Ultraviolet light-emitting diodes (UV-LEDs) are being investigated for potential use in food disinfection due to their customisable wavelength and high energy efficiency. The objective of this study was to examine the impact of UV-LED treatments, for up to 30 min, at wavelengths of 280, 300, and 365 nm, as well as simultaneous irradiation with 280 and 300 nm, on the culturability of Escherichia coli, Bacillus cereus spores, and Salmonella enterica in black peppercorns. It resulted in a reduction of up to 1.65, 1.35 and 1 log colony-forming units per gram (CFU/g) for E. coli, S. enterica, and B. cereus spores, respectively. The viability of S. enterica was also evaluated in black pepper using a viability PCR method with DyeTox13. No significant differences were observed between active and inactive non-culturable states. This finding suggests that UV light did not cause substantial lethal damage to the bacteria, but instead rendered them non-culturable, potentially leading to an underestimation of the food safety risk. These findings are encouraging concerning the potential applications of UV-LEDs in the spice industry.

The spread of antimicrobial resistance genes in the food production chain poses a major threat to food safety and public health. In particular, the emergence of tmexCD1-toprJ1 RND efflux pump gene cluster, which confers tigecycline resistance in foodborne Klebsiella pneumoniae heightens this risk. This study aimed to investigate the prevalence and genetic features of tmexCD1-toprJ1-positive isolates from retail food in Hainan, China, and to characterize the co-occurrence of mcr-1.1, mcr-3.40, and tmexCD1-toprJ1 on a hybrid IncFIB/IncHI1B plasmid. A total of 663 retail food samples were collected in 18 administrative regions of Hainan Island. Nine tmexCD1-toprJ1-positive Klebsiella spp. isolates were recovered, including eight K. pneumoniae and one K. quasipneumoniae subsp. quasipneumoniae. All isolates exhibited resistance to tigecycline (MIC = 4-32 mg/L), cefotaxime and ciprofloxacin, while remaining susceptible to meropenem and ceftazidime/avibactam. Conjugation assays showed that six isolates successfully transferred tigecycline resistance to recipients, and two of these isolates also transferred colistin resistance. These two isolates carried both tmexCD1-toprJ1 and mcr genes. Notably, K. pneumoniae HN2023DA127 simultaneously harbored tmexCD1-toprJ1, mcr-1.1, and mcr-3.40, all located on a hybrid IncFIB/IncHI1B plasmid designated pHN2023DA127-1. After 15 days of passaging without selective pressure, 75.7 % of cells in K. pneumoniae HN2023DA127 retained all three determinants, with mcr-3.40 most frequently lost. Further genomic analysis revealed that the mobilization of tmexCD1-toprJ1, mcr-1.1, and mcr-3.40 was mediated by IS26-, ISApl1-, and ISKpn40-related insertion events, respectively. This is the first report of the co-occurrence of mcr-1.1, mcr-3.40, and tmexCD1-toprJ1 on a hybrid IncFIB/IncHI1B plasmid in K. pneumoniae. The convergence of last-resort antibiotic resistance highlights the urgent need for integrated One Health surveillance to limit the dissemination of clinically important pathogens in the food chain.

The inoculation timing of starter cultures is a critical factor influencing the quality of fermented foods, yet it remains underexplored. This study evaluated how simultaneous (T1) and sequential (X1) inoculation of Leuconostoc, Levilactobacillus, and Lactiplantibacillus affects inter-species competition and fermentation dynamics in Chinese spicy cabbage (CSC). While the T1 strategy accelerated fermentation kinetics with Leuconostoc acting as the primary fermenter, the inoculation sequence altered the competitive hierarchy of the secondary fermenters: Levilactobacillus dominated in T1, whereas Lactiplantibacillus prevailed in X1. This differential microbial succession resulted in distinct aromatic signatures, with Random Forest modeling identifying methyl allyl disulfide (Day 6) and dimethyl trisulfide (Day 13) as key differential compounds driving these flavor differences. Although the T1 group developed a more intense fermented flavor, sensory analysis indicated that the sequential (X1) strategy achieved higher overall acceptability by yielding a more desirable balance between moderate flavor and preserved texture. These findings demonstrate that adjusting inoculation timing is an effective method to engineer microbial succession and systematically modify the final sensory profile of fermented vegetables.

