and stable antimicrobial properties. Further analysis revealed that the lipopeptides inhibit Staphylococcus aureus through multiple mechanisms， including disrupting cell membrane structure， increasing cell membrane permeability， and inhibiting protein synthesis. These multi-mechanism actions make it difficult for resistance to develop. This study suggested that the lipopeptides produced by Bacillus strains have promising applications and could potentially be developed as new drugs to combat Staphylococcus aureus.

Abstract:The study aimed to explore the preventive effect of Antarctic krill protein peptide(EHAK) on memory injury caused by scopolamine in mice. The mice were divided into 5 groups: Blank control group， memory damage model group， and low (31.25 mg/kg)， medium (62.5 mg/kg) and high (125 mg/kg) dose groups of EHAK. The behavioral indices， serum and biochemical indices of the mice and the protein expression levels of hippocampal nerve cells were determined， and the states of hippocampal neurons were observed. Behavioral experiments indicated that EHAK could improve the spatial learning and memory ability of mice. Regarding the oxidative stress levels and cholinergic systems， when 125 mg/kg EHAK was administered to mice， compared with the model group， the SOD activity in serum increased by(10.13 ± 1.00) U/mg prot and the MDA content in serum decreased by(1.04 ± 0.26) nmol/mg prot. The hippocampal AChE activity and MDA content declined by (0.90 ± 0.05) U/mg prot and (1.16 ± 0.01) nmol/mg prot， respectively， while the ACh content increased by (10.13 ± 1.00) μg/mg prot. These data indicated that EHAK could attenuate scopolamine-induced cognitive impairment by preventing oxidative stress and cholinergic dysfunction. The status of hippocampal neurons showed that the EHAK could effectively prevent hippocampal neuron apoptosis and uneven arrangement. In addition， EHAK could inhibit neuronal apoptosis and regulate prominent plasticity through the BCL-XL/Bax/ Caspase-3/p53/CREB/BDNF signaling pathway. Therefore， EHAK could prevent scopolamine-induced memory impairment by modulating the cholinergic system and protecting neurons in the hippocampus， which demonstrated the potential to be used as food ingredient with functional appeal.

Abstract:To study the protective effect of chitosan oligosaccharide on alcohol-induced hippocampal tissue， 39 newborn SD rats were randomly divided into three groups: Blank control group (CON group)， model group (ETOH group) and chitosan oligosaccharide intervention group (COS group). The alcohol injury model of newborn SD rats was established. The COS group received chitosan oligosaccharide intervention. At the end of the intervention on the 9th day after birth (PD9)， no intervention was conducted between PD9 and PD24. The phosphatidylinositol-4，5-bisphosphoinositol-3-kinase (PI3K)/protein kinase B (Akt) of PD9 and PD24 were observed respectively expression of glial fibrillary acidic protein (GFAP) and apoptosis-inducing factor1 (AIF1)， inflammatory factors interleukin 6 (IL-6)， interleukin 10 (IL-10)， tumor necrosis factor α (tumor necrosis factor alpha， TNF-α). The new object recognition experiment is carried out at PD24. The results showed that at PD9， PI3K， Akt proteins and their phosphorylation levels， GFAP and AIF1 protein in COS group were not significantly different from those in ETOH group， but IL-6 and IL-10 were significantly increased， TNF- α significantly decreased. At PD24， compared with ETOH group， the phosphorylation level of PI3K and Akt protein in COS group increased significantly， the expression of GFAP decreased， IL-6 and IL-10 increased significantly， and TNF- α significantly decreased. Chitosan oligosaccharide can alleviate the inhibition of PI3K/Akt pathway and inhibit the overexpression of astrocyte marker GFAP in PD24.

Abstract:Objective: To investigate the effect of cereal polyphenols (ferulic acid and caffeic acid) and dietary fiber (arabiNO_xylan and β-glucan) complexes in influencing high-fat diet-induced obesity in mice. Methods: Forty-eight male C57BL/6J mice were randomly divided into a control group(CON)， a cereal polyphenol and dietary fiber complex group (PPDF)， a high-fat chow group (HFD)， and a high-fat chow plus complex group (HFD+PPDF)， and after 18 weeks of ad libitum food intake， the effects of PPDF on obese mice were evaluated based on haematological biochemical and histopathological indices， and the effects of PPDF were analyzed by high-throughput sequencing technology to analyse the changes in colonic flora composition. Results: Compared with the HFD group， mice in the HFD+PPDF group showed significant reductions in body mass increase， liver index， serum alanine transaminase (ALT) and malondialdehyde (MDA) levels by 13.7%， 12.6%， 35.5%， and 23.0%， respectively； and a significant increase in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities by 43.1%， 36.7%， respectively； and glucose tolerance abnormality was significantly improved. PPDF increased the diversity of the gut microbiota of mice on high-fat diet， in which the Ace index and Chao1 index were significantly increased by 30.1% and 30.9%， respectively； and the abundance of Bifidobacterium， Roseburia and Lachnospiraceae_NK4A136_group were significantly increased by 76.6%， 76.6%， 1 727.5%， 315.5% and 315.6%， respectively； while the abundance of Lactobacillus， Romboutsia， Erysipelatoclostridium， Clostridium_sensu_stricto_1， and Blautia were significantly reduced by 68.5%， 90.2%， 61.4%， 75.2%， and 95.6%， respectively. Correlation analysis showed that Bifidobacterium and Akkermansia were significantly negatively correlated with increased body mass， liver index and abnormal glucose tolerance， and significantly positively correlated with antioxidant activity； whereas Lactobacillus， Romboutsia， Erysipelatoclostridium， Clostridium_sensu_stricto_1 and Blautia were inversely correlated with it. Conclusion: PPDF may improve glucose metabolism disorders and prevent obesity by increasing the diversity of gut microbiota and the abundance of beneficial bacteria in mice.

