Salmonella Enteritidis, an important foodborne pathogen, has posed a significant burden on clinical infection treatment due to the emergence of multidrug-resistant and highly pathogenic strains.In order to explore genetic evolutionary relationships among clinical isolates of S. Enteritidis, as well as their antibiotic resistance and virulence characteristics, this study conducted Whole Genome Sequencing (WGS) on five clinical strains, and their antibiotic resistance and virulence were characterized.Bioinformatic analysis of the WGS revealed that the five Salmonella strains belonged to the serotype of Enteritidis, the sequence type (ST) was identified as ST11.The cgSNP phylogenetic analysis indicated that the strain 48A clustered together with one strain isolated from chicken in the public database, while the other four strains showed a closer evolutionary relationship with clinically isolated strains from the database.Microbroth dilution assays confirmed antibiotic resistance of all five strains, with four of them exhibiting multidrug resistance.Strain 33A showed resistance to colistin and polymyxin B.Evaluation of motility, biofilm formation, and lethality to Galleria mellonella larvae revealed that strain 48A exhibited the highest virulence.However, this strain showed relatively weak adhesion and invasion capabilities to Caco-2 cells.The results suggested that strain 48A is a highly virulent strain, potentially originating from food, the resistance to multiple polysaccharides of strain 33A warrants attention.The findings of this study may contribute to the traceability and treatment of clinically resistant S.Enteritidis.

Pork and its products are often contaminated by Staphylococcus aureus, and the formation of S.aureus biofilm can cause cross-interaction between related food and processing equipment.Therefore, the construction of the boundary model under the combination of specific environmental factors is helpful to determine the growth probability and growth limit of planktonic bacteria, and can be combined with fence technology to control food quality.S.aureus in pork was inoculated in different pH (5.0,6.0,7.0,8.0) media at different temperatures (5, 15, 25, 35 ℃) for 24, 48, 72 and 96 hours, respectively.The viable bacteria were counted by plate counting method, and the boundary model of S.aureus adhesion or biofilm formation was established by logical regression.The results showed that culture temperature and culture time significantly affected the adhesion of S.aureus, while the biofilm formation of S.aureus was related to the interaction of culture temperature, pH and culture time.The adjusted coefficient of determination of the two boundary models are 0.881 and 0.944 respectively, and the root mean square errors are 0.087 and 0.108 respectively, while Akaike information criterion (AIC) and Bayesian information criterion (BIC) are in the acceptable range, indicating that the fitting effect of the model is acceptable.The results of this study are helpful to determine the probability of S.aureus adhesion and biofilm formation under the combination of various environmental factors, and can provide theoretical reference for the formulation of biofilm control measures in the processing and sale of meat.

Caffeic acid is a natural phenolic acid with various pharmaceutical properties, including antioxidant, anti-tumor and anti-inflammatory effects.It is also an important precursor for biosynthesis of other valuable compounds such as rosmarinic acid, chlorogenic acid and phenethyl caffeate.Therefore, caffeic acid has significant value in pharmaceutical, food, cosmetic and other industries.To achieve green and sustainable production of caffeic acid, the prephenate dehydratase gene (PHA2), which is involved in the biosynthesis of phenylalanine, was knocked out in a previously constructed caffeic acid produced Saccharomyces cerevisiae, resulting in a 42% improvement in caffeic acid production.Additionally, the anthranilate synthase gene (TRP2), which is responsible for tryptophan biosynthesis, was deleted.However, this had little effect on coffee acid production.The engineered strain was further complemented with auxotrophic marker URA3, HIS3, MET15.In a subsequent fed-batch fermentation process conducted in a 5 L bioreactor, the engineered strain achieved a caffeic acid production of 9.3 g/L, this is currently the highest reported titer of caffeic acid produced by engineered microbial cells.This study provides a foundation for the green production of caffeic acid and its derivatives.

