Abstract:Food safety is a critical national concern， essential for promoting robust socio-economic development and protecting human health. As the food industry undergoes rapid expansion and globalization intensifies at an unprecedented pace， the issue of food safety has become an increasingly pressing concern. It has become a major issue that requires an urgent global response. With rapid advancements in science and technology， emerging technologies， notably artificial intelligence (AI)， are increasingly being utilized in the field of food safety， showing substantial potential and significant value. With its powerful data processing capability， accurate pattern recognition and predictive analytics， AI provides strong technical support for the prediction and supervision of food safety issues， effectively improving the efficiency and accuracy of food safety management. Artificial intelligence has facilitated the detection of food pathogens， assessment of freshness， prediction of shelf life， identification of food adulteration， and issuance of food safety alerts. Therefore， this review summarizes the research progress of AI in the field of food safety. Firstly， the study primarily introduces the applications of AI in the detection of food safety risk factors， with a particular focus on the detection of microbial contamination in food. Furthermore， summarizes the applications of AI in the evaluation of food quality and safety， including the identification of food adulteration， the prediction of shelf life and the verification of food label authenticity. Additionally， the application of AI in food safety supervision is elaborated， including the development of an early warning system for food safety and the enhancement of food safety traceability technology through intelligent solutions. Finally， the current study discusses the current limitations of AI applications in the field of food safety and envisions future prospects， aiming to provide support for safeguarding public health and promoting the healthy development of the food industry.

Abstract:Food safety is crucial to global public health. In recent years， new hazards have arisen from changing consumption patterns and novel food sources， alongside traditional threats like foodborne pathogens， mycotoxins， and chemical residues. The rapid advancement of artificial intelligence (AI) technology provides innovative solutions to address these challenges. This article summarizes the applications of AI technology in the proactive prevention and control of food safety， including risk warning， toxicity prediction， rapid detection， and efficient prevention and control strategies. AI integrates meteorological statistics， mechanistic models， and machine learning algorithms to achieve early warning of risk factors such as foodborne pathogens， mycotoxins， pesticides， and heavy metals in food. AI also assists traditional toxicological models and incorporates transfer learning to facilitate toxicity prediction and risk assessment of new hazards. Besides rapid detection for food safety and quality， AI also plays a role in high-throughput design and screening of both traditional and novel recognition elements such as antibodies and aptamers. In the realm of proactive prevention and control， AI combines with bioinformatics， molecular biology， and synthetic biology to effectively predict and screen antimicrobial peptides， degrading enzymes， and bacteriophages， revealing their antimicrobial and degradation mechanisms. However， the application of AI in food safety still faces challenges such as insufficient data sharing， standardization， and handling of multimodal data. With the advancements of technology and evolvement of data sharing mechanisms， AI is expected to play an increasingly important role in ensuring global food safety and addressing complex and evolving food safety issues.

Abstract:In recent years， fruit freshness detection based on machine vision and deep learning has become one of the mainstream methods. This study explores the application of deep learning technologies， particularly convolutional neural networks(CNNs)， in feature extraction for fruit freshness identification. This paper introduces the CBAM (Convolutional block attention module) attention mechanism module into the ResNet34 (34-layer residual network) backbone network to achieve fruit freshness detection. Class activation mapping(CAM) techniques are employed to visualize the heatmaps of pixels that reflect the critical features in the images. On a public fruit dataset， the classification accuracy of the ResNet34 network before and after introducing the attention mechanism is 96.80% and 99.71%， respectively. The CAM heatmaps show that the attention model can more accurately capture the regions of interest in the fruit images， indicating that the proposed model improves the feature extraction capability of deep learning， not only enhancing the model's generalization ability but also increasing its interpretability.

Abstract:In order to characterize the biosynthetic pathway of 2，3，5，6-Tetramethylpyrazine (TTMP) in Bacillus spp.， the whole-genome information of Bacillus velezensis CS1.13 screened from high-salt liquid-state moromi was annotated， and its TTMP biosynthetic pathway and regulatory characteristics were studied in combination with solid-state fermentation. The results show that CS1.13 is rich in genes involved in amino acid metabolism and transport， carbohydrate metabolism and transport and coding glycoside hydrolase by COG， GO and carbohydrate active enzyme annotations. And KEGG annotation reveals that CS1.13 has a complete metabolic pathway of Acetoin， a key substrate of TTMP. The solid-state fermentation process revealed that the reducing sugar and amino acid nitrogen contents increased by 53.63 g/kg and 8.28 g/kg， respectively， and TTMP accumulated 159.86 mg/kg at 72 h of fermentation， which proved that CS1.13 has good carbon and nitrogen metabolism ability and TTMP synthesis potential. According to the TTMP synthesis pathway， the key substances such as threonine， acetic acid， pyruvic acid and 2，3-butanediol were selected to study the regulation of TTMP biosynthesis. The maximum accumulation of TTMP was achieved when threonine 2 mg/g， acetic acid 0.2 mg/g， pyruvic acid 0.2 mg/g and 2，3-butanediol 0.8 mg/g were added respectively， which increased 32.82%， 10.30%， 222.46% and 160.93% compared with the control sample. The accumulation of TTMP decreased as the content of the above additive increased. In addition to the amino donor threonine， the accumulation of the three pyrazines (TTMP， 2，5-dimethylpyrazine and 2，3，5-trimethylpyrazine) was favored by the lower concentrations of carbon skeleton donors acetate， pyruvic acid or 2，3-butanediol， and the accumulation of butanedione family compounds was favored by excessive carbon skeleton donors instead， suggesting that the synthesis of TTMP was regulated by the amino donor and carbon skeleton donor. The analysis of TTMP biosynthesis relation genes combined with fermentation regulation explored a feasible and effective way for Bacillus velezensis CS1.13 to accumulate TTMP efficiently， which will also lay the foundation for its application in rapid aroma enhancement in Jiang-flavor foods.

Abstract:This article used transcriptomic analysis and bioinformatics analysis to study the differentially expressed genes at the transcriptional level and related signal transduction pathways of antioxidant peptides from egg white on H2O₂-induced oxidative stress injury in human embryonic kidney 293. The results showed that when HEK293 cells were injured by H2O₂， 866 genes were differentially expressed compared with the control group. When egg white-derived active peptides were added， a total of 226 genes were differentially expressed in the protected group compared to the injured group. Among these genes， 95 genes are expressed in the H2O₂-induced injury group (H2O₂ alone) and the egg white-derived antioxidant peptide protection group (WNWAD+H2O₂). Among these genes， 41 genes were significantly up-regulated (≥2 fold) in HEK293 damaged by hydrogen peroxide， but these genes were significantly down-regulated in HEK293 cells pretreated with WNWAD， an antioxidant peptide derived from egg white； and 47 genes were significantly down-regulated (≤-2 fold) in HEK293 damaged by hydrogen peroxide， but these genes were significantly up-regulated in HEK293 cells pretreated with the anti-oxidant peptide. In the end， these differentially expressed genes were analyzed for GO function and KEGG pathway enrichment. The results showed that these differentially expressed genes may be involved in multiple biological processes such as cell proliferation， differentiation， apoptosis， and cell signal transduction. KEGG pathway enrichment analysis results show that the differentially expressed genes in HEK293 cells injured by hydrogen peroxide may be involved in the mitogen-activated protein(MAPK) signaling pathway， transforming growth factor signaling pathway， WNT signaling pathway， and hippo signaling pathway， inositol phosphate metabolism， p53 signaling pathway， cancer regulation pathway and many other pathways， these pathways have a greater correlation with oxidative stress and apoptosis. Among them， 13 differential genes are involved in the conduction of MAPK signaling pathway.

