Abstract:Objectives: This study aimed to develop a multidimensional analytical model for spatiotemporal trends and risk food categories， with the objective of achieving efficient early warning of food safety risks and providing a scientific basis and decision support for the intelligent and precise management of supervision. Methods: Based on the food sampling data from Jiangsu Market Supervision and Administration Bureau from 2019 to 2024， a spatio-temporal Transformer based multi-class prediction model was proposed. This model deeply explored the evolution patterns of food safety incidents in both temporal and spatial dimensions and established intrinsic associations with risk categories. To mitigate the long-tail distribution problem caused by disparities in data volume across multiple categories， a weighted mean squared error loss function was introduced to optimize model training， thereby enhancing the sensitivity of the model to tail categories. Results: The accuracy of the model was comprehensively evaluated using four high-risk category classification metrics and three all-category risk classification metrics. It not only achieved prediction accuracy comparable to statistical methods in regions where risks had occurred， but also efficiently predicted all-category risks across the entire spatiotemporal scope. Conclusions: The spatio-temporal Transformer multi-class prediction model provides a novel and effective tool for food safety regulatory authorities， enabling the optimization of random inspection strategies and enhancing regulatory efficiency.

Abstract:Objectives: With advancements in computer vision technology， accurately identifying and segmenting various components in food images has become essential for food nutrition analysis and promoting healthier diet management. However， most existing image segmentation models rely solely on a single image input， which often struggles to capture subtle distinguishing features in food images with minimal visual differences， ultimately impacting segmentation accuracy. This paper addressed the limitations of single-modality approaches in segmentation tasks by incorporating text information to provide richer contextual data for the model. Additionally， it leveraged self-distillation techniques to guide the model in effectively segmenting food images. Methods: This paper proposed a multi-modal self-distillation segmentation model guided by ingredient information to improve food image segmentation. The model leveraged the comparative languaged pre-training model (CLIP) to capture ingredient information and fused it with image knowledge. By combining the strengths of the diffusion model in dense prediction， the model achieved accurate segmentation of food images. Results: When evaluated on the benchmark dataset FoodSeg103， the model achieved an mIoU of 47.93%， surpassing the current best-performing FoodSAM model by 1.51%. On the UEC-FoodPIX Complete benchmark dataset， the mIoU reached 75.13%， outperforming the FoodSAM model by 8.99%. Conclusions: The proposed multi-modal self-distillation network demonstrated strong performance in food image segmentation， showcasing the effective role of ingredient information in guiding segmentation tasks. This approach significantly improves segmentation accuracy and presents a promising solution for food image analysis.

Abstract:In the study， lactic acid bacteria which could produce exopolysaccharids (EPS) were screened from pickled vegetables， the yield of the EPS was determined， and the strain PC715 which have the highest EPS producing ability was identified， at the mean time， the probiotic characteristics of PC715 were also evaluated， including its growth status， acid and bile salt tolerance， self-aggregation， co-aggregation， hydrophobicity， safety， antibacterial activity， and in vitro antioxidant capacities. The results showed that based on the 16S rDNA sequence， the strain with the highest EPS production yield (PC715) was identified as Lactobacillus plantarum. The yield of EPS715 was about 870 mg/L detected by the phenol-sulfuric method. The ultraviolet-visible spectrum indicated no proteins or nucleic acids were in EPS715. L.plantarum PC715 could grow well at both 28 ℃ and 37 ℃， its survival rates at acid conditions (pH=2.5， 3.0， and 4.0) were 75.54%， 91.77%， and 93.69%， respectively， and its survival rates in bile salts (1， 2， and 3 mg/mL) were higher than 40%. The self-aggregation rate of the stain was about 27.64%， the co-aggregation towards Escherichia coli was at about 16%， and the hydrophobic ability were between 0.88%-16.97% towards different organic solvents. L.plantarum PC715 were sensitive to tetracycline， ampicillin， erythromycin， chloramphenicol， and clindamycin， had no hemolytic activity， and had inhibitory effects on E.coli， Bacillus cereus， Staphylococcus saprophyte， Hafnia alvei， Staphylococcus aureus， and Acinetobacter sp. The scavenging capacity of DPPH， hydroxyl， and ABTS＋ radicals of L.plantarum PC715 cell-free supernatant were (62.90±0.87)%， (93.39±2.20)%， and (60.19±1.07)%， respectively. This study showed that exopolysaccharides producing-L.plantarum PC715 might had probiotic potential and could be used as the starter culture in the fermentation industry.

Abstract:Objective: The surface layer protein (SLP) of Lactobacillus， possesses adhesive functionalities， including facilitating the adherence of bacterial cells to intestinal epithelial cells or stable binding to surface constituents of cells. This study aimed to explore the adhesion properties of the SLP of Lactobacillus in Tibet kefir and evaluate its impact on the aggregation among microorganisms and biofilm formation. Methods: SLP-producing strains were selected from Tibet kefir using conventional separation techniques and an acidic lithium chloride extraction method. The impact of SLP on the hydrophobicity and surface charge of bacterial cells was investigated by employing the microbial adhesion to solvents (MATS) assay. Finally， the self-aggregation rate of Lactobacillus， their co-aggregation rate with yeasts， and the capacity for biofilm formation were determined to assess the influence of SLP on microbial aggregation and biofilm formation within the Tibet kefir microbiota. Results: 19 strains of SLP-producing Lactobacillus from Tibet kefir， with SLPs exhibiting an average molecular weight of approximately 70 ku， and the highest production level reaching 1.16 g/mL. By comparing the surface characteristics and aggregation abilities of bacteria before and after the removal of SLP， it was found that the removal of SLP caused the average auto-aggregation rate and co-aggregation rate of bacteria to decrease by 1.63%-7.56% and 0.96%-10.63%， respectively， and the reduction range of the average absorbance value corresponding to the growth of the mixed biofilm was 0.52-1.13 nm. Conclusion: Tibet kefir was found to harbor an abundant population of high SLP-producing strains， with the majority representing dominant microbial species. As a critical component governing aggregation and adhesion abilities， SLP plays a pivotal role in the biofilm formation and stable propagation of the microbial community within Tibet kefir.

Abstract:Objective: The inhibitory effects of phenyllactic acid on Enterobacter hormaechei and its biofilm was explored. Method: The inhibitory effect of PLA on E. hormaechei and its biofilm was assessed through various experimental techniques， including measurement of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)， growth curve， flow cytometry， alkaline phosphatase (AKP) activity， cell membrane integrity， DNA content， motility test， biofilm formation and confocal laser scanning microscopy observation. Results: The MIC and MBC of PLA to E. hormaechei was 1.25 mg/mL and 2.5 mg/mL， respectively， which could completely inhibit the growth of E. hormaechei. Flow cytometry results showed that 1/2 MIC and MIC phenyllactic acid could not cause apoptosis and necrosis， while 2 MIC PLA could cause cell death. The lag phase of growth curve of E. hormaechei cultured at 28 ℃ was nearly 1 h longer than that at 37 ℃， but the maximum biomass of E. hormaechei was not affected， and the apoptosis rate was not significantly different. PLA damaged the structural integrity of cells， resulting in decreased intracellular AKP activity and leakage of nucleic acids and proteins. 2 MIC PLA could significantly reduce the content of bacterial DNA. PLA treatment resulted in decreased motor capacity and biofilm production of E. hormaechei. Conclusion: PLA had a strong inhibitory effect on E. hormaechei and its biofilm.