Pediococcus acidilactici is a group of probiotics known for its high lactate production.This study aims to investigate the alleviation of depressive symptoms in mice by P.acidilactici CCFM6432 and its underlying mechanisms.A Chronic Unpredictable Mild Stress (CUMS) model in mice was established for 4 weeks, followed by probiotic interventions with Lactobacillus strains (CCFM6432 and control strain FXJKS25M4).Results from the analysis of gut microbiota and metabolites revealed that, compared to both the model and control groups, CCFM6432 intervention significantly regulated the levels of gut metabolites such as lactate, uracil, and adenine.This intervention reduced the abundance of pathogenic gut bacteria and increased the abundance of Lachnospiraceae, a family associated with short-chain fatty acid synthesis, thereby assisting in the restoration of intestinal barrier integrity and the normalization of elevated lipopolysaccharide (LPS) levels in the serum.Additionally, CCFM6432 downregulated the expression of receptor proteins and pro-inflammatory factors involved in the TLR4/NF-kB signaling pathway in the brain.This inhibition contributed to the suppression of excessive microglial cell activation in the hippocampus.This study elucidates how CCFM6432 alleviates depressive symptoms by regulating specific gut metabolites to inhibit the growth of pathogenic gut bacteria, shedding light on novel insights for the treatment of depression and the exploration of the gut-brain axis signaling pathways.

The objective of this study was to investigate the regulatory mechanism of α-linolenic acid-rich enzyme-esterified oil on steroid hormone secretion and metabolism in spontaneously hypertensive rat (SHR), aiming to provide a data basis for evaluating the physiological efficacy of the enzyme-esterified oil.Seven-week-old SHR were divided into five groups:blank group, enzyme-esterified oil group, sheep tail fat group, flaxseed oil group, and rapeseed oil group.They were fed with 10% different oils for three months.The levels of blood lipids, liver kinase, and sex hormones were determined using ELISA;while the expression of steroid hormone-related genes and proteins was detected through q-PCR and Western-blot analysis.The results revealed that compared to the blank group, LDL-C levels decreased in the enzyme-esterified oil group while HDL-C levels increased(P>0.05).There was no significant difference observed in liver kinase activity among all groups (P>0.05).Although testosterone level in the esterified oil group was higher than that in the rapeseed oil group, there was no statistically significant difference (P>0.05).Notably, expression levels of steroid hormone synthesis acute regulatory protein (StAR), cholesterol side chain cleavage enzyme (CYP11A1), and cytochrome P450 17A (CYP17A1) were significantly higher in both esterified oil and sheep tail fat groups compared to the rapeseed oil group (P<0.05).In conclusion, it can be inferred that enzyme-esterified oil is similar to its raw material sheep tail fat as it improves blood lipid profiles and liver function which subsequently enhances testosterone secretion along with its steroid hormone metabolism thereby alleviating symptoms associated with SHR.

To investigate the effect and mechanism of Peach gum polysaccharide (PGP) in relieving constipation.Constipation model mice were established by continuous intragastric administration of loperamide hydrochloride (10 mg/kg BW) for 14 days, and peach gum polysaccharides (100 and 300 mg/kg) were given for 3 weeks after the model was successful.The number of fecal grains, fecal water content, first black stool time, intestinal propulsion rate, gastric emptying rate and behavioral indexes were measured within 6 hours during administration.The contents of Gastrin (GAS), Motilin (MTL) and 5-hydroxytryptamine (5-HT) in serum were determined by ELISA.The number of goblet cells in colon tissues was observed by Alcian blue-periodate Scheff (AB-PAS) staining.The colonic morphology was observed by H&E staining.The expression of 5-HT3R (5-HT3R) in colon tissue of mice was observed by immunohistochemistry.The expression of tight junction proteins Occludin and Claudin-1 in colon tissue of mice was observed by immunofluorescence method.The relative expression of Occludin, 5-HT3R and tryptophan hydroxylase 1 (TPH-1) in colon tissue was determined by Western blot.Peach gum can significantly increase the grasping power, the number of autonomous activities, the number of open arm entry and the stay time of open arm in mice with constipation model.Increase fecal grain count, fecal moisture content and gastric emptying rate, shorten the time of first black stool;Increase the levels of GAS and MTL in serum;Increase the number of goblet cells in colon tissue, improve intestinal mucosal injury, and up-regulate the expression of Occludin and Claudin-1 proteins;The level of 5-HT in serum and the expression of 5-HT3R and TPH-1 protein in colon tissue were increased.Peach gum polysaccharide can ameliorate constipation, and its mechanism may be related to promoting gastrointestinal hormone secretion and activating 5-HT signaling pathway.