Abstract:In order to compare the preventive effects of wheat hydrolyzed peptide as well as probiotics and their mixtures on wheat allergy in young mice， and to assess whether there is a synergistic effect between probiotics and wheat hydrolyzed peptide， a wheat allergy model was established by observing the body mass， rectal temperature， visceral index， and jejunum pathological sections of the young mice， and detecting the levels of their serum-specific immunoglobulin E (IgE) and specific immunoglobulin G1 (IgG1)， specific immunoglobulin G2a (IgG2a) levels， and their spleen cytokine interleukin 4 (IL-4)， interleukin 5 (IL-5)， interleukin 13 (IL-13)， and gamma-interferon (IFN-γ) levels were determined. The results showed that early digestive intake of wheat hydrolyzed peptides significantly increased the thymus index and spleen index of young rats； significantly decreased the serum specific IgE level and specific IgG1 level (P < 0.01)； significantly decreased the spleen IL-4 level (P < 0.05) and IL-13 level (P < 0.01)； significantly increased the spleen IFN-γ level (P < 0.01)； and significantly rebounded the rectal temperature of young rats (P < 0.01)； significantly rebound rectal temperature in young rats (P < 0.01). Early digestive tract intake of probiotics and wheat hydrolyzed peptide mixture significantly inhibited the shifting of helper T-cell 2 (Th2) type response， with significant reduction of IL-5 level and Th2/Th1 ratio； and had a significant effect on the alleviation of jejunal pathology， such as jejunal villus breakage， shallow depth of crypt， and low height of villi. In conclusion， the synergistic wheat hydrolyzed peptide and probiotic wheat hydrolyzed peptide mixture has the potential to prevent wheat allergy in young mice， and it is expected to be used in the development of formulas for special medical purposes to prevent wheat allergy in infants and young children.

Abstract:In order to make full use of yak milk resources， using yak milk casein as the raw material， the response surface analysis method was adopted to determine the optimal acylation conditions of yak milk casein and prepare high-quality and good bioavailability ferrous succinylprotein products. The structure of the products was characterized by means of Fourier transform infrared spectroscopy， particle size distribution， scanning electron microscopy， amino acid composition， and in vitro simulated digestion. The results showed that the optimal acylation process parameters of yak milk casein were as follows: The mass ratio of casein to succinic anhydride was 2∶1， succinic anhydride was added five times， pH value was 9， the reaction temperature was 48 ℃， the reaction time was 50 min. Under these conditions， the acylation rate reached 93.27%， the iron content was 8%， and the chelation rate was 93.03%. The determination results of Fourier transform infrared spectroscopy showed that there were differences in the absorption peaks between ferrous succinylprotein and casein， and the iron ions in the acylated protein formed coordination bonds with carboxyl groups and amino groups. The particle size of ferrous succinylprotein was measured to be larger by the laser particle size distribution analyzer， confirming the formation of the chelate. The analysis by scanning electron microscope indicated that the surface of the sample was smooth and the structure was compact. By determining the protein content and amino acid composition of ferrous succinylprotein， the results showed that the protein loss of ferrous succinylprotein compared to casein was 28.12%. Among them， Glu， Asp， and Pro had the higher contents in casein and ferrous succinylprotein. Glu and Asp were the key amino acids for forming chelates， and the bioavailability was better than that of inorganic salts. The results of this study can provide a reference for the preparation and structural characterization of ferrous succinylprotein.

