Abstract:Food safety is of vital importance to people's lives. With the improvement of living standards， public concern about food safety has also increased， and the urgent need for reliable and effective information response has arisen. Existing intelligent question-answering systems， such as those based on text vector libraries， have made some progress in knowledge reasoning， problem handling， and semantic relationship recognition， but still have some shortcomings； question-answering systems based on knowledge graphs face inherent challenges in terms of graph construction cost and information recall rate； while question-answering systems based on template matching are poor in question generalization ability and context understanding. This paper proposes an innovative knowledge graph-based intelligent perception question-answering system based on large language models (LLM). Using large language models to improve the shortcomings of the template matching method， combining text vector libraries and knowledge graphs at the same time， and introducing high-dimensional vector semantic search technology into the knowledge graph retrieval process to improve the knowledge graph retrieval recall rate. This innovative approach significantly improves the overall performance of the question-answering system and the user's experience.

Abstract:With the increasing global demand for food consumption， food nondestructive detection technology has become increasingly important in food quality control and safety assurance. This paper systematically reviews the application and development trends of machine vision technology in food nondestructive detection. By analyzing current literature， various imaging technologies including RGB imaging， multispectral imaging， hyperspectral imaging， and Raman spectroscopy imaging， as well as detection algorithms such as traditional image processing， machine learning， and deep learning， are discussed in the context of food nondestructive detection. The paper also examines the technical challenges of machine vision in food nondestructive detection， such as the lack of datasets and the insufficient generalization ability of models in universal scenarios. Based on the current state of research， the paper envisions future research directions， proposing possible development paths such as multimodal data fusion， embedded detection systems， and close integration with deep learning technologies. This paper aims to provide a comprehensive research review for the development of food nondestructive detection technology and offer guidance and direction for technological innovation in practical applications.

Abstract:Spirulina protein isolate (SPI) was used as an emulsifier to prepare high-internal phase emulsions (HIPEs)， and the effects of emulsifier mass fraction， oil phase type and oil phase proportion on the construction of HIPEs were studied， and their storage stability at room temperature and protective effect on UV-induced β-carotene degradation were explored. The results showed that SPI has good surface wettability， foaming ability， interfacial tension reduction ability and UV absorption ability. It had good emulsifying properties for a variety of oil phases， and 75% (volume fraction) of oil phases could be emulsified with a mass fraction of 1%. HIPEs constructed based on SPI had good storage stability at room temperature， and could effectively encapsulate β-carotene， and after UV irradiation， the emulsion structure was intact， and the photodegradation of β-carotene was effectively inhibited， and the residue of β-carotene reached 45.56%. Conclusion: HIPEs with food grade， good biocompatibility， high stability and strong ultraviolet resistance were prepared， which have potential application prospects in food， cosmetics and medicine， and provide reference data for the preparation of natural protein-based emulsions.

Abstract:Objective: The study of the functional properties of active substances in postbiotic products is key to elucidating their probiotic mechanisms. By investigating the metabolic components and bioactive functions of Bifidobacterium cells， the probiotic functions of Bifidobacterium as a postbiotic can be better characterized. Methods: The dried cells of Bifidobacterium adolescentis B8589 and Bifidobacterium bifidum B1628 obtained from high-density fermentation were selected as the research subjects. Untargeted metabolomics was used to study the functional components of the cells. Results: A total of 48 bioactive metabolites， primarily flavonoids， lipids， and lipid-like molecules， were identified in B. adolescentis B8589， including daidzein and galangin. Meanwhile， 35 bioactive metabolites， primarily organic heterocyclic compounds， lipids， and lipid-like molecules， were identified in B. bifidum B1628， including tetrahydropyrimidine and isoglycyrrhizin. Among these， both B8589 and B1628 shared active metabolites mainly composed of flavonoids. These bioactive components exhibit antioxidant， antitumor， and anticancer properties， contributing positively to human health. Conclusion: During the development of Bifidobacterium-based postbiotic products， the identification of beneficial active components within Bifidobacterium cells can serve as a valuable reference for evaluating functional components and facilitating industrial applications.

Abstract:Objective: This paper mainly studies the influence of different applied rotating flow fields on the spatial structure of lysozyme， which can be used to guide the food processing of high protein content food. Methods: A rotational rheometer was used to apply a shear flow field in lysozyme solution. Circular dichroism spectroscopy， ultraviolet absorption and second derivative spectroscopy， fluorescence emission spectroscopy and dynamic light scattering were used to characterize the effects of shear flow field on the secondary structure and tertiary structure of lysozyme molecules. Results: When the shear flow speed was higher than 200 s-1 or the shear flow duration was longer than 1.5 h， the proportion of α-helix structure decreased and the proportion of disorder structure increased， the UV absorption spectrum changed blue shift， and the polarity of tryptophan residue in the molecular was enhanced. This change was irreversible and became more significant with the increase of shear speed， the extension of action time and the decrease of lysozyme concentration. Conclusion: The shear flow field can cause an impossible inverse conformational change of lysozyme， and the larger the shear rate and the longer the interaction time， the more significant the conformational change.

Abstract:B-type potato starch was selected as the test object to promote the nanocrystallization of starch granules by high static pressure combined with hydrochloric acid hydrolysis. Polarized light microscope， X-ray diffraction analyzer， Fourier infrared spectrometer and other instruments were used to analyze the size， remote structure and proximal structure of starch granules. The results showed that the optimal hydrolysis time of potato starch was 12 h， the hydrolysis rate reached 10.47%， and the molecular mass was 1.628×1044 ku. However， through HHP synergistic acid hydrolysis， the hydrolysis rate reached a maximum of 13.16% and the molecular mass dropped to 0.236×1044 ku after treatment under the optimal condition of 400 MPa for 30 minutes. This indicates that pressure-assisted acid hydrolysis can greatly improve the hydrolysis efficiency of starch. Intermittent HHP treatment (400 MPa， 5 min/d) for 6 weeks resulted in a maximum hydrolysis rate of 30.09%， the large particles of potato starch were significantly reduced， the small particles were significantly increased， and the number of nano-sized (D<1 μm) starch particles was significantly increased by 19.7%. RC (Relative crystallinity) reached 52.10%， indicating that HHP synergistic acid hydrolysis could promote the nanocrystallization of starch granules.

Abstract:Quantitative descriptive analysis， triangulation tests， and electronic tongue analysis were used to study the flavor characteristics of two umami peptides from Wuding stewed chicken. The results showed that the two peptides showed other basic flavor properties besides umami， such as salty. The umami thresholds of the peptides KIDE(KE-4) and LELR (LR-4) were 0.03 mg/mL and 0.06 mg/mL， respectively. The molecular docking results showed that the main binding regions for the docking between the umami peptides KE-4 and LR-4 and the umami receptor T1R1/T1R3 were all T1R3 subunits， the key amino acid residues for binding were Glu and Asp， and the main forces for binding were hydrogen bonding interactions and hydrophobic interactions. These results of experiment complemented the existing database of umami peptides and provided a theoretical basis for the production and application of umami peptides.