In order to explore the best formula of black garlic effervescent tablet and its effect on intestinal microecology.The optimal formula of black garlic effervescent tablets was determined by single factor analysis and response surface test using sensory score as index.By measuring the average thickness, hardness, average weight, moisture content, foaming amount, disintegration time and pH value;In vitro proliferation tests of Escherichia coli and Lactobacillus were conducted to evaluate their quality and effects on the proliferation of two intestinal bacteria in vitro.The best formula of black garlic effervescent tablet was black garlic powder 6.00 g, sucrose 3.50 g, alginateg 0.80 g sodium, citric acid 3.38 g, maltodextrin 1.0 g, fructooligosaccharide 0.5 g, xylo-oligosaccharide 0.5 g, sodium bicarbonate 2.5 g.The average thickness of black garlic effervescent tablets was (4.98±0.09) mm, the hardness was (48.7±1.2) N, the average weight was (1.96±0.07) g, the moisture content was (4.85±0.05)%, the foaming volume was (7.12±0.14) mL, and the disintegration time was (4.63±0.19) min.pH value 5.63±0.01.The in vitro value-added test showed that the inhibition or promotion effect of black garlic effervescent tablet on two common intestinal bacteria, E.coli and Lactobacillus, was significantly enhanced with the increase of dose, which confirmed the effect of black garlic effervescent tablet on some intestinal microorganisms, and may selectively participate in the regulation of human intestinal microecology.

In order to obtain a compound probiotic with a better comprehensive ability to lower blood glucose and lipid levels, this study tested the effectiveness of eight commonly available probiotics in blood glucose lowering abilities, cholesterol clearance, gastrointestinal tolerance, and other activities in vitro.Principal component analysis was used to screen out strains with better comprehensive ability by taking the measured indicators as factors.Antagonism analysis was then performed among the strains, and the optimal proportion of compound probiotics was also determined.Additionally, a preference analysis for prebiotics was performed on the compound probiotic.The results showed that Lactobacillus plantarum CFFM1031 and Bifidobacterium lactis CFFM2012 were the most effective strains in reducing blood glucose and lipid levels.No antagonistic effect was observed between these two strains.The study found that a compound with a 1:1 ratio of L.plantarum CFFM1031 and B.lactis CFFM2012 significantly lowered cholesterol by 43.56% in vitro compared to single strains and other compound ratios.Moreover, the compound probiotic exhibited a higher proliferation ability when galacto-oligosaccharide and stachyose were used as carbon sources, indicating a preference for these sources.This study can provide a reference for probiotic synergism and the development of functional food formulations.

As a common food-borne pathogen, Staphylococcus aureus can pose a threat to food safety and human health.This paper investigates the bacteriostatic stability and mechanism of silymarin for the development and application of natural preservatives. The study determined the minimum inhibitory concentration of silymarin against S.aureus strains ATCC25923, ATCC29213, ATCC6538 and Salmonella, with ATCC25923 identified as the most sensitive strain.The stability of silymarin was analyzed through alterations in temperature, pH, and ultrasonic treatment.The possible antibacterial mechanism was explored by measuring the growth curve, surface hydrophobicity, zeta potential, aggregation degree of bacteria, glucose utilization, as well as observing with fluorescence and scanning electron microscopes.The results show that the antibacterial activity of silymarin has good thermal stability and acid-base stability, but higher power ultrasonic treatment can reduce its antibacterial activity.At the same time, the minimum inhibitory concentration of silymarin to S.aureus ATCC25923 is 0.5 mg/mL, and the minimum inhibitory concentration to S.aureus ATCC29213 and ATCC6538 is 0.8 mg/mL, which can achieve the purpose of inhibiting bacterial growth by delaying and shortening the logarithmic growth period of bacteria, changing the surface characteristics of bacteria, affecting their aggregation degree, energy metabolism, destroying cell morphology and affecting the formation of biofilm.The results of this study clarified the diversity of antibacterial mechanism of silymarin, which provided a theoretical basis for its further development as a food preservation coating.

In order to improve the antioxidant activity and main ingredients of medicinal and dietary pine pollen, three yeasts commonly used in food, Saccharomyces cerevisiae 1002, Kluyveromyces lactis 1572 and Saccharomyces cerevisiae 1905, were used to ferment pine pollen.The changes of antioxidant activity in vitro, total phenol and total flavonoid contents of pine pollen after 1~9 days of fermentation were investigated, and the changes in the composition and content of phenolic compounds were analyzed using UPLC-QTOF-MS and HPLC-PDA.The results show that the DPPH radical, ABTS radical scavenging ability and iron ion reducing ability of pine pollen were significantly increased after fermentation, with the highest increase of 229.20%, 139.10% and 52.12%, respectively, compared with pine pollen water extract.Significant increase of 143.50% in total phenol content was observed in 7 days of fermentation using Kluyveromyces lactis 1572.After fermentation, the total content of phenolic compounds increased up to 12.10 times, and five phenolic compounds were newly detected, including gallic acid, 4-hydroxybenzoic acid, p-coumaric acid, taxifolin and naringenin, with contents of 42.80~63.27、162.20~274.57、11.74~49.07、24.83~63.28, 5.80~59.63 μg/g.The correlation analysis has demonstrated that all three yeast fermentations were able to significantly enhance the antioxidant activity of wall-broken pine pollen by elevating the original phenolic content of pine pollen as well as increasing the content of newly generated phenolics.This study can provide new ideas for the full utilization of pine pollen resources and new product development.

