Antibiotics are effective in treating bacterial infections, but they also disrupt the gut microbiota, thereby causing side effects such as diarrhea, flatulence and indigestion. Probiotics and fecal microbiota transplantation (FMT) have attracted widespread attention due to their ability to restore the balance of the gut microbiota and alleviate various conditions. In this study, the mechanism of action of FMT and the probiotic Lacticaseibacillus paracasei HNU502 in alleviating the side effects of cefotaxime, a common antibiotic, using combination of metagenomics, pathological analysis and gas chromatography. The findings suggested that FMT alleviated antibiotic side effects by restoring the disturbed gut microbiota, while HNU502 worked by reestablishing the balance of the gut microbiota. Both FMT and probiotic supplementation improved gut microbiota composition, but to varying degrees, prevented goblet cell loss, and increased the contents of mucin-2 (MUC-2) and zonula occludens-1 (ZO-1), thus aiding gut mucosal recovery. Moreover, the two approaches ameliorated the metabolic disorders of short-chain fatty acids, inhibited the secretion of pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α as well as blood urea nitrogen (BUN), and effectively reduced virulence factor enrichment. This study contributes to a better understanding of the link between human health and gut microbiota, and provides new therapeutic options for mitigating antibiotic side effects, which is of great significance for improving patients’ health status and quality of life.

This study was focused on 16 strains of Ligilactobacillus ruminis isolated from fecal samples of healthy persons from different families in Kashi, Xinjiang. Genomic and phylogenetic analysis were conducted, and the in vitro probiotic characteristics of the strains were compared. Genomic analysis revealed that the average genome size, gene number, and GC content of the L. ruminis strains were 1.4 Mb, 1 374, and 43.55%, respectively. Notably, there were significant differences in the number of strain-specific genes, ranging from 3 to 886 (strain K646-58L had a notably higher number of specific genes compared with all other strains). In phylogenetic analysis, strains from the same family did not cluster together as closely based on their hosts’ genetic relatedness. The carbon source utilization experiments showed that the L. ruminis strains could utilize soybean oligosaccharides, cottonseed xylose, and maltodextrin, but not sorbitol or xylitol. The carbohydrate-active enzyme database (CAZy) annotated a large number of genes involved in polysaccharide substrate metabolism, such as the glycoside hydrolase (GH)1 and GH13 gene families. The 16 strains showed resistance to aminoglycosides but susceptibility to tetracyclines and chloramphenicol, which was not completely consistent with resistance gene prediction. All L. ruminis strains had high self-aggregation ability (> 50%) and good hydrophobicity (> 20%). Based on the genetic and phenotypic characteristics, L. ruminis had excellent probiotic properties, especially strains K227-6L and K645-5L. This study lays the theoretical foundation for the development and application of potential probiotic strains.

Purpose: To explore the laxative effect of Lacticaseibacillus rhamnosus Glory LG12 from the perspective of the stem cell factor (SCF)/C-kit signaling pathway. Methods: Male ICR mice were randomly divided into five groups: control, model, low- (1.5 × 106 CFU/mouse), medium- (1.5 × 107 CFU/mouse), and high- (1.5 × 108 CFU/mouse) dose L. rhamnosus Glory LG12. After 15 continuous days of gavage, all mice were further gavaged with loperamide hydrochloride suspension (4 mg/kg) to establish a mouse model of constipation. Body mass, the time taken until the first black stool excretion, the number and mass of black stool within 5 hours, small intestinal transit rate, serum levels of gastrointestinal regulatory peptides and inflammatory cytokines, colonic SCF and C-kit transcription levels were measured, and colonic pathology was examined. Results: Compared with the model group, medium- and high-dose L. rhamnosus Glory LG12 significantly reduced the time taken until the first black stool excretion (P < 0.001), increased the number and mass of black stools within 5 h (P < 0.01 and P < 0.001, respectively), and improved the ink propulsion rate in the small intestine (P < 0.001). In addition, both treatments elevated the serum levels of motilin (MTL), gastrin (Gas), substance P (SP), and interleukin 10 (IL-10), reduced the levels of endothelin-1 (ET-1), somatostatin (SS), vasoactive intestinal peptide (VIP), and IL-6, up-regulated the relative mRNA expression of SCF and C-kit in colonic tissue was (P < 0.01, P < 0.001), and restored damaged colonic barrier. Conclusion: L. rhamnosus Glory LG12 promotes gastrointestinal motility by affecting the release of gastrointestinal regulatory peptides and inflammatory cytokines through the modulation of the SCF/C-kit signaling pathway, thereby alleviating constipation symptoms.

In order to investigate the occurrence of cellular autophagy and its effect on the meat color of Qinchuan cattle during postmortem aging, the changes in the meat color, relative myoglobin content, metmyoglobin reductase activity (MRA), beclin1, microtubule-associated protein light chain 3-II (LC3-II), autophagy-related protein 7 (ATG7), sequestosome 1 (p62), caspase 8, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels of the longissimus dorsi muscle of Qinchuan cattle were determined at different time points during postmortem aging at 4 ℃. It was found that as the aging time was prolonged, L* and a* values as well as beclin1, LC3-II and ATG7 protein expressions initially increased and subsequently decreased, caspase 8, p62 and ROS showed an opposite trend; the relative contents of deoxymyoglobin (DeoMb) and oxymyoglobin (OxyMb), MMP and MRA decreased, whereas b* value and the relative content of metmyoglobin (MetMb) increased. Moreover, the key proteins related to cellular autophagy were expressed to different degrees during the postmortem process, and muscle cells exhibited autophagy, the strongest autophagic activity being observed at 96 h. Correlation analyses showed a highly significant correlation among the key proteins related to cellular autophagy (P < 0.01), indicating that these proteins were closely related to each other in cellular activity. There were significant correlations between meat color parameters and cellular autophagy-related proteins and mitochondrial function at 0-96 h during the postmortem process (P < 0.05). The above results showed that the changes in mitochondrial function and autophagy in myoblasts during the early postmortem period affect meat color, and beclin1, LC3-II, ATG7, p62, and caspase 8 can be used as biomarkers to predict the changes of meat color during the postmortem process.

