Freezing is essential for industrial preservation of ready‑to‑cook marinated meat, yet the impact of freezing rate on quality remains insufficiently understood. This study evaluated the effects of three freezing rates, conventional freezing (RF-20, 0.06°C/min), ultra-low freezing (RF-80, 0.21°C/min), and liquid nitrogen freezing (LNF, 12.00°C/min) on the quality of marinated pork loin strips, using fresh and refrigerated marinated (RM) samples as controls. RM had best color, texture, water retention, protein stability, and flavor. Slower freezing (RF-20, RF-80) caused microstructural disruption, textural deterioration, impaired water retention, and induced protein/flavor deterioration, evidenced by increased centrifugal/cooking losses, elevated free water (S23, T23), higher TBARS and carbonyls, reduced sulfhydryls, and off-flavor shifts. LNF preserved quality similar to RM: centrifugal loss 11.35%, cooking loss 9.5%, immobilized water (S22) 95.49%, hardness 2193.58 g, enhanced protein stability, and 20 ester/ketone biomarkers (GC-IMS) matching RM. Thus, rapid freezing, especially LNF, minimizes deterioration and preserves marinated pork quality.

Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen, and beef-associated contamination remains a major food-safety concern. STEC in beef products is difficult to control when cells persist as biofilms on food-contact surfaces and in processing environments. Here, lytic phage vB-EcoP-B10 was isolated from cattle-farm wastewater using cattle-farm-derived STEC B10 as the host. Its genomic safety, biological properties, antibiofilm activity, and raw-beef efficacy were evaluated. TEM and genome analyses assigned vB-EcoP-B10 to a novel species within Kayfunavirus. Its 40,015-bp dsDNA genome encodes 48 ORFs and lacks detectable lysogeny, virulence, antimicrobial resistance, or tRNA genes. vB-EcoP-B10 lysed multiple pathogenic E. coli strains, including O157:H7, and selected Salmonella isolates. It showed a 10-min latent period, a burst size of 178 PFU per infected cell, and stability at pH 2.0–10.0, 20–60 °C, and after UV irradiation. vB-EcoP-B10 significantly inhibited STEC planktonic growth, reduced biofilm biomass and biofilm-associated viable cells, and disrupted mature biofilm architecture (P < 0.05). On stainless-steel coupons, it reduced biofilm-associated B10 by 2.9 log10 CFU/coupon and O157:H7 EDL933 by 1.6–2.6 log10 CFU/coupon. In raw beef, reductions of B10 and O157:H7 EDL933 reached 1.9–2.5 and 1.4–2.6 log10 CFU/g at 4 °C, and 3.7 and 2.0 log10 CFU/g at 25 °C, respectively (P < 0.05). The phage remained recoverable from raw beef without marked pH or perceptible color changes. These results support vB-EcoP-B10 as a residue-free candidate for STEC control on food-contact surfaces and in raw beef.

Staphylococcus aureus is a major contagious pathogen causing bovine mastitis, with persistence and antimicrobial resistance posing ongoing challenges in dairy herds. From July 2022 to July 2023, 942 mastitis milk samples (267 clinical, 675 subclinical) from 10 farms in northwestern China yielded 98 S. aureus isolates (10.4%), which were characterized by whole-genome sequencing, antimicrobial susceptibility testing, biofilm assays, and virulence profiling. Ten sequence types, seven clonal complexes, and 16 spa types were identified, dominated by ST1 (42.9%) and ST97 (24.5%). ST1 was mainly associated with subclinical mastitis, whereas ST97 was enriched in clinical cases; a novel ST9955 (13.3%) was exclusively detected in subclinical isolates. No methicillin-resistant S. aureus was detected. Resistance was most frequently observed to penicillin (42.9%), erythromycin (28.6%), clindamycin (22.4%), and tetracycline (10.2%), with higher rates in clinical isolates. 65.3% of isolates exhibited strong biofilm-forming ability, which was significantly more frequent in subclinical cases (70.3% vs. 55.9%, p < 0.05). Virulence genes showed conserved adhesion/biofilm determinants but lineage-dependent distribution of immune evasion and toxin genes, with stable co-occurrence among capsule, biofilm, T7SS, iron acquisition, and immune evasion loci. Overall, the population was diverse but strongly lineage-structured, dominated by a few successful clones, highlighting the value of lineage-resolved surveillance for understanding and controlling bovine mastitis.