The microbiological quality of truffles produced in Argentina was evaluated by analyzing the bacteria and fungi associated with fresh ascomata, the fungi that developed after storage (15 days in domestic refrigerator and industrial cooler), and those present in deteriorated truffles. Counts of mesophilic aerobic bacteria, Enterobacteriaceae family members, moulds, and yeasts were performed. Fungal identification was achieved by phenotypic analysis of cultures and sequence analysis of the ITS and CaM markers. The initial microbial load was low but increased during storage, as expected. A diverse fungal community was recovered under each condition. In total, 21 taxa belonging to 16 genera were identified from the peridium (25 strains) and the gleba (18 strains). The Hypocreales (Ascomycota) were the dominant taxa (70 %). In deteriorated truffles, 14 different taxa were identified, with only 4 species in common with the healthy ones. Overall, the fungal community isolated from local truffles significantly differs from those reported in previous studies from the Northern Hemisphere.

Pulsed electric field (PEF) is a promising technology for microbial decontamination of liquid products such as fruit juices and beverages. This study developed a database with 569 PEF experiments for Escherichia coli, Listeria spp., Pseudomonas spp., Staphylococcus aureus, Saccharomyces cerevisiae, Salmonella spp., and lactic acid bacteria (LAB) in a range of food matrices. The efficacy of PEF for different microbial species was evaluated through the decimal-reduction volumetric energy input D, which is the energy input required to achieve a one log microbial reduction. The matrix composition had a significant impact on the D, decreasing the D in high-acid fruit juices and increasing it in high-acid alcoholic products, revealing effects beyond acidity alone. Data for most species were available for high-acid fruit juices, and in this matrix, S. cerevisiae was the most sensitive species. A decision tree with eight matrix categories was developed to estimate the volumetric energy input needed for a 5-log reduction for different target microbial species in different matrices. The global kinetic parameters reported in this study provide a quantitative benchmark for food business operators and risk assessors, and can serve as a first indication of PEF treatment efficacy.

High hydrostatic pressure (HHP) can trigger bacterial spores to germinate and reduce their resistance, thereby facilitating the subsequent inactivation of germinated spores through mild treatments such as pasteurization. This approach is known as the "germinate to eradicate" strategy. However, the presence of superdormant (SD) spores that fail to germinate under HHP-termed high-pressure superdormant (HPSD) spores-poses a significant challenge to the efficacy of this method. We have previously found that a subset of HPSD spores isolated after 500 MPa treatment enter an irreversible germination commitment state and undergo spontaneous germination. However, there are still some stable HPSD spores that remain in deep superdormant state after 500 MPa induction treatment, hindering the effective implementation of the "germinate to eradicate" strategy. In this study, stable HPSD spores of Bacillus subtilis were isolated after 500 MPa treatment at 20 °C for 5 min and subsequent post-incubation (37 °C/12 h) to allow completion of spontaneous germination. These spores were characterized for germination capacity and resistance profiles. Compared with conventionally defined HPSD spores isolated immediately after 500 MPa treatment, the stable HPSD spores exhibited more pronounced germination defects in response to various stimuli, including L-alanine, the AGFK mixture, dodecylamine, and high-pressure treatments at 200 MPa and 500 MPa. Furthermore, they demonstrated reduced resistance to heat, hydrochloric acid, sodium hypochlorite, and formaldehyde, with decimal reduction times (D-values) decreased by 1.78, 2.42, 1.82, and 2.58 fold, respectively. In contrast, their resistance to UV irradiation was enhanced, showing a 2.18-fold increase in D-value. Additionally, we optimized the HHP treatment parameters along with post-incubation temperature and duration to minimize the quantity of stable HPSD spores of both B. subtilis and B. cereus, whether suspended in sterile double-distilled water or in food matrices such as skimmed milk and vegetable juice. The findings of this study enhance our understanding of HPSD spore behavior and contribute to the development of effective spore inactivation strategies for industrial HHP applications.