The research aimed to identify the dominant bacteria in the preparation liquid of Platycodon grandiflorum (PG) processed with rice swill and explore the impact of PG fermentation by these dominant bacteria on platycodon saponin D content.PG underwent processing with rice swill, and the dominant bacteria in the preparation liquid were isolated and purified using MRS medium.Identification of the isolated strains involved Gram staining, catalase testing, and 16S rDNA sequencing.PG underwent fermentation with these three purified strains, and the platycodon saponin D content was determined using HPLC.Three strains of lactic acid bacteria, namely Weissella cibaria, Enterococcus faecalis, and Lactobacillus casei, were isolated.It was found that the platycodon saponin D content in fermented PG was higher than that in unfermented PG.Notably, the first two strains, Weissella cibaria and Enterococcus faecalis, increased the platycodon saponin D content in the fermented PG extract by 8.19% and 10.72%, respectively.Lactic acid bacteria emerged as the dominant bacterial group in the rice swill-processed PG preparation liquid.Pure strain fermentation of PG led to an increase in the platycodon saponin D content, suggesting microbial transformation during the rice swill processing of PG, thereby enhancing its activity.

To explore the effects of soybean protein isolate (SPI) on monacolin K (MK) and Monascus pigments (MPs) production by three strains of M.pilosus and one strain of M.ruber, the yields and homologues of MPs and MK produced by the aforementioned Monascus strains were investigated in solid and liquid states fermentation by UV spectrophotometry and HPLC.The results indicated that the red MPs production by M.ruber MJ-1 was increased by 4.59 times, the MPs yields of M.pilosus MS-1 and M.pilosus YDJ-1 were significantly inhibited, and the MK production of three Monascus pilosus strains were enhanced, when 1% SPI were used in solid-state fermentation (P<0.05).The yields of red, orange and yellow MPs produced by M.ruber MJ-1 and M.pilosus YDJ-1 were improved respectively, and the MK production of M.pilosus YDJ-2 was increased by 0.88 times (P<0.05), when 1% SPI was used in PDB medium.In the synthetic medium with 1% SPI, the yields of MPs with three colors produced by M.ruber MJ-1 and M.pilosus YDJ-1 were increased, respectively, and the MPs production by M.pilosus MS-1 was significantly inhibited (P<0.05).Moreover, the MK yields of M.pilosus MS-1 and M.pilosus YDJ-1 were promoted by 0.95 and 1.15 times, respectively (P<0.05).The results can provide a reference for regulating the selective production of MPs or MK by SPI.

Aim to investigate the changing patterns of bacterial community and the potential key spoilage bacteria in the storage process of sauced duck necks and wings in different regions, the sauced duck necks and wings on the market in bulk were taken from four different areas in Nanchang, and then stored at room temperature (20 ℃) for 2-6 days.Illumina MiSeq sequencing was used to analyze the bacterial 16S rDNA in 24 samples, resulting in total of 989 839 valid sequences, which were clustered into 458 operational taxonomic units.Bioinformatics analysis revealed the following findings:1) All samples are generally clustered according to geographical location, but samples from different types of sauced duck meat products and different storage times were relatively dispersed, suggesting that geographical location is the main factor affecting the microbial diversity of sauced duck meat products, and types and storage time are the other two factors;2) Weissella viridescens, Staphylococcus vitulinus, and Brochothrix thermophacta are the most abundant microorganisms in the sauced duck necks and wings, and they are common microorganisms in all samples, indicating that they may be the main spoilage microorganisms during the storage of sauced duck necks and wings.Using pure culture and molecular biology techniques, a bacterial strain (6-M) was isolated from sauced duck meat products and identified as W.viridescens, which was hypothesized to be a key decay-causing microorganism.This study provides a theoretical basis and strain resources for understanding the microbial spoilage mechanism of sauced duck necks and duck wings, as well as developing effective preservation strategies.