In order to investigate the differences in the quality of different rice cultivars with geographical indication (GI), 9 GI rice landraces were analyzed for 18 quality indicators including appearance, nutritional quality, cooking and eating quality, and volatile compounds. Using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) followed by odor activity value (OAV) analysis, the major odor-active compounds of rice were identified as 2-acetyl-1-pyrroline, hexanal, heptanal, octanal, nonanal, trans-2-octenal, hexanol, 1-octen-3-ol, and heptanol. A total of 42 differential volatile compounds were detected in GI rice from Northeast China versus other regions in the country using multivariate statistical analysis, including 25 hydrocarbons and 17 volatile aroma compounds such as alcohols, ketones, aldehydes, and esters. The results of correlation analysis showed that the protein content was significantly negatively correlated with the amylose content and the taste value, and the amylose content was significantly related to the gelatinization properties of rice starch. The protein content had an extremely significantly negative correlation with the aldehyde content and a significantly positive correlation with the hydrocarbon content. Cluster analysis divided the nine GI rice varieties into three categories. The first category consisted of five varieties to Northeast China, characterized by low chalky grain rate and protein conetent, high amylose content, low pasting temperature, firm and elastic texture, and high proportions of aldehydes, alcohols and ketones. The second category included Yuanyang rice and Xiaozhan rice, characterized by moderate pasting temperature and amylose content and the highest levels of total volatile compounds (627.7 μg/kg) and hydrocarbons (269.6 μg/kg). The third category comprised rice varieties from Sheyang and Chongming in South China, characterized by low amylose content, high viscosity, high pasting temperature, soft and sticky texture, and medium levels of hydrocarbons (159.4 μg/kg). This study could provide the basis for the quality evaluation of different GI rice culvars.

This study was conducted in order to explore the changes in the texture and flavor of dried shiitake mushroom during rehydration. Dried shiitake mushroom was rehydrated at different constant temperatures (40 and 100 ℃) for up to 180 min. An electronic tongue, headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and laser scanning confocal microscopy (LSCM) were used to analyze the texture and flavor characteristics of shiitake mushroom during the rehydration process. The results showed that both rehydration temperature and time had significant effects on the texture, volatile flavor and taste of rehydrated mushroom. At 40 ℃, the rehydration ratio almost reached equilibrium after 30 min, and the umami intensity was the second highest, but the water retention capacity decreased compared with all other groups. The hardness and chewiness of the 40 ℃/30 min group were moderate, whereas the elasticity was the highest. The browning index of cap was the second highest, while the browning index of gills was not significantly different from that of any other group. Microscopic observation showed that the mycelium was unfolded and the shear force was moderate. In addition, the antioxidant activity of mushroom rehydrated at 40 ℃ was higher than that of mushroom rehydrated at 100 ℃, the loss of soluble protein was less, and the content of free amino acids was higher and reached its maximum after 30 min. Furthermore, the characteristic flavor substances, mainly sulfur compounds and ketones, were well retained after rehydration at 40 ℃, but decreased seriously at 100 ℃. In conclusion, the texture and flavor of shiitake mushroom changed significantly during the rehydration process, and rehydration at 40 ℃ for 30 min resulted in better quality of shiitake mushroom.

This study investigated the effect of different concentrations of salicylic acid (SA) on triterpenoid biosynthesis and reactive oxygen species (ROS) content in Ganoderma applanatum mycelium. The results showed that the maximum content of total triterpenoid of 60.793 mg/g was obtained at an SA concentration of 250 µmol/L. SA at 250 µmol/L was added at different time points during the 10-day culture period. The optimal timing of induction was found to be addition of SA on the 6th day, and the total triterpenoid content reached 67.413 mg/g upon culture completion, which was 59.2% higher than that of the control group. The analysis of antioxidant enzyme activity and malondialdehyde (MDA) levels in the mycelium of G. applanatum indicated that the intracellular catalase (CAT) activity and MDA levels peaked on the 8th day, which increased by 55.3% and 77%, respectively compared with the control group. The activity of total superoxide dismutase (SOD) continuously increased, indicating that SA could induce an increase in reactive oxygen species (ROS) content. Untargeted metabolomic analysis of terpenoid metabolites showed that under optimal induction conditions, 7 out of 22 terpenoid metabolites were up-regulated, one was down-regulated, and 14 remained unchanged. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway and heatmap analyses found that the up-regulated metabolite farnesol to be an important precursor in the triterpenoid biosynthesis pathway and its production was significantly correlated with ROS. In conclusion, SA is an effective exogenous inducer of triterpenoid biosynthesis in G. applanatum mycelium. This study provides an effective method for increasing the triterpenoid content in G. applanatum mycelium and offers new insights into the mechanism of SA-induced triterpenoid biosynthesis.