Abstract:The effects of commonly found Chinese honey (acacia honey， jujube honey， vitex honey， and lychee honey) and specialty honey (loquat honey， cinnacle honey， and kuding tea honey) on gut microbiota after in vitro simulated gastrointestinal digestion and colonic fermentation were investigated. The results showed that all seven types of honey had a regulatory effect on gut microbiota， increased the abundance of Actinobacteria and decreased the abundance of Firmicutes， lychee honey， acacia honey， vitex honey， kuding tea honey， loquat honey， cinnacle honey， and jujube honey reduced Firmicutes abundance by 30.08%， 21.2%， 34.83%， 35.5%， 32.73%， 35.7%， and 30.41%， respectively. Different types of honey had significantly different effects on gut microbiota. Lychee honey， locust honey， vitex honey， bitter tea honey， loquat honey， and Chinese sumac honey increased the abundance of Bacteroidetes， while lychee honey and locust honey decreased the abundance of Proteobacteria. Except for jujube flower honey， all other six types of honey reduced the Firmicutes/Bacteroidetes(F/B) ratio， with reductions of 341.99%， 337.37%， 106.36%， 128.14%， 141.59%， and 93.52% for lychee honey， acacia honey， vitex honey， kuding tea honey， loquat honey， and cinnacle honey， respectively， with lychee honey having the best effect. The effects of honey on gut microbiota were directly related to the plant source of honey， rather than the type of honeybee. The abundance of Firmicutes was negatively correlated with the total polyphenol content.

Abstract:Objective: To isolate and purify probiotic Lactobacillus from honey with high adsorption rate of heavy metal lead and edible. Methods: Physiological and biochemical experiments were performed on the isolated and purified strains， and a phylogenetic tree based on 16s rDNA was established for taxonomic identification； the probiotic properties of the strains were assessed by hemolysis， gelatinase activity， nitrate reduction and amino acid decarboxylase， self-aggregation and hydrophobicity， acid and bile salt resistance， and antimicrobial drug sensitivity. Meanwhile， inductively coupled plasma emission spectroscopy was used to determine the Pb2+ content in the solution before and after adsorption. The ability of the strains to adsorb heavy metals was explored. Scanning electron microscopy-X-ray energy spectroscopy was used to observe the adsorption of Pb2+ by the bacteria before and after adsorption. Fourier transform infrared spectroscopy was used to determine the adsorption of Pb2+ by the bacterium and the changes in protein structure. Results: Strain C10 screened from honey was identified as Lactobacillus plantarum， with no hemolytic and gelatinase activities； it could not reduce nitrate and did not decarboxylate to produce amines； self-aggregation and hydrophobicity reached 85.33% and 35.50%， respectively； survival under acid and bile salts was 39.39% and 98.79%， respectively； and it had strong sensitivity to chloramphenicol， erythromycin， ampicillin and cotrimoxazole. Lactobacillus plantarum C10 adsorbed 65.82% of heavy metals within 2 h. Scanning electron microscopy-X-ray spectroscopy showed that the percentage of lead element was 9.69%， and Fourier transform infrared spectroscopy showed that the secondary structure of the surface protein of the bacterium changed significantly after the adsorption of Pb2+. Conclusion: Lactobacillus plantarum C10 has good probiotic properties， can effectively adsorb Pb2+， and has the effect of preventing heavy metal poisoning.

Abstract:Purpose: To study the inhibitory effects of cinnamon， thyme and basil essential oils on pathogenic bacteria. Methods: Five common pathogenic bacteria were selected as test bacteria； Plant essential oils with synergistic antibacterial effects were selected by checkerboard dilution method and bacteriostatic circle method and et al. Then， the composition of 3 essential oils was analyzed by Gas Chromatography-Mass Spectrometry(GC-MS)， and the cell membrane permeability of Escherichia coli， Vibrio parahaemolyticus and Staphylococcus aureus were explored. Results: GC-MS analysis showed that cinnamaldehyde， thymol and eugenol were the main antibacterial components in cinnamon essential oil， thyme essential oil and basil essential oil， respectively. Cinnamon and thyme essential oils were combined with E. coli and Vibrio parahaemolyticus with a FIC of 0.5， and cinnamon with basil essential oil was combined with E. coli and Staphylococcus aureus with a FIC of 0.5. The OD280nm of Escherichia coli and Vibrio parahaemolyticus treated with cinnamaldehyde-thymol was 6.13% and 4.42% higher than that of single-component treatment， respectively， and 12.44% and 12.53% higher than that of single thymol， respectively. Similarly， the OD280nm of Escherichia coli and Staphylococcus aureus in the treatment of cinnamaldehyde-eugenol was 8.97% and 7.38%， respectively， and 17.02% and 24.69% higher than that of eugenol， respectively. Conclusion: Cinnamon and thyme essential oils have synergistic antibacterial effects on Escherichia coli and Vibrio parahaemolyticus， the main antibacterial components in cinnamon， thyme， and basil essential oils were cinnamaldehyde， thymol， and eugenol； The synergistic antibacterial effects of cinnamon-thyme essential oil and cinnamon-basil essential oil were due to the combined function of cinnamaldehyde-thymol and cinnamaldehyde-eugenol， respectively. The two compound components destroyed the cell membrane integrity of the bacteria， increasing the permeability of the bacterial cell membrane， a large number of nucleic acids， proteins and other cellular contents were leaked， resulting in the death of the bacteria.

Abstract:To investigate the effects of different thawing methods on the oxidation characteristics of protein after in vitro gastrointestinal digestion， four thawing methods， namely cold storage thawing (CST)， MNPs combined ultrasonic thawing (NUT)， MNPs combined microwave thawing (NMT)， and MNPs combined ultrasonic-microwave thawing (NUMT)， were used to simulate the gastrointestinal digestion of jumbo squid (Dosidicus gigas) in vitro. The results showed that compared with the control group CST， the three thawing methods all improved the digestibility of protein. The protein digestibility in vitro of the NUMT treatment group was up to 80.33%. The degree of protein oxidation in the NUMT group was the lowest after gastrointestinal digestion. Specifically， the carbonyl content was 2.66 nmol/mg in the stomach and 3.86 nmol/mg in the intestine； dipolytyrosine levels were reduced by 30.75% in the stomach and 23.73% in the intestine compared to the CST group； the sulfhydryl group contents were 19.25 nmol/mg in the stomach and 18.68 nmol/mg in the intestine. Additionally， the particle sizes of the NUMT group were the smallest， measuring 298.41 nm in the stomach and 327.48 nm in the intestine. The DPPH free radical scavenging rate and Fe2+ chelating ability in the NUMT treatment group were the highest， reaching 56.94% vs 25.59% in the stomach and 58.72% vs 32.27% in the intestine， respectively. In conclusion， under the four different thawing methods， the NUMT treatment group significantly reduces protein and lipid oxidation during the thawing process of jumbo squid， demonstrating the highest antioxidant activity following gastrointestinal digestion.

Abstract:Objective: Analyze the dynamic changes trend of main functional components in Wuniuzao green tea and black tea which are prepared from fresh leaves in summer and explore the intervention effects of Wuniuzao green tea and black tea (in summer) water extract on liver and gut microbiota in obese mice. Methods: Detect the dynamic changes trend of main functional components of samples from each processing procedures in Wuniuzao green tea and black tea (in summer). After acclimation feeding for 1 week， 50 mice were randomly divided into the following groups， such as normal control (NC) group， Wuniuzao green tea (WG) group， Wuniuzao black tea (WB) group， high-fat diet (HFD) group and positive control (PC) group， which were continuously administrated (NC and HFD group were given normal saline， PC group was given atorvastatin (10 mg/kg BW)， WG and WB group were given tea water extract (300 mg/kg BW) for 8 weeks. The changes of body weight， Lee's index， blood glucose levels， serum lipid， pathobiology in liver tissues， SREBP1c signaling pathway in liver lipid metabolism and gut microbiota were measured. Results: During processing procedures， the contents of main functional components of Wuniuzao green tea and black tea (in summer) changed obviously. Compared to the‘Fresh leaves’ sample of Wuniuzao green tea (in summer)， the contents of tea polyphenol and caffeine in the‘Drying’ sample were respectively increased by 3.87% and 0.61%， while the contents of free amino acids， soluble sugar， and soluble protein were respectively reduced by 0.56%， 0.47%， and 4.26%. Compared to the ‘Fresh leaves’ sample of Wuniuzao black tea (in summer)， the contents of tea polyphenol， caffeine， free amino acids， soluble sugar， and soluble protein were respectively reduced by 6.15%， 0.40%， 1.08%， 0.53%， and 4.11%. Compared to the HFD group， the WG group and WB group exhibited a significant difference (P < 0.05) in body weight (27.73 g， 26.78 g) and Lee's index (3.18， 3.15). Besides， tea water extract could also significantly improve blood glucose tolerance levels， serum levels and lipid deposition in liver， and regulate the level of SREBP1c signaling pathway related genes and proteins of liver lipid metabolism in mice. The results of gut microbiota analysis showed that tea water extract decreased the ratio of Firmicutes/Bacteroidetesd (F/B)， and increased the growth of beneficial bacteria， including Rikenellaceae and Alloprevotella. Conclusion: Wuniuzao green tea and black tea (in summer) water extract have obvious effects on intervening abnormal liver metabolism and gut microbiota dysbiosis in obese mice， and the Wuniuzao green tea water extract has a better effect.