Postharvest bacterial infections pose a significant threat to fruit and vegetable quality and safety, particularly due to pathogens' adaptive responses to storage conditions. This study utilized morphological and multi-omics approaches to investigate Pseudomonas marginalis survival and tomato soft rot progression under modified atmosphere packaging (MAP) conditions. Our findings indicate that MAP (initial 21 % O₂, 0 % CO₂, transitioning to 1 % O₂, 20 % CO₂ over 48 h) supported colony growth (12 ± 0.5 mm) comparable to air, whereas rapid shift to controlled atmosphere (1 % O₂, 20 % CO₂) markedly suppressed growth (10 ± 0.5 mm) and caused membrane disruption, consistent with the highest proportion of PI-positive cells (24.3 ± 2.7 %) after 2 days. In contrast, MAP maintained moderate viability (17.8 ± 2.0 %), indicating enhanced adaptive response. Transcriptomic and metabolomic analyses revealed that MAP gases influenced bacterial responses, specifically modulating two-component system (TCS) and ATP-binding cassette (ABC) transporter pathways crucial for adaptation. MAP decreased the expression of genes associated with multi-step phosphorelay signaling (fecl, pfeS, cheV, narL, vicR, spo0F) and glutamine signaling (potF, pstS), and altered iron homeostasis-related genes (fecl, fecR, pvdE). Metabolomics profiling showed elevated levels of L-type amino acids (LAA) and fumaric acids, with reduced D- (+)- Glucose. Transcriptomic patterns were validated by RT-qPCR with strong correlations (R = 0.83). In conclusion, MAP facilitates P. marginalis adaptation and soft rot development by modulating key stress and metabolic pathways. These findings provide a foundation for refining MAP strategies, suggesting rapid shifts to microaerobic conditions of controlled atmosphere or active O₂ scavenging to mitigate P. marginalis-induced postharvest losses.

Multidrug-resistant Salmonella Infantis carrying pESI-like megaplasmids have disseminated worldwide representing a serious threat to public health. Previous studies have investigated its population structure and temporal dynamics above the continental level. However, their conclusions were constrained by limited datasets and sampling biases. To address these issues, we analyzed all publicly available Salmonella Infantis genomes to characterize its global population structure and phylogeographic dispersal. We selected a non-redundant dataset of 14,010 genomes representing the temporal, geographic, isolation source, and genomic diversity of Salmonella Infantis from 77 countries across five continents, collected from 1910 to 2024. Phylogenomic analyses showed that emergent megaplasmid-positive Salmonella Infantis forms a monophyletic lineage with significant geographic structuring. The megaplasmid-positive lineage was inferred to have originated in Western Asia around 1990, followed by multiple introductions into Europe and a single transmission to South America which resulted in the dissemination of this pathogen to Northern America, and from there to the rest of the continent. Multiple recent transmission events of the American lineage to all continents were observed, driving the dispersal of the bla gene encoding extended-spectrum β-lactamases. Moreover, genomic evidence also suggests that the emergence of ESBL-producing strains in parts of Asia and Africa may be associated with poultry trading from the Americas. Our findings underscore the urgent need for integrating global human, animal, and environmental surveillance data with population genomic analyses to contain the threats posed by ESBL-producing Salmonella Infantis.

Salmonella is a major foodborne pathogen, frequently linked to poultry and posing serious food safety and public health risks. To investigate its epidemiology in retail chicken in Shaanxi Province, China, we conducted a comprehensive study integrating whole-genome sequencing (WGS), Clusters of Orthologous Groups (COG) analysis, and machine learning (ML). Genomic data of 331 S. Kentucky and 614 S. enteritidis isolates from the NCBI database were also analyzed to assess genetic relatedness between local strains and those from other sources across China. From 280 chicken samples collected in seven cities, 92 (32.86 %) were Salmonella-positive, yielding 132 isolates representing 29 serotypes. S. Kentucky predominated in wet markets, whereas S. enteritidis dominated supermarkets. All isolates were resistant to at least one antibiotic, with 87.88 % showing multidrug resistance (MDR) and 38.64 % exhibiting extensive drug-resistance (XDR). WGS of 78 representative isolates identified 61 antimicrobial resistance genes (ARGs) and seven quinolone resistance-determining region (QRDR) mutations, with ParC (Thr57Ser) being most frequent. It is worth noting that the high prevalence (100.00 %) of Yersinia high-pathogenicity island (HPI) genes detected in S. infantis in this study has hardly been reported previously. Phylogenetic analysis revealed S. Kentucky and S. enteritidis, which are the predominant serotypes detected in the investigation, showing close genetic relationship (SNP < 10) with those from chicken, pork, aquatic products, and humans in other provinces and host sources. Pan-genomic analysis showed that the number of accessory genes in S. Kentucky was higher than that in S. enteritidis, and supermarket- and human-origin Salmonella isolates possessed a higher proportion of accessory genes. This indicates that the genomes of these isolates are more open and have greater potential for acquiring exogenous elements. Functional enrichment analysis on the core and auxiliary genomes of S. Kentucky and S. enteritidis based on COG clustering indicated that significant differences could be found in the functions of the accessory genomes between the two serotypes. ML-based screening identified intS3, which is implicated in genomic stability and DNA damage repair, as a key feature gene in wet market isolates. Key feature genes identified in S. Kentucky and S. enteritidis from chicken were torI and rfaF, respectively, both associated with environmental adaptability. In human-derived isolates, ccmA and oadB1 were identified as feature genes, contributing to bacterial proliferation and host adaptation. This study provides comprehensive genomic and epidemiological insights into Salmonella in Shaanxi retail chicken, emphasizing the widespread MDR/XDR burden and cross-regional dissemination, and underscoring the need for strengthened genomic surveillance to protect food safety and public health.