Abstract:Blueberry juice was inoculated with Lactobacillus plantarum J26 (original Lactobacillus plantarum NDC75017， TD109， LJ26) and then fermented with saccharomyces cerevisiae. The pH value， total acid， sugar content， alcohol content， total phenol and anthocyanin contents of Lactobacillus plantarum + yeast fermentation group， yeast fermentation group and commercial blueberry wine were analyzed by pH meter， direct determination method， spectrophotometry and high-performance liquid chromatography to determine the effect of pre-fermentation with probiotics on the quality of blueberry wine. The results showed that the pH value， total acid， sugar content and alcohol content of blueberry wine after pre-fermentation with probiotics were all within the national standard range. During the fermentation time of 25 days， the total phenol content decreased to 8 010.21 mg/L， which was significantly higher than that of yeast fermentation group. The anthocyanin content in Lactobacillus plantarum + yeast group remained stable during fermentation， and the anthocyanin content at the end of fermentation was significantly higher than that in yeast fermentation group (7 200.65 mg/kg). After post-fermentation， the number of J26 viable bacteria in blueberry wine in Lactobacillus plantarum + yeast fermentation group could reach 9.3×106 CFU/mL. In this study， the blueberry wine obtained by pre-fermentation with probiotics was rich in total phenols and anthocyanins， and had a certain amount of probiotics， which could give blueberry wine certain probiotic functions and help improve the quality of blueberry wine.

Abstract:To investigate the difference in grape quality under large-scale terroir conditions and the evolution of the flavor substances in the overripe grapes， the present study selected Pinot Noir (Vitis vinifera L. cv.) grape berries from two regions of the Eastern Foothills of Helan Mountains and Hebei Huailai Shacheng at two maturity levels as the experimental samples. The physicochemical indicators， phenolic and volatile compounds were determined and combined with the principal component analysis and orthogonal partial least squares discriminant analysis， and the effects of wine region and maturity on the winemaking quality of Pinot Noir grapes were investigated. The results showed that the total soluble solids of the two regions were 20-21°Brix， with the titratable acidity from 4.5 to 5.5 g/L. The composition of the monomeric anthocyanins in grape skins was significantly affected by the wine region. Grape berries from the Eastern Foothills of Helan Mountains had higher content of seed flavanols， norisoprenoids and terpenes. Late harvest decreased the content of total anthocyanins and seed flavanols but promoted the accumulation of higher alcohols， benzenes， aldehydes and ketones. The PCA results showed that the difference caused by late harvest was greater than that of the wine regions. Anthocyanins and flavanols in grape skins were the main biomarkers among the grapes of different maturity， whereas C6/C9 compounds， norisoprenoids and terpenes were the dominant different compounds among wine regions. In general， the winemaking quality of Pinot Noir grapes from the two regions varied， and late harvest could improve some flavors of grapes for winemaking.

Abstract:To investigate the effect of co-inoculation of Saccharomyces cerevisiae (S. cerevisiae) and Oenococcus oeni on aroma compounds of simulated grape juice， autochthonous Oenococcus oeni strains MG-1， GF-2 and commercial strain VP41 were inoculated respectively during alcoholic fermentation to trigger malolactic fermentation. The volatile aroma compounds in simulated wine samples were determined by headspace-solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS) technique， and the influences of different strain combinations and inoculation time on the fermentation aroma compounds was revealed by multivariate statistical analysis. Results showed that co-inoculum of S. cerevisiae and Oenococcus oeni led to 6.67%-15.56% and 18.75%-40.63% reduction in the contents of volatile acids and residual sugars， respectively (P<0.05)， and increased significantly (P<0.05) the type and content of fermentation aromatic substances. Orthogonal partial least squares-discriminant analysis combined with odor active value of aroma substances showed that there were 11 common differential substances between the co-inoculated treatments of different Oenococcus oeni strains， especially in the wine sample of co-inoculated treatment of S. cerevisiae VW inoculated for 48 h followed by Oenococcus oeni MG-1 strain(VM48)， contents of ethyl hexanoate， ethyl caprylate， ethyl caprate， isoamyl acetate， phenethyl acetate and 2-phenylethanol were significantly increased by 46.16%-237.41% (P<0.05)， and the tropical fruit， red fruit and floral characteristics of wine were more prominent. Results of this study provide a theoretical basis for co-inoculation fermentation of Saccharomyces cerevisiae strains and excellent autochthonous Oenococcus oeni strains in the winemaking process.

Abstract:To investigate the synergistic stabilization effect of β-cyclodextrin (β-CD) and sodium caseinate(SC) on Antarctic krill oil Pickering emulsion. In this paper， Antarctic krill oil Pickering emulsions were stabilized by β-CD， SC and β-CD/SC complexes， respectively. The Pickering emulsions were characterized by macroscopic and microscopic morphological changes， particle size， ζ-potential， and viscosity. The results showed that the emulsion stabilized by β-CD/SC complex had the smallest particle size (13.66 μm)， highest absolute value of ζ-potential (31.90 mV)， and strongest viscosity. In addition， the stability of Antarctic krill oil Pickering emulsions stabilized by different stabilizers was evaluated by centrifugation treatment， thermal treatment， and freeze-thaw treatment. The results showed that the emulsion prepared by β-CD/SC complexes possessed the best overall stability. The complex of β-CD and SC had a significant synergistic stabilization effect on Antarctic krill oil Pickering emulsion and had remarkable potential for application in the emulsion field.