In order to develop a new way of resource utilization of corn steep liquor, 100% corn steep liquor was fermented with Aspergillus oryzae to prepare edible fungi nutrition.A.oryzae was acclimated continuously in 100% corn steep liquor solid medium to obtain A.oryzae strains that were more tolerant to 100% corn steep liquor, and then the optimal fermentation conditions for 100% corn steep liquor by A.oryzae were established.The results showed that compared with the original strain, the mycelia formation time and spore maturation time of A.oryzae were reduced by 40% and 30% after four consecutive acclimation in 100% corn steep liquor solid medium, respectively;the soluble protein content and amino acid nitrogen content were increased by 3.38% and 3.00%, respectively, when the acclimated A.oryzae was inoculated into 100% corn steep liquor.Using the acclimated A.oryzae as fermentation strain, the optimal fermentation conditions of 100% corn steep liquor were determined by single factor experiment and orthogonal test as follows:the inoculation amount 1.25×10⁵spores/100 mL, liquid loading amount 90 mL/250 mL,initial pH 5.9, temperature 25 ℃, fermentation time 8 d.Under these conditions, the amino acid content and soluble protein content were (21.75±0.12) mg/mL and (18.25±0.08) g/100 mL, which were 71.67% and 10.74% higher than unfermented corn steep liquor, respectively.

With the increasing market competition and industrial development needs, the distillation of Huangjiu into high spirits becomes a crucial approach for product diversification and new product development of Huangjiu.The study employed an industrial pot still to produce Huangjiu distillate, and the impact of heating power and discharge temperature on the flavor of Shaoxing Huangjiu distillate was examined, through quantitative descriptive analysis and GC-MS coupled with partial least squares discriminant analysis.Heating power significantly impacts the levels of 32 flavor components.At low power heating, the intensity of aromas reduces, especially for floral, fruity, and grassy flavors.Moreover, the levels of total esters and higher alcohols are significantly lower than other conditions.At medium heating power, the flavors of fruity, sweet, and grassy become robust, and the contents of ethyl acetate and isovaleraldehyde are higher.As the power increases, the wine releases more medicinal and smoky aromas, producing a slightly burnt and sweaty odor, and the levels of 4-ethylphenol, dimethyl disulfide, and hexanoic acid are further elevated.The discharge temperature significantly impacts the levels of 32 flavor components.At low discharge temperatures, the intensity of fruity, grassy, mushroom, and sweaty aromas significantly increases compared to other conditions, marking higher levels of ethyl lactate, isovaleraldehyde, 1-octen-3-ol, and hexanoic acid.The caramelized aroma is notable at medium discharge temperature, with high contents of 5-methylfurfural and hexanol.With increasing discharge temperatures, the content of 4-ethylphenol increases significantly, and the smoky aroma grows stronger.Furthermore, the wine yield rises with the increase of heating power and declines with the increase of discharge temperature.This study offers fundamental data and theoretical foundation for the accurate management of the distillation process of Huangjiu and the development of its products.

Daqu is known as the “bone of liquor” and its quality is very important for liquor fermentation.Illumina high-throughput sequencing was used to analyze the composition and change rule of the strong-flavor Daqu microbial structure in Qionglai producing area.The volatile flavor compounds were studied by headspace solid phase microextraction gas chromatography-mass spectrometry.Redundancy analysis and Heatmap correlation analysis were used to comprehensively analyze the correlation of microbial communities with the physicochemical properties of Daqu and volatile substances.The results showed that the properties of Daqu were negatively correlated with the storage time during preparation.The content of flavor substance was positively correlated with the storage time.Esters and alcohols are the main components of volatile substances.Esters are mainly methyl cetanoate, methyl 9-octadecanodienoate, methyl 9, 12-octadecanodienoate, and alcohols are mainly phenyl ethanol.The dominant bacterial genus were Staphylococcus, Escherichia-Shigella and Pediococcus. Thermoascus, Aspergillus and Pichia were the dominant fungi, respectively.Correlation analysis showed that the dominant bacterium Pseudomonas had a positive correlation with esterification power and a significant positive correlation with the content of methyl pentadecanoate (P<0.05), while the dominant fungi Archaeorhizomyces had a negative correlation with esterification power and an extremely significant negative correlation with the content of phenyl ethanol (P<0.01).The results showed that the properties and volatile substances of Daqu were significantly correlated with the dynamic changes of microbial structure.It studied the properties and dynamic changes of microorganisms in the preparation process of strong-flavor Daqu in Qionglai producing area, which provided certain theoretical basis for quality control of strong-flavor Daqu in Qionglai producing area.