Isolate characterization and comparison are central aspects in foodborne outbreak investigation and is nowadays regularly performed using whole genome sequencing (WGS). Despite its high accuracy, WGS is relatively expensive, time-consuming, and requires specific expertise for data analysis. Therefore, this study evaluates the use of Fourier-transform infrared (FT-IR) spectroscopy as rapid and cost-effective isolate typing alternative. Presumptive B. cereus was isolated from a food sample and five fecal patient samples collected after a foodborne outbreak event; 51 isolates were screened using FT-IR. The presence/absence of the cereulide biosynthesis cluster (ces) was determined by PCR and supplemented to the FT-IR spectra. The isolates were also characterized by WGS to evaluate the performance of FT-IR. 14 different strains were identified by core-genome multi-locus sequence typing (cgMLST) from WGS. Two strains were detected in the food and in four out of five patient samples, while cereulide toxin was detected in all samples. A representative set of 13 isolates was obtained (dereplication) by comparing the FT-IR spectra through three different clustering methods: hierarchical cluster analysis (HCA), principal component analysis (PCA) and linear discriminant analysis (LDA). The overall congruency of FT-IR with cgMLST in this dataset was 96.4 % (Adjusted Wallace Index). Therefore, this study demonstrates that FT-IR spectroscopy can be a useful technique in the investigation of foodborne outbreaks, especially as a first-line screening tool to reduce the number of isolates for subsequent confirmation using WGS.

With the increasing threat of foodborne diseases, photodynamic inactivation (PDI) has attracted attention as a non-thermal sterilization technology that preserves food quality. But the efficiency of photosensitizers (PSs) is limited by short lifespan and limited diffusion distance of reactive oxygen species (ROS). Therefore, it is necessary to develop PSs capable of penetrating cell membranes and directly generating ROS within cells to effectively inactivate foodborne microorganisms. Among emerging materials, carbon dots (CDs) are small, water soluble, exhibit low photobleaching rates, and possess a core-shell structure with abundant surface functional groups, making them promising candidates for PDI. In this study, functional carbon dots (M-CDs) were synthesized from Cinnamomum burmannii waste. The M-CDs demonstrated strong fluorescence, excellent water solubility, and surface groups such as carboxyl and hydroxyl, which enhanced their biocompatibility and antimicrobial activity. With a diameter of approximately 3.355 nm, M-CDs efficiently penetrated cell membranes to generate ROS directly within cells, thereby inactivating foodborne microorganisms via multiple targets. The PDI efficacy of M-CDs against Escherichia coli 8739 was evaluated, demonstrating that 50 mg/L M-CDs reduced bacterial counts by 3.8 log, and 200 mg/L achieved complete bacterial eradication. Transcriptome analysis revealed gene enrichment in pathways related to lipid metabolism, energy metabolism, DNA repair, and oxidative stress responses. Moreover, M-CDs effectively reduced microbial contamination in Psidium guajava (guavas) and extended their shelf life by eight days at room temperature. The findings of this study provide new insights for developing green, safe, and effective strategies to control foodborne pathogen.