Abstract:There are different varieties of rice for infant rice flour processing at home and abroad. In order to explore suitable materials for rice flour processing， 5 indica rice and 5 japonica rice with different rice genotypes were selected to process infant rice flour by drum drying in this research. The suitability of different varieties of rice for processing infant rice flour were investigated by measuring the physiochemical and quality properties of rice and rice flour. The results showed that the properties of different samples were significantly different. The moisture content of different rice flour samples prepared by drum drying decreased by more than 30% compared with the raw rice， while the content of total starch and amylose increased. RDS accounted for the largest proportion in all rice noodle samples， among which RDS of indica rice Chuangyu9# and japonica rice Yuanli9031 accounted for more than 82%， and rice flour with high RDS content also had high water solubility. In combination of the physicochemical qualities， gelatinization， rheological characteristics and SEM images， the infant rice flour processed by Chuangyu9# and japonica rice Yuanli9031 have good quality.

Abstract:To study the drying characteristics and water migration of Saimaiti apricot slices after different pretreatment during hot air drying. Samaiti apricot slices was used as raw material， the drying characteristics， effective diffusion coefficient and activation energy of water were investigated at three temperatures (40， 50 ℃ and 60 ℃) after four kinds of pretreatment (hot water blanching， steam blanching， microwave treatment and sulfur treatment) on the basis of eliminating enzymatic browning， and the drying kinetics model was established. The relationship between model parameters and drying temperature was studied. Further combining with low field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI)， the lateral relaxation time and pseudo-color images were used to elucidate the water migration in apricot slices during drying. Results showed that the drying time of apricot slices compared with 40 ℃ was shortened by 41.67%， 36.36%， 53.85% and 50.00%， respectively. Deff increased with the increase of temperature， mainly in the range of 5.9637×10-7 m2/s to 1.3530×10-6 m2/s. For model fitting based on drying kinetics， Wang and Singh model was the most suitable model for blanching and microwave heat treatment， with R2 of 0.9929， 0.9955 and 0.9942， respectively， while Page model was the most suitable model for sulfur treatment without thermal pretreatment (R2=0.9967). The results of LF-NMR experiment showed that the surface vaporization was the main factor in the early drying stage， and the free water was the first to be removed. In the late drying stage， the water diffusion was controlled by internal diffusion， and part of the free water was converted into immobilized water and bound water， and the water diffusion rate decreased. Color protection pretreatment combined with hot air drying had certain effects on drying characteristics and water migration of apricot slices. Analysis of variance showed that there was no significant difference in Deff of the four color protection treatments at different temperatures (P>0.05)， and the drying temperature played a decisive role in the water diffusion during drying. Combined with low-field NMR technology， the drying time of apricot slices in microwave and sulfur treatment group could be shortened by 4 h at 50 ℃ and 60 ℃ compared with that in blanching treatment group.

Abstract:In order to explore the effects of ozonated water treatment on the initial microflora of fresh grass carp fillets from different sources， fresh grass carp fillets at different sampling times were used as raw materials to determine the total viable count (TVC)， thiobarbituric acid (TBA)， pH value， chroma and sensory score， and to study the effects of different parameters of ozonated water treatment on the physicochemical properties of fresh grass carp fillets， so as to optimize the treatment conditions. The optimized conditions were used to treat fresh grass carp fillets， and the changes in the microflora of fresh grass carp fillets before and after ozonated water treatment were investigated using traditional isolation culture combined with 16S rRNA identification and high-throughput sequencing. The results showed that with the increase of ozonated water treatment mass concentration and treatment time， the number of residual bacteria and the rate of bacterial reduction of fresh grass carp fillets improved significantly and the microflora changed significantly after treatment (P<0.05). Ozonated water treatment mass concentration and treatment time had no significant effect (P>0.05) on TBA and pH of fresh grass carp fillets， but had a significant effect (P<0.05) on colour values. In terms of sensory scores， ozonated water treatment mass concentration had no effect， but treatment time had a significant effect and sensory quality decreased significantly with extended treatment time. After treatment of fresh grass carp fillets with 15 mg/L ozonated water spray for 5 min， the bacterial species of the three different sampling time of fresh grass carp fillets decreased by 52.17%， 50.00% and 60.00%， respectively， the bacterial diversity decreased significantly (P<0.05) and the proportion of Gram-positive (G+) bacteria increased. The results of the principal co-ordinates analysis showed that the degree of similarity in the microflora of grass carp fillets from different sampling time increased after ozonated water treatment. In conclusion， the treatment of raw grass carp fillets with 15 mg/L ozonated water for 5 min resulted in a reduction rate of 80.66%， and the microflora of fresh grass carp fillets at different sampling time became simple and similar after the treatment.