Abstract:In order to explore the antioxidant effect and molecular mechanism of five active peptides derived from wheat protein， five active peptides [Leu-Tyr (LY)， Pro-Tyr (PY)， Tyr-Gln (YQ)， Ala-Pro-Ser-Tyr (APSY)， Arg-Gly-Gly-Tyr(RGGY)] were isolated and identified from wheat protein. Five antioxidant evaluation systems including DPPH free radical scavenging capacity， hydroxyl free radical scavenging capacity， oxygen free radical absorption capacity (ORAC value)， reducing capacity and total antioxidant capacity (FRAP method) were used to investigate their antioxidant effects. The results showed that LY， PY， YQ， APSY and RGGY had good antioxidant activity in five evaluation systems， among which PY had the most prominent antioxidant activity， and the activity values were (88.90±2.25)%， (5 143.68±65.45) μmol Trolox/g， (55.64%±1.12)%， 0.27±0.02 and (0.68±0.01)mmol/L， respectively. The chemical structure of wheat protein-derived active peptides was simulated by quantum chemistry， and stable dominant conformation was obtained. The molecular energies were -2 792 298.02， -2 490 523.05， -2 831 549.24， -3 977 343.70 and -4 111 743.04 kJ/mol. The optimal docking configurations of five active peptides and DPPH were obtained by molecular docking technology. LY and RGGY bound to DPPH through hydrogen bonds and Π-cationic electrostatic interaction， PY bound to DPPH through Π-Π accumulation Π-cationic electrostatic interaction and Π-anionic electrostatic interaction， YQ bound to DPPH through Π-cationic electrostatic interaction and Π-qnionic electrostatic interaction， and APSY bound to DPPH through hydrogen bond， Π-Π accumulation， Π-cationic electrostatic interaction and Π-anionic electrostatic interaction.

Abstract:In order to obtain biological preservatives for application in food preservation， antibacterial functional microorganisms were screened and their antibacterial substances were studied. The Oxford cup method was used to screen the antibacterial functional microorganisms， and to study their inhibitory spectrum using the area of the inhibition circle as an indicator. The pH， temperature and UV irradiation stability of the antibacterial fermentation broth was investigated using the change in antibacterial potency as an indicator. The acid exclusion test and high performance liquid chromatography (HPLC) were used to study and analyse the antibacterial substances. It was found that among the 16 strains of acid-producing bacteria with antibacterial ability screened from sauce mash and kimchi， Staphylococcus saprophyticus JL03 and Lactobacterium plantarum L04-1 showed excellent antibacterial effect and broad-spectrum antibacterial properties. The antibacterial fermentation broth of the two strains decreased from 5 730.69 IU/mL and 5 772.35 IU/mL to 5 190.12 IU/mL and 5 122.20 IU/mL at pH 3.0， respectively. All retained more than 85% of their initial antibacterial activity， indicating good pH stability. When the two bacterial antibacterial fermentation broths were treated at 100 ℃ for 20 min， the antibacterial potency of JL03 decreased from 5 730.69 IU/mL to 4 588.52 IU/mL， retaining more than 80% of the initial antibacterial activity. In contrast， the antibacterial activity of L04-1 decreased by 44.11%， indicating that the thermal stability of JL03 antibacterial fermentation broth was better than that of L04-1. After 3 h of UV irradiation， the antibacterial potency of the two bacteria decreased from 5 730.69 IU/mL and 5 772.35 IU/mL to 4 697.29 IU/mL and 4 437.52 IU/mL， respectively. All of them retained more than 70% of their initial antibacterial activity， indicating that they have good antioxidant properties. The acid exclusion test revealed that the antibacterial substances of the two strains were mainly acids， and the inhibitory capacity of acidic substances accounted for 58.03% and 64.32% of the total inhibitory capacity， respectively. HPLC analysis of the antibacterial fermentation broth of the two bacterial strains fermented for 72 h showed that the main acids were oxalic acid， L-malic acid， lactic acid， acetic acid， citric acid， succinic acid and fumaric acid， with a total content of 9.64 g/L and 13.46 g/L， respectively. Correlation analysis showed that L-malic acid (0.43 g/L) and lactic acid (6.76 g/L) were significantly and positively correlated with the antibacterial potency of JL03 antibacterial fermentation broth (P < 0.05). Lactic acid (5.75 g/L)， succinic acid (1.32 g/L) and fumaric acid (0.32 g/L) were significantly and positively correlated (P < 0.05) with the antibacterial potency of L04-1 antibacterial fermentation broth. Screening of antibacterial microorganisms and the analysis of key antibacterial substances have laid the foundation for improving the antibacterial performance of antibacterial microorganisms and their application in the field of food preservation.

Abstract:The aim of the study is to explore the mixed biofilm interaction among dominant spoilage bacteria isolated from meat. The dual-biofilm characteristics of Pseudomonas lundensis and three spoilers were evaluated using by crystal violet staining， phenol sulfuric acid assay， bicinchoninic acid assay and confocal laser scanning microscope (CLSM) observation at 15 ℃ and 25 ℃， as well as protease activity and disinfectant tolerance. The results showed that Pseudomonas spp. accounted for 43.5%， followed by Brochothrix thermosphacta， Acinetobacter spp. and Myriodes spp. among 23 spoilers isolated from beef. The amount of biofilm formation of PL， AJ and BT at 15 ℃ was significantly higher than that at 25 ℃， and levels of dual-biofilms at 15 ℃ was significantly more than single culture， indicating that low temperature significantly promoted the formation of mixed biofilm. The number of cells in biofilm co-cultured with PL and AJ was 0.75-0.78 lg(CFU/cm2)， which were higher than that of single culture. Compared to PL single biofilm， the secretion of extracellular polysaccharides increased by 15.67-22.01 μg/mL， and the production of extracellular protein co-cultured with AJ or BT rose by 7.35 μg/mL and 6.70 μg/mL respectively. CLSM observation also revealed that the dual-biofilms of PL and AJ or MP formed clusters with heterogeneous structures， and their thickness of these biofilm increased to 48.99-49.22 μm. In addition， the co-culture of PL and three strains significantly enhanced its protease activity and chemical tolerance. After treatment with 0.06% sodium hypochlorite， the residual rate of dual-biofilms of PL， AJ or BT was 95.61% and 96.16% at 15 ℃， which was significantly higher than that of PL single biofilm. Thus， it was revealed that meat-derived spoilage bacteria PL and three strains formed a complex dual-biofilm with strains-dependence， and the PL cells as dual-biofilm formed at low temperature enhanced its resistance to sodium hypochlorite. This study provided a good foundation for exploring the contamination and control of mixed biofilms from meat-derived spoilage microorganisms.

Abstract:The effect of dextran(7 000 u) on the digestive properties of surimi gel was investigated using grass carp (Ctenopharyngodon idellus) and dextran as an antifreeze agent. An in vitro digestion model was used to simulate the gastrointestinal digestion process and to study the changes in digestibility， hydrolysis， free amino acids， digestion product structure and advanced glycation end-products (AGEs) of surimi gels at different digestion stages， to analyze the effects of dextran addition on the digestive properties of surimi gels， and to identify the dextranization sites by glycomics. The results showed that the digestibility of surimi gel was (69.56 ± 0.59)% and the degree of hydrolysis was (1.91 ± 1.27)% at the end of simulated digestion， that the digestion of surimi gel occurred mainly in the small intestine stage， and that the addition of dextran did not affect the digestibility of surimi gel. The relative content of α-helical results of proteins in the gel of minced fish after digestion decreased by 28.55% and the relative content of β-folded structures increased by 41.04%. In the surimi gel with dextran added， there were substantially less AGEs formed after digestion than in the CA group (P < 0.05). The main sites of action of dextran involved in the glycosylation reaction of surimi gel were A0A3N0Y8X2 (N698， N699) and A0A3N0Z907， and there were a total of 122 N-glycosylation sites， 69 N-glycosylated proteins， 70 N-glycosylated peptides (N74) identified in the LC-MS/MS mass spectrometry.

Abstract:In order to study the rheological and in vitro digestive properties of protein-rich dense Cordyceps militaris milk， whey protein isolate (WP) or soybean protein isolate (SPI) were added to make the protein content of Cordyceps militaris milk more than 10%， and thickening agents Xanthan gum (XG)， Kappa-Carrageenan (KC) or Carboxymethylcellulose sodiu (CMC) were added. The fluidity， viscoelasticity and digestive properties were determined. The results showed that all samples exhibited weak gel behavior， apparent viscosity (η): CM-WP-XG (1.986 Pa·s) > CM-SPI-CMC (1.826 Pa·s) > CM-SPI-XG (1.548 Pa·s) > CM-SPI-KC (1.201 Pa·s)； Gel strength(G0′-G0″) and compound modulus (η): CM-SPI-XG (996.3 and 121.39 Pa·s) > CM-SPI-CMC (613.41 and 56.80 Pa·s) > CM-SPI-KC (290.62 and 34.11 Pa·s) >CM-WP-XG (93.02 and 8.82 Pa·s)； Loss coefficient (Tanδ): CM-WP-KC (0.66) > CM-WP-CMC (0.61) >CM-SPI-KC (0.44) >CM-SPI-CMC (0.42). In vitro digestion showed that CM-SPI-CMC (0.3096%) and CM-SPI-XG (0.3033%) had higher content of free amino acids. Meanwhile， by comparing G and Tanδ， Cordyceps militaris milk with high G and low Tanδ was more suitable for people with dysphagic difficulty. According to the above comparison， CM-SPI-XG and CM-SPI-CMC had good elasticity and deformation resistance. More conducive to dysphagia and the elderly eat. In conclusion， CM-SPI-XG is the best combination suitable for patients with moderate dysphagia or the elderly. This study demonstrates how protein-thickener interactions and food substrates determine the rheological and digestive properties of samples， providing theoretical support for dysphagia and dietary needs of the elderly.

