Food Research International

Texture is one of the major barriers to acceptance of sustainable protein products, yet the relationship between instrumental texture and consumer perception remains poorly understood. Here we combined consumer sensory evaluation and texture profile analysis to identify the factors that drive burger acceptance across blended, animal-based, and plant-based formulations. A total of 472 diners evaluated beef-mushroom (n = 171), turkey (n = 100), bean (n = 100), and pea (n = 101) burgers served in Stanford University dining halls, while texture profile analysis quantified physical texture (n = 10 per product). The beef-mushroom burger achieved the highest ratings for meatiness (77.0/100), tastiness (69.4/100), and moistness (61.8/100), and 78% of consumers rated its moistness as just-about-right. Although the pea burger exhibited mechanical properties similar to the beef-mushroom burger, including indistinguishable cohesiveness values (0.53 vs. 0.53), it received substantially lower ratings for meatiness (56.1 vs. 77.0), indicating that mechanical similarity alone does not ensure consumer acceptance. Across products, moistness emerged as the primary sensory limitation, with 58% of turkey consumers and 46% of bean consumers reporting insufficient moisture. Cohesiveness showed the strongest association with perceived meatiness (r = 0.82). These findings demonstrate that successful burger reformulation requires more than mechanical matching; products must reproduce the moisture, flavor, and eating experience associated with meat. Blended burgers may represent the most practical near-term strategy for reducing meat consumption without compromising eating quality.

Developing structured cultivated meat requires integrated solutions that combine scalable cell sources with edible, foodgrade materials capable of supporting highdensity growth and differentiation. Here, we evaluate bovine mesenchymal stem cells derived from embryonic stem cells (ESCderived iMSCs) as a scalable adipogenic cell source and develop an integrated workflow combining these cells with edible plantbased scaffolds for structured biomass generation. Cell identity and functionality were assessed using transcriptomic, morphological, gene expression, flow cytometric, and adipogenic differentiation analyses, in both adherent and suspension culture systems. In parallel, lentil, pea, and soy-based scaffold formulations were screened for cell attachment, proliferation, and biomass accumulation. Soybased scaffolds supported uniform cell distribution and robust growth and outperformed lentil-based scaffolds. Under dynamic culture conditions, bovine iMSCs cultured on soy-based scaffolds achieved highdensity growth, showing biomass accumulation (cell wet weight/scaffold wet weight) reached an average cell wet weight to scaffold wet weight ratio of 15% within three days. Cultures demonstrated active glucose metabolism and retained adipogenic differentiation capacity, confirmed by lipid accumulation and positive oil red O staining. These findings demonstrate an integrated cell-scaffold platform for rapid threedimensional biomass generation. This approach supports the development of a cell culture strategy for structured cultivated meat by combining defined cell sources with foodgrade scaffold technologies to improve scalability, structure, and nutritional relevance. HighlightsO_LIBovine ESC-derived iMSCs enable scalable adipogenic cell production C_LIO_LIEdible soy-based scaffolds support 3D attachment and biomass accumulation C_LIO_LIDynamic culture achieved [~]15% cell wet weight fraction within 3 days C_LIO_LIiMSCs retained adipogenic differentiation capacity on edible scaffolds C_LIO_LIIntegrated cell-scaffold culture supports structured cultivated meat prototypes C_LI

Industrializing cultivated meat requires cell lines with high proliferative capacity, genetic stability, and suspension adaptability. We present a comprehensive multi-omics framework, integrating genomics, transcriptomics, and proteomics, to characterize a commercial duck Embryonic Stem Cell (dESC) line. Our analysis demonstrates continuous proliferation in protein-free suspension media while maintaining a stable genome and a functional conserved transcriptome. Broad-scale transcriptomics confirms the absence of hazardous pathway activation, and targeted assays verify sustained pluripotency marker expression during scale-up. Compositional analysis reveals a low-fat biomass containing all nine essential amino acids with an amino acid profile comparable to conventional duck meat. Furthermore, proteomic profiling demonstrates inter-batch reproducibility and protein distributions comparable to duck breast and liver. This study provides the first detailed molecular characterization of a commercial cultivated meat cell line, establishing a reference for the stability and safety assessment of future cultivated meat cell lines.