Abstract:To explore the characteristics and differences of volatile flavor compounds in Boletus edulis from different habitats， GC-IMS was used to detect and analyze the volatile flavor compounds in Boletus edulis from 9 habitats in Yunnan and establish fingerprints. The results showed that 91 volatile compounds were identified by GC-IMS， mainly including aldehydes， ketones， esters， alcohols， acids， hydrocarbons， ethers， etc. However， there were differences in the volatile flavor compounds of Boletus edulis from different habitats. Principal component analysis combined with heat map cluster analysis found that the differences in flavor substances of Tonghai (TH) and Yimen (YM)， Kunming (KM) and Songming (SM) were the smallest in statistical analysis， which may be the result of the comprehensive effects of ecological and climatic conditions formed by geographical locations and altitude. The specific causes need to be further studied. Fingerprint analysis showed that 1-octen-3-one， ethanol， pentanal， limonene， ethyl lactate， propanal were the characteristic flavor substances of Boletus edulis. The results of this study laid a theoretical foundation for the flavor recognition and origin identification of Boletus edulis.

Abstract:To study the lipids and active flavor substances of sauce beef during processing， gas chromatography-mass spectrometry (GC-MS) and other technologies were used to detect and analyze acid value， fats， fatty acids content， lipid oxidation and odor active components in sauce beef samples， which included raw meat， tumble marination samples， cooking samples， and samples secondary sterilization at 90， 100， 110， 120 ℃. Results showed that the acid value of cooking sample was the lowest (2.16 mg/g)， acid value of sauce beef samples increased with the increase of sterilization temperature， samples sterilized at 120 ℃ had the highest acid value (3.68 mg/g). The content of phospholipid in raw meat was the highest(61.33 g/100 g fat). With the increase of sterilization temperature， the content of phospholipid decreased 52.21 g/100 g fat， and the free fatty acid content gradually increased to 13.57 g/100 g fat. Tumble marination and cooking had no significant (P>0.05) effects on the total fatty acids in sauce beef. Thermal sterilization could increase the total content of saturated fatty acid(SFA) and decrease the content of (PUFA). UFA content was mainly affected by PUFA. Changes in MUFA were not significantly under different processes. Heat treatment could significantly(P<0.05) reduce the content of PUFA. Sterilization temperature above 105 ℃ could destroy the PUFA significantly. With the progress of the processing， n-6 PUFA/n-3 PUFA gradually increased and PUFA/SFA decreased. The sterilization temperature above 105 ℃ could significantly (P<0.05) increase the degree of lipid oxidation and promote the decomposition of fatty acids. OAVs of nonanal， octanal， 4-allylanisole and linalool were higher in sauce beef samples. Fatty acids were significantly (P<0.05) correlated with the changes of odor active components. Fat oxidation was significantly (P<0.05) correlated with 2-heptanone， 2-nonone， 2-pentylfuran， ethyl acetate and so on. In summary， the processing temperature below 105 ℃could slows down the deterioration of lipids in sauce beef， which can provide a theoretical reference for the quality control of sauce beef.

Abstract:In this study， four harvest periods were used to determine and analyze the raw material properties such as color， basic nutrients， amino acids of P. haitanensis， and further according to the correlation between the harvest period and the quality index of nutrient components， the identification technique of different harvest periods of P. haitanensis were established. The results showed that as the harvest period increased， the L and b values increased significantly (P<0.05)， while the a values showed a decreasing trend； the protein， essential amino acid， non-essential amino acid and total amino acid contents first decreased and then increased， fat and crude fiber showed decreasing and increasing trends respectively， and ash content first increased and then decreased. In addition， the highest TAV values for the fresh amino acids were found in the third harvest period， the highest TAV values for the sweet amino acids were in the fourth harvest period， C16∶1 and C18∶3 were only detected in the fourth harvest period， and the mineral element content was higher in the late harvest than in the early harvest. The regression curve fitted to the essential amino acid content expert emethionin allows accurate identification of the first harvest period of P. haitanensis from different sea areas. This study established a correlation model between harvest periods and related quality indicators， which provides a theoretical and technical reference for the identification and screening of different harvest periods and high value utilization of P. haitanensis.

Abstract:In order to conduct a comparative analysis of traditional medicine-food homology ingredients in China， 103 medicinal and edible plants (MEPs) were selected and divided into eight categories based on their appearance. The study evaluated the following properties of MEPs: Total phenolic content (TPC)， total flavonoid content (TFC)， in vitro antioxidant activity and α-glucosidase and acetylcholinesterase inhibition. Furthermore， their chemical constituents were identified by high-performance liquid chromatography (HPLC). The results showed significant differences in TPC and TFC among MEPs， where Flos caryophylli in the mosaic category and Fructus canarii in the fruit category had the highest TPC with values of 309.59 μg GAE/mg and 229.64 μg GAE/mg. For TFC， Taraxacum mongolicum Hand.-Mazz. and Cirsium setosum in the whole grass category were the highest (662.31 μg RE/mg and 505.33 μg RE/mg). Meanwhile， mosaic， fruit， and whole grass category had good antioxidant activities. In addition， Rubus chingii and Fructus canarii in the fruit category， Cinnamomum cassia Presl in the derma category， and Flos caryophylli in the mosaic category demonstrated strong α-glucosidase inhibition activity. While turmeric in the rhizome category， Cinnamomum cassia Presl in the derma category， Herba moslae in the whole grass category exerted a remarkable inhibitory activity against acetylcholinesterase. HPLC analysis revealed that the mosaic， fruit， and whole grass categories had the most abundant compound species. In addition， catechin， chlorogenic acid， and epicatechin were the main compounds and had a significant positive correlation with antioxidant activity， It may be the main active substance of antioxidant in these medicinal and edible plants. This is the first comparative analysis on the chemical constituents and functional activities of 103 traditional MEPs， which can provide a valuable reference for the application of the clinical therapy and resident dietary guidance of these MEPs.