β-Glucosidase (BGL), a pivotal enzyme in lignocellulosic saccharification, has been increasingly recognized as an "emerging green biocatalyst" in modern biorefinery processes. Here, Aspergillus niger An-BGL was rationally engineered to achieve high-level production of BGL under low-cost inducers. Corncob powder served as a cost-effective alternative inducer, enhancing BGL production to 14.2 U/mL. The knockout of CreA and the overexpression of Xln R increased the BGL yield by 75% and 27%, respectively. Combinatorial engineering of CreA and Xln R generated the XO-CK strain, which exhibited a derepression effect at high glucose concentrations. Supplementation with 1% glucose alleviated the delayed enzyme production in the engineered XO-CK strain, resulting in a BGL activity of 31.54 U/mL. Furthermore, integration of the bglA gene into the high-expression amyA site enhanced BGL to 40.68 U/mL. The rational modification strategy for A. niger strain established in this study offers an efficient and sustainable approach for transforming corncob agricultural waste into high-value enzymatic preparations.

This 3-year surveillance study investigated the contamination patterns and genomic characteristics of Staphylococcus aureus in 2133 imported food samples, including frozen beef, frozen pork, frozen fish, frozen chicken, and cheese. An overall S. aureus contamination rate of 4.4% (93/2133) was observed, with frozen beef showing the highest prevalence (6.0%, 68/1139). The 93 isolates showed high resistance rates to ampicillin at 61.3% and penicillin at 58.1%. Methicillin-resistant S. aureus (MRSA) strains were identified in 14.0% (13/93) of them. Substantial genetic diversity was observed, with 24 sequence types (STs) and 41 spa types identified. The major prevalent clones included the globally prevalent ST5 (19.4%), of which 44.4% (8/18) carried at least one enterotoxin gene, as well as the livestock-associated ST398 (11.8%), which was significantly lower than its prevalence rate in China. The clone ST1460-t156 (10 strains) derived from equine-associated lineages was detected in strains isolated from beef samples. Virulence gene profiling revealed diverse enterotoxin carriage, with some strains carrying four or five enterotoxin genes simultaneously. Although a relatively low contamination rate of S. aureus was observed in the imported food products, the high prevalence of MRSA and carriage of several virulent strains necessitate close monitoring of S. aureus within global food supply chains to provide essential data for developing risk-based food safety interventions.

This study investigated the effects of thermal-ultrasound treatment on the interactions between goat milk proteins, including whey protein and casein, and tea polyphenols. The structural and functional properties of the resulting complexes were systematically evaluated at different tea polyphenol-to-protein ratios. Tea polyphenols improved protein functionality in a concentration-dependent manner, with the optimal ratios identified as 0.4 for whey protein and 2 for casein. At these ratios, thermal-ultrasound treatment increased the solubility of whey protein and casein to 95.16% and 92.78%, respectively, compared with untreated samples, and enhanced their tea polyphenol loading capacities by 10.68% and 12.53%. Moreover, foaming capacity was markedly improved, reaching 124.33% for whey protein and 130.00% for casein. Molecular docking further revealed hydrogen bonding and hydrophobic interactions between EGCG and β-lactoglobulin or β-casein. In summary, thermal-ultrasound treatment significantly enhances protein-tea polyphenol interactions, thereby improving the functional properties of the goat milk system.

Niacin, an essential vitamin, inhibits Staphylococcus aureus (S. aureus) growth by disrupting its cell wall and membrane integrity. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of niacin against S. aureus ATCC 29213 were both 4 mg/mL. Alkaline phosphatase (AKP) levels indicate cell wall damage. Niacin depolarizes the bacterial membrane, alters cell morphology, and reduces intracellular adenosine-triphosphate (ATP) while increasing reactive oxygen species (ROS) and causing nucleic acid and protein leakage. Agarose gel electrophoresis and Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that high concentrations of niacin significantly degrade genomic DNA and proteins in S. aureus, with notable differences observed. RT-qPCR results indicate that niacin at sub-inhibitory concentrations modulates S. aureus quorum sensing, virulence gene expression, adhesion capacity, and overall regulatory gene expression (P < 0.05). The experimental results indicate that niacin can reduce the toxicity of S. aureus metabolites, with MIC niacin decreasing the hemolytic activity of the metabolites to 31.83%. In beef, niacin effectively reduces bacterial counts, decreasing them by 0.80 CFU/g, 1.30 CFU/g, and 1.00 CFU/g at 4 °C, 25 °C, and 37 °C, respectively. Niacin helps maintain pH and preserve color, thereby improving storage quality. These findings highlight the potential of niacin in preventing S. aureus contamination in meat products.