The development of cost-effective, serum-free media is critical for scalable cultivated meat production. This study used high-throughput screening through a Design of Experiments (DoE) approach to develop an animal-free, serum-free medium (MMM1) specifically for the C2C12 murine myoblasts model cell line with applicability in cultivated meat research including for pet food. Low cost, food-grade inputs such as methylcellulose and spirulina extract resulted in significant cell growth improvements. The optimised MMM1 formulation containing low cost, food-grade inputs, achieved cumulative population doublings comparable to 10% (v/v) fetal bovine serum over four consecutive passages. Furthermore, MMM1 supported scalable cell expansion on commercially available dextran-based microcarriers (Cytodex-3) in both static and agitated conditions in spinner flasks, matching growth rates of serum-based controls. Finally, transitioning to a food-grade DMEM/F12 basal medium maintained cell proliferation equivalent to the pharmaceutical-grade DMEM/F12, but at a significantly lower cost, thus offering a viable strategy to substantially reduce biomanufacturing costs which is a critical challenge in cultivated meat production.

Fermented foods are increasingly recognized for their health-boosting potential, yet the mechanisms involved are not fully resolved. Here, we tested whether kombucha reshapes the gastrointestinal microbiome and whether these changes are associated with stress-related behaviors under contrasting dietary backgrounds. Male C57BL/6 mice were fed either a total Western diet (TWD) or a control diet (CTRL) supplemented with kombucha or water three times weekly for seven weeks. Depressive-like and anxiety-related behaviors were evaluated using the forced swimming (FST) and marble burying tests (MBT). Ileum, cecum, and colon microbiomes were profiled via 16S rRNA, ITS2, and shotgun metagenomics, while feces and whole brains were profiled by LC-MS metabolomics. Serum cytokines were measured by ELISA. Results highlight diet-dependent effects of Kombucha on behavioral, microbial and metabolic outcomes. Kombucha reduced immobility in the FST under both diets, whereas fewer marbles buried were observed only under TWD. Kombucha intake enriched Bifidobacterium pseudolongum in the ileum under CTRL and TWD diets, while cecal microbial functions related to amino acid metabolism were stimulated mainly under CTRL. Only CTRL mice receiving kombucha showed higher fecal acetate and butyrate together with lower fecal levels of neurochemically relevant amino acids, including glutamine, phenylalanine, tryptophan, and tyrosine. Under TWD, kombucha was associated with lower spleen weight and altered brain tryptophan/kynurenine profiles. These findings identify kombucha as a food intervention that can remodel gastrointestinal microbial and neuroactive metabolism in a diet depending manner. Associations with reduced depressive and anxiety-related behaviors are promising but warrant further exploration. Key HighlightsO_LIKombucha supplementation reshaped the mice gastrointestinal microbiome and its neuroactive potential C_LIO_LIKombucha intake was associated reduced depressive and anxious like behaviors C_LIO_LIThe potential of kombucha to modulate microbial, metabolic and behavioral outcomes may be dependent on subject dietary background C_LI

In many tropical countries, fermentation of palm sap into palm wine is an important fermented beverage contributing to local economies, tradition, and culture. Traditionally made in villages and families, palm sap is not inoculated with starter cultures and fermentation commences spontaneously. It is therefore possible that fermentation is influenced by multiple ecological factors, which affect microbial dynamics and thus flavour outcomes. Here, we studied microbial communities during fermentation of palm sap from three different palm tree species (palmyra, coconut, and sugar palm) on the island of Bali, Indonesia in both the wet and dry seasons. Our results suggest that season of collection has a strong influence on microbial dynamics and succession, and these changes positively correlate to metabolite concentration. The change of the season from the dry to wet season led to the loss of microbial diversity with lower richness in the dry season. The dominance of Saccharomyces cerevisiae was not affected by season and fermentation time and was dominant in all samples. Potential spoilage species, such as Candida tropicalis were negatively correlated to ester production and more abundant in the dry season. As microbial species varied in incidence and thus biochemical activity, the chemical groups of esters from their metabolism related to the change of season and fermentation time, while volatile compounds and small molecules were highly discriminated by season in the resultant wines. Ethyl octanoate was consistently different across all variables through comparison by three-way ANOVA and is proposed as a biomarker of seasonal variation in palm sap fermentation. These findings improve our understanding of microbial dynamics in palm sap fermentation, revealing flavour differentiation within season and suggests that strategies for microbial management, product development and quality assurance will elevate this traditional product into the future.