Abstract:To investigate the structure characteristics of the corn peptide calcium chelate and the binding sites of peptides with calcium ions， corn peptide calcium chelate was prepared using corn peptides and calcium chloride as raw materials. The structures of corn peptide calcium chelate were characterized by Fourier transform infrared spectrometer (FTIR)， nuclear magnetic resonance (NMR)， thermogravimetry analysis (TG)， and mass spectrometry， and the binding sites of peptides and calcium ions were simulated by molecular docking technique. FTIR indicated that after the chelation of corn peptides with calcium ions， the amide I and amide II bands exhibited the red-shift and the N-H bond showed the blue-shift， and exhibited the red-shift at around 1 400 cm-1 because of stretching vibration of COO-. NMR showed that the absorption peak of corn peptide calcium chelate generally weakened and disappeared. The TG result showed that the degradation rates during the degradation stage were 43.26% and 65.05%， respectively， and the residual rate significantly increased from 19% to 38.6%. Seven peptide sequences were identified through mass spectrometry analysis. Two peptide segments with more hydrophobic amino acids were selected for molecular docking with calcium ions to simulate binding sites. The binding energies of Asn-Gln-Phe-Ser-Leu-Ile-Asn-Pro-Val-Leu-Ser-Arg (NQFSLINPVLSR) and Ser-Leu-Ile-Asn-Pro-Val-Leu-Ser-Arg-Gln-Gln-Pro-Ile-Val-Gly-Gly-Ala (SLINPVLSRQQPIVGGA) with calcium ions were -68.08 kJ/mol and -67.56 kJ/mol， respectively. It is speculated that the carboxyl oxygen atom and the amino groups on the amino acid residues of peptides were the main binding sites for chelating calcium ions. The thermal stability of corn peptide calcium chelate was significantly enhanced compared to corn peptides.

Abstract:Using whey protein as raw material and treated with high hydrostatic pressure technology， the effect of different pressures on the structure and properties of whey protein was studied. The results showed that the treated whey protein changed from the original hollow spherical structure to a honeycomb porous ordered structure. At 300 MPa， the average particle size (34.87 μm) and the absolute value of zeta potential (-211.57 mV) are minimal. The random was converted into β-turn， the β-turn content increased from 24.63% to 39.97%， and the random content decreased significantly from 30.67% to 15.60%. The free sulfhydryl content decreased， and the disulfide bond content increased from 1.69 μmol/g to 3.82 μmol/g. Fluorescence spectroscopy showed that whey protein had the best hydrophobicity at 400 MPa. Moreover， the processing characteristics of whey protein after high hydrostatic pressure treatment such as foaming， emulsification， water/oil holding capacity and oxidation resistance have been significantly improved. The foaming ability and emulsifying ability of whey protein reached the best value at 400 MPa， the foaming ability reached up to 40.67%， the emulsifying reached up to 108.4 m2/g， the water/oil holding capacity increased by 83.50%/144.52%， and the free radical scavenging capacity increased from 7.64% to 14.15%. This study provides a reference for the development and property of whey protein products with high hydrostatic pressure technology.

Abstract:To investigate the effect of Antarctic krill oil (KO) on dopaminergic neurons and gut microbiome in Parkinson's disease (PD) mice， the method of intraperitoneal injection of 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine (MPTP) were used to construct PD subacute model in mice. The mice were divided into Control group， PD group， KO_PD group and KO group. The immunohistochemical technique of TH was used to evaluate the protective effect of Antarctic krill oil on dopaminergic neurons and nerve fibers in PD mice. Combined with HE staining of colon and 16S rDNA high-throughput sequencing of feces， the effect of KO on the intestinal structure and intestinal microecology of PD mice was studied. The results indicated that， compared with the PD group， the number of TH-positive cells in the substantia nigra of the brain was significantly increased by about 5-fold， the number of epithelial cuprocytes was increased by about 2-fold， and the phenomena such as thinning of colonic intestinal glands were improved in the KO_PD group of mice. The gut microbiota of PD group mice was disrupted， while KO intervention significantly increased the relative abundance of Bacteroidetes phylum， Dubosiella genus， and Muribaculaceae_unclassified genus， Streptococcus genus， etc.， and significantly downregulated the relative abundance of Firmicutes phylum， Alistipes genus， Clostridiales_ unclassified genus and Helicobacter genus， etc. To sum up， oral administration of KO can effectively improve the loss of dopaminergic neurons in the substantia nigra and structural changes in the colon tissue of mice induced by MPTP injection， and maintain the homeostasis of mice gut microbiota at various levels. This effect may be related to the regulation of glucose metabolism， amino acid metabolism， and lipid metabolism， etc.， in gut microbiota.

Abstract:Objective: To investigate the effects of Ficus carica Linn. fermentation extract on immunomodulation and intestinal microflora in cyclophosphamide-induced immunosuppressed mice. Methods: Immunosuppressed mice models were constructed by intraperitoneal injection of cyclophosphamide， and the mice were randomly divided into blank control group (NC group)， model control group (MC group)， Ficus carica Linn. fermented extract group (FF group) and Ficus carica Linn. non-fermented extract group (NF group). The body weight of mice was recorded every 2 days during the gavage period. After 9 days of continuous gavage， the immune organ index， serum cytokines and blood routine were detected， the histopathological observation and intestinal microbial flora analysis were performed. Results: Compared with MC group， the body weight and immune organ indexes of thymus， spleen and liver in FF group and NF group were significantly increased (P<0.05)， the total number of leukocytes， monocytes and granulocytes were significantly increased (P<0.05)， and cytokines such as IL-4， IL-6， TNF-α and IFN-γ were significantly increased (P<0.05). The results of histopathological observation showed that the damage caused by cyclophosphamide to mice jejunum， thymus， spleen and liver in FF group and NF group was significantly reduced， and the effect was more pronounced in FF group than NF group. The analysis of intestinal microflora showed that the levels of Blautia， Lachnospiraceae， Paraprevotella， Clostridiales， Lactobacillus， and Bacteroides were closely related to immune traits， and compared with MC group， the abundance of Lactobacillus， Helicobacter， and Unclassified_S24-7 in FF group increased more significantly than that in NF group. Conclusion: Compared with the non-fermented Ficus carica Linn. extract， the Ficus carica Linn. extract fermented by Aspergillus niger can improve the immune function of immunosuppressed mice induced by cyclophosphamide and improve the intestinal microflora.

Abstract:The structure characteristics， antioxidant activity and anti-aging of melanin from Gomphidius viscidus D1 were studied. Ultraviolet-visible spectroscopy， infrared spectroscopy and scanning electron microscope (SEM) were used to evaluate structure characteristics； Hydroxyl， 1，1-diphenyl-2-picrylhydrazyl (DPPH)， superoxide anion radical scavenging assays， and potassium ferricyanide reducing power were used to evaluate antioxidant activity in vitro； Natural aging， hydrogen peroxide， heat and ultraviolet damage models were used to evaluate anti-aging and anti-stress injuries on Caenorhabditis elegans； SOD， CAT activities and MDA content were measured to evaluate antioxidant activity in vivo. The results showed that melanin from Gomphidius viscidus is an amorphous structure， it has typical ultraviolet visible and infrared absorption spectra of melanin； It has good scavenging activities， the DPPH， hydroxyl radical and superoxide anion scavenging rates reached 67.1%， 68.42% and 34.3%； The natural lifespan of Caenorhabditis elegans was prolonged significantly by 1.00 g/L melanin (P<0.05)， lifespan under oxidative stress， heat stress and ultraviolet radiation stress could be prolonged by melanin at the mass concentration of 0.50-1.00 g/L， 0.50-4.00 g/L and 0.25-4.00 g/L respectively (P<0.01)； At 0.50-1.00 g/L， the SOD (P<0.05)， CAT (P<0.01) activities were significantly increased， and MDA content (P<0.01) was significantly decreased. In conclusion， melanin from Gomphidius viscidus has good antioxidant activity both in vitro and in vivo and has good anti-aging and anti-stress injury effects.