Abstract:Tea residue contains approximately 10% pectin， which has the potential to serve as a raw material for edible film production. In this study， alkali-extracted tea residue pectin (ATRP) was employed that its basic composition was determined， and the influence of pectin concentration and the addition of Ca2+ on the rheological properties of ATRP was investigated. Edible films were prepared using ATRP as the matrix material， combined with sodium alginate， konjac glucomannan， and sodium carboxymethyl cellulose， to explore the changes in tensile elongation. The results showed that the ATRP contained 72.3% HG domain， while the side chain 'RG-I domain' accounted for 24.0%， and the solution exhibited non-Newtonian fluid behavior. When the ATRP mass concentration reached 70 g/L， the viscosity of the solution was 5×104 mPa·s， and the resulting gel showed a storage modulus (G′) of approximately 157 Pa and a loss modulus (G″) of approximately 21 Pa， and the gelation transition occurred at 300 s-1， demonstrating a significant increase in viscosity and gel properties compared to the 40 g/L ATRP solution. Furthermore， after adding Ca2+ to a 40 g/L ARTP solution， the maximum increases in its viscosity and gel strength could reach 80 times and 20 times their original values， respectively. but the Ca2+ concentration should not exceed 30 mmol/L. Compared to the film made by only ATRP， the films made by complex reagents exhibited improved appearance and superior tensile elongation properties. Among them， the film made by ATRP - konjac glucomannan (prepare according to a volume ratio of 1∶1) showed the highest tensile elongation， with a maximum load of 280 g (at a stretching time of 70 s)， which was seven times higher than that of film made by only ATRP and 70 times higher in terms of elongation. Therefore， ATRP exhibits promising potential as a raw material for edible film production.

Abstract:In this study， Lycium barbarum leaves polysaccharide (LBLP) was extracted by alkali extraction and ethanol precipitation. The monosaccharide composition and molecular weight distribution of LBLP were detected by ion chromatography and high performance gel permeation chromatography. The structure of LBLP was characterized by UV spectrum， infrared spectrum and X-ray diffraction. Its antioxidant and lipid metabolism regulation activities were evaluated by free radical scavenging test and enzyme activity inhibition test in vitro. The results showed that the total sugar content of LBLP was (65.78±0.85)%， the protein content was (12.25±0.25)%， and the uronic acid content was (19.26±0.14)%， indicating a protein complex acidic polysaccharide. LBLP was composed of 8 monosaccharides， the molar ratio of which was: narabinose ∶ ngalactose ∶ nrhamnose ∶ nglucose ∶ nxylose ∶ nglucuronic acid ∶ ngalacturonic acid ∶ nglucosamine hydrochloride=427∶293 ∶ 86 ∶ 73 ∶ 42 ∶ 40 ∶ 31 ∶ 8 of which arabinose had the highest content. LBLP mainly contained two polysaccharide components with different molecular weight distributions， among which the component with the highest content had a weight average molecular weight (Mw) of (67 380±288) ku. The UV spectrum showed that the Lycium barbarum leaves extract contains protein absorption peaks， indicating that it was a protein complex polysaccharide， consistent with the protein content determination results. It could be seen from the infrared spectrum that LBLP has the characteristic absorption peak of polysaccharide and contains pyranoside. In antioxidant experiments， LBLP showed good scavenging effects on 2，2-diazo-bis-3-ethylbenzothiazole-6-sulfonic acid cations (ABTS+)， 1，1-diphenyl-2-trinitrophenylhydrazine cations (DPPH+)， superoxide anions， and hydroxyl radicals. When the LBLP mass concentration was 5 mg/mL， the scavenging rates of DPPH+ and superoxide anions reached 90%. In the enzyme activity inhibition experiment， LBLP had good inhibitory ability on the activities of α-amylase， α-glucosidase， trypsin， and pancreatic lipase， and had a dose effect relationship. The IC50 was(23.80±0.17)， (9.53±0.39)， (23.36±0.81) mg/mL and (16.03±0.59) mg/mL， respectively. This study could provide theoretical basis for the development of functional foods related to antioxidant， hypoglycemic， and lipid-lowering effects of Lycium barbarum leaves polysaccharides.

Abstract:Aminopeptidase as a protein hydrolase is widely used in food fermentation and processing. Screening high aminopeptidase-producing strains and studying the enzymatic properties of the flavor enzymes in the strains are important for the development of high-quality soybean product ferments. In this paper， an aminopeptidase-producing strain of Bacillus sp. XYY1 was screened using L-Leu-PNA as substrate in the isolation medium， and identified by morphological observation， physiological and biochemical tests， and 16S rDNA technology， and optimized the enzyme-producing culture conditions by using a one-factor experiment and response surface methodology， and studied the enzymatic properties of the aminopeptidase Lap-Y produced by strain XYY1. The enzyme properties of the aminopeptidase Lap-Y produced by strain XYY1 were investigated. The results showed that strain XYY1 was identified as Bacillus licheniformis， with a starting pH of 6.5， and the content of aminopeptidase was as high as(4，132.75±11.94) U when it was cultured at a constant temperature of 36 ℃ for 35.5 h. The study of the enzymatic properties showed that the relative activity of Lap-Y was highest at the reaction temperature of 55 ℃ with good thermal stability， and that the optimal pH was 9.0， which was good for enzyme stability in the neutral alkaline environment， which was alkaline. The optimum pH value was 9.0， and the enzyme was alkaline in a neutral alkaline environment. Metal ions Mg2+， Fe2+， CO₂+ and Ca2+ could activate the activity of Lap-Y， among which the activation effect of Mg2+ was the most significant for the aminopeptidase Lap-Y when Mg2+ was 1.0 mmol/L， and the activation effect of EDTA， dithiothreitol (DTT) and sodium dodecyl sulphate (SDS) had a stronger inhibitory effect on the activity of Lap-Y. inhibitory effect. The aminopeptidase Lap-Y produced by Bacillus licheniformis XYY1 is suitable for industrialized production and has high application value for food and medical industries.

Abstract:Pea protein isolate is nutritionally rich and widely used in the food industry， but its poor water solubility limits its application scope. To explore the effect of γ-polyglutamic acid (γ-PGA) from microbial sources on the stability of pea protein isolate emulsions， a strain BM202001 with high production of gel-like fermentation products was isolated from traditional homemade soybean sauce using the plate separation method. The strain was identified as Bacillus subtilis through 16S rRNA gene sequencing and sequence homology analysis. The fermentation product was purified and identified as γ-PGA using methods such as ultraviolet spectroscopy， infrared spectroscopy， and amino acid analysis. By measuring the emulsion potential， particle size， and microstructure， it was found that 0.01% γ-PGA and 15 mg/mL pea protein could prepare emulsions with good stability， small and uniform droplets， which could improve the stability of pea protein emulsions. The results provide a reference for broadening the application of γ-PGA and pea protein in food.

Abstract:The interactions between whey protein (WPI) and alginate dialdehyde (ADA) identified by UV-vis spectroscopy， fluorescence spectroscopy and infrared spectroscopy were investigated for effects on the in vitro digestive properties of curcumin in O/W emulsions. The influence of the complexes on the emulsions was studied by droplet size， rheological properties， interfacial adsorption rate， emulsifying activity， turbidity and curcumin release characteristics. The results showed that the interfacial adsorption rate， emulsifying activity， droplet size and turbidity of emulsions driven by dynamic reversible covalent bond-Schiff base bond were improved. Compared with WPI emulsions， WPI-ADA complexes emulsions had higher interfacial adsorption rate and emulsifying activity. When the amount of ADA added was 0.8% of WPI， the emulsions had smaller droplet size (214.5 nm)， lower turbidity (30 061.8)， higher emulsifying activity (295.2 m2/g)， and better emulsifying stability (0.617). Furthermore， the WPI-ADA complexes emulsions， which were more stable in simulate gastrointestinal fluid， promoted the bioavailability of curcumin.