To find an effective method for eliminating white spots on the surface of soybean paste and enhancing its quality, this study analyzed the relationship between microbial community succession and physicochemical properties and the tyrosine metabolic pathway throughout the entire production cycle of soybean paste. The results showed that the dominant bacteria during the fermentation process were Klebsiella, Bacillus, Tetragenococcus, Pediococcus, Staphylococcus, Enterococcus and Weissiella, and the dominant fungi were Aspergillus, Zygosaccharomyces and Issatchenkia. The microbial community succession was primarily affected by pH, total acidity and amino nitrogen content. The primary functional communities involved in tyrosine metabolism were Enterobacter and Bacillus. Furthermore, in the initial stage of fermentation, Bacillus exhibited a higher potential for tyrosine degradation, whereas Enterobacter demonstrated a significantly greater potential for tyrosine synthesis during the whole fermentation process. These results provide a theoretical basis for reducing the tyrosine content in soybean paste and addressing the issue of white spots and holds practical significance for enhancing the visual quality of soybean paste products.

In order to effectively prevent and treat microbial contamination in foods, L-methionine-modified microcrystalline cellulose (M-MCC) with antibacterial effect was prepared by loading L-methionine (L-Met) on microcrystalline cellulose (MCC). The morphology, element composition and stability of M-MCC were characterized, indicating the successful grafting of L-Met. M-MCC had a good scavenging effect on 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radicals, with a scavenging percentage of 97.47% at 20 mg/mL. M-MCC had a marked antibacterial activity against the Gram-positive bacteria Listeria monocytogenes and Staphylococcus aureus, with minimal inhibitory concentration and minimum bactericidal concentration of 15 and 30 mg/mL, respectively. Finally, the effect of M-MCC on the cell membrane permeability, cell membrane integrity, cellular contents and DNA content of the two bacteria was studied. The results showed that M-MCC treatment had a significant inhibitory effect on the growth of L. monocytogenes and S. aureus, and delayed the time taken to reach the logarithmic phase compared with the untreated group. Furthermore, it resulted in obvious changes in extracellular conductivity and the contents of nucleic acid and protein, which was closely related to the treatment time. This study shows that M-MCC has great application potential as an antibacterial agent.

To study the in vitro cleavage effect of a recombinant lysin from bacteriophage vB_VpP_1 on Vibrio parahaemolyticus, the gp32 gene fragment of vB_VpP_1 was identified as a lysin gene according to the results of whole-genome sequencing (WGS) and functional analysis. The amino acid sequence and structure of gp32 were analyzed by various tools such as Expasy. Primers were designed using Primer 5.0 software and cloned into the pET-28a(+) vector for prokaryotic expression. The lytic activity of the purified lysin against the host bacterium before and after being treated with ethylene diamine tetraacetic acid (EDTA) was measured. Tertiary structure analysis showed that the lysin was a spherical hydrophilic protein, which was predicted to contain two catalytic domains. This was consistent with the basic characteristics of Gram-negative phage lysins. The lysin had no transmembrane region or signal peptide. The purified bacteriophage vB_VpP_1 had a lysin activity of approximately (1 487 ± 182) U/mg, which showed a strong capacity to lyse V. parahaemolyticus with damaged cell walls but not V. parahaemolyticus with intact cell walls. The prokaryotic expression vector for bacteriophage vB_VpP_1 lysin was successfully constructed, and the expressed and purified lysin could lyse V. parahaemolyticus with damaged cell walls.

The protective effect of Bacillus subtilis JZXJ-7 (JZXJ-7) on Vibrio parahaemolyticus (Vp) infected mice was investigated. Totally 28 male C57BL/6J mice were randomly divided into four groups: a Vp infection model group (infected with the standard virulence strain ATCC33847), two JZXJ-7 intervention groups (administered at low (106 CFU) and high (108 CFU) doses by gavage), and a control group. The control and model groups were administered with an equal volume of normal saline. Disease activity index (DAI), Vp load in the intestine tract (including the ileum, cecum, and colon), colonic pathological alterations, colonic cytokine contents, oxidative stress resistance, and changes in intestinal microbial community composition were detected in all groups. The results showed that the protective effect of JZXJ-7 was better at the high dose than at the low dose. High-dose JZXJ-7 significantly reduced the DAI and intestinal Vp load in Vp infected mice, alleviated inflammatory cell infiltration and collagen deposition, and increased the number of intestinal epithelial goblet cells (P < 0.05). Moreover, high-dose JZXJ-7 significantly inhibited cytokine-mediated inflammation, increased antioxidant enzyme activities and enhanced intestinal permeability. Furthermore, JZXJ-7 significantly increased (P < 0.05) intestinal microbial diversity, partially reversing intestinal flora disturbance, enriching Akkermansia, Bifidobacterium, Clostridium and other beneficial bacteria, and thus resulting in the restoration of intestinal microecological homeostasis. In summary, JZXJ-7 can effectively alleviate colonic pathological damage in Vp infected mice and maintain intestinal functions, and the underlying mechanism may be related to its regulatory effect on the intestinal microbiota.

In this study, bovine serum albumin (BSA) and genipin (GP) were used to prepare BSA nanoparticles loaded with black rice anthocyanins (BRA-BSAGP) to improve the stability and bioactivity of BRA. The interaction between BSAGP and BRA was analyzed, the release characteristics of BRA-BSAGP during simulated gastrointestinal digestion were explored, and the ameliorative effect and mechanism of BRA-BSAGP on Caco-2 cell damage induced by dextran sulfate sodium (DSS) were investigated. BRA-BSAGP showed a uniform spherical morphology with an encapsulation efficiency of (81.10 ± 0.08)%. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the successful encapsulation of BRA in BSA nanoparticles. In vitro gastrointestinal digestion demonstrated that BRA-BSAGP nanoparticles effectively delayed the release of BRA, with release percentages of 22.51% and 20.10% under simulated fasting and fed conditions, respectively. BRA-BSAGP significantly increased the survival rate of Caco-2 cells induced by DSS and up-regulated the expression of tight junction proteins (Claudin-1, occludin, and ZO-1). This study provides a theoretical basis for the application of BRA in developing functional foods for alleviating ulcerative colitis.