Abstract:Ovalbumin (OVA) is one of the main allergens that cause egg allergy， and pulsed electric field (PEF) is an emerging non-thermal physical processing technology that has an ameliorative effect on OVA-induced allergic reactions. Based on the BALB/c mouse model， the effects of PEF-assisted alcalase (AL) treatment on OVA-induced allergic reactions were systematically evaluated by body weight， body composition， allergy symptoms， histopathology， antibody levels， and inflammatory mediators release levels. The results showed that PEF-assisted AL treatment ameliorated the body composition changes caused by OVA-induced allergic reactions by improving body weight， lean content and free water content in mice. The results of clinical symptoms showed that PEF-assisted AL treatment improved the problems of hypertrophy and increased vascular permeability caused by allergic reactions， and significantly improved the problems of body temperature drop caused by allergic reactions. The histopathological results showed that PEF-assisted AL treatment significantly improved the inflammatory infiltration of spleen and lung， and made their morphology more similar to that of the control group. Serological results showed that， compared with OVA group， the binding levels of specific IgE and IgG1 in HOVA-PP' group were decreased by 68.87% and 31.20%， respectively， indicating that PEF-assisted AL treatment significantly reduced the binding levels of allergens and specific antibodies. In addition， PEF-assisted AL treatment significantly reduced the concentration of histamine and mouse mast cell protease-1 (mMCP-1) to 51.97 ng/mL and 51.97 pg/mL， regulated the release of IL-4 and IFN-γ， and promoted the balance between Th1 and Th2-type cells， thereby improving OVA-induced allergic reactions.

Abstract:To study the effects of quinoa on intestinal microflora and short-chain fatty acid (SCFAs) metabolism in healthy mice. Select 40 SPF (Specific Pathogen Free) adult male mice were randomly divided into high， medium and low concentration gavage group and control group. The mice were administered intragastrically at 0.2 mL/2 d for 2 months. Collect the contents of the cecum of mice in the ninth week， extract the total DNA of the gut microbiota， amplify the V3-V4 region of the 16S rRNA gene through PCR， and analyze the sequencing data. SCFAs were extracted from the feces of mice at the ninth week by ethyl ether extraction method， and the changes of SCFAs in mouse feces were detected by high performance liquid chromatography. Quinoa has the effect of altering the overall structure of mice intestinal microbiota. The proportion of Firmicutes and Bacteroidetes in the intestinal microbiota of three test groups significantly increased at the phylum level compared to the control group after feeding with quinoa syrup. At the family level， quinoa significantly increased the relative abundances of Bacteroidetes S24-7_group， Lactobacillaceae， Prevotellaceae and Rikenellaceae， and decreased the relative abundances of Clostridiaceae 1， Clostridium vadinBB60 group and Lachnospiraceae. At the genus level， the dominant genera in the mouse gut were changed. The relative abundances of Prevotellaceae， Alloprevotella， Lactobacillus and Ruminococcus were significantly increased， while the relative abundance of Lachnospira was significantly decreased. The contents of acetic acid and propionic acid at the medium concentration were increased by 16.5% and 23.9% respectively compared with the control group. Quinoa can inhibit the growth of harmful bacteria in intestinal microbiota to a certain extent， and maintain the balance of intestinal microbiota by promoting the proliferation of probiotics and the production of SCFAs. The results lay a theoretical foundation for the development of quinoa functional foods， and provide scientific basis for future rational diet and personalized precise nutrition.

Abstract:Objective: The purpose of this study was to explore the regulation effects of ammonium salt compensation on the formation of higher alcohols and flavor quality in the brewing process of Hongqu rice wine. Methods: By using the headspace solid phase microextraction， gas chromatography-mass spectrometry combined with sensory evaluation and analysis， the effect of ammonium salt compensation on the reduction and regulation of higher alcohol metabolism in Saccharomyces cerevisiae was also verified by functional microbial combination fermentation. Results: The addition of ammonium dihydrogen phosphate and diammonium dihydrogen phosphate could reduce the content of higher alcohols in Hongqu rice wine， and the addition of 400 mg N/L ammonium dihydrogen phosphate had the best reduction effect on the total amount of higher alcohols in Hongqu rice wine， with the reduction rate reaching 35.79%， which can also significantly increased the contents of ethyl acetate， ethyl butyrate， ethyl caproate and ethyl caprylate in Hongqu rice wine， and effectively enhanced the characteristic aroma of fruit， sauce， floral and woody， and reduce the bad taste of astringency， bitter and spicy in Hongqu rice wine. In addition， based on the functional microbial combination fermentation system， ammonium salt compensation (400 mg N/L ammonium dihydrogen phosphate) has a significant reduction effect on the metabolism of higher alcohols in Saccharomyces cerevisiae fermentation， with a reduction rate of 28.99%. Conclusion: Ammonium salt compensation， especially ammonium dihydrogen phosphate compensation (400 mg N/L)， can obviously reduce the formation of higher alcohols in the brewing of red koji rice wine， and improve the flavor quality of red koji rice wine. The research results will promote the application of ammonium salt compensation technology in the brewing industry of Hongqu rice wine， and provide scientific basis for improving the drinking safety and flavor quality of Hongqu rice wine.

Abstract:Objective: To investigate the regulatory effects of yeast fermentation in single-strain and mixed-strain modes on the production of biogenic amines and flavor compounds during the brewing process of Maiqu Huangjiu. Methods: With Wickhamomyces anomalus and Saccharomyces mikatae as the research subjects， the regulatory effects of yeast fermentation in single-strain and mixed-strain modes on the production of biogenic amines and flavor compounds during the brewing process of Maiqu Huangjiu were explored through techniques such as headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and sensory evaluation analysis. Results: The results of this study showed that both W. anomalus and S. mikatae enhanced fermentation significantly reduced the production of biogenic amines during the brewing process of Maiqu Huangjiu. S. mikatae - W. anomalus mixed-culture enhanced fermentation not only reduced the production of biogenic amines by 89.03%， but also significantly increased the contents of certain characteristic aroma components， including ethyl acetate， butyl lactate， ethyl caproate， ethyl caproate， butyl caproate， etc.， thus achieving a dual regulatory effect of reducing biogenic amines and enhancing aromatic flavor quality. Moreover， S. mikatae - W. anomalus mixed-culture enhanced fermentation can significantly reduce the acidity of Maiqu Huangjiu by 48.31% and notably increase the amino acid nitrogen content in the wine by 36.9%. The result of sensory evaluation and analysis demonstrated that the Maiqu Huangjiu produced by enhanced fermentation of S. mikatae - W. anomalus mixed-culture exhibitted a balanced sweet-sour taste， rich aroma， and smooth harmony. Conclusion: The enhanced fermentation of S. mikatae - W. anomalus mixed-culture exhibits a significant effect on reducing biogenic amines and improving the characteristic aroma in the production of Maiqu Huangjiu. This practice contributes to enhancing the safety and flavor quality of Maiqu Huangjiu， thereby promoting the healthy and sustainable development of the Huangjiu brewing industry.