Abstract:As one of the important components of milk， β-casein has high nutritional value. Due to genetic mutations， beta-casein appears in many variant forms， with the most common genotypes currently being A1 and A2. The A1 and A2 variants affect the structure and digestion of the protein due to differences in the single amino acid 67th. In this study， casein was first extracted from A1 and A2 milk by isoelectric point precipitation， and then β-casein was purified and identified by anion exchange chromatography and polyacrylamide gel electrophoresis. Finally， a digestive system was constructed to analyze the properties of A1 and A2 β-casein digestive products. The results showed that the mass concentration and purity of A1 and A2 β-casein were 0.58 mg/mL and 0.64 mg/mL， respectively， and 92.45% and 94.21%， respectively. After simulated gastrointestinal digestion in vitro， the digestibility of A2 β-casein reached 94% at 4.0 h， while that of A1 β-casein reached 93.47% at 5.0 h. With the increase of gastrointestinal digestion time， the particle size of A2 β-casein gradually decreased and was decomposed into substances less than 100 nm， while the particle size of A1 β-casein was still concentrated in the larger range of 100-500 nm. With the progress of digestion， the content of essential amino acids increased gradually， and the degree of hydrolysis increased rapidly during enteric digestion， and the content of β-fold structure decreased， and the disordered structure increased. These results suggested that A2 β-casein may be more conducive to gastrointestinal digestion than A1 β-casein.

Abstract:Maintaining and increasing the stability and bioefficacy of bioactive substances is the key to the development of functional foods. In this study， the pH-driven method was used to prepare pea protein-curcumin nanoparticles (PP-Cur) using pea protein as the embedding material and evaluate their stability and their antioxidant properties， using curcumin retention rate as the evaluation index to study the PP-Cur nanoparticles at different temperatures， light conditions. The stability of PP-Cur nanoparticles under different temperature， light conditions and simulated gastrointestinal conditions was investigated. Its scavenging effect on ABTS free radicals was examined and its total antioxidant capacity was determined by FRAP method. The results showed that the retention rate of curcumin in PP-Cur was significantly higher than that of free curcumin after treatment at 75， 85 and 95 ℃ for 2 h. The retention rate of curcumin in PP-Cur nanoparticles after irradiation under UV light for 3 h was still (89.9±1.95)%， which was significantly higher than that of free curcumin (P<0.05)， and that after simulated digestion in gastrointestinal tract， the retention rate of curcumin in PP-Cur nanoparticles remained (94.38±1.93)%， which was significantly higher than that of free curcumin after gastrointestinal simulated digestion (P<0.05). In addition， it was concluded that PP-Cur nanoparticles with ABTS radical scavenging capacity of 0.119 mol TE/g， DPPH radical scavenging rate of 71.27% and FRAP value of 0.019 mol FeSO4/g， the encapsulation of pea protein could maintain and improve the antioxidant capacity of curcumin. In summary， the results demonstrated that pea protein encapsulated curcumin could effectively improve the stability and antioxidant activity of curcumin and could be used as a delivery matrix for hydrophobic bioactive substances.

Abstract:Previous study found that 20% foxtail millet intake could effectively regulate the gut microbiota composition and increase the colonization of beneficial bacteria in mice in early life. However， excessive foxtail millet feeding (80%) reduced the diversity and homogeneity of intestinal flora and caused a decrease in the abundance of beneficial bacteria. The present study was based on non-targeted metabolomics to analyze the effects of intaking foxtail millet from the early life stage in mice on their fecal metabolic profile. Methods: Non-targeted metabolomics technique was used to detect changes in the fecal metabolic profile of mice after the intake of foxtail millet from the early life stage. Results: When the foxtail millet intake was 20%， compared to the normal group， there were 165 up-regulated， 11 down-regulated， and 467 non-significant changes in fecal metabolites， and these different express metabolites mainly enriched in taurine and hypotaurine metabolism， vitamin B6 metabolism， and neobiotics biosynthesis. When the foxtail millet intake increased to 80%， there were 178 up-regulated， 24 down-regulated， and 441 non-significant alternations in fecal metabolites， and the notably changed metabolism pathway mainly including tryptophan metabolism， vitamin B6 metabolism， and neobiomycin biosynthesis. In addition， both two foxtail millet intake dosages significantly influenced tryptophan metabolism， and the impact value of the tryptophan metabolism pathway greatly increased when the foxtail millet intake changed from 20% to 80%. Conclusion: Consumption of foxtail millet from the early life stage significantly affected fecal metabolite levels and related metabolism pathways in mice， especially the tryptophan metabolism pathway， which played a vital role in the cognitive ability and brain development of body. Thus， excessive foxtail millet supplementation might be detrimental to the organism's healthy development. The study aimed to provide a theoretical basis for improving the mechanism of millet's action in the daily diet， thus supporting data for the development and application of functional foods based on millet.

Abstract:Black soya ACE inhibitory peptide (<3 ku) was prepared， and a hypertensive mouse model was established by using N-nitro-L-arginine methyl ester induction， the mice were divided into control group， hypertensive model group， lisinopril drug group， the BSP low， medium and high dose groups (25， 50， 100 mg/kg) and L-NAME-induced simultaneous gavage BSP high-dose prophylaxis group (L-NAME+BSP). After 4 weeks of continuous gavage， plasma physiological indices were tested and histopathological sections of heart and kidney were observed to investigate the preventive and ameliorative efficacy of BSP and its mechanism of action on hypertensive mice. The middle and high dose groups of BSP had significant antihypertensive effects on hypertensive mice (P＜0.05)， inhibited the rise of ACE， AngⅡ， MCP-1， IL-6 and ET-1 in plasma of mice (P＜0.05)， and significantly increased NO content(P＜0.05)， avoided the disorders of the RAS system of mice， and possessed the efficacy of anti-inflammation and maintenance of the normal function of the vascular cells， and reduced the degree of cardiac damage， fibrosis and renal inflammatory infiltration in mice. Meanwhile， the L-NAME+BSP group delayed the onset of hypertension symptoms in mice， showing a favorable preventive effect. This food-derived black soya ACE inhibitory peptide acts to prevent and ameliorate hypertension in mice by modulating the RAS system.