This study investigated microbial succession and free amino acid (FAA) dynamics in Cougar Gold Cheddar cheese over 18 months of commercial cold storage, with a focus on identifying microbial signatures associated with puffing spoilage. Fourteen proteinogenic FAAs and ornithine were monitored over time, revealing a steady increase in total FAA concentration, particularly flavor-active amino acids such as isoleucine, leucine, phenylalanine, and valine. A notable surge occurred after 9 months, suggesting enhanced proteolytic activity during late-stage ripening. Amplicon-based 16S rRNA sequencing revealed distinct microbial succession. Lactococcus dominated the early stages (0-3 months), followed by a marked increase in Lactobacillus, particularly Lb. helveticus, by 6 months, which remained dominant through 12 months before declining in the final stages. Paenibacillus wasatchensis was detected at later stages of aging. Cheese from puffed cans exhibited significantly higher alpha diversity and distinct microbial communities compared to standard-aged samples. Puffed samples were enriched in Pa. wasatchensis and several heterofermentative non-starter lactic acid bacteria, including Lb. curvatus, Lb. sakei, and Lb. graminis, accompanied by a reduction in Lb. helveticus. While overall FAA profiles were largely maintained, puffed samples showed modest reductions in aspartate, glycine, and ornithine, suggesting altered microbial metabolism. These findings provide valuable insights into the interplay between microbiota, proteolysis, and potential spoilage in aged cheese.

Listeria monocytogenes is an important foodborne pathogen that can persist in food-processing environments and threatens public health by causing fatal listeriosis. During transmission from the non-host to the host environment, L. monocytogenes encounters a variety of stresses and regulates gene expression by coordinately relying on quorum sensing (QS). With many recent studies on QS inhibitors (QSIs) targeting L. monocytogenes, an in-depth understanding of the QS regulatory mechanisms and the updated application status of QSIs for combating L. monocytogenes is necessary. This review systematically discusses the accessory gene regulator (Agr) system and LuxS system in L. monocytogenes, with a special focus on their regulatory mechanisms associated with biofilm formation, virulence expression, and antimicrobial resistance. Notably, the regulation of Agr system can be modulated by environmental stresses including temperature, nutrient availability and disinfectant exposure. Furthermore, natural (plant-derived compounds and bacterial metabolites) and synthetic QSIs of L. monocytogenes are summarized, and their potential as alternative biocontrol agents is comprehensively evaluated. Finally, the challenges limiting the application of QSIs in the food industry are discussed, along with the outlines of potential avenues for future aspects such as incorporation or coating nanomaterials with QSIs. This review provides an overview of QS regulatory mechanisms in L. monocytogenes and perspectives on the potential of QSIs as novel antimicrobial agents in the food industry.

Faba beans are rich in protein and fiber, but their consumption is limited by off-flavors, and antinutritional compounds. This study explored fermentations with lactic acid bacteria (LAB) and Bacillus spp. as a strategy to improve the sensory and nutritional qualities of faba bean protein concentrate (FPC). Fermentations were performed with the strains isolated from African fermented foods, including Limosilactobacillus fermentum NSB2, Lactiplantibacillus argentoratensis 12-27B and Bacillus velezensis G17, and with Bacillus subtilis Natto. Strain identification was performed using Oxford Nanopore whole-genome sequencing. Samples of fermented FPC (8 % w/v) were analyzed after 8 h, 24 h, and 48 h fermentation for volatile aroma compounds (VOCs), organic acids, free amino acids, γ-glutamyl peptides, and vicine-convicine. All strains effectively reduced aldehydes associated with beany off-flavors, such as hexanal. LAB, particularly L. fermentum NSB2, promoted alcohol formation, B. velezensis G17 produced the greatest amounts of diacetyl and acetoin, while B. subtilis Natto generated the largest amounts of esters. L. argentoratensis 12-27B was the most efficient producer of lactic acid, whereas B. velezensis G17 uniquely generated high levels of propionic acid. Bacillus spp. exhibited strong proteolytic activity during FPC fermentation, producing free amino acids, including essential ones. Several γ-glutamyl dipeptides were increased in fermentations, highest with Bacillus spp., suggesting potential kokumi enhancement. Notably, L. argentoratensis 12-27B and B. velezensis G17 significantly reduced vicine and convicine, the primary antinutritional compounds in faba beans. These findings highlight the potential of targeted fermentation to enhance the sensory quality and nutritional value of faba bean protein for plant-based food applications.