Mushroom production generates large amounts of by-products, particularly stipes, which can represent up to half of the fruiting body biomass. Due to their similar composition to mushroom caps, these residues represent a promising substrate for the development of value-added foods. In this study, oyster mushroom stipes were used as a substrate for solid-state fermentation (SSF) with a Neurospora crassa strain isolated in Albacete to produce a novel meat analogue inspired by the oncom. Fermentation generated a cohesive matrix bound by hyphae that adopted the shape of the mold and exhibited a meat-like color, although with a softer texture. Nutritional analysis revealed a product with relatively low protein content but a complete amino acid profile, enriched in dietary fiber and containing unsaturated fatty acids. These results demonstrate that SSF with N. crassa provides a strategy to upcycle oyster mushroom by-products into fiber-rich meat analogues with potential applications in sustainable food systems.

In this research we inoculated Lacticaseibacillus casei (L. casei) into wheat sprouts and studied the viability of the bacteria in the sprout. L. casei (ATCC39392) strain was inoculated into sterilized wheat sprouts. The height of the sprouts and roots were checked and the active phenolic content, flavonoid compounds, and the antioxidant activity were measured. The bacterial viability was determined under simulated gastrointestinal (SGI) conditions. The physicochemical properties of the final product and its organoleptic properties were also investigated. The final confirmation of the presence of bacteria was also done by transmission electron microscope imaging. The number of bacteria increased from 8.18 Log CFU/g to 11.81 {+/-} 0.33 Log CFU/g. The increase in the phenolic content and antioxidant activity indicates the improvement of the nutritional value of the sprout. The physicochemical properties of the product changed due to the activity of bacteria. The inoculated bacteria also survived after exposure to SGI. The organoleptic properties of the product did not reveal a significant difference between the control and treatment groups. The increase in the number of bacteria and their survival after exposure to SGI indicates the suitable condition of wheat sprout as a proper substrate for L. casei bacteria.

Child-targeted marketing on packaged foods can shape children's food preferences and parents' purchasing decisions, yet many products with child-targeted marketing are ultra-processed foods (UPFs) and contain cosmetic additives such as food colorings, which have raised concerns about adverse effects on children's health and behavior. This mixed-methods study examined the prevalence of food colorings in child-directed UPFs and explored parents' perceptions and knowledge of these additives in beverages commonly consumed by children. Quantitative data were obtained from the Mintel Global New Products Database to identify child-directed products launched in Brazil between 2018 and 2021, measured as having at least one child-targeted marketing strategy in the food package, and whether they contained food colorings. Qualitative data came from seven focus groups with parents of children aged 2-5 and 6-11 years in Brazil, alongside a brief survey assessing participants' ability to identify food colorings on product labels. Among 5,078 UPFs launched during the study period, 23.0% contained child-targeted marketing, and 40.3% of these had food colorings. The highest prevalence was observed in carbonated beverages, candies, and ice creams, in which more than half of products contained food colorings. Parents generally understood that food colorings are used to make products more attractive to children and associated them with potential health risks, but reported difficulties avoiding them. These findings highlight the widespread presence of food colorings in child-targeted UPFs in Brazil and underscore the need for stronger regulatory measures to restrict the use of food colorings and improve labelling on food packages.

Background: Despite growing evidence that personalised nutrition (PN) can improve dietary behaviour and health outcomes, the implementation of PN food services in real-world settings remains largely unexplored. This study evaluated the feasibility of a comprehensive PN service for delivering personalised nutrition products (PNPs) in a military setting and assessed consumer acceptance following repeated consumption. Methods: A complete PN service was developed to design, produce, and distribute personalised nutrition products (PNPs). Twenty-five participants from the Royal Netherlands Army took part in a feasibility study, using a single-cohort pre-test post-test design. Each participant consumed a PNP on 10 consecutive days during a two-week combat training exercise. Product liking was assessed through daily questionnaires, while broader user experiences were assessed at baseline (t=0), one week follow-up (t=1) and two-week endline (t=2). Results: The PN service was succesfully implemented during a real-life military training exercise. In total, 229 PNPs were produced and distributed. Participants evaluated all aspects of the PN service from just below neutral to slightly positive (3.4 to 5.0 on 7 point scales). Across the different product combinations, mean overall liking and all sensory attributes were slightly positive (5.7 to 6.1 on 9 point scales). Overall liking did not change over time (F (9,194) = 1.242, p=0.27). Attitudes toward a PNP service in the army decreased over time, but remained just-above neutral at study end. Conclusions: This study demonstrates the feasibility of a personalised nutrition service in a military setting. Both the service and PNPs received modestly positive evaluations, while repeated exposure did not change overall liking of the products. Although further optimisation of the service is warranted, these findings support the potential for broader implementation of PN services in military and other high performance environments.

