To reveal the change pattern of microbial community structure in fresh pork during storage, samples were stored at 4 ℃ in this experiment. Five samples were collected at 0, 1, 3, 5, and 7 days respectively. The changes in the total number of colonies, the total number of mold and yeast, and the content of volatile basic nitrogen were measured. Furthermore, the bacterial 16S rRNA genes and fungal ITS high-throughput sequencing were further used to analyze the changes in the structure of microbial flora. The results showed that throughout the storage period, both the TVC and TVB-N content exhibited upward trends, increasing from 3.88 lg CFU/g and 5.77 mg/100 g to 6.83 lg CFU/g and 23.26 mg/100 g, respectively (P<0.05). The mold and yeast counts showed a trend of first increasing and then decreasing, with a significant increase to 2.71 lg CFU/g observed at 3 days of storage (P<0.05). Both Chao1 richness and Shannon diversity indices of bacteria and fungi exhibited significant declines (P<0.05). The β-diversity analysis revealed that the structures of bacteria and fungi were significantly difference across storage periods (P<0.05). At the genus level, the relative abundance of Brochothrix increased significantly during the storage stage and reached to 70.56%, becoming the dominant genus at Day 7, while Lactococcus and Acinetobacter showed marked depletion (P<0.05). Fungal communities were predominated by Kurtzmaniella, Debaryomyces, Aspergillus, Filobasidium, and Candida. Notably, the relative abundance of Kurtzmaniella increased significantly with prolonged storage (P<0.05), contrasting with reductions in Candida, Filobasidium, and Aspergillus (P<0.05). Spearman correlation analysis demonstrated significant positive correlations between the bacterial genera Brochothrix and Lactococcus and the fungal genera Kurtzmaniella and Candida, respectively. This study highlights Brochothrix, Lactococcus, Acinetobacter, and the fungal taxa Kurtzmaniella and Candida as critical contributors to chilled pork spoilage. These findings provide a theoretical foundation for optimizing shelf-life extension and quality control strategies in chilled pork preservation.

In order to explore the effect of compound antifreeze preservation liquid (3.5% CS+1.5% Inulin+0.5% PPP+0.04% Nisin) on the quality of golden pomfret in repeated freeze-thaw cycles, this study constructed a repeated freeze-thaw model, and compared the changes in the quality of golden pomfret under two treatment conditions: Without the addition of antifreeze and preservative solution (CK) and with the addition of a compound antifreeze and preservative solution composed of 3.5% CS, 1.5% Inulin, 0.5% PPP and 0.04% Nisin (EG) through the determination of the freezing rate, colour difference, water-holding capacity, freshness, texture characteristics, flavour characteristics, and other quality indexes. The results showed that the time required for EG to form the maximum ice crystal zone was about 20 minutes shorter than CK. After four freeze-thaw cycles, the brightness (L^*), yellowness (b^*), and whiteness (W) of both EG and CK increased, with the increase in EG being significantly lower than CK (P<0.05), and the redness (a^*) of both groups continuously decreased. With the increase of the number of freeze-thaw times, the texture characteristics of the two groups gradually deteriorated, and the deterioration degree of hardness, cohesion, adhesion and chewiness of EG was significantly lower than that of CK (P<0.05), and the comprehensive taste was better than CK. The pH of both groups tended to decrease and then increase. The TBARS and TVB-N values of the two groups also showed an increasing trend after multiple freeze-thaw cycles. After four freeze-thaw cycles, the TBARS and TVB-N values of CK were significantly higher than those of EG (P<0.05). During the freeze-thaw process, the electronic nose detected a continuously increasing sulfide signal (W1W, W2W). After four freeze-thaw cycles, the W1W response value of EG increased significantly less than that of CK (P<0.05), indicating that EG produced fewer sulfur-containing compounds after multiple freeze-thaw cycles. The CK held the water retention decreased to 75.85% and EG decreased to 80.93%, and the low-field NMR properties of EG were better than those of CK, and the water retention performance exhibited by T2 relaxation time was more stable. Based on various quality indicators, the degree of quality deterioration of the EG samples was significantly lower than that of the CK samples, indicating that this compound antifreeze and preservative solution can improve the texture and color of the flesh of the frozen and thawed golden pomfret, enhance water retention, and effectively maintain its commercial value. The research provides a reference for the preservation and quality maintenance of aquatic products during the circulation process.