Huangshui is a typical by-product during solid-state fermentation of Baijiu brewing process, which has a large annual output and presents a dual nature of pollution and resource.In the present study, the in vitro fermentation model was employed to evaluate the intestinal probiotic activities of two types of polysaccharides, including the crude and the purified polysaccharides, extracted from Huangshui in our previous research.The changes in pH, contents of short chain fatty acids, and molecular weights of two polysaccharides during the fermentation process were measured.Additionally, the composition of intestinal microbiota was determined after the fermentation periods.The findings revealed that compared with the negative control group, both the crude polysaccharide and the purified polysaccharide could significantly promote the production of short-chain fatty acids (P<0.05), consequently lowering the pH of the fermentation solution.Furthermore, the crude polysaccharide exhibited the ability to produce a higher concentration of short-chain fatty acids (P<0.05) comparing with the positive control group (inulin).Notably, there were varying degrees of changes in the molecular weights of the two polysaccharides during the fermentation process, indicating that they could be degraded and utilized by intestinal microbiota.Abundance measurements of intestinal microbiota illustrated that the crude polysaccharide effectively stimulated the proliferation of beneficial bacteria, such as Bacteroidota, Firmicutes, Actinobacteriota, Bacteroides, Coprococcus, Collinsella, and Anaerostipes, while reducing the relative abundance of Fusobacteriota, Fusobacterium, and Tyzzrerlla.Meanwhile, the purified polysaccharide showed an up-regulation effect on the relative abundance of Collinella and Blautia.In summary, both the crude and the purified polysaccharides had potential for probiotic activity, and the crude polysaccharide gave better results than the purified polysaccharide, which might be attributed to the presence of various polysaccharides as well as the higher levels of esters, proteins, and other substances in the crude polysaccharide.Therefore, we should also pay attention to the research and application of crude polysaccharide components in the quest for enhancing the high value utilization of Huangshui.

The dry red wine ‘Cabernet Sauvignon' was used as the research object to analyze the effects of different concentrations of chitosan, gelatin, and saponin treatments on the adsorption effect of ochratoxin A (OTA) in wine and the quality of wine.High-performance liquid chromatography (HPLC) was used to analyze OTA in wine samples.The results showed that for an initial concentration of 3.3 μg/L OTA, a 48-hour treatment with 1 g/L chitosan could achieve a 75.87% adsorption rate.Compared with gelatin and saponin at the same concentration, the adsorption rate of OTA increased by 11.27% and 21.02% with chitosan, respectively.Additionally, the adsorption rate of OTA increased with an increase in the concentration of the clarifying agent.In terms of the effects of different clarifiers on wine quality, the smallest loss of polyphenols occurred in the 0.6 g/L chitosan treatment.This treatment resulted in a 15.78% loss of total phenols, a 13.48% loss of total anthocyanosides, and a -11.41% loss of tannins, with the wine's transmittance reaching 78.02%.The 1.0 g/L chitosan treatment followed closely with similar effects.Considering the highest adsorption rate of OTA by the clarifier and the minimal influence on wine quality, the optimal treatment for OTA adsorption in wine was determined to be 1.0 g/L chitosan.Under this treatment, the adsorption rate of OTA reached 75.87% and the transmittance rate was 78.22%, providing technical support for the selection of a suitable OTA adsorbent.

Ciders were brewed through natural fermentation or yeast inoculated fermentation with six grape varieties, ‘Red Fuji', ‘Qing Xiangjiao', ‘Xiao Guoguang', ‘Pink Lady', ‘Granny Smith', ‘Hong Jiangjun' as raw materials.The effects of apple varieties on methanol production in cider and the correlation between pectin, pectinase activity and methanol content in cider were investigated in terms of physicochemical indexes, pectins and pectinase activities in apple juice and cider.The results showed that among the six apple varieties tested, the highest total pectin content was found in ‘Qing Xiangjiao', ‘Hong Jiangjun' and ‘Granny Smith', all of which exceeded 6 μmol/g.The naturally occurring pectinase activities in ‘Hong Jiangjun', ‘Qing Xiangjiao' and ‘Xiao Guoguang' were relatively high, all of which exceeded 80 U/g, and the pectinesterase activity in ‘Hong Jiangjun' was the highest at 1.78 U/g, followed by ‘Qing Xiangjiao' at 1.50 U/g.For inoculated fermentation treatments, the methanol content was lowest in ‘Red Fuji' cider at 0.17 g/L and highest in ‘Qing Xiangjiao' cider at 0.29 g/L.For the natural fermentation treatments, the methanol content was highest in ‘Xiao Guoguang' cider at 0.61 g/L, and lowest in ‘Pink Lady' and ‘Granny Smith' at 0.42 g/L and 0.41 g/L, respectively. The methanol content in naturally fermented cider was significantly higher than that in inoculated fermentation treatment, which may be related to the fact that the microbial-derived pectinesterase activity was always significantly higher in the natural fermentation than in the inoculated fermentation treatment.This study provides data reference for the selection of apple varieties suitable for cider brewing and the safe production of cider products.