This study aimed to explore the ameliorative effect of Hovenia dulcis fruit pedicel polysaccharides (HDPs) on intestinal injury in alcohol-exposed mice. Using high-throughput 16S rRNA gene sequencing technology and metabolomics, we investigated the impacts of HDPs on the gut microbiota and metabolic profile of mice with alcohol-induced intestinal injury. Additionally, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, real-time quantitative polymerase chain reaction (qPCR), and Western blot were employed to detect the changes in the expression of intestinal inflammatory factors, tight junction proteins, bile acid metabolism-related genes and proteins. The results indicated that HDPs significantly reduced the levels of pro-inflammatory factors such as interleukin-4 (IL-4), interferon-gamma (IFN-γ), and tumor necrosis factor-α (TNF-α) in mice with intestinal injury induced by alcohol, decreased the levels of lipopolysaccharide (LPS) and lipopolysaccharide binding protein (LBP), increased the level of α-amylase (AMS), and upregulated the tight junction protein Claudin 1, thereby improving intestinal barrier function. 16S rRNA sequencing revealed that compared to mice gavaged with alcohol at 114 µL/20 g mb, HDPs increased the abundance of the Lactobacillus genus and reduced alcohol exposure-induced disorders in gut microbiota diversity and structure. Metabolomics analysis found that HDPs could regulate bile acid metabolism and reduce the levels of bile acids (especially taurocholic acid and chenodeoxycholic acid) in the intestine of alcohol-exposed mice. Furthermore, HDPs inhibited the mRNA and protein expression of apical sodium-dependent bile acid transporter (ASBT) in the intestine of alcohol-exposed mice, thus reducing the absorption of bile acids and alleviating the negative impact of alcohol on the intestine. In summary, HDPs has the potential to ameliorate alcohol-induced intestinal damage by improving intestinal barrier function through the modulation of the gut microbiota and bile acid metabolism. This finding will provide a new perspective and theoretical basis for the application of HDPs in functional foods.

Objective: To investigate the sleep-aiding effect of casein-derived peptide TPTLN and explore its possible mechanism of action. Methods: Thirty mice were divided equally into three groups, an experimental, a positive control and a blank control group, which were gavaged with TPTLN at a dose of 5 mg/kg mb, intraperitoneally injected with diazepam at a dose of 1 mg/kg mb, and gavaged with sterilized water at a dose of 5 mg/kg mb, respectively. The body mass of all the mice was recorded every day. After 7 days of continuous administration, a sodium pentobarbital-induced sleep test was carried out to evaluate sleep quality. Following 4 more days of administration, the mice were euthanized and dissected to collect blood and tissue samples for analysis. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (GABA), 5-hydroxyindoleacetic acid (5-HIAA), glutamate (Glu), β-endorphin (β-EP), cortisol, norepinephrine (NE) in the serum and brain tissue, and the GABA/Glu ratio was evaluated. real-time quantitative polymerase chain reaction (qPCR) was used to detect the effect of TPTLN on the mRNA relative expression levels of γ-aminobutyric acid A receptor α1 (GABAA-α1) and 5-hydroxytryptamine receptor 1A (5-HT1A) in the hypothalamus. Results: Compared with the control group, TPTLN and sodium pentobarbital synergistically increased the sleep onset rate to 100%, significantly shortened the sleep latency by 31.7% (P < 0.05), and extended the sleep duration 2.1 times (P < 0.05); increased the GABA/Glu ratio in the serum and brain tissue by 68.8% and 19.3%, respectively and significantly improved the excitation/inhibition imbalance (P < 0.001, P < 0.000 1) as evidenced by a 49.4% increase in the serum GABA level (P < 0.001), a 7.6% increase in the brain 5-HT level, and a 24.3% and 23.4% decrease in the brain levels of cortisol and NE (P < 0.05); and significantly up-regulated the expression levels of the GABAA-α1 and 5-HT1A genes 1.5 and 1.3 times, respectively (P < 0.01, P < 0.05). Conclusion: Casein-derived peptide TPTLN exhibited a favorable sleep-aiding effect, and the underlying mechanism may be associated with the regulation of GABAA-α1 and 5-HT1A expression levels, as well as the modulation of neurotransmitter contents including GABA, Glu, 5-HT, cortisol and NE in the brain.

In this study, three levels of grape load (15, 20, and 25 spikes/m shelf) were set for the primary wine grape cultivar ‘Cabernet Sauvignon’. The effect of different harvest times, four growth stages according to the Eichhorn-Lorenz scale: E-L35, E-L36, E-L37, and E-L38 was investigated on the compositions of organic acids, monomeric phenols and volatile compounds and sensory quality of wine. The results showed that at the E-L38 stage, the total acid of grape berries in the medium-load group significantly increased, while the opposite was true for the low- and high-load groups. For all groups, the total acid content of wine peaked at the E-L35 stage and reached its lowest point at the E-L37 stage. The total phenol content reached its peak at the E-L36 stage, and then decreased rapidly. Under the low-load condition, the sensory quality of wine produced from early harvested grapes was superior to that of late harvested grapes, whereas the opposite result was found at the high load. The typicality and richness of wine were significantly improved with the delay of harvest time, samples J-20-6 (medium load + E-L37) and J-20-7 (medium load + E-L38) outperforming all other samples. The overall sensory score of sample J-20-5 (medium load + E-L36) was the highest, and the total volatile content and sensory richness score of sample J-25-7 (high load + E-L38) were the highest among all tested samples. Thus, meticulous regulation of grape load and harvest time holds substantial promise for enhancing wine quality.