This study investigated the effects of tamarind seed polysaccharide (TSP) addition on the quality attributes of beef meatballs during frozen storage. Using liquid rapid freezing technology, meatballs formulated with varying TSP concentrations (0%, 0.5%, 1%, 1.5%, and 2%, w/w) were analyzed over the storage period for changes in thawing loss, water-holding capacity, texture profile, color parameters, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), salt-soluble protein content, and sensory properties. The results demonstrated that TSP addition significantly enhanced frozen storage quality, with the 1% TSP treatment identified as optimal. Throughout storage, all samples exhibited increased thawing loss, TVB-N, and TBARS values, alongside decreases in water-holding capacity and salt-soluble protein content. Color and texture were also notably influenced. After 120 days of storage, the 1% TSP group showed 39.73%, 41.18%, and 8.91% reductions in thawing loss, TVB-N, and TBARS, respectively, compared to the control, while water-holding capacity and salt-soluble protein content were 14.67% and 12.82% higher. Moreover, the 1% TSP formulation received the highest sensory scores for aroma, color, taste, microstructure, and texture. These findings support the use of TSP as an effective polysaccharide-based additive for improving the quality and extending the shelf life of frozen meat products.

In this study, to mitigate quality deterioration in pre-fermented frozen red bean Baozi dough (PF-FRBBD) during freeze-thaw cycles, water-soluble yeast β-D-glucan (WSYG) was employed as an additive to investigate the effects of varying WSYG concentrations on gas production capacity, viable yeast count, moisture distribution, microstructure, and thermal properties of PF-FRBBD subjected to freeze-thaw cycles. Results revealed that, compared with non-frozen-thawed samples, PF-FRBBD subjected to 6 freeze-thaw cycles exhibited a 36.6% reduction in total gas production within 120 min and a 96.3% decrease in viable yeast count. Concomitantly, the water loss rate and water activity increased significantly (P<0.05), while the proportion of strongly bound water decreased, resulting in a rough and porous microstructure. After 6 freeze-thaw cycles, compared to the untreated samples, the PF-FRBBD supplemented with 0.5% WSYG showed a 17.2% increase in total gas production and a 66.7% increase in viable yeast count, with significant reductions in water loss rate and water activity (P<0.05), while maintaining an intact gluten network. In the 0.5% WSYG group, the specific volume and sensory score of steamed Baozi were determined as 1.67±0.02 mL/g and 63.5±1.6 points, respectively, reflecting a rise of 9.9% and 29.3% from untreated samples. The research findings affirm that water-soluble yeast β-D-glucan can effectively improve the quality of pre-fermented frozen red bean Baozi dough during freeze-thaw cycles, with the optimal addition level identified as 0.5%.

This study addresses the issues of poor water solubility and tendency to aggregate of 4-hexylresorcinol (4-HR) by preparing a β-cyclodextrin/4-hexylresorcinol inclusion complex (β-CD@4-HR) via the co-precipitation method. The structural characteristics of the complex were systematically analyzed using multiple characterization techniques. Using Litopenaeus vannamei as the subject, the preservative effect of β-CD@4-HR immersion treatment during 4 ℃ refrigeration was comprehensively evaluated through the analysis of typical freshness indicators, microbial determination, and sensory evaluation. The results showed that β-CD and 4-HR formed a stable inclusion complex at a 1:1 molar ratio, with an inclusion rate of 69.8%. Scanning electron microscopy (SEM) revealed that the surface morphology of the inclusion complex became regular and smooth. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses indicated that 4-HR existed in an amorphous state within the β-CD cavity. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H NMR) confirmed the interaction between the two via hydrogen bonding. Molecular docking further demonstrated that β-CD and 4-HR had the lowest binding energy (−4.376 kcal/mol), indicating the most stable structure. After inclusion, the water solubility of 4-HR significantly improved (saturation solubility reached 338 mg/mL), and in vitro release exhibited sustained-release characteristics. Moreover, the free radical scavenging ability was superior to that of free 4-HR. In the preservation of Litopenaeus vannamei during 4 ℃ refrigeration, β-CD@4-HR effectively inhibited melanosis, delayed texture deterioration, reduced polyphenol oxidase (PPO) activity, suppressed pH increase, controlled the rise in total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) values, and significantly inhibited the growth of total viable count (TVC). The overall preservative effect was superior to that of the free 4-HR group and the control group. Therefore, water-soluble β-CD@4-HR is a highly promising antioxidant preservative for aquatic products.