In order to understand the composition of abiotic precipitate in Sichuan bran vinegar and its variation during the post-process and storage, ingredients of vinegar sample and sediment sample taken from different processes were analyzed and quantified in present study, including the raw vinegar and sediment from the whole or partial post-treatment process, and the liquid and sediment of the final product during storage.The results showed that the total acid content of raw Sichuan bran vinegar ranged from 4.6 to 4.9 g/100 mL, and it maintained between 6.0 to 6.4 g/100 mL after a series of processes.The sediment of Sichuan bran vinegar is mainly composed of protein and starch, which represent the major substances in sediment and account for 50%-60%.Among all the post production processes, double-effect falling film and boiling will cause 20% water evaporation and further led to concentrating the vinegar.These two processes considerably contribute to the increase in the content of protein, starch, and other substances in liquid.Although large tank static aging and membrane filtration can remove the sediment that have already formed, no significant effect on the prevention and control of subsequent turbidity has been observed.The amount of sediment in the final product gradually increased to about 0.29% along the storage time, mainly with an increase in protein, starch, pectin, iron ions, calcium ions, etc.The results of this study are intended to provide a theoretical basis for the vinegar enterprises to adjust the post-process vinegar and control measures towards non-biological precipitates.

In this study, pure culture technology was used to analyze the diversity of lactic acid bacteria in acidic-gruee in Shuozhou, Shanxi Province, and lactic acid bacteria that can be used in food processing were selected to fermented acidic-gruee, and then electronic tongue, high-performance liquid chromatography and amino acid analyzer were used to evaluate the taste quality of acidic-gruee.The results showed that 135 strains of lactic acid bacteria isolated from 40 acidic-gruee samples were identified to 20 species of 12 genera, among which Lactiplantibacillus argentoratensis (17.04%) was the dominant lactic acid bacteria in Shuozhou acidic-gruee.17 strains of Lactobacillus were selected to fermented acidic-gruee, and it was found that the taste quality of acidic-gruee was significantly different, mainly reflected in the sourness and umami aftertaste.The pure breed fermented acidic-gruee was rich in organic acids and amino acids.The main organic acids were lactic acid, acetic acid and citric acid, among which lactic acid was the main organic acid that causes the sour taste difference of acidic-gruee;The main amino acids were isoleucine, glutamic acid, and aspartic acid.To sum up, there were abundant lactic acid bacteria species in acidic-gruee in Shuozhou area.The taste quality of acidic-gruee prepared by different lactic acid bacteria was significantly different, and lactic acid was the main organic acid that affects the sour taste of acidic-gruee.

Biogenic amines are potential risk substances in food.In recent years, the accumulation of biogenic amines in pickles has gradually attracted widespread attention.In this study, 490 samples of pickles were collected from all over the country, and the biogenic amine content of pickles was determined by HPLC, and the formation reasons of biogenic amines in eight typical pickles were analyzed based on Pearson correlation.The results showed that the biogenic amine content of pickled vegetables was 0-2 093.49 mg/kg, in which 80.4% of the samples had a total biogenic amine content of less than 500 mg/kg, 13.5% had a biogenic amine content of (500-1 000) mg/kg and 6.1% had a biogenic amine content of ≥1 000 mg/kg.Putrescine, tyramine, cadaverine and histamine are the main biogenic amines in pickles.The content of biogenic amines in different processing techniques is quite different:Nanchong Dongcai have the highest biogenic amine content, with an average biogenic amine content of (1 031.64±509.26) mg/kg;Sichuan industrial pickled vegetables, Northeast sauerkraut and Fuling Zhacai are the second, with average contents of (722.1±406.10), (572.88±158.13) and (360.72±318.18) mg/kg respectively.The average biogenic amine content of other traditional Sichuan pickles, Zizhong Dongjian, Yibin Yacai and Spicy cabbage is less than 500 mg/kg.Total acid, pH, salinity and fermentation time are the key factors affecting biogenic amine accumulation.Pickled vegetables with higher acidity have higher biogenic amine content, while samples with low salt content have higher histamine content, and the longer fermentation time, the higher biogenic amine content.In microorganism, Lactobacillus, Leuconostoc, Streptococcus, and Occanobacillus have a positive correlation with biogenic amine content, with Lactobacillus having the most significant correlation (P<0.05).There was a significant positive correlation (P<0.05) between the Debaryomyces and histamine, while the Pichia, Kazachstania, Wickerhamomyces and Sterigmatomics were positively correlated with cadaverine, putrescine, and tyramine.This study can provide reference for food safety evaluation and biogenic amine content control of traditional pickles in China.