Salmonella enterica is a major public health concern due to its widespread contamination of food products and the increasing prevalence of multidrug-resistant strains. Bacteriophage-based biocontrol has emerged as a safe and effective alternative to conventional antibiotics. Here, we isolated and characterized the broad-spectrum lytic phage vB_SgulP_SP124, which lysed 81.08% of 148 tested Salmonella strains across five clinically important serotypes: S. Enteritidis, S. Typhimurium, S. Pullorum, S. Choleraesuis, and S. Dublin. The phage exhibited high viability across a pH range of 2-10 and temperatures ranging from 4°C to 60°C. Its 40,499 bp dsDNA genome (G+C content 49.60%) was classified within the class Caudoviricetes, subfamily Guernseyvirinae, and genus Jerseyvirus. Genomic analysis confirmed the absence of virulence, lysogeny, or antibiotic resistance genes, supporting its safety profile for biocontrol applications. In planktonic assays conducted at the optimal multiplicity of infection of 0.01, the phage significantly inhibited the growth of four Salmonella strains, with viable counts of two strains reduced within 2 h. Moreover, the phage significantly reduced S. Enteritidis levels on chicken breast, milk, liquid egg, and lettuce during 36 h of storage at 4°C. Pharmacokinetic analysis in specific pathogen-free broilers showed that intraperitoneal (IP) administration provided superior phage persistence and biodistribution compared with oral and intramuscular routes. Both early and delayed IP phage treatment significantly lowered bacterial burdens in blood and organs, although early intervention showed a consistent (but non-significant) trend toward greater efficacy. These results establish phage vB_SgulP_SP124 as a promising biocontrol agent for Salmonella contamination across the farm-to-table continuum.

Ferrate(VI) is emerging as a promising eco-friendly oxidant for advanced water treatment, yet its interactions with bacterial dormancy states and subsequent water-safety implications remain poorly understood. This study investigated the formation and implications of the viable but non-culturable (VBNC) state in Escherichia coli under ferrate(VI) stress in both saline and surface water matrices. While ferrate(VI) effectively induced a rapid loss of culturability in E. coli, it generated a non-culturable but membrane-intact population associated with physiological adaptation mechanisms, including oxidative stress response, metabolic repression, and membrane remodeling. This adaptive strategy not only supported cellular persistence but also conferred significant cross-resistance to environmental stressors and antibiotics. Crucially, upon resuscitation, the bacteria partially recovered epithelial-cell interaction-associated phenotypes, including adhesion, invasion, and cytotoxicity-related responses in Caco-2 intestinal epithelial cells. These findings demonstrate that ferrate(VI) oxidation may inadvertently select for resilient bacterial populations that evade conventional detection while retaining resuscitation-associated host-cell interaction capacity. This discrepancy between non-detectability and residual physiological activity poses a critical challenge to current culture-dependent water quality standards and engineering dosing strategies. Consequently, this study highlights the necessity of integrating molecular viability assessments into water safety monitoring to manage the hidden risks associated with resuscitable non-culturable bacterial populations in full-scale facilities.

Fruit juice shows promise in modified milk systems; however, the effects of different fruit-derived organic acids on stability and sensory properties remain unclear. Here, a simplified organic acid-modified milk model was used to evaluate the effects of citric, malic, and tartaric acids, with lactic acid as a reference. Tartaric acid-modified milk exhibited a significantly lower water-holding capacity than other samples (p < 0.05), accompanied by pronounced casein aggregation. Citric acid-modified milk contained significantly higher levels of volatile compounds (p < 0.05) but showed relatively low aroma scores. In contrast, malic acid caused the least disruption to system stability, induced limited protein aggregation, and achieved the highest sensory score (82.21). Correlation analysis indicated associations among colloidal properties, volatile profiles, and sensory perception. Overall, this study provides a simplified reference for understanding how typical organic acids influence stability and sensory attributes in milk-based systems relevant to fruit juice modification.

hvKp has emerged as a significant pathogen, with an increasing incidence of infections among diabetic patients. Previous research has primarily focused on the detrimental effects of hyperglycemia on host immunity, largely overlooking its potential impact on bacterial virulence. This study investigates the effects of three common types of blood sugar, glucose, fructose and galactose on capsular synthesis and virulence in hvKp. Our results demonstrate that these sugars promote hvKp growth, increase capsular thickness and polysaccharide production, upregulate capsule-associated gene expression, and elevate virulence in the Galleria mellonella infection model. Collectively, these findings provide novel insights into the regulatory mechanisms governing hvKp virulence and hold significant implications for the prevention and treatment of hvKp infections in diabetic patients.