Abstract:In order to clarify the role of low-field nuclear magnetic resonance and imaging techniques in the study of food water migration， and to study the drying characteristics， moisture distribution change pattern and quality changes during the far-infrared assisted heat pump drying of Agaricus bisporus， different heat pump temperatures (45， 55 ℃ and 65 ℃) were used to dry Agaricus bisporus， and the transverse relaxation time during the drying process was measured using low-field NMR technique， and the signal amplitude， peak area， MRI images and changes of microstructure and quality of Agaricus bisporus before and after drying were analyzed. The results showed that with the increase of heat pump temperature， the time to reach the drying end point of Agaricus bisporus was 510， 420 min and 390 min， respectively. The drying rate of Agaricus bisporus increases rapidly at the early stage of drying， and then gradually decreases and tends to level off. Three different relaxation peaks could be seen from the T2 inversion spectrum: T21(3-23 ms)， T22 (25-155 ms) and T23 (155-1 084 ms)， representing three different states of water: Bound water， less mobile water and free water， respectively. During the drying process， the moisture content gradually decreased and the degree of bonding of moisture gradually becomes higher， and at the end of drying， the relaxation peaks corresponding to T23 decreased by about 99.80%， leaving only some of the relaxation peaks corresponding to T21 and T22， indicating that the free water was almost completely removed and only bonded water and a small amount of non-flowable water remained. NMR images showed that the moisture was basically removed after 360 min drying at 65 ℃， while the moisture was basically removed after 390 min drying at 55 ℃ and 450 min drying at 45 ℃. The moisture on the outside of Agaricus bisporus was removed first and the moisture on the inside migrated outward， and the higher the temperature， the faster the internal moisture migration rate. In addition， BI values at 65 ℃ were 30.55% and 22.69% lower than those at 45 ℃ and 55 ℃， respectively， indicating that 65 ℃ could better maintain the original color of Agaricus bisporus. Furthermore， the ascorbic acid， total phenol， and total flavonoid contents of dried Agaricus bisporus at 65 ℃ were 84.61%， 55.80%， and 36.77% lower than before drying， respectively， and the nutrient loss of Agaricus bisporus at 65 ℃ was the smallest compared to those at 45 ℃ and 55 ℃. This study showed that low-field NMR and imaging technology provided a direct reference for the change of water content in the drying process of Agaricus bisporus， and this study could provide a reference for optimizing drying parameters and improving product quality by the far-infrared assisted heat pump drying process of Agaricus bisporus.

Abstract:Color is the first perceptual indicator for evaluating frozen meat quality， and establishing an in-situ method for evaluating the color of frozen pork will be critical to stabilize the consumer market. This work proposed a real-time method for detecting the color of frozen pork based on the image threshold segmentation algorithms including canonical discriminant analysis (CDA) and global threshold segmentation (GTS). A total of 120 multispectral images of frozen pork were segmented. These segmented images were then converted into corresponding spectra， which were applied to establish calibration models for predicting the color characteristics (L， a and b) of frozen pork by using various algorithms such as successive projections algorithm (SPA) and partial least squares regression (PLSR). The results showed that three optimal models for predicting L， a and b values were built by combining the GTS with SPA and PLSR， and their corresponding determination coefficients (R2) and residual prediction deviations (RPD) were 0.9565 and 4.7745， 0.9593 and 4.6265， and 0.9570 and 4.2126， respectively. Results of high accuracy and robustness would provide a theoretical basis for non-destructive and rapid detection of the color of frozen pork in industrial practice.

Abstract:Currently， boiled peanut varieties are disordered in the field， the evaluation standard is vague， and the quality of boiled peanuts of different varieties varies dramatically. Evaluation of the suitability of different peanut varieties for boiled peanut processing is urgently necessary， and the corresponding evaluation methods and indicators should be established to provide a reference basis for the evaluation of the suitability of boiled peanut processing and to assist the high-quality development of the boiled peanut industry. In this study， 23 fresh-edible peanuts were fully evaluated for their basic nutrient composition， and quality indicators of boiled peanuts. Hierarchical cluster analysis， correlation analysis and logistic regression model were used to establish the evaluation methods and indices for the suitability of boiled peanut processing， and to screen out the special varieties suitable for boiled processing. The first-grade standard of boiled peanut quality was determined: Boiled peanut pod length 29.13-36.37 mm， pod width 15.38-15.87 mm， hardness 3 137.35-3 363.29 g， protein content 23.01-24.14 g/100 g， sucrose content 3.55-5.19 g/100 g. Five significantly related variables were screened and determined: The contents of fat， protein， sucrose， crude fibre， and arginine at P < 0.05. The suitability evaluation model of boiled peanut was established using logistic regression， and the accuracy of internal validation was 91.30%. The suitability evaluation methods and indices of boiled peanut processing were established， and six special varieties (1， 7， 8， 9， 10， 19) were screened to be suitable for processing boiled peanut.