To evaluate the international interoperability of food composition databases, we assessed the compatibility of seven national food composition tables with USDA FoodData Central (FDC) using the LLM-based matching method reported previously (Nakagawa and Yamamoto, 2026). Databases from four English-speaking countries (Canada, United Kingdom, Australia, and New Zealand), South Korea, and Japan were compared with 8,158 USDA FDC entries (SR Legacy and Foundation Foods, excluding Survey/FNDDS). Match rates varied by country (62.0-89.7%) and food category. After excluding six USDA categories unsuitable for cross-national comparison, 45.2% of the remaining 6,290 entries were not matched by any country. Canada showed the highest concordance, reflecting shared North American food supply. Japan and South Korea showed similar low coverage for vegetables and spices. These findings suggest that while USDA FDC represents a practical foundation for a globally comprehensive food composition database given its breadth, systematic incorporation of country-specific foods and classification schemes will be necessary to achieve true international interoperability.

Background: Yeast (Saccharomyces cerevisiae) is a model organism in agricultural and industrial fermentation with nutritional benefits, yet less is understood about its nutritional value for supporting whole-body protein synthesis in vivo, and its comparison to animal-based protein. Objective: This study aimed to determine the effect of microbial-based protein (yeast) compared to a high (whey) and low (collagen) quality animal-based protein on the ability to support whole-body protein synthesis using the indicator amino acid oxidation technique. Methods: Thirteen healthy participants (M: n=6, 24{+/-}4 yr; F: n=7, 27{+/-}7 yr) consumed eight hourly yeast (Y), whey (W), or collagen (CH) protein beverages at 0.9 g{middle dot}kg-1{middle dot}d-1 supplemented with L-[1-13C]phenylalanine in a randomized, cross-over, counterbalanced design. Breath and urine were collected to measure fraction of expired 13CO2 (F13CO2) and [1-13C]Phe oxidation (PheOx) as inverse correlates of whole-body protein synthesis. An a priori 20% noninferiority margin was used to determine equivalency between protein sources. A Visual Analog Scale (VAS) was provided to assess fullness and hunger by protein sources. Results: Protein source had no effect on F13CO2 (P=0.15) or PheRa (P=0.10). PheOx was greater in CH compared to both Y (14.94{+/-}2.16 vs. 12.93{+/-}2.80 mol{middle dot}kg BM-1{middle dot}h-1, P<0.05) and W (14.94{+/-}2.16 vs. 12.50{+/-}2.75 mol{middle dot}kg BM-1{middle dot}h-1, P<0.05) whereas there was no significant difference between Y and W (P=0.59). Change in PheOx (mean difference [90% CI]) between CH and W (2.44 mol{middle dot}kg BM-1{middle dot}h-1 [0.98, 3.90], P<0.05) and between Y and W (0.44 mol{middle dot}kg BM-1{middle dot}h-1 [-1.34, 2.21], P>0.99) confirmed respective inferiority and noninferiority to W compared to the 20% noninferiority margin (2.50 mol{middle dot}kg BM-1{middle dot}h-1), while Y was superior to CH (-2.00 mol{middle dot}kg BM-1{middle dot}h-1 [-3.01, -0.99], P<0.05). Protein source did not significantly influence satiety (P=0.32) or hunger scores (P=0.15). Conclusion: EAA-enriched whey and yeast protein similarly reduced PheOx as compared to EAA-deficient collagen hydrolysate, suggesting these proteins were similarly superior in supporting whole-body protein synthesis.