Abstract:Objective: To analyze the optimal nutritional requirements of Lactobacillus helveticus H11， so as to explore its low cost and high viable count medium formulation. Methods: The optimal nutritional requirements of Lactobacillus helveticus H11 were determined by single-factor experiment with Box-Behnken response surface test design using viable bacterial count， bacterial density and maximum specific growth rate as indicators. Results: The optimized optimal static fermentation medium formulation of Lactobacillus helveticus H11 was obtained as follows: lactose 29.70 g/L， yeast extract FM808 41.78 g/L， yeast peptone FP102 13.93 g/L， Sodium citrate 2.02 g/L， sodium acetate 5.05 g/L， K2HPO4 2.02 g/L， MgSO4·7H2O 0.20 g/L， MnSO4·5H2O 0.06 g/L， Tween-80 1.00 g/L， L-cysteine hydrochloride 0.30 g/L， vitamin B6 0.01 g/L. The viable bacteria count of Lactobacillus helveticus H11 fermentation broth after optimized high-density culture was (9.02±0.23) × 109 CFU. Conclusion: By analyzing the optimal nutritional requirements of Lactobacillus helveticus H11， the optimal fermentation process for the industrial production of Lactobacillus helveticus H11 was determined， and the production cost was reduced while increasing the viable bacterial count， which provides a theoretical basis for the industrial production of Lactobacillus helveticus H11.

Abstract:In order to investigate the effects of the dominant genus Weissella on the flavor and quality of high-salt liqud-state soy sauce， five salt-tolerant acid-producing bacteria were isolated and screened from high-salt liquid-state moromi， and identified with 16S rDNA sequencing， morphology and physiological and biochemical tests. Strains WS09， WS11 and WS12 were identified as Weissella thailandensis， while strains WS20 and WS23 were identified as Weissella cibaria. The fermentation performance of the strains were investigated， and it was found that the optimal growth temperature of all five strains was 30 ℃， and the strains grew well with a salt concentration of 100 g/L. Among them， the acid-producing capacity， salt-tolerant growth capacity， antibacterial capacity and probiotic properties of Weisseria cibaria WS20 were optimal and could be used for soy sauce fermentation. It was added to the moromi and a 60-day fermentation study was conducted. The physicochemical indicators， organic acid content， the quantity and content of volatile flavor compounds of the soy sauce during fermentation were analyzed， and the sensory evaluation was performed. The fermentation of WS20 addition could promote the accumulation of total acid， ammonia-nitrogen and soluble salt-free solid in soy sauce， which were enhanced by 11.71%， 5.18% and 8.03%， respectively， compared with the control group. Lactic acid and acetic acid were the two organic acids that accounted for the highest percentage in the fermentation of soy sauce， both of which accounted for 70.24% of the total content of seven organic acids， which were 12.50% and 19.69% higher than the control group， respectively. The quantity of volatile flavor compounds was 8 more than the control group， with the content reaching (4 211.64±94.06) μg/L and an increase of 38.92%. The contents of ethyl lactate， ethyl acetate， phenylethanol and 2，3-butanediol were (5.96±0.02)， (236.22±7.81)， (386.17±4.35)， (84.03±1.15) μg/L， which were increased by 4 484.62%， 103.39%， 59.14% and 137.64% compared with those of the control sample， respectively. The aroma， taste， color and body of soy sauce in the test group were better than the control group in sensory evaluation. The screening of Weissella spp. in moromi and its fermentation study in soy sauce laid the foundation for the application of Weissella spp. in soy sauce brewing， and enriched the resources of flavored strains for soy sauce brewing.

Abstract:To effectively reduce the high content of ethyl carbamate (EC) in traditional Chinese yellow wine， exogenous Lactobacillus paracasei FMES22， FMES56 and Bifidobacterium lactis FMES99 were inoculated at the start of the post-fermentation stage for the co-fermentation. The contents of EC， γ-aminobutyric acid (GABA) and flavor compounds in the yellow wine were determined by high performance liquid chromatography fluorescence (HPLC-FLD)， Berthelot colorimetry and solid-phase microextraction-gas phase-mass spectrometry (SPME-GC-MS)， respectively. The results suggested that the addition of FMES22， FMES56 and FMES99 significantly increased the total amino acid content. And the amount of flavor positively correlated amino acids， including aspartic acid， threonine and others were significantly higher than the control group. The total content of free amino acid in FMESS22 group sample reached 2 869.21 mg/L， while only 1 120.8 mg/L in control group sample. In addition， compared with traditional fermented rice wine， the content of GABA in rice wine added with Lactobacillus and Bifidobacterium was significantly increased， while the content of EC was markedly decreased. Especially， the content of GABA in FMES22 group reached 62.04 mg/L， while the content of EC was only 11.39 mg/L. Moreover， the contents of acetic acid， 2，3-butanediol， ethyl lactate， ethyl acetate， diethyl succinate and other typical flavor substances in the experimental groups were higher than those in the control group. The transformation of characteristic flavor substances contributed to a fresh flavor that different from the traditional rice wine. In conclusion， the directionally fermented rice wine with Lactobacillus and Bifidobacterium added in the post-fermentation stage significantly improved the nutrition， safety and flavor richness of traditional yellow rice wine.

Abstract:Different probiotic fermentation can give different flavor and nutrient to juice. Five probiotics， including Lactobacillus paracasei， Lactobacillus plantarum， Bifidobacterium lactis， Lactobacillus rhamnosus， and Lactobacillus acidophilus were selected to ferment Hanfu apple juice in this study. Their fermentation characteristics in Hanfu apple juice and the influence on the flavor and nutritional quality of fermented apple juice (FAJ) were analyzed. The results showed that the sensory receptivity of apple juice fermented by Lactobacillus paracasei， Lactobacillus rhamnosus， and Bifidobacterium lactissan were better， and the total number of lactic acid bacteria colonies after fermentation were higher than 106 CFU/mL， which met the industry standard of fruit and vegetable fermented juice. These three probiotics can give apple juice good flavor， and the total amount of free amino acids before and after fermentation has no significant change， maintaining at about 10 mg/100 g. Moreover， their alcohol production capacity is not strong and the acid production capacity is moderate， which can avoid the risk of post-acidification after FAJ. The results could provide some theoretical reference for the development of probiotic fermentation products of Hanfu apple juice.

Abstract:The poor water solubility and instability of curcumin hinders its widespread application. The use of plant proteins as delivery vehicles for curcumin can effectively improve its solubility and stability. A pH-controlled method was used to realise the nanoencapsulation of curcumin using pea protein (PPI)， and the effects of pH combination， quality concentration of curcumin and quality concentration of pea protein on the loading rate of pea protein-curcumin nanoparticles were investigated by one-way experiments. Taking the loading efficiency and loading amount as indicators， the preparation process of PPI-curcumin nanoparticles was optimised by response surface methodology experiments， and the optimal preparation process of PPI-curcumin nanoparticles was obtained， i.e. the pH combinations of pH 13 and pH 8， the mass concentration of curcumin at 0.455 mg/mL， and the mass concentration of pea protein at 43.64 mg/mL. The PPI-Cur nanoparticles prepared by the optimal process were then systematically characterized in terms of particle size， ζ-potential， appearance and morphology， UV spectra and secondary structure changes. The results showed that the average particle size of the PPI-Cur nanoparticles was (254.5±9.0) nm， the ζ-potential was (-39.7±0.14) mV， the PPI-Cur nanoparticle system was stable， and the complex interaction between curcumin and pea protein complexation existed， and the secondary structure of PPI-Cur nanoparticles changed， with a significant decrease in β-folding from 33.6% to 25% (P < 0.05) and a significant increase in random curling from 23% to 31% (P < 0.05). The results provide an optimal process for the preparation of PPI-Cur nanocomplexes by pH-driven methods and a parametric basis for the development and application of plant protein-based delivery systems.