Abstract:In order to explore the growth characteristics of non-Saccharomyces yeasts and the evolution of their flavor enzyme activity during alcohol fermentation， autochthonous strains with high esterase and alcohol acyltransferase production were isolated from spontaneous fermentation of wine grapes in Hexi Corridor region of Gansu Province. The selected non-Saccharomyces yeast strains were inoculated into simulated grape juice and the growth kinetics， fermentation kinetics and flavor enzyme activity of these strains were dynamically monitored in the process of fermentation. Results showed that autochthonous HX-6 and HX-7 strains had higher total C2-C6 esterase activity (102.69， 102.51 U/mL)， while HX-6 strain had the highest alcohol acyltransferase activity (3.46 U/mL). These two strains were identified as Torulaspora delbrueckii through sequence analysis of the D1/D2 domain of 26S rDNA. The result of fermentation kinetics and biomass analysis for autochthonous HX-6， HX-7 strains and commercial strains TD-n confirmed that all three strains could not independently complete alcohol fermentation. Dynamic detection of enzyme activity showed that the cumulative activities of C2-C6 esterase (143.74， 121.85 mU/mL) and alcohol acyltransferase (15.75， 12.74 U/mL) were the highest during simulated wine fermentation triggered by HX-6 strain. The cumulative activity of C6 esterase (86.63 mU/mL) of HX-7 strain was high in the process of simulated red wine fermentation. Based on comprehensive analysis， the selected non-Saccharomyces yeasts autochthonous strains have application potential for wine aroma enhancement.

Abstract:The low solubility and high polymer quality of rice protein lead to poor emulsification performance， which limits the application of rice in food processing and delays the process of high-value utilization of rice. It is of great significance to improve the solubility and emulsification of rice protein by modifying its molecular structure. In this experiment， crushed rice was used as raw material， and pre-gelatinization， ultra-fine grinding， and ultra-fine pre-gelatinization were carried out respectively， then the structure and functional characteristics of the extracted rice protein were detected to evaluate the effect of different processing methods on the emulsifying properties of rice protein. The results showed that compared with pre-pasteurized rice protein (PRP) and ultra-micro-milled rice protein(URP)， the intensity of infrared characteristic absorption peaks of pre-pasteurized ultra-milled rice protein (PURP) increased， and the ultraviolet absorption spectra showed a blue-shift phenomenon； the synergistic technique of pre-pasteurization and ultra-micro-milling increased the total sulfhydryl group and disulfide bond contents from 19.21 and 7.53 μmol/g in RP to 24.49 and 11.36 μmol/g； the β-folding content of all four proteins ranged from 38.74% to 41.30%， with the highest ratio and stable secondary structure； and， the total sulfhydryl and disulfide bond content increased， with the highest β-folding content and stable secondary structure. The hydrophobic sites and sulfhydryl groups of the PURPs were exposed， which promoted the hydrophobic interactions and sulfhydryl group-to-disulfide bond exchange reactions， and the protein particles aggregated with each other to form a gluten-like network structure. It indicates that the synergistic technique of pregelatinized ultrafine milling improved the emulsification， emulsion stability， foaming rate， and foaming stability of rice protein， and the four properties were improved by 58.29%， 53.13%， 11.85% and 50.46%， respectively.

Abstract:The potato cell wall pectinase was isolated and purified by ammonium sulfate gradient precipitation with a combination of three phase partitioning method， and the effects of environmental conditions on the activity and enzymatic features of cell wall pectinase in potato were studied. The results showed that when the saturation of ammonium sulfate was 60%， pectinase reached the maximum precipitation point. Through a process of two three phase partitioning and purification， the specific activity of pectinase， the purification fold and the recovery rate reached 2 012.40 U/mg， 5.72 and 82%. The optimal temperature was 20 ℃ and the optimal pH was 4.8. Ca2+ and Cu2+ could significantly amp up pectinase activity， and Ca2+ possessed the strongest promoting effect on pectinase(251%)， while Zn2+ and Na+ had no effect on pectinase activity， Whereas K+ and Mg2+ had a significant inhibiting effect on pectinase activity. The enzymatic activity reached to the climax (4 667.10 U/g) when the reaction was conducted at the optimal temperature and pH for 40 min. The kinetic constants of pectinase were Km=0.13 mg/mL and Vmax=277.80 U/g. Simultaneousl enzymolysis effect the gelled potato pectin and the original pectin were compared. It turned out to be that gelled pectin was resistant to potato cell wall pectinase.

Abstract:In order to improve the flavor and quality of fermented radish pickles， radish was inoculated with Lactiplantibacillus plantarum PJ-7 producing γ-aminobutyric acid and commercial starter， respectively. The microbial count， physical and chemical characteristics， organic acids， volatile flavor compounds and bacterial diversity of fermented radish were determined using HPLC， headspace solid-phase microextraction gas chromatography-mass spectrometry and high-throughput sequencing. Effect of L. plantarum PJ-7 producing γ-aminobutyric acid on the flavor and nutritional quality of fermented radish was analyzed in the study. The results showed that the count of microorganisms and physical and chemical characteristics in radish fermented by L. plantarum PJ-7 were better than that commercial starter group and natural fermentation group. The content of γ-aminobutyric acid reached 1.33 mg/mL， and the total amount of organic acids was 28.52 mg/mL， among which the content of lactic acid was the highest， reaching 22.91 mg/mL. The volatile flavor compounds of fermented radish in PJ-7 group were abundant. A total of 48 volatile flavor compounds in PJ-7 group， mainly including esters， alcohols and thioethers， the relative contents of which were 9.65%， 21.16% and 22.10%， respectively. Lactobacillus， Weissella and Streptococcus are the dominant bacteria genus in PJ-7 group. The results demonstrated that L. plantarum PJ-7 could increase the γ-aminobutyric acid content and improve the flavor and quality of fermented radish. This study aims to provide a basis for development of pickles rich in γ-aminobutyric acid.

Abstract:The effects of two traditional and innovative manning techniques on the taste composition and flavor quality of jasmine tea were investigated through the analysis of taste composition， determination of free amino acid and catechin fractions and sensory evaluation， gas chromatography-mass spectrometry(GC-MS) and other techniques. The results showed that the quality of jasmine tea was fairly affected by different manning techniques， and the tea polyphenol and free amino acid contents of jasmine tea were 23.13% and 3.16%， respectively， which were higher than those of the traditional manning (22.11% and 2.40%)， and presented a better fresh and refreshing flavor； and the bitter and astringent taste index (CAI) of the jasmine tea from the innovative manhole was obtained through the analysis of catechin fractions. The bitter taste index (CAI) was 14.77%， which was 1.57% lower than the 16.34% of the traditional manching process， and the bitter taste was lighter. The GC-MS analysis results showed that the first two categories of aroma substances of jasmine tea from innovative and traditional manching were esters and olefins， and the combined amount of the two was 75% of innovative manching， which was higher than that of the traditional manching of 62.49% by more than 10%， and the fruity and sweet aroma was more intense. The aroma utilization rate of innovative manning was 70.19%， while that of traditional manning was 21.86%， which was 221% higher in aroma utilization rate. The results of this study can provide a reference for the enhancement of flavor quality and application of jasmine tea.