Objective: This study aimed to investigate the regulatory effects of Lacticaseibacillus paracasei LPB27, a strain isolated from infant intestines, on gut microbiota and elucidate its underlying mechanisms, thereby providing a scientific basis for its potential development as a novel probiotic agent. Methods: A total of 48 male BALB/c mice were randomly assigned to four groups: A control group and low-dose, medium-dose, and high-dose intervention groups, following the guidelines outlined in the "Test Methods for Regulating Intestinal Flora" from the ''Functional Evaluation Procedures and Test Methods for Health Foods (2023 Edition)''. The animals were administered LPB27 probiotic powder via gavage at doses of 0, 0.08, 0.17, and 0.50 g/kg body weight, respectively, over a period of 21 days. Body weight changes and alterations in target intestinal bacterial populations in fecal samples were monitored throughout the experiment. The composition and differential microbial species within the gut microbiota were analyzed using 16S rDNA high-throughput sequencing, while PICRUSt2 was employed for predictive functional profiling. Additionally, the concentrations of fecal short-chain fatty acids (SCFAs) were quantified. Results: Following the 21-day intervention, all mice remained in good health with consistent weight gain observed across groups. Notably, significant increases in the levels of Lactobacillus and Bifidobacterium were detected in the medium- and high-dose groups, particularly in the high-dose group. No significant changes were observed in the abundance of pathogenic bacteria, including Enterobacter, Enterococcus, and Clostridium perfringens. These findings confirm the efficacy of LPB27 in modulating intestinal flora in the animal model. Further analysis using 16S rDNA sequencing and SCFA profiling revealed that LPB27 may exert its beneficial effects by modulating key genera such as Akkermansia and Ruminococcus, reshaping the microbial community structure, and enhancing SCFA metabolic pathways. Specifically, butyrate production was significantly elevated in the high-dose group. Conclusion: Lacticaseibacillus paracasei LPB27 demonstrates effective regulation of gut microbiota through a synergistic "microbiota-metabolite" network, involving activation of the L-Methionine Biosynthesis III pathway, enrichment of beneficial genera such as Akkermansia and Ruminococcus, and increased production of beneficial metabolites, particularly butyrate. This study provides a solid scientific foundation for the development of LPB27 as a novel probiotic formulation aimed at regulating intestinal microecology.

Objective: Given the limitations of current interventions for hyperuricemia and the potential of Eurotium cristatum fermentation to enhance the bioactivity of natural products, this study aimed to investigate the urate-lowering effect and safety of E. cristatum-fermented Taxilli Herba tea, thereby providing experimental evidence for developing efficient, low-toxicity natural urate-lowering agents. Methods: A "pretreatment-modeling synchronous intervention" design was adopted. Mice were first administered fermented Taxilli Herba tea via oral gavage for 5 consecutive days for pretreatment. Subsequently, a hyperuricemia model was established by intraperitoneal injection of hypoxanthine combined with subcutaneous injection of potassium oxonate, during which the fermented tea was continuously administered for three days. To elucidate its urate-lowering mechanism, serum uric acid (SUA) levels and hepatic xanthine oxidase (XOD) activity were measured. Concurrently, liver and kidney function indices—alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and serum creatinine (SCr)—were assessed to evaluate organ protection. Safety was evaluated via acute toxicity tests (single gavage of maximum concentration, with 14-day observation to determine LD₅₀) and subacute toxicity tests (28-day continuous gavage, with measurements of body weight, hematological, biochemical, and urinary parameters, plus histopathological examination of organs to assess toxic effects). Results: Relative to the blank group, the model group exhibited significantly elevated SUA levels, hepatic XOD activity (P<0.01), and abnormal liver/kidney function indices (ALT, AST, BUN, SCr, P<0.01), confirming successful model establishment with concurrent organ damage. In contrast, all dose groups of fermented Taxilli Herba tea showed significantly reduced SUA levels (P<0.05) and XOD activity (P<0.01) versus the model group, alongside improved liver and kidney function indices (P<0.05 or P<0.01). These findings indicated that the fermented tea reduced urate production by inhibiting XOD activity and exerted protective effects on liver and kidney function. Safety evaluation revealed an oral LD₅₀>10 g/kg·bw in both male and female mice, classifying it as practically non-toxic. After 28-day continuous gavage, no significant abnormalities in body weight, hematological, or biochemical parameters were observed in rats across all dose groups, and no test substance-related histopathological changes were detected in organs. Conclusion: E. cristatum-fermented Taxilli Herba tea exerts a significant urate-lowering effect by inhibiting XOD activity and simultaneously ameliorates hyperuricemia-induced liver and kidney dysfunction. Its "synergistic urate-lowering and organ-protective effects" outperform single-target interventions and present high safety.