Abstract:In this study， infrared-assisted spouted bed drying (IRSBD) of Chinese yam was carried out using constant temperature drying (40， 50， 60 ℃ and 70 ℃) and variable temperature drying (staged rising temperature and staged falling temperature) processes to investigate the effects on drying kinetics， uniformity， and quality properties (texture， rehydration， total phenolic content， microstructure， and shrinkage). The mathematical modeling results of the Chinese yam IRSBD drying curve showed that the Midilli model had the best fit， with the maximum R2 value (0.99989) and the minimum RMSE and χ2 values (0.00319 and 1.69872×10-5， respectively)， indicating that it was most suitable for describing the IRSBD kinetics of Chinese yam. In the comparative analysis of different drying processes， it was found that increasing the drying temperature under constant-temperature drying conditions was beneficial for shortening the drying time and reducing energy consumption. Staged rising temperature drying had energy consumption only slightly higher than that of constant-temperature drying at 70 ℃， but it exhibited the best drying uniformity， the highest total phenolic content [(85.25±7.41) mg GAE/100 g DW]， and the lowest shrinkage and hardness [(74.3±3.96)% and (24.95±7.41) N]， respectively， as well as a desirable color. The staged falling drying process produced samples with higher equilibrium rehydration ratio and crispness， but it did not show significant advantages over the staged rising temperature process in terms of drying time， energy consumption， uniformity， hardness， shrinkage ratio， and total phenolic content. Therefore， it can be concluded that staged rising temperature drying is a more ideal drying process for Chinese yam using IRSBD. This study provides data reference and theoretical support for the application of IRSBD technology in agricultural product processing and industrial production.

Abstract:Lactobacillus plantarum， as a probiotic， has many functional properties in the food industry， such as improved nutritional quality， flavor properties， antioxidant activity and antibacterial activity， which can be beneficial to health when consumed in sufficient quantities. However， probiotics are subject to various types of adverse environmental conditions in the gastrointestinal tract， particularly gastric acid and bile salts， which strongly inhibit their effective colonization of the active site in the colon with significantly reduced survival rates. To improve the stability of Lactobacillus plantarum in the human gastrointestinal tract and during processing and storage， microcapsules of Lactobacillus plantarum were firstly prepared by extrusion using whey isolate protein fibril and sodium alginate as wall materials. The effects of the mass concentration of the composite wall material and CaCl2 on the encapsulation effect of Lactobacillus plantarum were optimized by using the encapsulation rate as the index. The results showed that the optimum preparation conditions of Lactobacillus plantarum microcapsules were 2% mass fraction of WPIF， 2% mass fraction of ALG and 1% mass fraction of CaCl2， under which condition the highest encapsulation rate of Lactobacillus plantarum microcapsules was achieved at 92.13%. The stability of WPIF-ALG-L. plantarum 90 core-shell microcapsules were evaluated through in vitro gastrointestinal digestion for 5 h and storage at 4 ℃. It showed that the survival rate of WPIF-ALG-L. plantarum 90 core-shell microcapsules was 87.65% in simulated gastric fluid and 89.18% in intestinal fluid， and the survival rate was 79.98% after 25 d storage at 4 ℃. All results indicate that the core-shell microcapsules have good tolerance， intestinal solubility and storage stability.

Abstract:To enhance the stability of collagen peptide from squid skin， taking the embedding rate and yield of the product as indicators， the optimal process of preparing collagen peptide microcapsules by spray drying was optimized through single factor and response surface experiments， and the physicochemical properties and stability of the microcapsules were also analyzed. The results showed that with microporous starch as the adsorption carrier and arabic gum as the wall material， the optimum conditions for the preparation of microcapsules were air inlet temperature 173 ℃， core to wall ratio 1∶4， solid content 17%. Under these conditions， the embedding rate and the sample yield of squid skin collagen peptide was (74.65±0.05)% and (72.32±0.16)% respectively. The prepared microcapsules had low water content， good solubility， high acceptability and strong thermal stability. Squid skin collagen peptide had a certain slow-release effect after microencapsulation， and its digestive stability was also improved. This study provides a theoretical basis for improving the level of intensive processing and comprehensive utilization of squid resources.

Abstract:In this paper， the preparation technology， analysis and stability of hypouricemic peptide from Katsuwonus pelamis were discussed. Taking the inhibitory activity of xanthine oxidase (XO) and the hydrolysis degree as indicators， enzymatic hydrolysis process of hypouricemic peptide was optimized， and the molecular weight， amino acid composition and stability of the hydrolysate were also analyzed. The results showed that the neutral protease was the most suitable protease for preparing the hypouricemic peptide of Katsuwonus pelamis， through single factor and response surface optimization tests， the optimal process conditions were determined of 40 ℃ temperature， pH 7.1， 10 400 U/g enzyme addition， enzymolysis time 4 h and material to liquid ratio 1∶5(g/mL). Under these conditions， the XO inhibition rate and hydrolysis degree of the prepared enzymatic hydrolysate were (83.91±0.16)% and (38.67±0.39)% respectively， and its yield was (18.24±1.02)%. Molecular weight distribution and amino acid analysis showed that the prepared hypouricemic hydrolysate was mainly composed of small molecular peptides， whose molecular weight less than 1 ku and hydrophobic amino acids accounted for 91.9% and 49.61% respectively. The prepared hypouricemic hydrolysate had good stability to heat， acid and alkali as well as metal ions such as Ca2+， Mg2+， AI3+， K+， Na+ and NH+. Adding Zn2+ and Cu2+ could significantly increase the XO inhibitory activity of hydrolysate， whereas the presence of Fe2+ and Fe3+ significantly reduced the XO inhibitory activity. In addition， the enzymatic hydrolysate was relatively stable in the gastrointestinal simulated digestion environment， and its XO inhibitory activity was significantly enhanced after in vitro intestinal simulated digestion. This study provides a theoretical basis for the deep and high value-added utilization of Katsuwonus pelamis resources.

Abstract:Objective: To guide the rational use of sturgeon skin resources， this study aimed to compare the production efficiency and bioactivity between the gelatin-peptide complex (GPC) made from sturgeon skin by the method of pyrolysis and enzymatic hydrolysis， respectively. Methods: Using sturgeon skin as raw material and GPC yield as an indicator， pretreatment condition of sturgeon skin and the preparation of GPC by pyrolysis were optimized. On the other side， using the GPC with given maximum molecular weight as substrate， and trichloroacetic acid soluble oligopeptide (TCA-SP) was used as an index， the enzymatic hydrolysis efficiency of several kinds of protease on this substrate was investigated. Finally， the effects of GPCs prepared by pyrolysis and protease hydrolysis， with the highest TCA-SP yield， on the viability of normal and D-galactose-induced oxidative damage PC12 cells was compared. Results: Alkali treatment did not contribute significantly to the extraction of GPC from sturgeon skin， while acid treatment did. The optimized condition for acid treatment was incubating the sturgeon skin at 0.25 mol/L HCl for 6 h. The most suitable conditions for GPC preparation by high-temperature pyrolysis were found at 100 ℃ for 2 h， with a highest GPC and TCA-SP yield of 34.72% and 31.22%， respectively. The GPC obtained by low-temperature pyrolysis at 60 ℃ for 1 h had the highest viscosity and the lowest TCA-SP， suggesting it had maximum molecular weight and relatively complete structure. GPC-60 ℃-1 h was then used as the substrate to be hydrolyzed by several proteases respectively. A highest TCA-SP content of 28.74% was observed in the hydrolysate of neutral protease for 0.5 h. GPC-100 ℃-2 h and GPC-N-0.5 h had no cytotoxic effect on normal PC12 cell viability at 50-1 000 μg/mL. And both had a certain protective effect on PC12 cells against D-galactose-induced oxidative damage at 12.5-200 μg/mL， and there seemed no significant difference between them. Conclusion: The TCA-SP content in the GPC obtained by high-temperature pyrolysis was similar to that prepared by neutral enzymatic hydrolysis， and their protective effect on PC12 was also similar.

Abstract:Total flavonoids were extracted from Hemerocallis citrina Baroni(H. citrina) in Qidong County of Hunan Province by ultrasonic and cyclodextrin aqueous solution. On the basis of single factor experiment， response surface design method was used to optimize the extraction process. The total yield of flavonoids and the antioxidant effect of the extracts with and without cyclodextrin were compared under optimal conditions. The results indicate that the optimal process for the extraction of total flavonoids from H. citrina with ultrasound-assisted cyclodextrin in aqueous solution is: the amount of cyclodextrin added was 26 mg/mL， the liquid-solid ratio was 31∶1 (mL/g) and the ultrasonic power was 490 W. The total flavonoid content of the extraction under these conditions was(9.26±0.07) mg/g， which was similar to the predicted value (9.28 mg/g)， showed that the optimized extraction process was stable， reliable， practicable and repeatable. Compared with extracted by water， the extraction rate of total flavonoids increased from 0.791% to 0.926% after cyclodextrin was added. Meanwhile， the in vitro antioxidant tests (FRAP， ABTS， DPPH) of the latter showed superior in vitro antioxidant activity. Therefore， the cyclodextrin-assisted extraction of total flavonoids is an effective extraction technology that is easy to operate and environmentally friendly.