Abstract:In order to explore the mechanism of histamine degradation of Bacillus subtilis under salt stress， B. subtilis JZXJ-7 was used as the experimental strain， and cultured in liquid culture environment with 170 mmol/L and 340 mmol/L NaCl for 48 h. Histamine degradation rate and colony growth were measured， and transcripome high-throughput sequencing was performed on the degraded strain. The differential gene expression and related metabolic pathways of strains in different NaCl addition groups were detected during reducing amine process. Results showed that the degradation rate of histamine after adding 170 mmol/L and 340 mmol/L NaCl was significantly higher than control group (P<0.05)， which were 62.93% and 84.87%， respectively. The total number of colonies was significantly increased (P<0.05)， which were 4.13×105 CFU/mL and 4.53×105 CFU/mL， respectively. Transcriptome analysis showed that differentially expressed genes were significantly up-regulated in the salt stress group， and the main up-regulated functional genes were serine acetyltransferase， major facilitator superfamily (MFS) transporter and type I secretory system penetrase. The significantly down-regulated functional genes were histidine kinase， type II 3-dehydroate dehydrase and shikimic dehydrogenase. GO functional enrichment analysis mainly involved metabolic process， cell transformation， cell anatomical entity， structural molecular activity， catalytic activity and binding ability. The metabolic pathway of KEGG involved pyruvate metabolism， pentose phosphate pathway， two-component system and arginine biosynthesis. Results revealed that salt stress was more conducive to B. subtilis to promote gene expression， activate metabolic pathways， and increase histamine degradation rate. This study provided an important theoretical basis and reference for the subsequent strains to be applied in food fermentation industry to further degrade biogenic amines efficiently.

Abstract:Thermostable enzymes in raw milk can seriously affect the quality stability of the shelf life of products. However， the main sources and contamination pathways of thermostable enzymes have been debated. In this study， metagenomic technology was performed to analyze the microbial community composition and gene abundance of extracellular protease (EC 3.4.24.40) and lipase (EC 3.1.1.3) in environmental samples (barn bedding soil， TMR feed) and fresh milk samples (the first three milk， after the first three of milk， and raw milk of storage tank) from a farm in China. This study aimed to investigate the source of thermostable enzyme contamination of raw milk in milk storage tanks. The results of diversity analysis showed that the abundance of typical psychrophilic bacteria such as Pseudomonas(1.57%) and Acinetobacter(1.56%) in the barn bedding soil was much higher than that of the other samples. It was much higher than the first three milk (0.26%， 0.54%). Through gene analysis of microbial enzyme production， the microorganisms that thermostable enzymes in raw milk of storage tank were mainly from psychrophilic bacteria， Pseudomonas and Acinetobacter. The abundance of extracellular protease-producing genes in each sample was barn bedding soil: 8.71 and the first three milk: 0.18； the abundance of extracellular lipase-producing genes in each was barn bedding soil: 16.19， TMR feed: 0.33， the first three milk: 0.18， after the first three of milk: 0.39 and raw milk of storage tank: 0.22. In addition， the lipase gene of raw milk in storage tanks had the lowest gene duplication of 57.14% during the raw milk collection line. In addition， microorganisms and their psychrophilic bacteria contaminate the teats of cows through barn bedding soil. Then， they enter the raw milk collection line and cause contamination during milking. This study provided a theoretical and data basis for the effective prevention and control of thermostable enzymes contamination in raw milk.

Abstract:To analyze the environmental adaptation and spoilage-related genes of Pseudomonas fragi， and to provide a theoretical basis for the subsequent study of its spoilage-causing mechanism， spoilage bacteria were isolated from spoiled frozen tuna， and the isolates with quorum sensing were screened using Agrobacterium tumefaciens KYC55 and then their secreted AHLs were detected by GC-MS. The strain type was determined using 16S rRNA comparison and ANI analysis. Gene function and annotation were determined by sequencing the whole genome. The content of siderophore secreted by the strain at different temperatures was measured by CASAD plate and UV detection. The changes of total viable count and total volatile basic nitrogen in frozen tuna inoculated with MS-10 were detected， and the putrefactive ability of MS-10 was analyzed in combination with the spoilage metabolite yield factor YTVB-N/CFU. Results: The isolated strain was P. fragi， named MS-10， secreting quorum sensing signals， mainly C8-HSL and C10-HSL. Its genome size was 5.25 Mb， with 58.2% GC. Comparison of multiple databases revealed that the gene functions of MS-10 were mainly focused on biometabolism， signal transduction and environmental stress， including quorum sensing regulatory genes traI/R and a large number of spoilage-related genes. Low temperature conditions were more favorable for strain MS-10 to secrete siderophore. Tuna blocks inoculated with MS-10 showed a significant increase in total viable count and TVB-N values during refrigeration compared to the blank group， with YTVB-N/CFU values measuring 2.77×10-7 mg/CFU. Conclusion: P. fragi MS-10 possessed a quorum sensing system and was a cold-tolerant putrefactive bacterium. It was demonstrated that it had strong putrefactive potential and environmental adaptability at the genetic level， which could help to further investigate the regulatory mechanism of MS-10 quorum sensing and to provide data support for future research on its putrefactive properties.