To elucidate the chemical material basis of the flavor quality of Chongjue Luohan tea, four representative tea samples (Zifu, Ankang, Ping’an and Jufu teas) were analyzed by sensory evaluation and metabolomics based on ultra-high performance liquid chromatography-quadrupole-mass spectrometry (UPLC-Q-MS). The results showed that Luohan tea contained higher levels of tea polyphenols, ranging from 13.7% to 18.1%, than traditional black tea (9.6%). In addition, a total of 206 secondary metabolites were identified in Luohan tea, including flavonoids (71), amino acids and their derivatives (31), organic acids (24), nucleotides and their derivatives (19), phenolic acids (16), alkaloids (12), and saccharides and their derivatives (7). Multivariate statistical analysis pinpointed 46 differential metabolites. Notably, Zifu and Ankang tea samples contained higher levels of bitter and astringent components, such as flavanols, proanthocyanidins and flavanol glycosides, whereas Ping’an and Jufu tea samples were richer in umami and sweet components, such as L-asparagine and L-theanine. The results of this study provide a reference for research to develop new types of Luohan tea.

In order to investigate changes in the lipid composition of different tissues of Cyperus esculentus L. at different growth stages, non-targeted lipidomics based on ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was employed for relative quantitative analysis of the lipid metabolites in the above-ground stems, tubers, and roots of C. esculentus L. after 70, 93, and 120 days of growth. A total of 16 904 lipid metabolites were identified and 720 differential lipid metabolites were found between the three tissues, the contents of differential lipid metabolites being significantly higher in the tubers than in the above-ground stems and roots. The main lipids accumulated in the growth process of C. esculentus L. were triacylglycerols (TAG). All three tissues had high proportions (higher than 57.3%) of unsaturated fatty acids relative to the total fatty acids (FAs), and the relative contents of unsaturated fatty acid FA(18:1) and FA(18:2) in the tubers were also high. This study provides basic data and a scientific basis for the application of C. esculentus L. in various fields such as food processing and product development.

Auricularia auricula was selenized by adding exogenous selenium to the compost. The effect of selenization on the dynamic changes of metabolic pathways and metabolites in A. auricula was investigated using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics combined with different multivariate statistical analyses such as principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and hierarchical cluster analysis. Totally 669 metabolites were identified in A. auricula, inorganic selenized A. auricula grown on sodium selenite, and organic selenized A. auricula grown on selenium-rich corn straw. A total of 228 differential metabolites (DEMs) were obtained in A. auricula vs inorganic selenized A. auricula, and 267 DEMs in A. auricula vs organic selenized A. auricula. It was found that selenization had a great effect on the contents of organic acids and their derivatives, lipids and lipid-like molecules in A. auricula, and the effect of organic selenization was more pronounced. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis found that selenization had a significant effect on lipid and amino acid metabolism. These results showed that lipid metabolism, amino acid metabolism and the biosynthesis of other secondary metabolites in A. auricula changed significantly after selenization, which had a significant effect on lipids, amino acids and other metabolites in A. auricula. This indicated that selenization affected the nutritional composition and flavor quality of A. auricula.

In order to investigate changes in the quality, flavor and major aroma components of pickled chilies in ceramic jars during fermentation, this study used headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze the volatile substances of pickled chilies in ceramic jars from a certain producer after storage for 1–5 years and determined their physicochemical indexes and total bacterial counts. The results showed that the levels of soluble salt-free solids, total acids, total esters, amino nitrogen and total colony count of chopped chili peppers kept changing with storage time, and the quality and aroma kept improving in the first three years, and then the quality declined in the fourth year. A total of 112 volatile compounds were detected, including 22 acids, 12 alcohols, 36 esters, 5 ketones, 9 aldehydes, 5 phenols, 18 hydrocarbons, and 5 other compounds. The volatile composition and content varied with storage time, and 36 volatile compounds with odor activity values (OAVs) greater than 1 were found, which played an important role in the overall aroma of chopped chili peppers. Among them, linalool and methyl salicylate, ethyl salicylate, 4-ethyl-2-methoxyphenol were common to all samples. The samples stored for 1–3 years were superior in terms of organoleptic quality, physicochemical properties and volatile components, while those stored for more than 3 years had a strong aroma but poorer texture.

In order to explore the sensory characteristics of Pixian Douban (PXDB), a Chinese geographical indication product, a trained sensory panel was used to establish a sensory wheel and a quantitative descriptive profile (QDP) for PXDB. The pivot profile method and the M-value were combined to develop 53 sensory descriptors in terms of appearance, basic taste, aroma, flavor and texture for 21 commercial PXDB products. Out of these 53 sensory descriptors, 23 were further selected and an intensity reference sample was developed for each of them. Quantitative descriptive analysis (QDA) was used to evaluate the sensory quality of different types and grades of PXDB. The results showed that traditional PXDB had stronger soy sauce-like and spicy flavor, a stickier texture, more complete broad beans, and greater hardness. Compared with traditional PXDB, chili oil PXDB, reddish brown in color, had stronger oily and spicy aromas, wettability, and oily flavor. Higher grades of PXDB had more prominent soy sauce-like aroma and fermented soybean-like flavor and tasted more mellow. This study provides basic data and a reference for the sensory quality evaluation, quality control and improvement of PXDB.