Abstract:To improve the quality of konjac glucomannan gel prepared by acidic low-temperature sterilization (95 ℃， 30 min)， four kinds of coagulating hydrocolloids， namely， curdlan， gellan gum， κ-carrageenan， and agar， were compounded with the gel. Rheological properties， textural properties， water distribution， and microstructure were evaluated as indicators to assess the effect of different hydrocolloids. The results demonstrated that compared with the blank control group， the addition of all four hydrocolloids reduced the complex viscosity and increased the loss tangent value of the composite gel before alkali induction， which means the flow properties were enhanced. Different hydrocolloids had different effects on the modification of the textural properties of the composite gels after acidic low-temperature sterilization， with the addition of curdlan improving springiness by 9.8%， and the addition of gellan gum， κ-carrageenan， and agar improving chewiness by 94.6%， 159.0%， and 65.2%， respectively. In addition， the composite gels with the addition of the four hydrocolloids were all enhanced in their ability to bind to water， and the disruption of the network structure by the thermal acid treatment was all reduced. This effect probably achieved by the strengthening of the network structure of the composite gels by hydrogen bonding interactions among the molecules. Overall， the structural strength and texture type of KGM composite gels are effectively improved by hydrocolloids. This study provides a theoretical reference for the development or optimization of related products.

Abstract:Pickled food may contain spore pathogenic bacteria and spoilage bacteria， high pressure thermal sterilization (HPTS) can kill these spores， and sodium chloride in pickled food may improve its bactericidal effect. The bactericidal effect of high pressure thermal sterilization (600 MPa， 75 ℃) combined with sodium chloride (15%， 25%， saturated sodium chloride solution) on Bacillus subtilis spores was studied. After treatment， the leakage rate of 2， 6-dipyridinolinic acid (DPA) and the damage of the intima of the spores were measured. The changes of spore intima， protein secondary structure and nucleic acid stability were analyzed by Fourier transform infrared spectroscopy (FTIR). The results showed that the combined treatment of 600 MPa， 75 ℃ and 15% sodium chloride had the best inactivation effect on Bacillus subtilis spore [5.43 lg (CFU/mL)]， and the DPA leakage rate of spore under this condition was 92%. HPTS combined with 15% sodium chloride had the greatest damage to the intima， protein secondary structure and nucleic acid stability. Under the conditions of 600 MPa， 75 ℃ binding concentration of 25% and saturated sodium chloride， the kill amount of treated spores was about [3.48 lg (CFU/mL)] and [3.08 lg (CFU/mL)]， and the leakage rate of DPA was 82% and 63%， respectively. Compared with 15% sodium chloride， the inner membrane permeability of the spore was reduced， the α-helix ratio of the secondary structure of the spore protein increased significantly， and the secondary structure of the protein was more orderly. Studies have shown that 25% and saturated sodium chloride unexpectedly protected Bacillus subtilis spores and reduced the damage of the spore intima， proteins and nucleic acids caused by HPTS treatment.

Abstract:Due to the inherent disadvantage of heat transfer， the traditional water bath pasteurization technology may lead to excessive heating of fresh-cut Chaenomeles sinensis slices， resulting in serious deterioration of flavor quality. Radio frequency (RF) combined hot water bath pasteurization， which can improve the heating efficiency and uniformity through volumetric heating for the food， thus reducing the heat resistance of microorganisms and inactivation time and can effectively minimize the adverse effects of heat transfer on heat-sensitive components such as flavor， nutrition， and colors of the fruit slices. In this study， E. coli was selected as the target microorganism to assess the impact of different RF electrode gaps on the heating characteristics and pasteurization efficiency of inoculated E. coli fruit slices. The inactivation kinetics of RF combined hot water bath pasteurization were fitted using Linear， Weibull， and Log-logistic models. The results revealed that RF combined hot water bath heating significantly increased the heating rate of Chaenomeles sinensis slices and reduced the heat resistance of E. coli and inactivation time compared with water bath pasteurization， when employing 100 mm electrode gaps， RF combined hot water bath pasteurization reduced the inactivation time by approximately 57% (lethality>5 lg). Compared the fit evaluation parameters Af， Bf， RMSE， and R2 of the inactivation kinetic model， the Log-logistic model exhibited the highest fitting accuracy (Af: 1.0884， Bf: 0.9334， RMSE: 0.1189， R2: 0.9931). Furthermore， the predicted values of the Log-logistic model closely aligned with the measured values， confirming that the Log-logistic model provided a more accurate representation of the inactivation pattern of E. coli inoculated in fresh-cut Chaenomeles sinensis slices during RF combined hot water bath pasteurization. Results suggested that RF combined hot water bath pasteurization can be considered as an effective pasteurization method for fresh-cut Chaenomeles sinensis slices.

Abstract:Plasma-activated water(PAW) was prepared by using atmospheric pressure plasma jet technology with compressed air at 0.15 MPa as the working gas. PAW was activated for 30 s， 60 s， and 90 s at a power of 380 W. The physicochemical properties of PAW were analyzed， and the inhibitory effects of different plasma-activated waters on various spoilage bacteria (Hafnia alvei， Hafnia paralvei， and Serratia grimesii) isolated from spoiled salmon as well as Escherichia coli and Staphylococcus aureus were studied. The inactivation kinetics model of PAW was analyzed using the GInaFIT Tool. The integrity of cell membrane and changes in intracellular nucleic acids after sterilization were determined. Furthermore， the inhibitory and dispersion effects of PAW on the biofilm of H. alvei， H. paralvei， and S.grimesii were investigated. It was found that the pH value of PAW gradually decreased with increasing discharge time， while the redox potential， conductivity， and content of H2O₂， O3， NO₂-， and NO3- increased. PAW activated for 60 s could completely kill the pathogenic bacteria after 6 min of treatment. PAW60 and PAW90 exhibited a better fit to the logarithmic model when treating H. alvei A2， H. paralvei A3， and S.grimesii A5 for 6 min. Cell integrity was disrupted， and DNA leakage occurred after PAW treatment. The formation of biofilms by the pathogenic bacteria mentioned above could be inhibited by PAW treatment for approximately 2 min， and the dispersion of mature biofilms required 20-30 min. This study provides a theoretical basis for using plasma-activated water to inhibit pathogenic and spoilage bacteria in seafood products.

Abstract:Yanfeng rice' was stored at different temperatures (15 ℃， room temperature， 20-25 ℃ and 37 ℃) for 300 d， and its physical and chemical indexes， color difference， gelatinization characteristics， texture characteristics and cooking characteristics were evaluated regularly in order to provide reference for predicting the quality change of rice during storage. The results showed that the quality characteristics of 'Yanfeng Rice' changed significantly during storage at different temperatures， and the higher the temperature， the more obvious the change trend was. Among them， rice moisture content， protein content， sulfhydryl content， L， a， adhesion value， pH of rice soup decreased with the extension of storage time， at 37 ℃， the indicators decreased by 2.44%， 0.49%， 1.1%， 12.81， 2.84， 0.21 and 1.2， respectively； b， setback value， gelatinization temperature， water absorption rate， and expansion volume increased， at 37 ℃， the indicators increased by 18.69， 349cP， 12.2 ℃， 152%， and 197%， respectively. In addition， the change trend of other indexes at different temperatures is different. Under the condition of low temperature storage at 15 ℃， the chewiness of 'Yanfeng Rice' increased at first， and then the elasticity did not change significantly， and the peak viscosity decreased and the recovery increased. However， the peak viscosity and disintegration value of masticatory resilience increased at first and then decreased at 37 ℃， and the elasticity showed a downward trend as a whole combined with the correlation between peak viscosity disintegration value of chewiness and taste value， the taste of 'Yanfeng Rice' reached after being stored at 37 ℃ for 60 d.