Abstract:To reveal the patterns of nutrient migration and changes in flavor characteristics of pork skull soup during high-pressure boiling. The nutritional composition， particle characteristics and flavor components of pork skull soup were determined under high-pressure boiling times (20， 40， 60， 90 min and 120 min) using pork skull as raw material， and the sensory evaluation of the soup was performed using electronic tongue and electronic nose techniques. The results showed that the contents of solids， soluble protein， total sugar and minerals showed an overall increasing trend during boiling， and the bone broth had high whiteness and brightness at 60 min. The particle size of bone broth D[3，2] and D[4，3] reached the minimum value at 90 min of boiling and then increased slightly， the absolute value of potential decreased continuously and stabilized after 60 min of boiling. The microstructure showed that the particles increased during the boiling process， and some aggregated particles appeared at 120 min. The content of most fatty acids and glutamic acid and aspartic acid increased during the boiling process from 20 min to 90 min， and then decreased， while the content of other amino acids increased. 5'-AMP decreased and then increased， and 5'-IMP， 5'-GMP， 5'-CMP content all increased first and then decreased， and reached the maximum value at 40， 60 min and 40 min， respectively. The electronic nose and electronic tongue data showed that the odor and taste of pork head bone broth with different high pressure boiling time had large differences， and the odor characteristics of pork head bone broth boiled for 60 min and 90 min were better and light fishy smell. The response value of freshness was the highest in 60 min boiling pork head bone soup. Aldehydes， alcohols and olefins were the main volatile flavor substances in pork head bone soup， and the types and relative contents of volatile flavor substances varied among samples with different boiling times. The comprehensive analysis concluded that 60 min of high pressure boiling was the best boiling time for making pork skull soup， which had higher nutrient content， more stable system and better flavor.

Abstract:To investigate the effect of pretreatment methods on the formation of advanced glycation end products (AGEs) in air-fried fish cakes. Fish cakes were prepared from frozen silver carp surimi， and the fish cakes in the experimental group were treated with three pretreatment methods (pre-frying， pre-frying + freezing， and pre-frying with coating) before air frying， and the direct air-fried fish cake was the control group. The AGEs contents， physicochemical indicators and their correlations in the interior， surface and batter layer of air-fried fish cakes were analyzed. Compared with the samples of control group， the pre-frying and pre-frying + freezing significantly increased the oil absorption (83.83% and 203.48%) in the surface layer of fried fish cakes， which accelerated the Maillard and lipid oxidation reactions， leading to an increase of 120%~151% in CML content. On the contrary， the golden crust formed in the pre-frying with coating group reduced the oil absorption (72.63% and 60.00%) and water loss (3.87% and 0.70%) in the interior and surface layer of the samples， and further decreased the generation of AGEs by weakening the lipid oxidation and the degradation of furosine. And the CEL content decreased by 59.32%. Correlation analysis showed that oxidation reaction and Maillard reaction had a positive correlation with the generation of AGEs in fish cake， and the highest correlation coefficient was found between lipid oxidation and AGEs content. In conclusion， the battered pre-frying not only improved the color of fried fish cakes but also decreased their AGEs contents via depressing the lipid oxidation and Maillard reaction.

Abstract:Effects of drying temperature (50， 85， 95， 105， 120 ℃) on physicochemical， rheological properties and microstructure of black pearl waxy corn flour was investigated. The results showed that with the increase of drying temperature， the dispersion time of the flour increased from 13.4 s to 29.0 s， indicating the dispersion capacity of corn flour decreased. In addition， in comparison with the sample treated at room temperature (control)， the loose bulk density and tap bulk density， particle density of the flour obtained at 120 ℃ increased significantly by 8.77%， 27.94% and 108.22%， respectively. The Carr's index， Hausner ratio， the angle of repose and slide also increased by 86.90%， 19.49%， 21.62% and 26.20%， and the porosity decreased by 9.89%. Other results also demonstrated that sample at high drying temperature (120 ℃) exhibited higher G′ and lower final tanδ value (0.54 vs. 0.15) compared to the control during the heating， indicating the dispersion capacity of corn flour treated at high temperature showed solid-like properties. Confocal micrograph (CLSM) results showed that heat treatment could effectively destroy the network structure of protein， thus destroying the combination of starch and protein. The results showed that drying temperature could affect the physicochemical， rheological properties and microstructure of the treated black pearl waxy corn flour， and therefore affect dispersion capacity of the obtained flour.

Abstract:In order to investigate the optimal proportions of soybean isolate protein (SPI) and pea isolate protein (PPI) added in plant-based sausage making and the effects of different fermenters on the flavor of this product， the pH， color difference， texture， moisture content， processing characteristics and microstructure of plant-based sausages made by mixing different proportions of SPI and PPI were examined and the optimal proportions of sausages made with the additions of fermenters B (Lactobacillussakei， Staphylococcus carnosus) and fermenter L (Pediococcus acidilactici， Pediococcus pentosaceus)， respectively， and their volatile flavor substances were examined and analyzed by quantitative descriptive analysis (QDA). The results showed that the plant-based sausages with SPI ∶ PPI = 9 ∶ 16 (SP9) had the best physicochemical properties， with hardness， chewiness， and elasticity values of 6 470±436， 2 731±130， and 0.89±0.04， respectively， and that both the fermenter B and the fermenter L significantly enhanced the content of volatile flavor substances of the plant-based sausages， with the L group (3 394.30 mg/kg) and the B group (1 945.77 mg/kg) had significantly higher content of total flavor substances than that of CT group (1 197.22 mg/kg) and may have inhibited the fishy flavor substances of plant-based sausages. Conclusion: The plant-based sausages made from SPI and PPI have good tissue structure and processing characteristics， and fermentation can be used to significantly enhance the flavor of sausages.

Abstract:In order to study the effects of temperature fluctuations and LED blue light on the quality changes of blueberries during low temperature circulation， this experiment was conducted with dark treatment as the control group and temperature fluctuation treatment groups with no fluctuation， one， two， and three fluctuations and different chain break times (25， 55 min， and 3 h) designed under LED blue light conditions， and the effects of temperature fluctuations under cold break time on blueberry quality indicators and related oxidative enzymes were comparatively analyzed. The results showed that the temperature fluctuation treatment caused a continuous decrease in the quality of blueberries during storage. Compared with the no fluctuation group， blueberries with three fluctuation treatments showed a significant decrease in hardness； titratable acid， vitamin C and anthocyanin contents decreased by 60.49%， 71.82% and 42.27%， respectively； and PPO and POD activities increased at 15 days. Compared with the dark control group， LED blue light treatment could effectively delay the degradation of blueberry nutrients. In addition， the tolerance of blueberries to chain break time varies， and the rate of quality degradation is as follows: 3 h > 55 min > 25 min. The correlation analysis among the indicators showed that hardness， vitamin C and anthocyanins were significantly correlated (P<0.05)， which could be used to evaluate the quality changes of blueberries during low-temperature circulation. In summary， temperature fluctuations exacerbated the quality deterioration and nutrient loss of blueberries， so while avoiding severe temperature fluctuations， LED blue light irradiation could be considered to improve the quality deterioration of blueberries caused by temperature fluctuations during the circulation process.

Abstract:To study the effect of electric field treatment on oxidation stability of soybean crude oil. Based on the influence of single factor about electric field intensity or treatment time on lipid peroxide value (POV)， the optimal conditions of electric field treatment were determined. The content changes of sterol， squalene and tocopherol under the optimal electric field condition were determined by GC-MS and HPLC. The antioxidant capacity of oils with the electric field treatment was evaluated in vitro. The optimal electric field intensity was 3 000 V/m and the electric field treatment time was 3 h. The relative loss inhibition rate of sterol， squalene and tocopherol were 23.08% and 19.99%， respectively. The loss inhibition rate of sterol and squalene were different for tocopherol. The protection order was δ-tocopherol > β-tocopherol > α-tocopherol > γ-tocopherol， and the electric field had a relatively obvious effect on the inhibition rate of δ-tocopherol loss in soybean crude oil. Electric field treatment slowed down the decrease rate of DPPH and ABTS+ free radical scavenging activity and FRAP reducing ability of oils， and protected the antioxidant capacity of oils. Electric field can inhibit the oxidation rate and the degree of oxidation of oils， and has an inhibitory effect on the loss of antioxidant components in oils， which protects the antioxidant capacity of oils and has a good antioxidant effect.