In this study, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) coupled with high-throughput sequencing was used to analyze physicochemical properties, volatile flavor compounds and bacterial community structure of broad bean paste from Sichuan and Chongqing. The results showed that the contents of water, salt, total acids and amino nitrogen of the nine tested samples ranged from 54.33% to 70.46%, 12.49% to 16.90%, 0.44% to 1.46% and 0.17% to 0.41%, respectively. Based on their odor activity values (OAVs ≥ 1), a total of 32 volatile substances including 3-methyl-1-butanol, linalool, phenethyl alcohol, isovaleraldehyde, 2-methylbutyraldehyde, phenylacetaldehyde, ethyl phenylacetate, methyl laurate, ethyl laurate, isovaleric acid, 4-ethylphenol, 4-ethyl-2-methoxyphenol were identified as the characteristic flavor compounds of broad bean paste from the two regions, which contributed to the floral, fruity, malty and soy sauce-like flavor characteristics. In broad bean paste, the dominant bacterial phyla were Firmicutes, Proteobacteria and Cyanobacteria, and the dominant bacterial genera were Bacillus, Pseudomonas, Staphylococcus, Oceanobacillus, Lactobacillus and Enterobacter. Orthogonal partial least squares-discriminant analysis (OPLS-DA) was employed to establish a prediction model with good stability for discriminating the nine samples of broad bean paste. Using the cutoff of variable importance in projection (VIP) score > 1, 29 characteristic volatile compounds were selected. Spearman’s correlation analysis found a correlation between the characteristic flavor substances and the dominant bacterial genera in broad bean paste. This study lays the foundation for further in-depth study on broad bean paste from Sichuan and Chongqing, and provides a reference for optimizing the production of related products.

To investigate the effect of milling equipment on the quality of whole wheat flour, four whole wheat flours with similar average particle sizes were obtained by direct crushing methods (hammer cyclone mill, gear mill, and low-temperature impact mill) and back addition method (Chopin mill), and their nutritional compositions, polyphenol contents, damaged starch contents, and gelatinization properties were evaluated. The particle size distribution of the resulting brans and the rheological properties of dough made from each of the four whole wheat flours were analyzed. The results showed that back addition had less damaging effect on bran than direct crushing. Among the three direct crushing methods, the particle size of bran ground by low-temperature impact mill was the smallest (118.00 μm). The soluble dietary fiber and free polyphenol contents of whole wheat flour ground by low-temperature impact mill were 2.22% and 48.11 mg/100 g, respectively, which were significantly higher than those of all three other flours. The relative content of damaged starch in whole wheat flour prepared by the back addition method was 3.85%, which was significantly lower than that of the direct crushing methods. Moreover, the former had better gelatinization properties and viscoelasticity. The results of this study provide a theoretical basis for the preparation and application of high-quality whole wheat flour.

In this study, a custom apparatus was utilized to obtain blueberry samples with high and low levels of mechanical injury (DI and DII group), which were subsequently stored at 4 or 25 ℃ and analyzed using low-field nuclear magnetic resonance (LF-NMR) spectroscopy. Spectroscopic data and proton density images were collected at 0, 6, and 24 h post-damage. The results demonstrated a significant impact of injury on the water state and distribution of blueberries. Notably, the cell wall water content A21 decreased, whereas the cytoplasm water content A22 increased over time post-damage. The A22 of the high injury group increased by 1.45 times at 24 h compared with that at 0 h, while the vacuole water content A23 and the total water content A2 notably declined, indicating a rapid redistribution and transfer of water from damaged blueberries to the external environment. As the degree of damage increased, the major peak of vacuole water shifted to the right and decreased significantly. Furthermore, increasing storage temperature further exacerbated these changes. At 25 ℃, the emergence of 4 relaxation peaks at both 6 and 24 h after damage indicated a significant deterioration in the quality of blueberries. Compared with 25 ℃, storage at 4 ℃ was more conducive to maintaining fruit integrity and slowing down the rate of moisture loss from damaged blueberries. The experimental results provide a theoretical basis and data reference for the rapid detection and mechanistic understanding of mechanical damage in blueberries.

This study established a novel method for measuring the contents of asparagine (Asn) and glutamine (Gln) in fruits and vegetables based on enzymatic hydrolysis combine with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After enzymatic hydrolysis with Pronase E, samples were treated with butylated hydroxyanisole as an antioxidant. The supernatant was collected for analysis by UPLC-MS/MS. The chromatographic separation was accomplished on a Phenomenex kinetex F5 column using gradient elution with a mobile phase consisting of methanol and 0.02% formic acid in water. The mass spectrometer was equipped with an electrospray ionization source and operated in the positive ion mode with multiple reaction monitoring (MRM), and quantification was achieved using stable isotope-labeled internal standards. The calibration curves for Asn and Gln showed a good linearity in the range of 10–1 000 ng/mL (R2 > 0.999), with limit of detection (LOD) and limit of quantification (LOQ) of 1.5 and 5.0 mg/100 g, respectively. The recovery rates were in the range of 80.0%–112.8% with relative standard deviations (RSDs) of 1.2%–9.1%. The contents of Asn and Gln in 49 common vegetables and 50 common fruits were determined by the UPLC-MS/MS method. In vegetables, the average total content of Asn and Gln decreased in the order of bean > potato > onion and garlic > edible fungi > melon > solanaceous > cabbage. Notably, the total contents of Asn and Gln in beans were significantly higher than those in green leafy vegetables (P < 0.01). In fruits, the average total content of Asn and Gln decreased in the order of drupes > melons > aggregate fruits > berries > citrus > banana > nuts, and drupes had significantly higher total contents of Asn and Gln than nuts (P < 0.05). These findings suggested that individuals with urea cycle disorders should eat more nut fruits and green leafy vegetables, with less asparagine and glutamine, in daily life, especially vegetables and fruits with higher ratio of branched-chain amino acids to Asn plus Gln such as Chinese cabbage, Auricularia auricula, green onion, coconut juice, longan, and pomelo, and should eat less vegetables and fruits with lower ratio of branched-chain amino acids to Asn plus Gln such as potato, pumpkin, green bean, cantaloupe, red plum and yellow peach.