Abstract:Objective: Aflatoxin B1 pollution is the key factor affecting food quality and safety. How to degrade aflatoxin B1 to reduce pollution and explore the degradation mechanism is the current urgent demand. Methods: Aflatoxin B1 in acetonitrile solution was degraded by plasma treatment with a discharge power of 200 W， a discharge time of 5 s and a discharge distance of 0.4 cm， and analysed by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) and high resolution mass spectrometry (HRMS) with the aim of obtaining the products and pathways for the degradation of aflatoxin B1 in the dielectric barrier discharge plasma method. Results: The molecular and structural formulae of five degradation products were analysed， and their degradation pathways were Criegee mechanism， Benzyl Methoxy Reaction and Nucleophilic Reaction. With the degradation rate of 35.8%， it was demonstrated that the toxicity was consistent with the degradation rate after dielectric barrier discharge plasma treatment based on the loss of toxicity sites of the five degradation products. Conclusion: This study provides a theoretical reference for the degradation of aflatoxin B1 in peanut， corn and nut products using dielectric barrier discharge plasma， and the potential toxicity validation after degradation of aflatoxin B1 by dielectric barrier discharge plasma can be further explored in subsequent experiments through animal experiments or cell experiments.

Abstract:The objective characterization of food odor is important for the optimization of food production process and quality evaluation. However， the complexity of the food odor formation mechanism and its complicated composition， coupled with the fact that the odor evaluation process is susceptible to a variety of factors such as environmental， psychological and perception modes， make it necessary to deal with a large amount of high-dimensional and complex information in the characterization of food odors， which requires the use of tools with powerful data processing capabilities. Along with the rapid development of artificial intelligence， computer science and big data technology， machine learning has powerful data processing capability， it has become possible to characterize food odors using machine learning， and the implementation of this process relies heavily on machine learning algorithms. In this paper， the application of various machine learning methods in food odor characterization was summarized， and the advantages and problems to be solved in using machine learning methods for food odor characterization were pointed out. Finally， the future development direction of machine learning algorithms applied to food odor characterization was foreseen.

Abstract:Human milk oligosaccharides (HMOs) are complex carbohydrates with unique structures in human milk， and their diversity is much higher than that of other mammalian milk. The functional role of HMOs can continue from the initial establishment of infant gut microbiota to adulthood， including supporting beneficial bacterial growth and anti-pathogen adhesion. It also has the potential to produce beneficial effects in cognition. It is worth further studying whether HMOs can promote the healthy development of the infant brain by regulating the intestinal flora and using the gut-brain axis. This paper reviewed the composition and structure of HMOs， focused on the role of HMOs in shaping the intestinal flora of infants， and discussed the promotion of HMOs and their metabolites on infant cognition through the gut-brain axis， aiming to provide a theoretical reference for promoting the application of HMOs in infant formula.

Abstract:Background: The consumption of Edible Bird’s Nests (EBN) has a long history. It has been regarded as a high-grade health food and tonic due to its characteristics of high nutritional values and medicinal properties. Although some studies stated that EBN or its active ingredients， sialic acid， has antioxidant effects， there is a lack of studies that systematically investigate the antioxidant effects of EBN. Objective: To systematically evaluate the efficacy of EBN on antioxidant capacity. Method: Relevant studies published between September 1， 2012， and September 1， 2022， were searched and selected using ‘bird nest OR sialic acid’ and ‘antioxidant’ as search terms across China National Knowledge Infrastructure (CNKI)， Wanfang Database， China Biology Medicine disc (CBMdisc)， PubMed and Embase. The selection of relevant studies was guided by predefined inclusion and exclusion criteria. The bias risks of selected studies were based on the SYRCLE's animal research bias risk tool. Result: Six animal model experiments were finally included in total. Results suggested that EBN and sialic acid has a potential role in up-regulating antioxidant activities. EBN or sialic acid may enhance antioxidant capacity by increasing the levels of antioxidants， while simultaneously reducing the occurrence of inflammation and oxidative stress. However， this review did not conduct a meta-analysis. Conclusion: Animal studies indicate a dose-dependent improvement in antioxidant capacity with EBN and sialic acid， but their effects on humans remain uncertain due to the absence of clinical trials.