Bis(2-methyl-3-furyl) disulfide (BMFDS) is a key aroma compound in meat that interacts with α-amylase in the mouth, affecting the perception of aroma.The interaction mechanism between BMFDS and α-amylase and the influence of pH value were studied by gas chromatography-mass spectrometry, ultraviolet absorption spectroscopy, fluorescence spectroscopy, zeta-potential measurement, and protein surface hydrophobicity, molecular docking analysis here.The results showed that the spontaneous interaction between BMFDS and α-amylase formed a ground state complex that produced static quenching of α-amylase fluorescence.The interaction intensity order under different pH conditions was pH 7.0>pH 8.5>pH 5.0, and all of them were dominated by hydrophobic interactions.The interaction between BMFDS and α-amylase is affected by pH, but interaction force and reaction type are unaffected.In summary, there is a non-covalent interaction between BMFDS and α-amylase, resulting in a loose structure of α-amylase and different intensities under the three pH conditions.This study can provide a theoretical basis for subsequent meat flavor regulation.

To investigate the preventive effects of corn peptides on alcoholic liver injury, high-performance liquid chromatography-tandem mass spectrometry was used to identify the composition and sequence of corn peptides.And the peptides with preventive activity of alcoholic liver injury were screened from the identified corn peptides by molecular coupling method and pharmacokinetic and toxicological simulations of the peptides were also performed.The results showed that three peptides, Ile-Pro (IP), Ala-Pro (AP), and Val-Ala-Tyr-Pro-Glu (VAYPE), were identified from the corn peptides by product ion scanning and quantitative analysis with multiple reaction monitoring.The peptides were molecularly docked to the receptors of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase 2*2 (ALDH2*2).After analyzing the binding energies and the interaction forces of each docking, it was found that IP and VAYPE can bind with the receptors of ADH and ALDH well.Therefore, both IP and VAYPE can prevent alcoholic liver injury by accelerating alcohol degradation.After toxicological analysis, all three peptides were non-toxic, non-carcinogenic, non-sensitizing, non-mutagenic, and had good water solubility.In this paper, a fast and convenient molecular docking method was used for screening the peptides, which is more efficient than the traditional enzymatic method.Moreover, the method provided new thoughts for the screening of bio-active peptides of animal and plant origin, and this paper lays the foundation for the in-depth study of the activity of corn peptides in the prevention of alcoholic liver injury.

Prunus cerasifera Ehrh is rich in polyphenols and named ‘precious fruit in the snow region', but the anti-diabetic activity and its bioactive compounds remain unclear.In this study, 70% ethanol extraction and solvent fraction were applied to extract the polyphenols in purple PE (PPE).The antioxidant and hypoglycemic activities were evaluated by radical scavenging ability, enzymes inhibition ability, promotion of glucose consumption in HepG2 cells and anti-glycation ability assays.The major bioactive compounds were identified by liquid chromatography-mass spectroscopy technique.Results indicated that the ethyl acetate fraction of PPE showed the highest total phenolics (219.27 mg GAE/g E) and total flavonoids (165.58 mg QuE/g E) content, along with the strongest ABTS cation radical scavenging ability (163.36 μg /mL), α-glucosidase inhibition activity (28.95 μg /mL), promotion glucose absorption in HepG2 cells and anti-glycation abilities.The α-glucosidase inhibition was 31 times higher than that of acarbose.The n-butanol fraction of PPE showed the highest DPPH radical scavenging and DPP-4 enzyme inhibitory capacity.Forty-three compounds were identified from EAF by HPLC-QTOF-MS/MS, including 12 organic acids, 9 phenolic acids, 16 flavonoids and 6 other class of compounds.Therefore, ethyl acetate and n-butanol are the suitable solvents to extract active ingredients from PPE, phenolic acids and flavonoids are the major antioxidants and hypoglycemic compounds.This study could provide theoretical guidance for the application of PPE in hypoglycemic nutritional foods or dietary supplements.