A novel metal-organic framework (MOF) material, UiO-66-NH2, was synthesized using a solvothermal method. Subsequently, a high performance liquid chromatography (HPLC) method with solid phase extraction using UiO-66-NH2 was established for the simultaneous detection of five fluoroquinolone (FQ) residues in aquatic products. The sample was extracted with acetonitrile in 1.0% formic acid, degreased with n-hexane, and concentrated by rotary evaporation. The extract was then redissolved in aqueous ammonia solution at pH 8.0. The FQs were enriched and purified with a solid phase extraction (SPE) column filled with 30 mg of UiO-66-NH2 using 6 mL of 20% acetic acid-methanol solution as the eluent. The collected eluate was blown to dryness under nitrogen, redissolved and detected by HPLC with a fluorescence detector. Under the established experimental conditions, good linear relationships were achieved for the five FQs in the concentration range of 0.005–0.50 mg/L, with determination coefficients (R2) of 0.999 9–1.0. The recovery rates ranged from 81.4% to 104.8% with relative standard deviation (RSD) of 1.29%–4.93%, and the limits of detection (LOD) were in the range of 0.21–2.05 μg/kg. The prepared SPE column could be reused up to five times, which was environmentally friendly and cost-effective. The established method had good accuracy, precision, reproducibility, and selectivity, and was suitable for the simultaneous detection of various trace FQ residues in aquatic products.

A method for the determination of 14 human milk oligosaccharides (HMOs) in infant formula milk powder was established by hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The sample was deproteinized by ethanol precipitation and degreased by freezing prior to separation by HILIC. The analytes were detected by multiple reaction monitoring (MRM) and quantified by an external standard method. Under optimized conditions, all HMOs showed good linear relationships within their respective concentration ranges, with determination coefficients (R2) greater than 0.994. The average recovery rates from blank goat’s and cow’s milk powders at three spiked levels ranged from 90.3% to 109.2%, with relative standard deviation (RSD) in the range of 0.7%–9.7% (n = 6), and the limit of detection (LOD) between 0.002 and 0.048 μg/mL. The developed method is characterized by fast analysis speed, high sensitivity and good accuracy, and meets the requirements for the rapid detection of the 14 HMOs in infant formula milk powder.

In this study, a method based on weak cation exchange (WCX) solid phase extraction (SPE) coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 13 aminoglycoside (apramycin, amikacin, paromomycin, hygromycin B, ribostamycin, kanamycin, streptomycin, gentamicin C1, dihydrostreptomycin, tobramycin, spectinomycin, neomycin and micronomicin) residues in milk. Samples were extracted using a mixture of ammonium acetate buffer solution and acetonitrile, and purified using a WCX SPE column. Chromatographic separation was achieved using a SILICA SG80 column with gradient elution using a mobile phase made up of 0.1% formic acid aqueous solution and acetonitrile. Detection was accomplished using an electrospray ionization source (EIS) in the positive ion mode, and quantification was carried out using a matrix-matched external standard method. Excellent linear relationships were observed for the 13 aminoglycosides in the concentration range of 5.0-500.0 ng/mL (R2 ≥ 0.998 3). The limit of detection (LOD) for hygromycin B, ribostamycin, streptomycin, tobramycin, and dihydrostreptomycin were 3 μg/kg, and the limit of quantification (LOQ) were all 10 μg/kg for these aminoglycosides. For apramycin, amikacin, paromomycin, kanamycin, gentamicin C1, micronomicin, neomycin and spectinomycin, the LODs and LOQs were 15 and 50 μg/kg, respectively. The recovery rates of milk spiked at 1 ×, 2 × and 5 × LOQ levels were 73.8%–107.4%, with relative standard deviation (RSD) of 1.0%–9.8%. This developed method is sensitive, simple, stable, and suitable for the determination of these 13 aminoglycoside residues in milk.

The contamination of foods by foodborne pathogenic and spoilage microorganisms is one of the major causes of foodborne diseases. Therefore, ensuring food quality and extending its shelf life are urgent concerns for researchers. The application of electrospinning technology to encapsulate bioactive substances in antimicrobial food packaging is an effective method to ensure food safety. First, this article reviews the basic principle of electrospinning, the types of electrospinning used for antimicrobial food packaging, the factors influencing electrospinning, and the electrospinning materials used in antimicrobial food packaging. Next, the bioactive substances encapsulated in electrospun nanofibers and the co-encapsulation systems for bioactive substances based on electrospinning are summarized systematically. Finally, we examine recent progress in the application of electrospun nanofibers encapsulating bioactive substances in antimicrobial packaging for meat, dairy products, fruits and vegetables, and we also discuss the challenges and future trends for antimicrobial food packaging based on electrospinning. The aim of this study is to provide theoretical support and a basis for the application of electrospun nanofibers encapsulating bioactive substances to effectively inhibit foodborne pathogens and spoilage microorganisms in the food industry.

Tenderness is one of the most important indicators to judge meat quality, and it is also the most important sensory index for consumers to choose meat. Postmortem muscle undergoes complex biochemical processes, and apoptosis is considered to be a key biochemical pathway to regulate postmortem muscle tenderization. Lysosomes are rich in cathepsins, and a large amount of cathepsins are released after lysosomal membrane permeabilization, which activates the caspase cascade through the intrinsic lysosomal-mitochondrial pathway, triggering apoptosis and consequently accelerating postmortem muscle tenderization. This article introduces the action mechanism and metabolic processes of lysosomes and elaborates the activation pathways of lysosomal membrane permeabilization through reactive oxygen species (ROS), sphingosine, B-cell lymphoma-2 (Bcl-2) and p53 proteins. Furthermore, it explores the pathway for the involvement of lysosomes in apoptosis, and summarizes the regulatory mechanism of lysosomes on muscle tenderization from the perspectives of the release of cathepsins and Ca2+, caspase activation and iron-induced oxidative stress. We hope that this review can provide a theoretical reference for improving meat tenderness.