Animal cell-cultured ingredients are entering the EU and UK pet food markets under frameworks that do not require pre-market, ingredient-level safety assessments, creating an ethical need for transparent safety disclosure. We present the first public safety dossier for this sector, describing the proprietary mouse embryonic stem cell line PE25 and its derived, non-viable cellular and conditioned media ingredient produced in food and feed-grade media. PE25 characterization confirmed Mus musculus identity, sterility, absence of mycoplasma and replication-competent retroviruses, and stable growth. Doxorubicin-induced p53 stress testing, CD44/BMI1 profiling, and soft agar assays showed no cancer-like traits and a non-tumorigenic profile; the final ingredient contains no viable cells. Independent OECD TG 471 and 487 assays confirmed non-genotoxicity. Heavy metals, biogenic amines, solvents, and chemical residues were below regulatory limits. Given process variability, we recommend case-by-case safety evaluation and propose this dossier as a model for responsible commercialization.

Alpha-gal Syndrome (AGS) is a potentially life-threatening allergy caused by an IgE-mediated immune response to galactose--1,3-galactose (alpha-gal), a carbohydrate epitope present in most mammalian meats. Currently, strict avoidance of mammalian meat remains the primary management strategy for affected individuals, and alpha-gal-free beef is not commercially available. Here, we leverage cultivated meat as a biotechnology plat-form to address this unmet clinical need by engineering alpha-gal-free bovine muscle cells. Using CRISPR/Cas9 genome editing, we disrupted GGTA1, the gene encoding 1,3-galactosyltransferase, in immortalized bovine satellite cells (iBSCs). High-efficiency editing produced clonal GGTA1 knockout iBSCs harboring a homozygous frameshift mutation. Flow cytometry and immunofluorescence confirmed loss of the alpha-gal epitope, while bulk RNA-seq indicated minimal disruption of global gene expression and preserved myogenic differentiation capacity. Importantly, lysates from GGTA1 knockout iBSCs elicited substantially reduced basophil activation in assays using plasma from a patient with AGS, indicating reduced basophil activation consistent with reduced allergenic potential. Together, these findings establish a proof of concept for engineering AGS-compatible cultivated meat and demonstrate the potential of cultivated meat technologies to address human health challenges. HIGHLIGHTS{circ} CRISPR/Cas9-mediated disruption of GGTA1 eliminated alpha-gal from bovine satellite cells {circ}GGTA1 knockout cells retained myogenic identity and differentiation capacity {circ}GGTA1 knockout reduced basophil activation in an alpha-gal syndrome immune assay {circ}Genome-edited bovine cells provide a proof of concept for AGS-compatible cultivated meat

Edible seaweed has the potential to become a valuable marine resource for food applications due to its potential health benefits and ecological sustainability. The brown seaweed Alaria esculenta is rich in essential minerals, vitamins, and dietary fibers, making it a nutritious food source. Fermentation, as a traditional preservation method, can enhance seaweed shelf-life and be useful for the development of new foods/ beverages. In this study, the effects of fermentation of A. esculenta, by the lactic acid bacterium (LAB) Lactiplantibacillus plantarum, on the nutritional profile, and the content of potentially toxic elements, was investigated. L. plantarum was successfully cultivated on A. esculenta using two modes of operation, submerged (SmF) and solid-state fermentation (SSF), resulting in production of cells and lactic acid, and reduction of the pH to below 4.3 within 3 days, which was not achieved in parallel spontaneous fermentations using indigenous seaweed microbiota. A. esculenta s macro-nutritional profile was altered, reducing mannitol but increasing fucose and glucose content (after acid hydrolysis) while also concentrating the protein content. LAB fermentation significantly increased the concentration of antioxidant phenolic compounds, such as phloroglucinol, syringic acid, and epicatechin, compared to untreated samples. However, lipophilic compounds like carotenoids decreased after both spontaneous and LAB-fermentation. A reduction in total mineral content was observed after LAB fermentation and water soaking, and SmF with L. plantarum effectively reduced arsenic and iodine levels. Overall, fermentation using L. plantarum showed potential as a bio-preservation method for the edible brown seaweed, A. esculenta, improving its nutritional profile and enhancing food safety.