Abstract:This study aimed to investigate the suitability of tangerine peel processing for 16 citrus varieties in Hunan Province and to establish a comprehensive evaluation method of tangerine peel processing quality. The nutritional qualities of the main functional components， antioxidant capacity and volatile aroma components of 16 kinds of tangerine peel were analyzed by UPLC， colorimetric and GC-MS methods， and the processing qualities were comprehensively evaluated by principal component analysis. The results showed that there were significant differences in the contents of main functional components and antioxidant capacity of 16 kinds of tangerine peel. The contents of total phenol (28.91 mg/g DW)， total flavonoid (17.61 mg/g DW)， hesperidin (98.64 mg/g DW) and synephrine (12.71 mg/g DW) in the peel of Wenzhou mandarin were the highest. The contents of sinensetin (2.29 mg/g DW)， nobiletin (5.26 mg/g DW)， tangerine (6.20 mg/g DW) and volatile oil (8.95%) in Ponkan were the highest. The scavenging ability against DPPH radical of Clementinen radical was the strongest (30.81 μmol Trolox/g DW)， and the scavenging ability against ABTS radical of Yura radical was the strongest (43.27 μmol Trolox/g DW). The reducing power of FRAP and APC of Ponkan was the strongest， respectively 47.46 μmol Trolox/g DW and 96.52%. A total of 81 volatile aroma components were detected in 16 kinds of tangerine peel， and different samples contained a variety of unique volatile aroma components. The main aroma components of tangerine peel were β-laurene， Linalool and D-limonene. Five principal components were extracted by principal component analysis， and the cumulative variance contribution rate reached 88.824%. Results showed that the main functional components had the greatest influence on the processing integrated quality of Chenpi， followed by aroma components and antioxidant capacity. Ponkan and Wenzhou mandarin had the highest comprehensive scores of peel quality. Finally， the processing characteristics of 16 citrus peels were classified as suitable and unsuitable by K-means cluster analysis， and the processing quality of Wenzhou mandarin and Ponkan was the best. This study can provide reference for the search of high bioactive citrus peel suitable for processing and the use of both medicine and food， and provide reference for the development and utilization of tangerine peel products， raw material selection and quality evaluation.

Abstract:Baijiu is the Chinese national alcohol， and its unique flavor carries a rich culture and history and is an important part of Chinese culture. The flavor of Baijiu mainly depends on the aroma and taste of the compounds in the Baijiu. The threshold and content of the compounds directly affect their contribution to the overall flavor of Baijiu. Threshold is a bridge connecting chemical content and sensory characteristics in flavor chemistry and is a reference index for studying the importance of key flavor compounds in Baijiu. There is extensive research on the aroma threshold of flavor compounds in Baijiu， while research on taste thresholds is still in its infancy. So it is urgent to carry out systematic research. In this paper， the volume fraction of 46% ethanol aqueous solution was used as the matrix， and the three-alternative forced-choice (3-AFC) was used to determine the threshold by optimizing the alcohol content of the matrix and the sensory evaluation method. The taste thresholds of 48 important flavor compounds in Baijiu were determined， including the detection threshold and its taste characteristic threshold. The study found that a single compound could exhibit various taste characteristics， and there were great differences in the taste characteristics of different compounds. Still， the taste characteristics of the same kind of compounds had certain similarities. Most of the acid compounds could present a variety of taste characteristics such as sour， bitter， and astringent taste， and some acid compounds had no obvious sour taste. Ester compounds were mainly sweet and bitter， but the sweetness threshold was not greater than its bitterness threshold. Alcohol compounds could show bitterness， and some could also show sweetness and astringency. Two aldehydes and pyrophenols could show a bitter taste. The results provided a more detailed and accurate threshold reference for studying Baijiu taste， which was of great significance to the sensory evaluation， flavor chemistry research and product quality improvement of the Baijiu industry.

Abstract:In order to explore the change rule of microorganism and physical and chemical factors during the fermentation of rice flavor Baijiu， this experiment measured the physical and chemical indexes and microbial community changes on the 0， 1， 2， 3， 4， 5， 6， 7， 8， 15， 22， 29， 36， 43， 50， 64 and 94 days during the fermentation process. The results showed that during the fermentation stage， pH showed a trend of decreasing first， then increasing and then decreasing， and at the end of fermentation pH was about 4.1， while total acid showed a gradual increase trend. The starch content is rapidly hydrolyzed and consumed in the early stage of fermentation， and tends to be flat in the later stage of fermentation. However， the reducing sugar content shows an increasing trend within 0-2 days of fermentation， reaching a maximum value of about 180.14 g/L on the second day. Within 2-15 days， it is utilized by microorganisms and its content rapidly decreases. In the early stage of fermentation (0-3 d)， no alcohol content was generated， at 22 days of fermentation， the alcohol content reached its maximum value of 9.5°，however， in the later stage of fermentation， the alcohol content decreased. The total phenol content showed an increasing trend with the increase of fermentation time， and the final content was 375.63 mg GAE/L at the end of fermentation. In the fermentation process， Proteobacteria and Firmicutes were the main dominant bacteria， and the main dominant bacteria were Enterobacter， Pantoea， Pediococcus and Lactococcus. The results of the principal coordinate analysis showed that all samples were divided into 6 clusters on the PCoA plot， Redundancy analysis (RDA) showed that Lactococcus， Pseudomonas and Pediococcus were positively correlated with total acid composition， Pantoea， Cronobacter， Enterococcus and Klebsiella were negatively correlated with total acid composition. However， Pantoea， Cronobacter， Enterococcus and Klebsiella were positively correlated with pH， starch (St) and reducing sugars (Rs)， and total acids had the greatest impact on the dominant bacteria， pH， starch (St) and reducing sugars (Rs) had similar effects on the dominant bacteria.

Abstract:In this study， the differences in alkaloid composition and antioxidant activities in vitro were investigated based on plant wide targeted metabolomic techniques using the ‘Ningqicai No. 1’ goji leaves from three origins in Ningxia (Yinchuan， Zhongning， and Guyuan). The results showed that the alkaloid extracts of the samples from the three origins all had in vitro antioxidant activities. Among them， the scavenging ability of ABTS+ is Zhongning (35.4%) > Yinchuan (29.6%) > Guyuan (28.9%). The scavenging ability of superoxide anion is Yinchuan (84.8%) > Guyuan (83.9%) > Zhongning (82.1%). The total reduction capacity is Zhongning (0.46) > Guyuan (0.45) > Yinchuan (0.41). A total of 12 categories and 162 alkaloid metabolites were detected in the three regions. Under the screening conditions of multiple difference ≥ 2 or ≤ 0.5， P<0.05， and VIP ≥ 1， there were 53 significantly changed alkaloid differential metabolites in the comparison group between Yinchuan and Guyuan (including 21 up regulated and 32 down regulated)， 25 significantly changed alkaloid differential metabolites between Zhongning and Guyuan (including 16 up regulated and 9 down regulated)， and 59 different metabolites with significant changes between Yinchuan and Guyuan (including 31 up regulated and 28 down regulated). Five alkaloid metabolites with significant differences were identified through simultaneous comparison among the three production areas (dihydrocaffeioyl putrescine， panthenol mercaptoethylamine， wolfberry D， acetaminophen， and 3，4-dimethoxybenzamide). The KEGG database pathway enrichment analysis found that the five alkaloid metabolites with significant differences were mainly distributed in four metabolic pathways， namely metabolic pathway， biosynthesis of secondary metabolites， carbapenem biosynthesis， and pantothenate and CoA biosynthesis pathways. This study provides a theoretical basis for nutritional exploration of ‘Ningqicai No.1’ goji leaves from different regions in Ningxia.