Objective: The protective effects of Craterellus cornucopioides water extracts (CCWE) on rat model of UC were investigated in this study. Methods: Trinitrobenzene sulfonic acid (TNBS) was used to induce an ulcerative colitis (UC) model in rats. Pathological injury was assessed by monitoring body weight changes, disease activity index (DAI) scores, and hematoxylin-eosin (HE) staining of colonic tissues. The levels of myeloperoxidase (MPO) activity, nitric oxide (NO), superoxide dismutase (SOD) activity, malondialdehyde (MDA), and pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) in colon tissues were examined to evaluate the therapeutic effects of CCWE on UC. Network pharmacology was employed to screen active ingredients, targets, and pathways of CCWE against UC, followed by molecular docking validation of key interactions to elucidate its material basis and mechanism of action. Results: The DAI score of the TNBS group was significantly higher than that of the control group (P<0.05). Compared with the TNBS group, CCWE significantly reduced the DAI score (P<0.05) and improved macroscopic and histological damage. In addition, compared with the TNBS group, CCWE also significantly decreased the levels of MPO, NO, MDA, IL-1β, TNF-α and IL-6 (P<0.01), while significantly increasing the level of SOD (P<0.01). The core targets of CCWE in treating UC were predicted to be STAT3, SRC, MAPK3, PIK3R1 and AKT1 by network pharmacology. The mechanisms of action encompass the HIF-1, relaxin, and PI3K/Akt signaling pathway. The main components of CCWE for treating UC might be illudin T, quercetin, 4-hydroxy-4-isopropenylcyclohexanemethanol acetate, 4-oxo-hex-5-enyl acetate, craterellins B, ferulic acid, craterellins A, caffeic acid, 4-oxohex-1,6-diyl diacetate, and illudin M. Molecular docking results indicate that the active components of CCWE exhibit good binding affinity with these five core targets, with quercetin and 4-oxo-hex-5-enyl acetate showing the most significant docking scores. Conclusion: The active ingredients in CCWE, quercetin and 4-oxo-5-hexenyl acetate, modulate the expression of proteins including STAT3, SRC, MAPK3, PIK3R1 and AKT1, ultimately activating the HIF-1, relaxin, and PI3K/Akt signaling pathways to treat ulcerative colitis.

To contribute to better understanding of the structural composition, bioactivity, and intestinal health effects of Huaishan polysaccharides (HSP), analyzed the changes in the molecular weight and monosaccharide composition of HSP after digestion with simulated gastric juice, and evaluated its impact on intestinal cell proliferation and differentiation using a three-dimensional (3D) organoid model. The study findings showed that Huaishan polysaccharide molecular weights averaged 139.173 kDa prior to source plant digestion, and 1.676 kDa after digestion. Prior to digestion, D-glucose (89.72%) was the dominant monosaccharide, but its levels decline significantly after digestion, while levels of other monosaccharides (e.g., D-mannose, D-galactose) tend to rise. Immunofluorescence analyses confirmed key intestinal cell markers, including Ki67 (proliferation), Chromogranin A (secretory), Mucin2 (goblet cells), Lysozyme (Paneth cells), Villim (absorptive), and Olfm4 (ISCs), were present in the 3D organoids. Chinese yam polysaccharide-treated organoids exhibited significantly enhanced mRNA levels and immunofluorescence signals for Ki67 and Muc2. Huangshan polysaccharides also upregulated respective Lgr5, Olfm4, Wnt3, and Hes1 mRNA levels 1.32, 1.15, 1.1, and 1.12 fold (P<0.05). These data suggested that Huaishan polysaccharides enhance ISC proliferation via Wnt-mediated Lgr5/Olfm4 activation while promoting goblet cell differentiation via Notch inhibition. These data revealed the structure of Huaishan polysaccharides at stages during digestion, and its intestinal proliferation and differentiation promoting effects, laying a foundation for Huaishan polysaccharide application in functional foods.

Objective: This study aimed to investigete the potential and molecular mechanisms of Oudemansiella raphanipies extract (ORE) in ameliorating lipid metabolism dysregulation. Methods: A lipid accumulation model was established in HepG2 cells using free fatty acids (FFA) to investigate the effects of ORE on obesity-associated hepatic steatosis. Oil red O staining were used to detect lipid deposition within cells. Relevant cellular parameters were measured using biochemical assay kits. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were employed to elucidate the molecular mechanisms underlying ORE's improvement of lipid metabolism. Results: ORE effectively reduced lipid accumulation in HepG2 cells. It significantly downregulated the expression of adipogenesis-related genes and proteins, including C/EBPα, PPARγ, SREBP-1c, and FAS. Additionally, ORE significantly reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels while enhanced the activity of superoxide dismutase (SOD) and catalase (CAT). Conclusion: ORE can improve the lipid metabolism level of lipid-deposited HepG2 cells. The underlying mechanism may be achieved by downregulating C/EBPα and PPAR-γ to further inhibit the SREBP-1c/FAS synthesis pathway. Concurrently, ORE alleviates oxidative stress in HepG2 cells, potentially through reducing ROS, MDA, enhancing SOD and CAT activities, thereby modulating the cellular redox system.