Abstract Background and Objective: To investigate the efficacy of a new, proprietary high-resistance potato starch as a prebiotic in comparison to inulin and a control. Methods: In this prospective study, an intervention of 9 g of resistant potato starch (RPS, Potatodaat), inulin, or accessible corn starch was given to participants with mild to moderate indigestion for 30 days. Short chain fatty acid (SCFA) levels, changes to the gut microbiome, and changes in clinical symptoms of indigestion were assessed as primary outcomes. Results: Subjects in the RPS (n = 22), inulin (n = 23), and accessible corn starch (n = 22) groups demonstrated similarity in age, sex, and baseline parameters. At 30 days, the groups experienced 21.1%, 6.29%, and 9.15% increases in stool butyrate, respectively. Clinical symptoms like indigestion and flatulence showed greater improvement with the use of RPS compared to the other two groups. Conclusion: Consumption of high resistance potato starch helps improve stool SCFA levels along with clinical symptoms related to digestion, showing its better prebiotic potential as compared to inulin and accessible corn starch. The new high-resistance potato starch can be considered an effective replacement for inulin.

Fungal contamination of food with yeast and moulds is associated with major economic losses due to spoilage and also poses health risks in the form of mycotoxin production. The strain Pantoea agglomerans APC 4211 isolated from leaves of Ilex aquifolium (holly tree) has broad spectrum antifungal activity against a variety of food spoilage fungi. Genomic analysis of the strain confirmed the presence of biosynthetic gene clusters potentially encoding for the enzymatic machinery required for the production of the antifungal lipopeptide herbicolin A. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis of the cell-free supernatant (CFS) confirmed the presence of molecular masses corresponding to herbicolin A (1300.8 Da), and herbicolin B (1138 Da). Purified herbicolin A has desirable properties for biotechnological applications, including potent antifungal activity against a range of spoilage fungi, thermal stability and resistance to proteases. Herbicolin A has low cytotoxicity against epithelial cell lines and has minimum inhibitory concentrations (MICs) lower than those of some commercial antifungal drugs (0.2 - 2.5 {micro}g/ml). In a model dairy system (10% skim milk), herbicolin A demonstrated excellent solubility and stability, effectively eliminating Aspergillus niger and Penicillium notatum at a concentration of 5 {micro}g/mL. In conclusion, herbicolin A is a potent, naturally occurring antifungal agent with the potential to be applied as a biopreservative in food systems, providing a safe, clean-label, and efficient compound for synthetic preservatives replacement. HighlightsO_LIHerbicolin A has a strong potential as a natural preservative for food protection C_LIO_LIHerbicolin A shows lower MICs than several antifungal agents C_LIO_LIHerbicolin A is stable under heat and resistant to proteolytic degradation C_LIO_LIHerbicolin A has strong solubility and stability in a model dairy system C_LIO_LIHerbicolin A indicates low cytotoxicity against epithelial cell lines C_LI Data summaryThe authors confirm all supporting data, code and protocols have been provided within the article or through supplementary data files.

Sustainable agriculture has driven increased exploration of microbial inoculants as a promising strategy to boost plant growth for higher yield and enhance secondary metabolism to increase crop nutritional value. However, their influence on fruit-specific metabolites under field conditions remains understudied. This study investigated the impact of inoculating cranberry (Vaccinium macrocarpon) plants with Bacillus velezensis EB37 and Lachnum sp. EC5, applied individually and in combination, on cranberry fruit phytochemistry. Over two growing seasons (2019 and 2021), cranberries were collected from treated and control plots and analysed using untargeted and targeted LC-MS-based metabolomics. Multivariate analysis revealed no significant metabolomic differences due to treatments. However, samples clustered strongly by year of harvest, highlighting a pronounced environmental effect. Quantitative analysis of six representative phenolic compounds: chlorogenic acid, catechin, p-coumaric acid, phloridzin, myricetin, and quercetin, showed no statistically significant differences between treated and control cranberries. These findings indicate that microbial inoculation alone does not alter cranberry fruit metabolome, including phenolic levels, at field conditions. This study underscores how multiple factors, such as environmental conditions, can affect the outcome of microbial inoculation under field conditions and suggests that additional interventions may be required to achieve microbiome-based improvements in cranberry fruit quality.