Exosomes are small extracellular vesicles secreted by cells that play a critical role in intercellular communication by transferring biomolecules, considered one of the most valuable cancer biomarkers. Traditional bulk analysis averages signals across many cells, masking the unique properties of exosome secretion from individual cells. Herein, a surface-enhanced Raman scattering (SERS) microfluidic platform was constructed to detect exosome secretion at the single-cell level. This platform is available for analyzing exosomes derived from breast epithelial cells and various subtypes of breast cancer cells, enabling precise cell type identification and cancer diagnosis. Integrating machine learning, the exosomal receptor profiles of different breast cancer subtypes were assessed following drug treatment. Notably, the expression of specific biomarkers on exosomes may be closely related to cell migration. Using visual clustering, cells with distinct secretion characteristics were isolated, facilitating the investigation of the relationship between exosomal protein expression and cellular drug resistance. The strategy depicited in this study enables the multiplex analysis of exosome proteins at the single-cell level, uncovering the heterogeneity of exosome secretion. Furthermore, it provides a dynamic approach for monitoring single-cell exosomal protein expression during drug treatments. This platform advances single-cell exosome analysis and proteomics, providing a foundation for developing personalized drug targets to enhance cancer diagnosis and treatment.

This study explores the synergistic antibacterial effects of ultrasound (US) combined with calcium chloride-slightly acidic electrolyzed water (CaCl2-SAEW) against Salmonella Thompson and the application in the cleaning and preservation of sliced onions. The results showed that the antimicrobial effect of US + CaCl2-SAEW was superior to the single treatment. A treatment of 161 W/cm(2) US combined with 1.5 mg/L CaCl2-SAEW for 10 min reduced S. Thompson populations from 7.63 +/- 0.15 CFU/mL to 2.71 +/- 0.04 log CFU/mL. The antimicrobial mechanism was elucidated through an in-depth investigation of the destabilizing effects of CaCl2-SAEW on bacterial membranes induced by US. N-Phenyl-l-naphthylamine and flow cytometry showed that US enhanced the exacerbation of CaCl2-SAEW on the permeability changes and disruption of the integrity of S. Thompson cell membranes. Field emission scanning electron microscope observed irreversible damage to the structure of cell membranes by US + CaCl2-SAEW. In addition, US + CaCl2-SAEW significantly (p < 0.05) enhanced the storage efficacy of onion slices. Ca+2 played a key role in mitigating the quality deterioration of onions during storage, highlighting the dual function of Ca+2 in enhancing the antimicrobial efficacy and maintaining the quality of the product with US + SAEW. These findings suggest that US + CaCl2-SAEW offers a promising application strategy for the cleaning and preservation of fresh-cut fruits and vegetables.

Context Incretin hormones, primarily composed of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), are secreted by enteroendocrine cells (EECs) and play crucial roles in maintaining blood glucose homeostasis. Notably, GIP accounts for two-thirds of the entire incretin effect. However, the secretion and function of GIP are impaired in individuals with type 2 diabetes mellitus (T2DM), and the regulatory mechanisms governing GIP secretion remain unclear.Objective Our study aims to explore the role of an EEC-enriched protein, Secretagogin (SCGN), in the regulation of GIP secretion.Methods We collected duodenal tissues from both humans and mice to observe the colocalization of SCGN and GIP in EECs. Additionally, we utilized human cohorts and gene-edited mouse models to investigate the effect of SCGN on GIP secretion. Our study included 128 subjects, comprising 64 individuals diagnosed with newly onset diabetes and 64 age- and sex-matched nondiabetic healthy controls. At the animal level, we employed leptin receptor-deficient (db/db) mice and Scgn knockout mice for our investigations.Results Our findings indicate that SCGN is abundantly expressed in GIP-producing K cells within the intestinal epithelium of both humans and mice. We observed a positive correlation between SCGN and GIP levels in postprandial states among patients with T2DM, db/db mice, and their healthy controls. Notably, Scgn knockout mice exhibited decreased GIP and insulin secretion. However, SCGN deficiency did not affect K-cell number, GIP mRNA expression, or intestinal morphology.Conclusion Collectively, these findings demonstrate that SCGN is a key regulator of nutrient-induced GIP secretion.