Abstract:Objective: The study aimed to investigate the alleviating effect and mechanism of Sparassis latifolia polysaccharides (HSCPs) on intestinal barrier damage in lead-exposed mice under cohousing conditions. Methods: Sixty Kunming mice were randomly divided into blank control group (NC)， Pb group (Pb)， HSCPs group， co-housing group between Pb group and HSCPs group (CO Pb+CO HSCPs). After 8 weeks of feeding， the concentrations of red blood cells and hemoglobin were measured by an automatic blood cell analyzer. ICP-MS was used to determine the Pb content in the blood， small intestine， and feces of mice. The content of lipopolysaccharides in serum， and levels of small intestine lysozyme， β-defensin and sIgA were detected by ELISA kit. HE staining and AP-PAS was used to observe the microstructure and the number of goblet cells in the small intestine. qPCR was used to measure the mRNA expression levels of ZO-1， ZO-2， Occludin， Claudin-1， Lyz， and Ang4 in the small intestine； intestinal flora was analyzed by 16S rRNA amplicon sequencing. Endogenous metabolites in serum were explored by metabolomics analysis. Results: Compared with the NC group， the Pb group showed a significant increase in levels of blood Pb， small intestine Pb， fecal Pb and serum lipopolysaccharide， and relative abundance of Desulfovibrio (P < 0.05). The number of red blood cells， hemoglobin concentration， levels of lysozyme， β-defensin and sIgA， mRNA levels of ZO-1， ZO-2， Occludin， Claudin-1， Lyz and Ang4， and the relative abundance of Lachnospiraceae_NK4A136_group， Alloprevotella and Faecalibaculum significantly decreased (P < 0.05). The villi of the small intestine became shorter， broken and partly falling， the space between villi increased， and the goblet cells decreased significantly. Compared with the Pb group， the levels of blood Pb， small intestinal Pb， and the relative abundance of Desulfovibrio significantly decreased (P < 0.05)， while the numbers of red blood cells， hemoglobin concentration and the relative abundance of Faecalibaculum increased significantly in the CO-Pb group (P < 0.05). In addition， the levels of lysozyme， β-defensin and sIgA， and mRNA expression levels of ZO-1， ZO-2， Occludin， Claudin-1， Lyz， and Ang4 were not significantly affected. The villi of the small intestine were short and broken， goblet cell were less. The contents of serum lipopolysaccharides， blood Pb， and small intestinal lead， and the relative abundance of Desulfovibrio in the HSCPs and CO-HSCPs groups significantly decreased (P < 0.05)， while hemoglobin concentration， fecal Pb content， levels of lysozyme， β-defensin， and sIgA content， the expression levels of ZO-1， ZO-2， Occludin， Claudin-1， Lyz， and Ang4， and the relative abundance of Alloprevotella increased significantly (P < 0.05). There were 14 different metabolites in the co-housing mice involved in seven metabolic pathways including glycerol phospholipid pathway， arachidonic acid pathway and linoleic acid pathway. Conclusion: Co-housing could improve the damage of intestinal barrier in Pb-induced mice by transfecting the intestinal flora in the CO-HSCPs mice to the CO-Pb mice， thus increasing the relative abundance of beneficial bacteria in the CO-Pb group and affecting seven metabolic pathways， including glycerol phospholipid pathway， arachidonic acid pathway， linoleic acid pathway， and so on.

Abstract:In order to explore the effects of N-terminal on acid stability of xylanase， this paper cloned and expressed a gene sequence screened from NCBI database， designed response surface test to obtain the best expression conditions， and constructed N-terminal displacement mutants from N-terminal by overlapping extension SORPCR technology， characterized its enzyme activity and related enzymatic properties， and finally applied it to apple juice to explore the clarification effect. The results showed that the optimal xylanase xynP expression condition was 1 884 U/mL by adding 1.5% seed solution into 100 mL TB medium， the induction time was 3.5 h， 200 μL of 500 mmol/L isopropyl β-D-thiogalactoside (IPTG) was added， and the enzyme activity was induced at 20 ℃ for 21.6 h. The optimum temperature of xylanase xynP and mutant xynP-1 was 40 ℃， and the optimum pH value was 4.5 and 5.0， respectively. After different pH value treatments， it was found that the stability of mutant enzyme xynP-1 was slightly weaker than that of wild type xylanase xynP under acid conditions (pH=4.0)， but with the increase of pH (pH 4.5~5.5)， its acid stability was all plateau enzyme xynP， indicating that N-terminal had an impact on the acid stability of xylanase. Metal ions Pb2+ and chemical reagents sodium dodecyl sulfate (SDS) and ethylene diamine tetraacetic acid (EDTA) have a significant inhibitory effect on the activity of the two enzymes. When beechwood xylan was used as substrate， the Km values of the two enzymes were 1.72 mg/mL and 2.57 mg/mL， respectively. The vmax values were 0.93 nmol/(mg·min) and 1.15 nmol/(mg·min)， respectively， indicating that the substrate affinity and catalytic efficiency of the mutant enzyme were lower than those of the original enzyme. Two enzymes were applied to apple juice. After the addition of the original enzyme xynP and the mutant enzyme xynP-1， the light transmittance of the juice increased from 24.33% to 90.03% and 95.70%， respectively， indicating that the addition of xylanase xynP had a significant clarifying effect on apple juice. The results provided a reference for further research on the application of xylanase in fruit juice processing.

Abstract:In this study， a strain Y4 producing ethyl caproate was selected from strong-flavor Baijiu Daqu， and the strain Y4 was identified as Saccharomyces cerevisiae. Strain Y4 has relatively good tolerance. A high yield of ethyl caproate was obtained following the fermentation conditions: Sugar content 10 °Bx， initial pH 7.0， 6% ethanol， 0.04% caproic acid， cultivation temperature 25 ℃ and static fermentation 48 h. Through the simulated fermentation experiment， it was shown that the content of ester compounds such as ethyl hexanoate in the fermentation products of strain Y4 was relatively the highest. The research showed that strain Y4 was a strain with excellent characteristics， which could effectively increase the content of ethyl caproate in Baijiu.

Abstract:The poor edible quality of whole wheat steamed bread has been the primary limiting factor for their wider application. Existing studies have shown that traditional starter culture can improve the edible quality of white steamed bread， but there are few studies on the effect of traditional starter culture on the edible quality of whole wheat steamed bread. In this paper， 21 traditional starter culture from different regions were selected to investigate their effects on the edible quality of whole wheat steamed bread in terms of color， textural characteristics， specific volume and sensory evaluation， using commercial yeast whole wheat steamed bread as a control. The traditional starter culture suitable for the improvement of edible quality of whole wheat steamed bread were preferentially selected by principal component analysis. The results showed that all the 15 fermentation preparations improved the edible quality of whole wheat steamed bread compared with the common whole wheat steamed bread. Among them， the hardness of whole wheat steamed bread decreased by 5.03%-40.76%， the specific volume could be improved by 0.66%-41.72%， and the overall sensory evaluation score improved by 0.29%-9.08% in the textural characteristics. Among the principal component analysis， the indices that mainly showed positive correlation with the top three principal component factors were cohesiveness， reversibility， chewiness and elasticity and color and specific volume of whole wheat steamed bread， and the top three ranked in order of comprehensive edible quality were the traditional fermented preparation whole wheat steamed bread numbered 15， 6 and 18. The results of this study provide data support for the improvement of edible quality of whole wheat steamed bread by traditional starter culture and help to promote the application of whole wheat steamed bread.

Abstract:This work investigated the effects of fermentation time， inoculation amount， and strain ratio on the taste and nutritional characteristics of cooked brown rice after fermentation with the complex strain (Lactobacillus plantarum and Saccharomyces castellum). Results showed that the optimum parameters for brown rice fermentation were as follows: The fermentation time was 6 h， inoculation amount was 1.0% and the ratio of Lactobacillus plantarum to Saccharomyces castellans was 2∶1. Compared with raw brown rice， the setback value of brown rice was significantly decreased under this fermentation condition， and the volume expansion rate and water absorption rate increased from 131.67% and 194.27% to 186.10% and 253.17%， respectively. Meanwhile， the brightness of the prepared brown rice was higher (L* was 64.23)， and the hardness was reduced from 1 388.05 g to 407.28 g， and increased sensory quality (from 71.88 to 78.88). Moreover， the content of reducing sugar， γ-aminobutyric acid (GABA) and soluble protein of cooked brown rice increased obviously. These results indicated that the fermentation of composite strains could improve the taste and nutritional characteristics of cooked brown rice， which could provide a certain reference for the development of cooked brown rice.