Abstract:The volatile flavor components of fresh walnut kernels stored at different temperatures were analyzed and compared by gas chromatography-ion mobility spectrometry (GC-IMS). The results showed that 54 volatile flavor compounds were detected from walnut kernels stored at 25， 4 and-18 ℃， including 16 esters， 15 aldehydes， 11 alcohols， 7 ketones， 2 acids， 2 pyrazines and 1 furan. The relative contents of alcohols and esters in the volatile flavor substances of walnut kernel were higher， followed by aldehydes， ketones and acids， and the relative contents of pyrazines and furans were the least. There were differences in the volatile flavor substances of walnut kernel at three temperatures， among which the flavor of walnut kernel at 25 ℃ changed most dramatically. Principal component analysis and Euclidean distance analysis showed that GC-IMS technology could better distinguish the flavor of walnut kernels at different storage temperatures. Conclusion: Based on GC-IMS technology， the fingerprint of volatile flavor substances of walnut kernels at different storage temperatures was established， and the profile of volatile organic compounds of walnut kernels stored at different temperatures was visually outlined， which provided a reference for the selection of walnut storage methods and the evaluation of walnut kernel deterioration degree.

Abstract:Zearalenone (ZEN) is mainly produced by Fusarium graminearum and widely exists in wheat， soybean and other grains and their derivatives. It has estrogen effect and a variety of toxicity， which can cause nervous system excitement. In this study， a fluorescence aptamer sensor based on Hairpin probe-mediated Isothermal Amplification (HIAmp) was established to detect ZEN in food. Firstly， a new hairpin probe was designed according to the ZEN aptamer sequence. Secondly， the hairpin structure was opened to initiate the amplification reaction by using the specific binding property of ZEN to the aptamer. Finally， a quantitative detection method of ZEN was established by combining with fluorescence technology， and the method was evaluated. The results showed that this method can complete the detection in about 1 h under the optimal reaction conditions， and the detection limit can reach 0.2 pg/mL. The linear equation constructed by -lgCZEN and Ct value was Ct = -1.195 lgCZEN + 14.082 (R2 = 0.9975)， and the linear relationship was good. The results of specific analysis showed that only two groups of samples containing ZEN produced signals， and the other five groups of samples without ZEN did not produce signals. The recoveries obtained by this method were 93.4%-99.6%， higher than those obtained by liquid chromatography (92.5%-99.0%) and ELISA kit(93.1%-98.4%). In summary， the fluorescent aptamer sensor based on hairpin probe mediated isothermal amplification constructed in this study has the advantages of strong specificity， short time consuming， simple operation， high sensitivity and high accuracy， and its detection limit is much lower than those of national standard liquid chromatography (5 μg/kg) and ELISA kit method (0.5 ng/mL). It provides a new strategy for the quantitative detection of ZEN in cereal foods and has a good application prospect in the field of food safety detection.

Abstract:As a new type of food safety risk factor， microplastics (MPs) can accumulate into the human body through the food chain， resulting in serious health risk issues. In order to explore the existence and potential risks of MPs in seafoods， we took solarized sea salt as the representative research object. Firstly， we removed organic impurities in sea salt by using 30% H2O₂ oxidant digestion as pretreatment method. Then， we confirmed the existence of MPs in sea salt by visual method， microscopic observation， microscopic fourier infrared spectroscopy， and microscopic Raman spectroscopy. Results: through visual analysis， microscopic fourier infrared spectroscopy， and microscopic Raman spectroscopy， it was found that the number of MPs in sea salt samples is approximately 2 550/kg， (750±200)/kg， and (1 500±500)/kg， with white and colorless colors as the main colors， and a small amount of red， blue， and black. Polymer types included polyester， nylon， and polypropylene. Conclusion: by comparing the advantages and limitations of common detection methods. it was determined that micro-Raman spectroscopy is more effective for both qualitative and quantitative analysis of microplastics. It will provide certain technical support for the risk warning of MPs in solarized sea salt.

Abstract:Histamine is a kind of biogenic amine， which is produced by decarboxylation of histamine acid. It is one of the by-products of Huangjiu fermentation and is closely related to human health. In this study， surface-enhanced Raman spectroscopy (SERS) and chemometrics were combined to detect histamine in Huangjiu quickly. SERS spectra of histamine were obtained by using silver nanoparticles (Ag NPs) as SERS substrate and NaCl solution as aggregating agent. Firstly， the SERS reaction conditions were optimized by using the concentration of histamine aqueous solution to NaCl solution， the mixing volume ratio of histamine to NaCl and Ag NPs， and the mixing time of the three. Then， based on the optimal conditions， the purification effects of C18 solid-phase extraction column and PXC strong cation exchange reversed-phase solid-phase extraction column on Huangjiu were further compared to quantitatively analyze histamine in Huangjiu. The results showed that when NaCl solution concentration 0.5 mol/L， histamine solution∶NaCl solution∶Ag NPs=2∶1∶3， and mixing time 15 s， the enhancement effect at the characteristic peak of histamine at 1 002 cm-1 was the strongest. Under this condition， the detection limit of histamine solution was 1 mg/L. At the same time， under this condition， PXC strong cation exchange reversed-phase solid phase extraction column was determined as the pretreatment method of Huangjiu， and the detection limit of histamine in Huangjiu was 2 mg/L. Finally， multiple linear regression analysis and partial least squares regression (PLSR) prediction models of histamine content are established， and the effectiveness of competitive adaptive weighted sampling (CARS)， Principal component analysis (PCA) and Successive projections algorithm (SPA) in screening characteristic variables of original spectrum was compared. Among them， the calibration set and verification set of PLSR model established by using 51 variables screened by CARS have obtained higher determination coefficients Rc2=0.9777， Rv2=0.9604， and lower root mean square error RMSEC=0.0712 mg/L and RMSEV=0.1405 mg/L. The results showed that the rapid quantitative detection of histamine in yellow rice wine could be realized based on SERS technology and chemometrics method， which provided a new idea for the on-site monitoring of histamine in fermented alcoholic beverage.

Abstract:In this study， we developed an accurate and reliable ddPCR-based method for identifying and quantifying duck derivative in beef. Single-copy nuclear gene ACTB encoding a β-Actin was selected and used as the target to designed specific primers and probes for both beef and duck. In order to transform the ratio of DNA copy number to the mass fraction of targeted meat， a fixed constant (transfer coefficient) was introduced， which was designated as K. Based on the relationship between the known mass fractions in simulated meat mixtures and the actual DNA copy numbers measured by ddPCR， the K value was calculated and validated. A quantitative formula was consequently established and applied for quantifying the content of duck in both the artificial duck/beef-mixed samples and commercial beef products. The results revealed that the established ddPCR method was highly specific for the detection of duck-derivative in beef. The K value was 0.16 and hence the quantitative formula was established as MD/MB=0.16×QD/QB， where MD and MB refer to the mass of duck and beef， respectively. QD and QB refer to the copy number of the target gene detected in the ddPCR assays， respectively. The linear regression was established within the duck content of 1%-90% with the correlation coefficient (R2)≥0.99. The limit of detection (LOD) and limit of quantification (LOQ) of the established ddPCR method are 0.1% and 0.5%， respectively. When the artificial mixed samples with the duck content of 20%-80% were detected， the absolute errors were all <1%. Duck derivative was detected in two out of 16 commercial beef products， with the content of 44.87% and 18.21%， respectively， which were inconsistent with statement on the product labels. In summary， the ddPCR method developed in this study demonstrated good specificity， sensitivity， accuracy and applicability for quantifying duck derivative in beef， could provide technical support for the quality and safety inspection of beef and beef products in China.