Cereals, as the staple food for humans, are rich in a variety of nutrients such as moisture, proteins, fats and carbohydrates. However, the quality of cereals can be seriously affected by long-term storage, mold contamination and heterogeneous cereals, which jeopardize food security. Therefore, accurate and rapid detection of nutrients, physicochemical properties, and mold contamination in cereals is essential for food quality control and nutritional assessment. Near infrared spectroscopy has been widely used as a rapid and non-destructive detection method for cereal analysis in recent years. This paper aims to review the current status of the application of near infrared spectroscopy in the detection of cereals nutrients (starch, fat, protein and bioactive compounds), physicochemical properties (starch viscosity, hardness and farinograph parameters), mold contamination and other aspects (freshness, variety identification, heavy metals and pesticide residues), summarize and compare the advantages and disadvantages of common model algorithms, and propose some problems and future trends in the application of near infrared spectroscopy in cereal detection, in order to provide a reference for further improvement of near infrared spectroscopy in the detection of cereals.

The Maillard reaction imparts appealing aroma, color and texture to foods such as bread and coffee; however, in milk and dairy products, the Maillard reaction decreases their nutritional value and generates various harmful compounds, including furosine, furfural, and advanced glycation end-products (AGEs), which are associated with chronic diseases in humans. Understanding the formation mechanisms of harmful Maillard reaction products in dairy products and establishing control methods for these compounds are crucial for improving the quality of dairy products. This article elaborates on the biohazardous nature of harmful Maillard reaction products in dairy products, and focuses on the formation pathways of furosine, 5-hydroxymethylfurfural, and AGEs. Furthermore, the advantages and disadvantages of the methods used for the detection of harmful products from Maillard reaction are reviewed, as well as recent advances in the area. Lastly, this review highlights the current strategies for controlling harmful products from Maillard reaction in dairy products. The aim of this paper is to provide scientific guidance for monitoring and controlling harmful products of Maillard reaction in dairy products.

Rutin, a flavanol glycoside derived from quercetin, is classified as a secondary metabolite from the phenylpropane metabolic pathway in higher plants. It possesses various pharmacological and physiological activities, including antioxidant, anti-aging, anti-inflammatory, anti-diabetic, and anti-cancer properties. With the deepening of pharmacological and physiological research on rutin, plant-derived foods rich in it have garnered significant research attention in the food industry. Biotransformation techniques, such as germination, have been shown to effectively enhance the rutin content and nutritional value of plant-derived foods by regulating the synthesis and metabolism of rutin in plants. This article summarizes the natural sources and biosynthesis pathways of rutin in plants as well as the characteristics and regulation of the key enzymes involved in rutin metabolism, hoping to provide a theoretical basis and research ideas for enriching rutin in plant-derived food materials and facilitating the development and application of functional and plant-based foods.

Soybean protein has high nutritional value and excellent functional characteristics, which has attracted much attention in the food industry, and is often used to improve the processing performance and nutritional value of foods. However, the functional characteristics of natural soybean protein are only limitedly applied, which cannot meet the needs of food processing, so modification of soybean protein has become a research focus. Modification technologies such as heat, high pressure and enzymatic treatments have been widely used and breakthroughs have been made. Soybean protein monomer or polypeptides can self-assemble and aggregate into amyloid-like fibrils under acid and high temperature conditions, resulting in changes the solubility and gelation properties of soybean protein. To enhance our understanding of recent progress in soybean protein amyloid-like fibrils (SPAF), this paper reviews the preparation methods and the formation mechanism of SPAF analyzes the influence of processing conditions on SPAF, and outlines the functional characteristics of SPAF such as solubility, gelation, foaming and emulsification properties. Furthermore, this review summarizes the application of SPAF and gives an outlook on future development in this field. It is our hope that this review will provide a reference for the application of SPAF in the food field.

Taurine is a non-essential sulfur-containing amino acid that is widely distributed in the human body, primarily supplemented through the diet. Taurine can combine with bile acids to form taurine-conjugated bile acids (Tau-Bas), which can be dissociated to release taurine by the gut microbiota. The interaction between taurine/Tau-Bas and the gut microbiota significantly influences both physiological and pathological processes. This article provides an overview of the gut microbiota and the sources and transformation of taurine in the body, and focuses on the interaction between taurine and the gut microbiota and the effect of taurine supplementation on reshaping gut microbiota homeostasis. The aim is to provide a scientific basis for the development of preventive and therapeutic measures for diseases related to gut microbiota imbalance.

Mung bean proteins have become a new source that can replace animal and soybean proteins due to their high nutritional value and health benefits, and have ideal functional characteristics. As one of their important functional properties, the gel properties of mung bean proteins are widely used in food processing. It is found that the gel properties of mung bean proteins can be enhanced by adding different exogenous substances or by different modification methods to meet the needs of food processing. In this paper, the formation mechanism of mung bean protein gels, the effects of different exogenous additives and processing technologies on the structure and gel characteristics of mung bean proteins are dissected, and the current status of research on the gel characteristics of mung bean proteins is summarized. Finally, the application of the gel characteristics of mung bean proteins in foods is summarized, aiming at providing a reference for furthering the application of mung bean proteins in the food industry.