Abstract:In order to explore the effects of different simulated oral processing methods and different α-amylase additions on the bolus characteristics and in vitro starch digestion， ready-to-eat whole wheat crispbreads were used as an experiment. The effects of cutting and mixed artificial saliva (CA)， cutting with blending and mixed artificial saliva (CBA)， cutting with grinding and mixed artificial saliva (CGA) and different α-amylase contents in artificial saliva on the bolus characteristics and in vitro starch digestibility of whole wheat crispbreads after chewing were studied. Using human oral chewing method (HM) as a control， principal component analysis was applied to screen for in vitro simulated starch digestion suitable for crisp products. The results showed that the hardness (17.44~32.99 N)， adhesiveness (122.29~317.30 g·s) of the bolus of CBA and CGA treatments were lower than HM treatment. While the particle size of the bolus was higher in SSF group (105.08~273.89 μm， 290.02~801.69 μm) than human chewing (315.19 μm， 764.08 μm)， but the particle size tended to decrease with the increase of α-amylase addition. The final starch hydrolysis rates of CBA， CGA and HM treatments were significantly higher than CA treatment， with CBA treatment fitting more closely to HM treatment. Both mechanical damage and salivary α-amylase content affected bolus characteristics and the starch digestion kinetics. In addition， the SSFH group of CBA treatment was shown to be used as a pretreatment in simulating starch digestion in crisp foods based on principal component analysis.

Abstract:The rice bran (0%， 3%， 6%， 9%， 12% and 15%) treated by atmospheric pressure cooking were added into indica rice flour， and the effects of rice bran addition on the properties of indica rice flour and the quality of rice cake was investigated. The results showed that atmospheric pressure cooking of rice bran could increase the solubility of reconstituted powder， and the solubility increased with the increase of rice bran addition amount. When the rice bran addition was 15%， the solubility of reconstituted powder increased by 70.7% compared with the control group. The swelling potential of reconstituted powder was reduced by atmospheric pressure cooked rice bran. In addition， the fluidity of the reconstituted paste was weakened， the shear resistance was improved， and the gelling property was enhanced. The elasticity and viscosity of the recombinant powder gel system were enhanced， and the freeze-thaw water extraction rate was reduced， which indicated that rice bran with atmospheric pressure cooking treatment could effectively regulate the gel properties of rice starch based food. The index test results of rice cake also showed that the specific volume of rice cake was significantly increased by the addition of atmospheric pressure cooked rice bran， and the specific volume of rice cake increased with the increase of rice bran addition amount. The specific volume of rice cake containing 15% rice bran increased by 26.5% compared with white rice cake. The texture characteristics and pore structure of rice cake were also significantly improved by the addition of atmospheric pressure cooked rice bran. When the addition amount of rice bran was less than 9%， the sense of rice cake could be accepted by consumers. The results indicated that rice bran prepared from atmospheric pressure cooking treatment could improve the quality of rice cake and was a potential food raw material.

Abstract:In order to study the effect of different fermentation methods on the quality and volatile substances of mussel cooking liquor. The mussel cooking liquor was fermented by lactic acid bacteria alone， yeast alone and lactic acid bacteria/yeast mixture. Effects of different fermentation methods on the qualities of mussel cooking liquor were studied through the changes of pH value， glucose， total soluble nitrogen (TSN)， amino acid nitrogen (AAN)， free amino acids (FAA) and organic acids (citric acid， malic acid， lactic acid and succinic acid) content. Moreover， the changes of volatile substances in mussel cooking liquor after fermentation were analyzed by gas chromatography mass spectrometry (GC-MS)， and the effects of different fermentation methods on the volatile substances of mussel cooking liquor were studied. The results showed that the mixed fermentation group had the lowest pH (4.6)， glucose content (6.36 mg/mL) and trimethylamine content (22.15 μg/mL)， and the highest TSN content (18.68 μg/mL)， FAA content (24.21 mg/mL) and AAN content (77.39 mg/mL)， indicating that the mixed fermentation had the best quality. In addition， mixed fermentation could produce more alcohols and esters， and reduce unpleasant flavor substances such as unsaturated aldehydes and amines in the sample. Lactic acid bacteria/yeast mixed fermentation could give samples better quality and flavor， suitable for the fermentation of mussel cooking liquid. This paper aimed to study the effects of different fermentation methods on the quality and volatile substances of mussel cooking liquor， and provide reference for the valorization of mussel cooking liquor.

Abstract:Radish is rich in nutrients and has a variety of physiological functions. However， the strong spicy flavor and taste of radish affected the quality of its processed products. It is necessary to improve the flavor of radish by blanching and other pretreatments， so as to further expand its application. In this study， white radish was used as the raw material to investigate the influence of different pretreatment method (hot water blanching， microwave blanching and steam blanching) on the nutrition and flavor of radish juice. The results showed that， the contents of nutrient substance， such as， soluble protein and ascorbic acid of juice all decreased somewhat， while the flavor markedly improved after the three blanching pretreatments. The content of ester substances increased and the contents of isothiocyanates， alcohols and ethers decreased significantly (P＜0.05). Especially for the characteristic flavor substance， such as， methyl mercaptan， dimethyl disulfide， dibutyl ether and allyl methyl disulfide， which contents significantly decreased (P＜0.05). The better condition for each pretreatment was: 90 ℃ hot water blanching for 6 min， 700 W microwave blanching for 4 min and atmospheric steam blanching for 6 min， respectively. The retention rates of water-soluble protein and ascorbic acid were higher after microwave blanching， which retained 77.15% and 79.24%， respectively. However， the retention rate of isothiocyanate by microwave blanching was also higher， which resulted in the measurable spicy and the pungent taste of juice and the lower sensory score. After steam blanching， the content of isothiocyanate compounds of radish juice was relatively lower， and the contents of butyl propionate， butyl butyrate and pineapple ester were effectively increased， which improved the flavor of radish juice. In addition， the retention rate of nutrients of radish juice was higher and the sensory synthesis score was the best after steam blanching， which showed that the steam blanching was the more suitable pretreatment method. This study could provide some experimental reference for the development of white radish products.

Abstract:In order to improve the product quality of fried wheat chips and alleviat the problems of high frying temperature， poor flavor and nutrition of products in the usual processing process， the yellow tea was added to the wheat chips after ultra-fine grinding， and the product was processed by low temperature vacuum frying. Meanwhile， the processing parameters were optimized， and the physical and chemical properties and antioxidant activities of the products were explored. The effect of yellow tea powder on the flavor quality of wheat crisp was evaluated by GC-IMS. The results showed that the optimum parameters were as follows: The content of yellow tea powder was 3% (by wheat flour quality)， the grain size of yellow tea powder was 150 mesh， the frying time was 35 min， and the frying temperature was 90 ℃. Under this optimized conditions， the specific volume and hardness of yellow tea flavor chips were 5.17 g/mL and 289.47 g， which were higher than those without yellow tea powder， and showed better antioxidant activity， the scavenging rate of DPPH free radical was 88.46%， and the scavenging rate of ABTS cationic free radical was 92.49%. The results of GC-IMS showed that the content of aldehydes in yellow tea chips was higher. In conclusion， the application of yellow tea powder in wheat chips processing could enrich the variety and quality of fried wheat products.