Abstract:The unique flavor of Yunnan Xuanwei ham is related to its natural fermentation time and the rich metabolites produced by fermentation. In this study， headspace solid-phase microextraction combined with gas chromatography-mass spectrometry and non targeted metabolomics techniques were used to explore the differences in volatile flavor compounds and metabolites of Xuanwei ham that had been naturally fermented for two years and fermented for three years. The identification results of volatile flavor compounds in Xuanwei ham from different fermentation years showed that a total of 59 volatile flavor compounds were identified， of which 30 were common volatile flavor compounds in Xuanwei ham fermented for 2 and 3 years. According to the odor activity value (OVA)≥1， 17 volatile compounds were characteristic flavor compounds of Xuanwei ham， with most of the characteristic flavor compounds belonging to aldehydes and alcohols. Multivariate analysis of metabolites showed that there were differences in the diversity and expression patterns of metabolites in Xuanwei ham from different years. A total of 290 significantly different metabolites were identified， with the highest content of amino acids， peptides， and analogues， totaling 52 species (20.63%)， followed by fatty acids and their complexes， with 16 species. KEGG pathway analysis showed that there were 21 and 14 metabolites involved in amino acid metabolism and lipid metabolism pathways in ham metabolites from different fermentation years， respectively. This study revealed the differences in volatile flavor compounds and metabolites of Xuanwei ham in different fermentation years， which can lay a foundation for distinguishing and improving the fermentation quality of Xuanwei ham.

Abstract:Precooked squid dishes with different frying time (0， 5， 15 min) were taken as the research object. Based on amino acid targeted metabolomics method， the changes of amino acid metabolites in precooked squid dishes during frying were analyzed， and multivariate statistical analysis and metabolic pathway analysis were performed on amino acid metabolites. The results showed that a total of 23 amino acid metabolites were detected during the frying of squid precooked dishes. By analyzing the types of amino acid differential metabolites， it was found that with the extension of frying time， the types of amino acid differential metabolites increased significantly. There were 9， 10 and 12 kinds of amino acid differential metabolites screened from the three groups of squid precooked dishes (S1vsS3， S1vsS5 and S3vsS5)， respectively， and there were 3 common differential metabolites among the three comparison groups， namely γ-aminobutyric acid， serine and asparagine. By analyzing the metabolic pathways of amino acid differential metabolites， 9， 11， and 13 amino acid metabolic pathways were enriched among the three comparison groups， respectively， of which 5 pathways were amino acid metabolism， 1 pathway was amino acid degradation， and 2 pathways were amino acid biosynthesis. These metabolic pathways contribute to flavor and nutrient formation in squid precooked dishes.

Abstract:This study aimed to investigate the influence of natural fermentation on the quality characteristics of Cabernet Sauvignon wines produced at the Helan Mountain east foothill during different periods. Two different wineries were selected， and commercial brewing yeast was used as a control group to compare the effects of natural fermentation on the physical and chemical parameters. The analysis of aroma compounds was performed using headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Sensory evaluations were conducted to assess the wine's sensory characteristics after fermentation. The results demonstrated that natural fermentation significantly affected the physical and chemical composition of the final Cabernet Sauvignon wines. Parameters such as total acid (5.67， 6.67 g/L)， pH (3.52， 3.37)， glycerol (12.53， 12.79 g/L)， total phenol (1 871.01， 1 614.33 mg/L)， and anthocyanin content exhibited (363.31， 440.57 mg/L) significant variations (P<0.05). Throughout the fermentation process， total acids and polyphenols gradually increased， while glycerol and anthocyanin content initially increased and then decreased. pH values showed an initial decrease followed by an increase. Aroma analysis revealed that several aroma compounds， including n-propanol (631 944.22， 480 893.41 μg/L)， 3-methyl-1-pentyl alcohol (204.61， 147.07 μg/L)， n-caproic acid (2 297.09， 3 054.19 μg/L)， trans-3-hexenol (24.21， 31.43 μg/L)， and 4-terpenol(4.65， 6.39 μg/L)， were significantly higher in naturally fermented Cabernet Sauvignon wines compared to the control group (P<0.05). Total aroma (1 495 527.85， 1 410 009.04 μg/L)， esters (70 686.36， 135 191.45 μg/L)， higher alcohols (1 373 156.7， 1 219 543.05 μg/L)， fatty acids (50 933.23， 53 754.49 μg/L) showed an increasing trend with fermentation. The content of aldehydes and ketones (566.51， 1 331.15 μg/L) first increased and then decreased， whereas the content of isoprene and other substances remained relatively stable. Sensory evaluation indicated that the overall rating of naturally fermented wines was slightly higher than that of inoculated fermentation. Odor Activity Value (OAV) analysis and principal component analysis (PCA) revealed a positive correlation between natural fermentation and ester compounds among 29 typical aroma substances. Pearson correlation analysis showed that natural fermentation was positively correlated with total sugars， total acids， total phenols， esters， higher alcohols， and isoprene substances， with a significant positive correlation observed with total acids (P<0.05). Conversely， it was negatively correlated with pH， volatile acids， glycerol， anthocyanins， and fatty acids. In conclusion， natural fermentation significantly influenced the physical and chemical parameters and aroma compounds of Cabernet Sauvignon wines produced at the eastern foot of Helan Mountain. Natural fermentation resulted in wines with superior flavor quality compared to inoculated fermentation.

Abstract:Based on the multiomics detection technology of human milk developed by the China maternal and infant nutrition health cohort study， the lipidomics， glycomics and proteomics of human milk and different brands of infant formula were compared and analyzed， and the differences in the important nutritional composition of simulated human milk of infant formula were explored. The species number of glycerides (94)， phospholipids (224)， oligosaccharides (152) and milk fat globule membrane protein (1 043) in human milk were significantly higher than those of infant formula (P<0.05). The contents of phospholipids (256.77 mg/L)， oligosaccharides (10 150.60 mg/kg) and total sialic acid (521.30 mg/100 g) in infant formula were significantly different from those in human milk(P<0.05). The species and abundance of milk fat globule membrane proteins of infant formula and human milk were quite different， and only 10 kinds of human milk fat globule membrane proteins were reduced. In the future， the development of infant formula not only needs to simulate the richness of important nutritional molecules， but also needs to increase its content accordingly to bring it closer to the composition of human milk.

Abstract:To investigate the effect of roasting degrees on physicochemical properties and flavor substances of Yunnan sun-dried and washed coffee beans， chromatic aberration， crude fat content， fatty acid content， and amino acid content of sun-dried and washed beans with different roasting degrees were measured. Their volatile compounds were analyzed using gas chromatography-time of flight-mass spectrometry (GC-TOF-MS) and gas chromatography-ion migration spectroscopy (GC-IMS). The GC-TOF-MS results showed that a total of 142 volatile compounds were identified in the 6 samples， and a total of 35 compounds with OAV≥1 were selected through odor activity value (OAV) analysis， which made an important contribution to the overall aroma of Yunnan coffee beans； partial least-squares discriminant analysis (PLS-DA) can better distinguish between sun-dried beans and washed beans； 53 volatile compounds with VIP values＞1 were identified through variable importance in projection (VIP) analysis of PLS-DA. By GC-IMS analysis， 105 volatile compounds were identified qualitatively. The fingerprint showed that 2-methyl-1-propanol， 3-pentanol， 2，3-butanediol and (E)-β-caryophyllene are the characteristic volatile compounds of sun-dried beans， 2-hexanone， octanoic acid ethyl ester， 1-terpinen-4-ol， 1-phenylethanone， 4-methyl-2-pentanone and β-myrcene are characteristic volatile compounds of washed beans； principal component analysis (PCA) can accurately distinguish Yunnan sun-dried beans and washed beans with different roasting degrees. This study utilized GC-TOF-MS and GC-IMS techniques combined with PLS-DA and PCA methods to characterize the flavor compounds of Yunnan sun-dried beans and washed beans with different roasting degrees， and screened out characteristic volatile compounds， providing theoretical reference for elucidating the aroma characteristics of two post-harvest processing methods of coffee beans.