Penicillium roqueforti, a key fungus in the manufacture of blue-veined cheeses, can produce mycotoxins such as roquefortine C and mycophenolic acid. The production of these metabolites is highly strain- and condition-dependent. In industrial manufacture, hypotoxigenic P. roqueforti strains are typically used as controlled adjunct starters under standardized conditions, resulting in minimal mycotoxin accumulation, whereas naturally matured or artisan cheeses display more variable strain composition and ripening environments, which can elevate risk. In this context, the development of strains incapable of mycotoxin biosynthesis represents an important step toward safer cheese products. Here, we report the generation of P. roqueforti strains lacking the ability to synthesize roquefortine C and mycophenolic acid using CRISPR/Cas9. Single and double mutants deficient in one or both mycotoxins were obtained. Laboratory-scale cheeses produced under artisan-like conditions with these engineered strains contained no detectable levels of the target mycotoxins, in contrast to cheeses made with the wild-type strain. All mutants retained the ability to colonize cheese but displayed altered fungal biomass production compared to the native strain. These differences were consistent in curd and laboratory media and were not associated with changes in lipolytic or proteolytic activities. Further analyses revealed that while the absence of mycophenolic acid did not affect NaCl sensitivity, the lack of roquefortine C increased sensitivity to salt. Collectively, these results demonstrate the feasibility of producing mycotoxin-free blue cheeses using strains deficient in roquefortine C and mycophenolic acid biosynthesis, thereby laying the foundation for developing mycotoxin-free cheeses with engineered atoxigenic P. roqueforti strains.

A survey of 75 commercially available, unpasteurised, spontaneously fermented vegetables was conducted, focusing on the culturable microbiota. Foodborne pathogens (Listeria monocytogenes, Salmonella sp.), indicator bacteria (generic E. coli, Enterobacteriaceae), and lactic acid bacteria (LAB) were analysed both at the day of purchase and at the end of shelf life. Selected samples were further examined for biogenic amines, and dominant culturable LAB were isolated and identified. Challenge tests evaluated the growth potential of L. monocytogenes during white cabbage fermentation. Results showed considerable variation in pH (3.1-4.3) and LAB counts (<1.0-8.8 log CFU/g), reflecting the spontaneous nature of the vegetable fermentations. No Salmonella sp. (detection in 25 g), L. monocytogenes (LOD 10 CFU/g), or E. coli (LOD 10 CFU/g) were detected, indicating no immediate food safety or hygiene concerns, although Enterobacteriaceae were present (LOD 10 CFU/g) in six samples, suggesting an inadequate (spontaneous) fermentation process to ensure die-off of enteric pathogens. LAB isolates were dominated by Pediococcus parvulus, Lactiplantibacillus plantarum, Levilactobacillus brevis, and Lentilactobacillus buchneri. High biogenic amine levels highlight an increased risk for adverse health effects related to spontaneous vegetable fermentations. Challenge tests confirmed that rapid acidification to pH <4.4, followed by a minimum 14-day holding period under optimal fermentation conditions, effectively limits pathogen outgrowth and/or survival. Good fermentation practices, together with a sensory evaluation are essential to ensure the microbiological safety, quality, and consistency of spontaneous vegetable fermentations.

This study demonstrates the potent antibacterial activity of terpinen-4-ol against Listeria monocytogenes, with a minimum inhibitory and bactericidal concentration (MIC/MBC) of 3 μL/mL. Mechanistic investigations revealed a multi-target mode of action. Terpinen-4-ol compromised bacterial membrane integrity, as evidenced by SYTO9/PI staining and leakage of intracellular nucleic acids. It also induced structural DNA damage, as indicated by DAPI staining, and triggered oxidative stress through ROS accumulation. Additionally, terpinen-4-ol disrupted cellular energy metabolism by reducing intracellular ATP levels and ATPase activity, which correlated with impaired motility, decreased metabolic activity, and reduced biofilm formation. In practical application, fumigation with terpinen-4-ol effectively reduced L. monocytogenes populations on lettuce. These findings clarify the multifaceted antibacterial mechanism of terpinen-4-ol and support its potential as a natural preservative for foods stored at low temperatures.