Abstract:In order to improve the quality and taste of freshwater fish surimi products， fourier transform infrared spectroscopy， low field nuclear magnetic resonance and scanning electron microscopy were used to explore the effects of different levels of Aronia melanocarpa polyphenols on surimi gel properties， and the water retention， whole texture， chemical force， total sulfhydryl content， relaxation time， protein secondary structure and scanning electron microscopy of surimi gel were measured. The results showed that when the content of polyphenols was 0.375%， surimi gel had the best water holding capacity， gel properties， elasticity， and chewability. In the relaxation spectrum， the peak of the group with 0.375% of polyphenols was the highest and shifted to the left the most， indicating that the surimi gel with 0.375% of polyphenols had the most difficult flowing water and promoted structural stability. In the scanning electron microscope， the structure of surimi gel became denser with the increase of polyphenol addition. The surimi gel in 0.375% group was the densest with smooth surface. When the amount of polyphenol added increased to 0.500%， the structure of surimi gel became loose again. The disulfide bond in the chemical force gradually increased and was inversely proportional to the total sulfhydryl content. The disulfide bond hydrophobic interaction played an important role in surimi gel. Fourier transform infrared spectroscopy indicated that alpha helical structure gradually transformed into a beta folded structure， and the area of the beta folded peak gradually increased indicating that the protein secondary structure of the protein was more regular and orderly， which promoted the enhancement of surimi gel properties. In SDS-PAGE， myosin heavy chain (MHC) and actin (AC) of surimi gel gradually weakened， indicating that a stable surimi gel network structure was formed.

Abstract:Objective: This study aimed to investigate the effect of partial substitution of complex phosphate by alkaline electrolyzed water on the quality of Dosidious gigas. Methods: The effects of soaking gain rate， freezing loss rate， thawing loss rate， cooking loss rate， water holding capacity， pH value， hardness， color difference， tissue structure and sensory evaluation of Dosidious gigas were measured within 0， 30， 60， 90 and 120 days. Results: The sensory scores of alkaline electrolyzed water and complex phosphate solution treatment (MIX) were better. The soaking weight gain rates in the MIX treatment group were (7.53±0.31)%， which increased by about 1.18%， 2.90% and 3.97% compared with alkaline electrolyzed water treatment (AEW)， complex phosphate treatment (CPH) and water treatment (WAT). In terms of total chromatic aberration， the AEW group outperformed the CPH group and the MIX group (P<0.05). In terms of tissue structure， after freezing， the tissue texture of squid in AEW group and MIX group was clear， evenly arranged and compact， while the muscle fibers of WAT group and blank (NOT) group were obviously scattered， and the degree of damage was more serious. There was no significant difference between freezing loss and thaw loss (AEW， CPH， MIX)， and the soaking weight gain rate of the MIX group [(7.53±0.31)%] was significantly higher than that of AEW [(6.35±0.24)%] alone and CPH [(4.63±0.30)%] alone， while the hardness was significantly reduced. The cooking loss rate of the AEW group and the MIX group was significantly lower than that of CPH alone. Conclusion: The use of AEW or MIX can be used to improve the quality of Dosidious gigas and provide feasible technical conditions for future storage and preservation methods of Dosidious gigas.

Abstract:Fermentation， contributing to convert polyphenol glycosides to their respective aglycones， could improve their bioavailability as well as flavor of the product. This study performed Lactobacillus plantarum YHG1-155 fermentation of sea buckthorn juice (SBJ) to analysis the changes of its antioxidant activity in vitro and explore the biotransformation process of polyphenols in the fermentation. The results showed that L. plantarum fermentation increased the viable cell count， free phenolic content， total phenolic content， and antioxidant activity of SBJ. In total， 116 significantly different metabolites were identified in L.plantarum fermented SBJ using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Among them， 67 (53 upregulated and 14 downregulated)， 64 (32 upregulated and 32 downregulated)， and 116 (74 upregulated and 42 downregulated) kinds of differential metabolites were identified between the groups Y2 and Y4， Y4 and Y8， and Y2 and Y8. Furthermore， KEGG pathway enrichment analysis showed that 18 kinds of differential metabolites between Y4 and Y2 and 13 kinds of differential metabolites between Y8 and Y4 were mainly involved in three pathways， namely the biosynthesis of secondary metabolites， flavonoid， flavone and flavonol biosynthesis pathways. Among them， the biosynthesis pathway of secondary metabolites was an important pathway for polyphenol biotransformation， and polyphenol glycosides might mainly be converted to their respective aglycones through this pathway. Our findings revealed the biotransformation of polyphenol glycosides of SBJ by L. plantarum YHG1-155 fermentation， providing a theoretical reference for the deep processing of hippophae rhamnoides.

Abstract:In the fermentation process of strong aromatic Chinese spirit， the different levels of fermented grains was uneven， the bottom fermented grains was affected by Haungshui immersion fermentation， and the bacterial community structure from Huangshui had a great contribution to organic acid metabolism. To identify the succession and potential function of bacterial community structure in Huangshui during the fermentation process， high-throughput sequencing was borrowed to reveal the succession of bacterial community structure， the relationship between bacterial community structure and the content of organic acid content was analyzed in different fermentation stages. PICRUSt analyse was used to predict the potential function of bacterial community in Huangshui. The results showed that the changes of bacterial community structure in Huangshui could be divided into two stages during the fermentation process， 5-20 d and 20-60 d， respectively. Lactobacillus was the absolute dominant bacterial genus in Huangshui， with a relative abundance of more than 97% at 5-10 d. The relative abundance of Caproiciproducensz， Clostridium， Petrimonas， Hydrogenispora， Proteiniphilum increased significantly in late fermentation stages. PICRUSt analysis showed that Huangshui bacterial communities may mainly participate in glycolytic pathways during fermentation. The relative abundance of functional enzymes related to lactic acid， acetic acid， caproic acid， and butyric acid was relatively high. The results showed that the bacterial community in Huangshui has great potential for aroma-producing and an important impact on the fermentation of strong aromatic Chinese spirit fermented grains.

Abstract:Using the Lactobacillus plantarum 01 (Lp01) and Lactobacillus fermentatum 01(Lf01) as the fermentation strain of pickled potherb mustard， the effects of different lactic acid bacteria inoculation conditions (Lp01 single bacteria， Lf01 single bacteria and Lp01 complex Lf01) on bacterial community structure and volatile flavor compounds of pickled potherb mustard were studied by 16S rDNA sequencing and headspace solid phase microextraction combined with GC. The results showed that the group inoculated with Lp01 combined with Lf01 started quickly， the pH dropped to 4.05 on day5， and the sensory synthesis score of pickled potherb mustard was significantly higher than that of other groups (85.40). Different lactic acid bacteria inoculation had significant effects on the bacterial community structure changes before and after fermentation. The Lf01 single bacteria inoculation group and its complex Lp01 inoculation group immediately multiplied lactic acid bacteria after fermentation for 1 day， and the abundance was significantly higher than other groups， which enriched the microbial diversity. In addition， different lactic acid bacteria inoculation had no significant effect on the total amount of volatile flavor compounds， but the contents of different types of compounds were significantly different. The contents of esters and alcohols in Lf01 single bacteria inoculation group and its compound Lp01 inoculation group were higher than those in Lp01 single bacteria inoculation group and natural fermentation group. ROAV showed that ethyl 2-methylbutyrate， β-lonone， damascenone， 2-methoxy-3-sec-butyl pyrazine and dimethyl trisulfide were the key flavor substances in pickled potherb mustard. Spearman correlation analysis showed that dominant bacteria were positively correlated with many key flavor substances. In conclusion， the single Lf01 inoculation and its complex Lp01 inoculation could improve the bacterial community structure in the early fermentation stage， and many key flavor substances were correlated with the dominant strains.