BackgroundRaw broiler meat products are highly perishable, and microbial activity is the main factor limiting their shelf lives. The spoilage microbiomes of broiler meat products have been studied mainly using traditional culturing methods and 16S rRNA gene amplicon sequencing, neither of which can show the activity of whole microbiome. Previous metatranscriptomic research of broiler spoilage has also remained limited to specific spoilage organisms rather than entire microbiomes. ResultsOur longitudinal study of broiler meat spoilage discovered the successions of active bacterial microbiomes and metabolic pathway activities of spoilers at 4{degrees}C and 6{degrees}C. Samples taken daily were subjected to metatranscriptomic analyses in combination with non-targeted metabolomic, traditional microbiology, and sensory analyses until advanced spoilage took place. Carnobacterium divergens, Carnobacterium maltaromaticum and Vagococcus proximus were the most active species at both temperatures. Carnobacteria are known poultry spoilers whereas Vagococcus proximus, a species recently described, played an unexpected active role in the microbiome. It became dominant in samples stored at 6{degrees}C and its activity increased also at 4{degrees}C after the use-by date. Central carbohydrate metabolism was the most common KEGG orthology pathway module of the microbiome at both temperatures. C. divergens and C. maltaromaticum showed stable metabolic profiles during the spoilage process, whereas V. proximus displayed a shift from high ATP synthesis activity to increased fatty acid and carbohydrate metabolism when spoilage advanced in samples stored at 4{degrees}C. Non-targeted metabolomics showed similar metabolomic trends across both temperatures. At 6{degrees}C, time-dependent changes were generally more pronounced, and the spoilage markers tyramine and spermidine showed greater accumulation. ConclusionsAs expected, the rate of spoilage is higher at 6 than 4{degrees}C, however we did not anticipate a similar overall trajectory of the spoilage processes. Our results link V. proximus as a key active spoiler in broiler meat and demonstrate the efficacy of using RNA-seq together with metabolomics to decode the function of a meat spoilage microbiome. This demonstrates that spoilage microbiomes consist of active species we have been neglecting due to the technological limitations of the standard methods. Future studies targeting to the metabolism and detecting of Vagococcus are warranted.

Listeria monocytogenes can persist in niches of meat processing environments despite routine cleaning and disinfection. Its persistence may depend not only on stress tolerance but also on interactions with resident microbial communities, which may promote or inhibit survival. However, these ecological relationships remain poorly understood. We combined 16S rRNA V3/V4 amplicon sequencing, culture-based detection, and multilocus sequence typing (MLST) to characterize microbial communities in six German meat processing facilities over one year. We examined associations among community structure, sampling sites (drains and food-contact surfaces), and the occurrence of Listeria spp., including L. monocytogenes. Microbial communities were dominated by core genera typical of food-processing environments, particularly Pseudomonas spp. and Acinetobacter spp., but differed significantly among facilities (PERMANOVA, p = 0.001; pairwise R{superscript 2} = 0.023-0.079), indicating facility-specific communities. Culture-based analyses detected Listeria spp. in 51 of 370 environmental samples (13.8%), mainly from drains (44/51, 86.3%). L. monocytogenes was detected in five of six facilities, with 19 of 21 isolates originating from drains (90.5%). MLST of 74 typeable L. monocytogenes isolates revealed high diversity, comprising 21 sequence types across 15 clonal complexes, with lineage II predominating (86.5%). Overall microbial community composition was significantly associated with Listeria spp. and L. monocytogenes presence (PERMANOVA, p = 0.001; R{superscript 2} = 0.0137 and 0.0083). In drains, ASVs assigned to Acinetobacter, Rhizorhapis, and Vagococcus species showed positive associations with Listeria spp.-positive samples. Together these findings suggest that drains are key ecological niches for Listeria spp. and that associated taxa may indicate drain communities linked to Listeria spp. recovery. IMPORTANCEListeria monocytogenes is a major foodborne pathogen that can persist in meat processing environments despite routine cleaning and disinfection. Resident microbial communities may influence its survival, but longitudinal studies linking those communities with culture-based Listeria spp. detection remain limited. Here, we characterized microbial communities in six German meat processing facilities over 1 year using 16S rRNA gene amplicon sequencing and culture-based Listeria spp. detection, and MLST of L. monocytogenes isolates. We identified facility-specific microbial communities, identified floor drains as key niches for Listeria spp., and observed repeated recovery of different L. monocytogenes sequence types across facilities. In drains, ASVs assigned to the genera Acinetobacter, Rhizorhapis, and Vagococcus species were positively associated with culture-positive samples, identifying candidate taxa that may reflect microbial conditions associated with Listeria spp. recovery. These findings highlight the importance of considering not only whether Listeria spp. are detected, but also the resident microbial communities that may support their fitness.