Abstract:In order to promote the development and utilization of the liver， a by-product of Takifugu rubripes' processing， high content of n-3 polyunsaturated fatty acid fish oil was obtained from Takifugu rubripes' liver by enzymatic method. The sensory properties， basic physicochemical properties， tetrodotoxin content， fatty acid composition， liposoluble substances， and volatile compounds of fish oil before and after refining were analyzed. The results showed that the crude and refined fish oil meet the standards of grade II crude fish oil and grade I refined fish oil in the aquatic industry standard respectively； No tetrodotoxin was detected in both crude and refined fish oil， and 20 kinds of fatty acids were detected in both， with unsaturated fatty acids as high as 71.50% and 71.11%， the total contents of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were 25.98% and 25.64%， respectively； The total amount of tocopherol in refined fish oil decreased slightly， but it could still reach 1.51 mg/100 g. 38 volatile compounds were detected in both oils by gas chromatography ion mobility spectroscopy (GC-IMS) system， including 8 alcohols， 1 ether， 18 aldehydes， 8 ketones， and 3 esters； 31 different volatile compounds (VIP>1) were screened by orthogonal partial least squares discriminant analysis (OPLS-DA) combined with variable importance in the projection (VIP)； Quantitative descriptive analysis (QDA)， differential spectrogram and thermographic cluster analysis all showed that compared with crude fish oil， aldehydes， ketones and other undesirable flavor substances in refined fish oil were significantly reduced. This study provides a theoretical basis for Takifugu rubripes liver oil as a new type of fish oil.

Abstract:In this paper， an amine-sensitive fluorescent probe CHM was designed and synthesized using benzopyran as a fluorophore by introducing an electron-withdrawing group tricyanofuran to extended conjugated system. The probe can recognize 11 amines with an off-on fluorescence response， a large Stokes shift (120 nm)， a low detection limit (putrescine， 1.3 μmol/L) in EtOH/H2O (5/5， V/V) solution， and can imaging for putrescine in living cells. Probe CHM is loaded onto the gelatin to obtain sensing gelatin CHMGL. CHMGL shows significant color changes to volatile amines， which can be used to monitor the freshness of salmon fish in real time through colorimetric and fluorescence dual-channels， and can accurately judge the freshness of fish.

Abstract:Due to the potential carcinogenic and teratogenic health risks caused by synthetic antioxidants， it has become a research hotspot and development trend in food preservation to develop natural， safe and efficient plant-derived antioxidants to replace synthetic antioxidants. However， most antioxidant active components have application defects， such as poor stability and short persistence. Functional groups in nano delivery carriers are an international frontier technology to realize efficient utilization of active components of drugs or food. It integrates interdisciplinary， basic theoretical research and new product development closely. Due to its extremely high specific surface area and diverse surface controlled release structure， it can realize the effect of micro-addition of functional factors and efficient utilization， showing great research and application value. It has become a research hotspot at home and abroad in recent years. This paper summarizes the development and principle of electrospinning technology， focuses on the latest research progress of electrospinning preparation of antioxidant nano-functional materials in the food field in recent years， and puts forward the current development status and problems of electrospinning preparation of antioxidant nano-functional materials， in order to grasp the development trend of antioxidant regulation at home and abroad in time. This study provides essential information support for the development of antioxidant materials in the future.

Abstract:It was found that polysaccharide has the characteristics of low toxicity， high efficiency and good biological activity， and it is widely used in the prevention of gastrointestinal diseases. Based on an overview of the source and chemical structure of polysaccharides， this paper systematically analyzed the regulatory mechanisms of different kinds of polysaccharides on gastrointestinal function and their protective effects on gastric mucosa， providing new ideas for exploring the biological activities of polysaccharides and their mechanisms of action in the body， as well as the regulatory mechanisms of gastrointestinal diseases.

Abstract:Peanut varieties in China are rich in resources and have a large space for development and utilization. The protein composition and subunit content of different peanut varieties are quite different， which determines their different functional characteristics and affects the application field of peanut protein. This paper reviews the current situation of peanut variety resources in China， introduces the composition of peanut protein， and summarizes the differences in protein composition between different varieties and the relationship between different protein components and subunits and their functional characteristics from the perspective of peanut protein composition and structural changes. The relationship between the structure and functional properties of peanut protein under the influence of new technology， enzyme treatment and other factors， and its application in the food field were introduced， aiming to provide a theoretical basis for the processing and utilization of peanut protein in the future.

Abstract:Wheat bran is widely available and rich in a variety of nutrients， which are beneficial to human health. However， adding wheat bran to flour to make whole grain products results in poor palatability and low consumer acceptance， which hinders the utilization of its nutritional functions in the food system. Enzymes are usually used to change wheat brans' structure and increase SDF content to improve physicochemical properties and expand the application of wheat bran and increase its economic interests. In the current review， the types of enzymes， the changes in dietary fiber structure (molecular weight， degree of branching and ferulic acid) and physicochemical properties (water holding capacity， water absorption， viscosity， solubility， crosslinking) before and after modification were summarized firstly. Besides， the effects of modified wheat bran on the water distribution state， rheological properties， thermal properties， gluten network structure， gelatinization， and starch regeneration of dough were also reviewed. The current review reveals the effect of dietary fiber structure changes on wheat bran and dough quality， providing a reference for the application of modified wheat bran in whole wheat products.

Abstract:The basic taste of food is closely related to our daily life and food research. Although a large number of landmark achievements have been achieved in this field， and a consensus on some mature mechanisms， laws， and applications has been formed， the present research status， main academic context and future development trends of this field have not been systematically analyzed and summarized. Therefore， 15 445 literature from the core database of the Web of Science from 2012 to 2021 have been selected as the source data， and the bibliometric analysis methods have been used to analyze the number and distribution of literature on the basic taste of food， as well as the evolution trend of the main academic context and Keywords. The results indicate that the study of the basic taste in food not only involves in the food flavor and sensory perception， but also involves in the interdisciplinary and integrated fields such as the food texture， biochemistry， molecular biology， molecular simulation technology， sensors， biological activity， and psychology. The number of the taste publications is gradually evolving into the following pattern: sweetness > acidity > bitterness > umami > saltiness， and the first three types of tastes are still the mainstream tastes in the food studies. The United States， China， and Japan are among the top three countries in the basic taste research， and the cooperation between countries is relatively frequent. China ranks second in the world in terms of total publication number， H-index， and total citation frequency， but only in the field of umami， China ranks top ten in terms of total publication number， and the publication number of the individual institutions or authors. In addition， in this paper， the evolution trend and main emerging Keywords of basic taste research hotspots in recent years have been analyzed through the literature analysis of the taste combination and keyword jump analysis. Therefore， this paper provides an important guidance for experts and scholars in the fields of food science and so on to grasp the scientific direction， development rules and research hotspots of food basic taste research as a whole， and also provides a theoretical support for the decision-making in the food flavor industry.

Abstract:The issue of food safety in schools is of vital interest to a large number of teachers and students and is a focal point of public concern， which can easily trigger significant negative public opinion on the internet. Adhering to the institutional logic of ‘structure-operation-assurance’， constructing an analytical framework of ‘regulatory body-regulatory methods-regulatory evaluation’ to analyze the current food safety supervision in schools. There are issues such as oversight in the implementation of policies by the regulatory bodies， insufficient capacity to respond to emergencies， an inadequate regulatory system， the need for improvement in the school food outsourcing model， an imperfect performance evaluation system， and a lack of food safety awareness. Based on the analysis of these issues and their causes， and in conjunction with relevant experiences from abroad， including a comprehensive legal system， multi-level regulatory models， strict industry access， severe punishment and penalties， and a focus on campus food safety education and parental participation， the following suggestions are put forward: strictly implement the school ‘first-in-command’ responsibility system， continuously improve the institutional mechanisms for school food safety， continuously improve the school food safety supervision system， focus on strengthening the management of school canteen food outsourcing， build a smart integrated food safety system platform， improve the food safety emergency response mechanism， and strengthen the safety training of school catering industry personnel. These suggestions provide effective strategies for improving the governance of school food safety conditions.

Abstract:As the cornerstone of national economy and people's livelihood， the dairy industry promotes the diversification of food supply as well as the modernization of food industry and agriculture. Furthermore， it significantly improves the nutritional health of the national population. Based on down-to-earth accumulation for more than 70 years， Chinese dairy industry has cut a striking figure on the global stage and achieved the transition from ‘learning from others’ to ‘focusing on innovation’. Facing the challenges of globalization， scientific and technological innovation has occupied center stage in Chinese dairy industry. This article sorts out 12 innovation hotspots of Chinese dairy industry based on new transformation in the development of global dairy industry， including evidence of dairy nutrition and health， customized breeding of dairy cows， bioactivity of milk components retention， exploration of high value-added ingredients， and digital and intelligent management of the whole industrial chain. Those hotspots will provide insight and guidance for scientific and technological innovation as well as development of Chinese dairy industry.