Abstract:Fresh fish are susceptible to degradation and oxidation by endogenous enzymes after death， such as degradation of adenosine triphosphate (ATP) and protein denaturation， resulting in reducing quality and flavor characteristics. To delay the degradation of IMP and to preserve the flavor properties of fish， rosmarinic acid (RA) and epicatechin (EC) were used to inhibit ACP activity. The flavor characteristic was investigated mainly by electronic nose and gas chromatography-mass spectrometry (GC-MS) in sea bass. The results showed that nucleotides content and K value in sea bass treated with RA and EC decreased significantly， and the IMP content increased from 0.61 μg/100 g to 1.70 μg/100 g and 1.39 μg/100 g， respectively， when the flavor to bitterness ratio was the highest， and the degradation of IMP started after 2 d， and the degradation rate coefficients were 0.079 and 0.037， respectively， and both RA and EC could effectively retard the degradation of IMP. A total of 25 volatile substances were detected by GC-MS in the pre-storage period， including 3 aldehydes， 4 alcohols， 2 esters， 3 ethers， 9 amines， and 4 acids and other alkanes. In the middle of storage， 39 volatile substances were detected， including 2 aldehydes， 1 ketone， 6 alcohols， 6 esters， 4 ethers， 10 amines， 10 acids， and other alkanes. 44 volatile substances were detected， including 2 aldehydes， 7 alcohols， 3 esters， 3 ethers， 11 amine substances， and 18 acids and other alkanes in the late storage period. The volatile odors of sea bass treated with RA and EC were more significantly different from that of the control. RA and EC could also slowdown the water loss in the muscle of sea bass.

Abstract:In order to explore the variation rule of volatile flavor compounds in green pepper sauce during the boiling process， the types and contents of volatile flavor compounds were analyzed by gas chromatography-mass spectrometry， and the differences of volatile flavor compounds at different stages were identified by principal component analysis and hierarchical cluster analysis. Finally， orthogonal partial least square discriminant analysis combined with statistical analysis of heat map was used to determine the characteristic flavor substances which had important influence on the flavor difference of green pepper sauce in the cooking process. The results showed that 54， 52， 57， 53 and 71 volatile flavor compounds were detected in fresh green pepper and green pepper sauce at 50， 60， 80 ℃ and 100 ℃， respectively. The results of principal component analysis and cluster analysis showed that the increase of final cooking temperature had positive significance on the formation of volatile flavor characteristics of green chili sauce. Heat map was drawn and cluster analysis showed that with the increase of final temperature， the volatile flavor characteristics of green pepper sauce in each stage were significantly richer than those of fresh green pepper， especially the contents of alcohols， ketones and aldehydes increased significantly(P < 0.05). Linalol， 4-terpenenol， 1-amyl alcohol， basil， sabinene， 1-octene-3-one could be used as the key difference compounds to distinguish other stages of cooking temperature 100 ℃. The results could provide theoretical basis for the subsequent research on the formation mechanism and flavor quality control of green pepper sauce.

Abstract:Objective: To analyze the differences of goji flavonoids from different origins from the perspective of proteomics. Methods: The protein differences of goji berries from different origins were explored by tandem mass tag (TMT) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology in Ningxia， Qinghai and Gansu. Results: A total of 716 differential expressed proteins(DEPs)， and a total of four metabolic pathways associated with flavonoids were found in the KEGG pathway， and the phenylpropane biosynthesis pathway was significantly enriched in all three comparison groups (P < 0.05)， indicating that the phenylpropane biosynthesis pathway might make a greater contribution to the synthesis of goji flavonoids. Further screening of 24 key differentially expressed proteins related to flavonoid synthesis， it was found that phenylalanine ammonia-lyase (PAL)， cinnamic acid 4-hydroxylase (C4H)， chalcone isomerase(CHI)， chalcone synthase (CHS)， etc. might be important DEPs for the biosynthesis of flavonoids in Ningxia， Qinghai and Gansu. Conclusion: The differential proteins related to the biosynthesis of goji flavonoids were identified from the protein level， and the anabolic pathway of goji flavonoids was preliminarily speculated， which laid a foundation for exploring the differences in the biosynthesis of goji flavonoids in different origins.

Abstract:The traditional TVB-N method for evaluation of freshness has defects such as complicate process， delay result and other defects. Therefore， it is extremely significant to develop a rapid， non-destructive and real-time approach for detecting the freshness of salmon. In this paper， a benzopyran derivative HDX was constructed through condensation reaction. HDX could sensitively recognize 10 amines， moreover， within the EtOH/H2O (volume ratio 1∶9) system， obvious color and fluorescence changes occurred within 5 s. The detection limit of HDX for spermine was 0.75 μmol/L. By utilizing HDX， fluorescence imaging of spermine and putrescine could be achieved in living cells. The sensing label HDXIL was prepared by loading HDX onto filter paper， and HDXIL could respond for fish freshness by colorimetric and fluorescence dual channels. This sensor label HDXIL showed significant recognition effect on different grades of salmon meat (distinguished by three colors). Its evaluation results were highly accurate and trustworthy， and it was suitable for real-time and on-site monitoring of the freshness of salmon meat.

Abstract:Peanut is one of the eight kinds of allergens， which can cause a variety of allergic reactions in the human body， and even endanger the lives of peanut allergy patients. Currently， the most effective treatment for peanut allergy is to avoid contact with products containing peanut matrix. Plant polyphenols may reduce the sensitization of peanut protein from two aspects: On the one hand， plant polyphenols can directly interfere with the mechanism of peanut allergy by affecting related signal transduction and gene expression in the process of allergic reaction. On the other hand， the IgE binding epitopes of peanut sensitized proteins can be masked or destroyed by the interaction of plant polyphenols with peanut proteins， so that they cannot be recognized by IgE antibodies. At present， the treatment of peanut protein with plant polyphenols is considered to be an effective and feasible strategy to reduce its sensitization. In this paper， the types and sequence length of peanut sensitizing proteins and the sensitization mechanism of peanut proteins were reviewed， the factors affecting peanut protein sensitization were summarized， and two desensitization mechanisms of plant polyphenols were introduced， providing theoretical reference for reducing peanut protein sensitization by plant polyphenols.

Abstract:Celiac disease is an autoimmune enteropathy induced by dietary gluten in genetically susceptible individuals. Gluten is a type of protein complex widely present in the daily diet， whose proteins are not easily absorbed by the digestive tract， thus activating abnormal innate and adaptive immune responses in the gut of genetically susceptible individuals. Recent research supports that intestinal flora dysbiosis is one of the key factors in the development and progression of celiac disease. This article reviewed the pathogenesis， pathology and treatment strategies of celiac disease， aiming to reveal the role of intestinal flora in celiac disease and provide theoretical reference for clinical prevention and treatment of celiac disease.