The microcapsules were fabricated using the complex coacervation of quinoa protein (QP) and sodium alginate (SA) to protect the biological activities of dihydroquercetin (DHQ). The optimum preparation conditions of DHQ microcapsules were determined by zeta potential, turbidity, encapsulation yield (EY), encapsulation efficiency (EE) and loading capacity (LC) of DHQ. The physicochemical properties including microstructures, driving forces, thermal stability, storage stability and antioxidant capacity of DHQ microcapsules were characterized. The results showed that the DHQ microcapsules obtained optimum EY (59.59 ± 0.41

Chronic wounds present a major global healthcare challenge, with bacterial infections significantly impeding healing processes and increasing treatment costs. This study addresses the critical need for multifunctional wound dressings by developing a novel thermosensitive hydrogel incorporating Schizonepeta annua essential oil nanoemulsions (SEO-NE-TG). We hypothesized that this formulation would provide both controlled antimicrobial protection and enhanced tissue regeneration capabilities. Through systematic optimization, we formulated a stable oil-in-water nanoemulsion using Tween-80, achieving uniform nanoparticles (10-20 nm) confirmed by TEM and DLS analysis. The resulting hydrogel demonstrated ideal properties for wound applications, including temperature-responsive gelation (transition at 15.7 degrees C), favorable shear-thinning behavior, and erosioncontrolled release of bioactive terpenes. The SEO-NE-TG maintained antimicrobial efficacy against critical wound pathogens including MRSA (MIC 3906 mu g/mL), while significantly accelerating wound healing in a rat burn model. Cytotoxicity studies with HaCaT keratinocytes revealed that SEO-NE maintained good biocompatibility at antimicrobial effective concentrations. Treatment resulted in 35 % higher wound contraction rate, enhanced epidermal regeneration, improved collagen organization, and significantly modulated inflammatory markers (IL-6, TGF-beta, VEGF) compared to controls. These findings establish SEO-NE-TG as a promising platform for advanced wound management, offering a natural alternative to conventional antimicrobial dressings with superior healing promotion capabilities.

Methicillin-Resistant Staphylococcus aureus (MRSA) is one of the pathogens that cause food poisoning. Prodigiosin (PG) is a kind of microbial secondary metabolites with antibacterial, anti-inflammatory, anti-tumor and other biological activities. In the present study, PG as the natural metabolite of Serratia marcescens was found to have the significant bacteriostatic activity against MRSA undergoing division and proliferation. It can damage cell walls, cell membranes and biofilms of MRSA, and cause leakage of proteins and nucleic acids. PG also could cause cells die due to the oxidative stress by inhibition of SOD and CAT activities. The differences of accumulation metabolites (DAMs) and expressed genes (DEGs) were mainly involved in ribosome, ABC transporters, DNA replication and repair, amino acid synthesis and metabolism, and carbohydrate metabolism according to the metabolomics and transcriptomics. In conclusion, the present study explored the bacteriostatic activity and inhibitory mechanism of PG, which will provide a research basis for PG’s development and application in food safety.

Hepatitis B virus (HBV) represents one of the major pathogenic factor that leads to chronic liver diseases and the development of hepatocellular carcinoma (HCC). The currently approved anti-HBV drugs cannot eradicate the virus or block the development of HCC. HBV nucleocapsid consists of the hepatitis B core antigen (HBcAg) and the HBV relaxed-circular partially double-stranded DNA (rcDNA), indispensable in virus replication. The present study reported a cell-penetrating bispecific antibody targeting HBcAg and preS1, fused with the cell-penetrating peptide R9TAT, named Anti-preS1 × Anti-HBcAg-R9TAT. The antibody could recognize preS1 and HBcAg and internalize into living cells efficiently, suppressing the extracellular hepatitis B surface antigen (HBsAg) and hepatitis B envelope antigen, and the intracellular HBsAg and HBcAg in vitro. This cell-penetrating bispecific antibody is a novel approach to suppressing HBV replication and secretion and is a promising anti-HBV therapeutic antibody candidate.

The aim of the present study was to evaluate the mechanism of antimicrobial action of Lysine (Lys) against Escherichia coli (E. coli) O157:H7. Lys alters the permeability and morphology of bacterial cell membranes, leading to leakage of intracellular material. Using agarose gel electrophoresis and sodium dodecyl sulfatepolyacrylamide gel electrophoresis(SDS-PAGE), it was found that high concentrations of Lys disrupted the DNA and protein primary structure of E. coli O157:H7. Lys also inhibited the ability of E. coli biofilm formation in a concentration-dependent manner. Subinhibitory concentration of Lys reduces the swimming and swarming ability of E. coli O157:H7 and its ability to adhere and to invade Caco-2 cells. The use of Lys on lettuce inoculated with E. coli O157:H7 showed good disinfection efficiency. Further studies revealed that Lys had both preventive and therapeutic effects on the severity of colitis induced by E. coli O157:H7 infected mice, and that the preventive effect was greater than the therapeutic effect.