Abstract:To explore the effect of roasting time on quality and flavor of the roasted chicken wings， three chicken wing samples roasted in electric oven for 16， 18， and 20 minutes were analyzed by sensory evaluation and determination of fatty acids and amino acids， thiobarbituric acid reaction substances (TBARS)， protein carbonyl content， and volatile flavor composition. The results showed that with the extension roasting time， the fatty acid content first increased from 13.00 to 17.41 mg/g and then decreased to 10.52 mg/g. The amino acid content first increased from 10.60 to 11.71 g/100 g and then decreased to 10.8 g/100 g. The TBARS value increased from 1.71 to 4.73 mg/kg， and the protein carbonyl content increased from 7.69 to 15.61 nmol/mg. In contrast， the chicken wings roasted for 18 min possessed the best sensory flavor and the optimal nutritional indexes， represented by 36.01% of polyunsaturated fatty acids and 43.38% of essential amino acids among total. In comparsion， the chicken wings roasted for 18 minutes possessed the best sensory flavor and optimal nutritional indexes indicated by the percentage of polyunsaturated fatty acids in total fatty acids and that of essential amino acids in total amino acids. A total of 108 volatile compounds were identified using solvent assisted flavor evaporation/gas chromatography-mass spectrometry analysis (SAFE/GC-MS). Orthogonal partial least squares discriminant analysis (OPLS-DA) according to VIP>1 (variable importance projection above 1) showed that acetoin， tetrahydropyran-2-one， 4-hydroxybutyric acid， 1-hydroxy-2-acetone， etc. formed from the Maillard reaction， and hexanal， nonanal， pentanal， (Z)-2-decenal， (E，E)-2，4-decadienal， heptanal， 2，3-octedione， etc. formed from the lipid oxidation played significant roles in differentiation of volatile compositions of the three samples. SAFE combined with aroma extract dilution analysis/gas chromatography-olfactometry analysis (SAFE/AEDA/GC-MS) identified 56 odor active compounds in the three samples， while the 18 minute-roasted chicken wings had the highest number. Those with high dilution factors (log2FD≥6) in common in the three samples included 3-(methylthio)propanal， hexanal， (E，E)-2，4-heptadienal， decanal， (E)-2-nonenal， (E)-2-undecenal， (E，E)-2，4-decedienal， 4，5-epoxy-2(E)-decanal， 1-octen-3-one， and 2-nonenone. OPLS-DA analysis according to (VIP>1) showed that 12 compounds via the Maillard reaction， including 2-methylbutanal， 3-methylbutanal， 2，3-butanedione， furfural， 3-(methylthio)propanal， dimethyl disulfide， 2-methyl-3-furanthiol， 2，5-dimethylpyrazine， etc. and 14 compounds via the lipid oxidation， including heptanal， propenal， trans-2-hexenal， (E)-2-decenal， (E，E)-2，4-nonadienal， octanal， hexanal， 4，5-epoxy-2(E)-decenenal， etc. played key roles in differentiation of compositions of the odor active compounds of the three samples. The work can provide guidance to select cooking technologies for roasted chicken wings with an optimal quality and flavor.

Abstract:Sub-health is an intermediate between health and disease， which is manifested by physical fatigue， sleep disorders， emotional depression， inability to adapt to the social environment， etc. It can directly or indirectly affect the physiology， psychology， social interaction， and other aspects of human being. Long-term sub-health state can even result in chronic diseases. In recent years， the state of sub-health has gradually attracted the attention of society， and how to prevent or alleviate sub-health has become a hotspot in related fields. Many basic and clinical studies showed that dysbiosis of gut microbiota was closely associated with the sub-health status of host， and targeted regulation of gut microbiota could improve the related symptoms. In this review， the gut microbiota from the sub-health population and the effect of probiotics on improving their harms were summarized. This article also proposes the possible mechanisms that probiotics could affect the production of short-chain fatty acids， neurotransmitters， hormones and other microbial metabolites to alleviate sub-health by regulating the composition and structure of gut microbiota， which provides new directions and strategies for the prevention and improvement of sub-health.

Abstract:With the global prevalence of food allergy increasing every year， food allergy has become a growing food safety and public health concern. So far， there is no effective drug treatment for food allergy， and avoiding intake or contact with food allergens is still the most effective treatment. Therefore， it is urgent to establish food allergen modification methods. Glycation modification is an effective method. Glycation modification is a method in which amino compounds in proteins react with carbonyl compounds to change the properties of proteins. This reaction not only has mild reaction conditions and does not add any chemical substances， but also improves the flavor and functional properties of food， which is very popular among consumers. It can reduce the allergenicity of allergen proteins while guaranteeing the safety and nutritional properties of food， and has a better development prospect in the prevention and control of food allergen allergenicity. This paper reviews the mechanism of glycation modification of allergenic proteins， the factors affecting the regulation of allergens by glycation reaction， and provides theoretical references for the processing and production of hypoallergenic or desensitized products.

Abstract:The primary objective of daily management in athletes is to optimize performance during competition and to enhance recovery efficiency during training. Accumulating studies indicate that athletes' gut microbiota composition is closely correlated with their performance. In this article， we summarize the distinct characteristics of athletes' gut microbiota， as well as the mechanisms on enhancing athletic performance modulated by gut microbiota， focusing on in promoting lactate metabolism and key roles in regulating glycogen storage and gut barrier function associated with gut microbiota metabolites， such as short-chain fatty acids. Moreover， the progress on nutrition interventions to improve athletic performance through modulating gut microbiota， including probiotics， prebiotics， and dietary supplements for muscle synthesis， has been reviewed. Finally， we provide an outlook on future research and application aiming to enhance endurance and athletic performance through nutrition modulating the gut microbiota.

Abstract:Depression is one of the most common psychological disorder in modern society， which seriously affecting both mental and physical health. Currently， long term use of medications for treating depression could result in various adverse reactions. Therefore， there is an urgent need to find new approaches to improve depression symptoms while minimizing side effects. Dietary flavonoids are commonly present in plants and have a positive impact on human health. Several studies have confirmed their significant antidepressant effects. This article provides an overview of the mechanisms underlying depression from six aspects: neurotransmitters theory， neurotrophic theory， neuroinflammatory， oxidative stress， hypothalamic-pituitary-adrenal axis， and the microbiota-gut-brain axis. It elaborates on the formation mechanisms of depression and elucidates how flavonoids can improve cognition and emotions， acting as the main components for alleviating depressive symptoms. This paper serves as a theoretical basis for the development of dietary prevention， as well as the improvement of depression and related functional foods.

Abstract:Plant-based meat analogue， also called plant-based meat， is one of the novel approaches to use plant protein. In recent years， under the influence of multiple factors such as price， product quality， environmental protection， nutrition and health， plant-based meat has attracted more and more attention from consumers and food researchers， exhibiting great potential for development and utilization. This paper summarized the main components of plant-based meat analogue and their roles in product quality， and analyzed the processing technologies applied in processing plant-based meat， as well as the research status and evaluation methods in flavor， texture， color， nutrition and health， aiming to provide references for the research of plant-based meat analogue and related fields in China.

Abstract:Daylily is rich in various nutrients and bioactive substances， and is known as one of the four treasures among vegetables along with shiitake mushrooms， fungus， and winter bamboo shoots. This article reviews the biological activity of daylily and the current research status of its deep processing technology. It explores the relationship between the bioactive components and functions of daylily extracts， and further analyzes that the weak links in the value-added processing of daylily mainly lie in the development of daylily extracts as new food raw materials and the study of their toxicity. Summarizing the potential applications of daylily and its extracts in antioxidant， antidepressant， anti-tumor， anti-inflammatory and other related diseases， and elaborating on the application of daylily deep products such as daylily powder， daylily beverage， ready to eat products， daylily extracts， etc. It is proposed that daylily and its extracts can be used as new food raw materials in the future， providing some reference for the development of daylily functional products.