Abstract:Human milk oligosaccharides are one of the most critical components of breast milk， with valuable functions such as regulating immunity and promoting brain development， and they have significant commercial potential in infant nutrition and medical therapy. The rapidly growing market demand has put new requirements on their supply， and new production methods of human milk oligosaccharides have emerged. The biosynthetic routes have broken traditional barriers and brought new opportunities and challenges to the industry. This review first introduced the basic properties and industrial application of human milk oligosaccharides， then focused on the research advances in the biosynthesis pathway of human milk oligosaccharides and discussed in depth the key technologies， advantages， and pain points of the chemoenzymatic method and microbial cell factory in their synthesis. Finally， the future outlook of human milk oligosaccharides had been prospected.

Abstract:Mammals induce an innate aversive response by sensing H+ dissociated from sour substances to prevent the ingestion of harmful substances. Several sour taste candidate receptors have been ruled out over the past decades， only in recent years Otopetrin1 (Otop1) has been identified as a sour taste receptor， and sour taste neurotransmitters and sensing pathways have been discovered. This paper reviewd three sour taste perception pathways， detailing the structure of the Otop1 sour taste receptor and its function. The Otop1 signaling pathway was explained with emphasis on the H+ inward flow blocking the inwardly-rectifying potassium channel 2.1 (Kir2.1) to enhance cell depolarization， the release of the activating sour taste neurotransmitter serotonin (5-hydroxytryptamine， 5-HT)， and the pathway of sour taste information from the periphery to the centre via. The effects of specific diet， individual differences， transmembrane state perception， and disease on sour taste perception were discussed. The aim was to understand the causes of changes in personal sour taste perception， to provide a theoretical reference for the development of sour foods for different populations and looked forward to future research on unknown signaling pathways in sour taste transmission.

Abstract:Furanocoumarins are natural compounds distributed in fruits and vegetables such as citrus， celery， and radish. They have attracted the attention of researchers because of their special biological activity and phototoxicity. Human ingestion or exposure to furanocoumarins along with UVA radiation can cause dermatitis and even cancer in the human body， but it can also be used to treat skin diseases. This article systematically explained the chemical structure of furanocoumarins， distribution in fruits and vegetables， dietary intake， phototoxicity and its application in disease treatment， in order to provide theoretical reference for research on the photoactivity of fruits and vegetables.

Abstract:Bioactive components are of great interest to researchers because of their excellent efficacy in health regulation and disease prevention. However， their bioavailability is low and easily affected by environmental conditions， limiting their application scope. The nano-delivery system has become one of the effective ways to embed bioactive components and improve their bioavailability. The nano-delivery system based on whey protein stands out among many nano-delivery systems because of its excellent functional characteristics， the advantages of loading bioactive components and achieving controlled release to improve their bioavailability and stability. This paper reviewed the composition and functional properties of whey protein， summarized the types of whey protein-based nano-delivery systems， including nano-emulsion， multi-emulsion， emulsion gels， self-assembly， and nanoparticles， and summarized the application status of these methods for delivering bioactive components. At the same time， the application status of relevant delivery systems was summarized， and the existing problems and future research directions in this research field were summarized， which provided a reference for subsequent research to improve the stability and loading rate of whey protein carriers and expand their application fields.

Abstract:Polysaccharides are the main components in food and have a wide range of physiological functions. However， some natural polysaccharides are limited in application due to large molecular weight， poor solubility and unsatisfactory function. Fermentation is a traditional processing method to improve the nutritional quality of food， besides， it is a promising biological modification method， which has been more and more widely used in the structural modification of natural products. During the fermentation process， microorganisms secrete carbohydrate active enzymes to degrade and convert polysaccharides to lower molecular weight polysaccharides， oligosaccharides and monosaccharides， and also change their biological activities. This review focused on the dominant bacteria to polysaccharides utilization in fermented foods and their effects on the content， structure and bioactivities of polysaccharides in raw materials， thus giving an insight into green transformation of polysaccharides and providing ideas for future research in related fields.

Abstract:Dysphagia is a dietary disorder caused by the decline of physiological function， and patients have difficulty swallowing thick liquids and foods with greater hardness like normal people， resulting in health problems such as malnutrition. The research and development of dysphagia food can meet the dietary needs of people with decreased chewing and/or swallowing function. Hydrophilic colloid can be used as a thickening agent and texture modifier in dysphagia food. In addition， the combination of hydrophilic colloid and 3D printing provides more possibilities for the design of dysphagia food. In this paper， the physical properties and technical requirements， the improvement mechanism of hydrophilic colloid on dysphagia food， and the application of hydrophilic colloid in YISHI food in recent years were reviewed in order to provide some help for the subsequent research and development of the dysphagia food.

Abstract:Saponins are a class of glycosides in which aglycones are triterpenoids or spiral steranes. They are regarded as common active ingredients and have important nutritional value， such as bacteriostasis， anti-tumor， hypoglycemic， and regulation of intestinal flora. At the same time， saponins also have many limitations， such as hemolysis， organ toxicity， low bioavailability， strong tissue irritation， which greatly limits the application of saponins in functional foods. At present， some methods are used to improve these problems. This paper reviewed the research progress of common plant-derived saponins in recent years. Based on their classification and structural analysis， this paper introduced their physiological activities， limitations of clinical application and solutions， aiming to provide theoretical basis for the application of plant-derived saponins in disease prevention and treatment.

Abstract:Dairy products， as a food with almost perfect nutritional value， are indispensable to humans. However， the high content of fat in dairy products may have adverse effects on human health. With the increasing awareness of health， people have started to consume low-fat or low-fat foods as a way of life. Therefore， fat substitutes， which can maintain the delicious taste of dairy products and related functional properties such as texture and rheological properties， and can reduce fat content， have emerged， which has a very broad market prospect. The classification and preparation of fat substitutes， the research progress of their role and application in the field of dairy products were reviewed， which provided theoretical support for the research of new dairy fat substitutes. And the research direction and prospect of fat substitutes in the dairy market were discussed.

Abstract:Freezing maintains food quality and extends shelf life by inhibiting microbial growth and changes in physical and chemical properties. Traditional freezing treatment， although it has the effect of prolonging the shelf life of food， but still inevitably cause undesirable quality changes in food. The formation of ice crystals and denaturation of proteins are the main causes of deterioration in food quality. In recent years， in order to alleviate the decline in quality of food in the process of frozen storage， there is research on new technologies to inhibit the growth of ice crystals， add cryoprotectants to enhance the role of the various food components and change the environmental conditions of food to delay the quality of food in the process of frozen storage changes. This paper pinned the effect of freezing on moisture， protein and fat fractions during storage of protein-based foods. Focusing on mechanical damage caused by freezing-induced ice crystal formation and recrystallisation， and the effects of protein freeze denaturation and other changes in proteins on their functional properties. The effects and interactions of protein and fat oxidation on food quality and the impact on food quality of altered protein-protein， protein-lipid and protein-sugar interactions were given special attention. It also provided an overview of freezing technology and cryoprotectants and provided theoretical support for the development of new freezing techniques and technologies.

Abstract:To bolster academic research and foster industrial innovation in the field of global food safety and health， while supporting government decision-making and addressing industry priorities， the Chinese Institute of Food Science and Technology (CIFST)， in collaboration with the International Union of Food Science and Technology (IUFoST)， had jointly launched an initiative on global research hotspots in food safety and health. Drawing on current research and the insights of leading experts from related fields worldwide， the latest research hotspots and trends in global food safety and health had been distilled and formulated. The outcomes will play a crucial role in promoting interdisciplinary collaboration， forecasting future research trends in global food safety and health， and seizing the initiative in technological and developmental innovation in the food sector， thereby providing valuable guidance for leading industrial innovation and growth.