Light-flavor Baijiu is a Chinese liquor characterized by a short brewing cycle and a relatively simple process, making it an ideal model for evaluating the effects of raw materials on brewing outcomes. This study investigated two glutinous (GS-L, GS-S) and two non-glutinous (NGS-G, NGS-A) sorghum varieties using solid-state fermentation over a period of 0, 15, 30, and 45 days to analyze the evolution of microbial communities, physicochemical properties, and dynamic changes in flavor components. Results showed that sorghum type significantly influenced the microbial communities and function. Klebsiella was exclusively detected in fermentations with glutinous sorghum. Meanwhile Saccharomycopsis dominated these samples throughout the process. Differences in microbial communities between glutinous and non-glutinous sorghum were primarily reflected in fungal genera. Kazachstania, Epicoccum, Fusarium, Hyphopichia, Trichosporon and Alternaria were commonly detected in GS-L and GS-S. Microbial community succession was primarily driven by acidity, amino acid nitrogen, starch, and reducing sugars, with starch and reducing sugars being particularly influential. During fermentation, 129 flavor compounds were discovered. GS-L and GS-S outperformed NGS-G and NGS-A in producing most flavor compounds, exhibiting significantly higher concentrations and greater stability after long-term fermentation. PICRUST II functional prediction revealed significant differences in the relative abundance of genes linked to carbohydrate metabolism, starch and sucrose metabolism and amino acid biosynthesis among sorghum varieties. FUNGuild prediction further indicated that environmental microorganisms also influence fermentation outcomes. These findings provide a basis for selecting raw materials and optimizing fermentation parameters, ultimately contributing to improving Baijiu quality.

Effective biopreservation strategies are essential to minimize chilled meat waste, ensure product quality, and extend shelf life. However, the low storage temperature (4 °C) of modified atmosphere packaging chilled meat limits the growth and activity of most protective cultures, highlighting the need for cryotolerant strains. This study investigated the bioprotective potential of Pediococcus acidilactici L1 (a cryotolerant strain) and Latilactobacillus sakei B2 (a commercial strain) on the pork under the modified atmosphere packaging (MAP) at 4 °C for 14 days. The results indicated that Pe. acidilactici L1 and Lat. sakei B2 groups exhibited significantly higher a* values and shear force, and a lower mass loss rates, pH, and total volatile base nitrogen compared with the control (P < 0.05), which revealed that Pe. acidilactici L1 and Lat. sakei B2 retarded the quality deterioration of pork. Compared to Lat. sakei B2, Pe. acidilactici L1 more effectively inhibited the growth of Brochothrix thermosphacta in chilled pork and plates. The samples inoculated with Pe. acidilactici L1 exhibited significantly higher scores for color and overall acceptability on day 14 (P < 0.05). Moreover, Pe. acidilactici L1 and Lat. sakei B2 significantly (P < 0.05) decreased the content of spoilage related volatile organic compounds such as 1-pentanol, 1-octanol, 1-heptanol, 1-nonanol, hexanoic acid, and nonanal, slowed down the development of spoilage odors. Overall, Pe. acidilactici L1 exhibited a superior bioprotective effect on MAP chilled pork compared to Lat. sakei B2. This study provides a promising bioprotective culture for chilled meat preservation.

Oenococcus oeni is the lactic acid bacteria species best adapted to wine. It proliferates during alcoholic fermentation and typically becomes the most abundant species during malolactic fermentation. A large diversity of O. oeni strains is present in all wine-producing regions. These strains group into several genetic lineages, which are more product-specific rather than linked to geography. I. e. strains of one genetic lineage are often detected in the same wine type produced in distant regions. This study aimed to investigate the biodiversity of O. oeni involved in malolactic fermentations of Cognac wines produced for distillation. These wines have several specific characteristics: they are low-pH white wines, low in alcohol, produced without added sulfites, and from a single grape variety (Ugni blanc). Nearly 3500 O. oeni isolates were obtained from 132 wines collected from 24 cellars across the main cognac-producing areas. 458 different strains were identified by genotyping, representing in between 1 and 249 isolates. A distribution analysis showed a large diversity of strains in each wine and cellar. Forty-nine strains were sequenced and a phylogenomic tree was reconstructed including 247 previously published genomes of strains from other regions and products. This tree revealed a new genetic lineage harboring exclusively Cognac strains whose predominance on Cognac wines was further confirmed by a specifically developed quantitative PCR test. The results highlight the existence of a new sub-lineage indicative of the domestication of O. oeni strains to a single type of wine, and across an entire wine-producing region.