International journal of food microbiology最新文献

{"title":"Novel molecular mechanisms of gamma-aminobutyric acid production mediated by LuxS/AI-2 quorum sensing system in Limosilactobacillus fermentum B41","authors":"Yunmei Chai,&nbsp;Wentao Zheng,&nbsp;Shaomei Hu,&nbsp;Tingting Yang,&nbsp;Guangwei Chen,&nbsp;Aixiang Huang","doi":"10.1016/j.ijfoodmicro.2025.111269","DOIUrl":"10.1016/j.ijfoodmicro.2025.111269","url":null,"abstract":"<div><div>LuxS/AI-2 quorum sensing (QS) systems promotes the production of various functional factors in lactic acid bacteria (LAB) including the production of gamma-aminobutyric acid (GABA). However, the molecular mechanisms underlying GABA biosynthesis mediated by the LuxS/AI-2 QS system in <em>Limosilactobacillus fermentum</em> (<em>L. fermentum</em>) B41 remain unclear. This study investigated the molecular mechanisms of GABA production in <em>L. fermentum</em> B41 by integrating LuxS/AI-2 QS system, proteomic, western blot technology, and fermented milk preparation. The results showed that autoinducer-2 (AI-2) positively correlated with cell density and GABA content of <em>L. fermentum</em> B41, suggesting LuxS/AI-2-QS system regulation of GABA production. Proteomic analysis revealed 657 differentially expressed proteins (DEPs) between the LuxS/AI-2-QS system peaks (10<em>h</em>) and lows (2 h), of which 335 were up-regulated, including the critically important s-ribosylhomocysteinase (LuxS) and GABA transaminase (ArgD). The KEGG pathway enrichment analysis revealed that the DEPs were mainly involved in cysteine and methionine metabolism and GABA biosynthesis. Additionally, western blot confirmed that LuxS and ArgD are key proteins for GABA synthesis. The GABA-enriched fermented milk produced using <em>L. fermentum</em> B41 demonstrated a significantly high GABA content of 201.53 ± 7.83 μg/mL (<em>p</em> &lt; 0.05), indicated it promotes GABA production via LuxS/AI-2-QS system. In summary, this study providing new insights into efficient GABA production and the development of GABA-enriched fermented milk.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111269"},"PeriodicalIF":5.0,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of spoilage microbial communities in modified atmosphere-packed ready-to-eat salad during cold storage: A comparative study using MALDI-TOF MS identification and PacBio full-length 16S rRNA and ITS sequencing","authors":"Atefeh Asadi,&nbsp;Anna Angerjas,&nbsp;Viiu Paalme,&nbsp;Lachinkhanim Huseynli,&nbsp;Inga Sarand","doi":"10.1016/j.ijfoodmicro.2025.111268","DOIUrl":"10.1016/j.ijfoodmicro.2025.111268","url":null,"abstract":"<div><div>Effect of storage temperatures and modified atmosphere packaging (MAP) on the shelf-life and spoilage microbial dynamics of industrially produced mayonnaise-based potato salad was studied over two years (Spring 2021, Autumn 2021, Spring 2022). Three salad batches, stored at chilling and abuse temperatures ranging from 0 °C to 12 °C, were analyzed. Microbial communities were evaluated using ISO-standard microbiological methods, MALDI-TOF MS identification, and PacBio full-length 16S rRNA gene and fungal ITS amplicon sequencing. The results showed that sensory and microbiological quality strongly depended on storage temperature, MAP packaging, and salad batch. The recommended upper temperature limit of 6 °C did not preserve salad quality at the end of its shelf-life, while storage below 4 °C extended the seven-day shelf-life to 10 days. Distinct spoilage communities were identified across batches, dominated by <em>Dellaglioa algida</em>, <em>Leuconostoc carnosum</em>, and <em>Latilactobacillus sakei</em> (Spring 2021); <em>Leuconostoc inhae</em> and <em>Leuconostoc gelidum</em> (Autumn 2021); and <em>Lactococcus carnosus</em> (Spring 2022). The microbial communities of ingredients and processing facilities influenced salad microbiota. Comparative analysis showed that full-length 16S rRNA sequencing provided higher resolution, detecting species missed by culturing methods, including psychrotrophic and fastidious lactic acid bacteria. However, fungal community analysis, using full-length ITS amplicons, requires the selection of specific fungal primers. This study provides a comprehensive evaluation of microbial profiles in RTE salads under different storage conditions, highlighting the critical role of temperature and microbial management in preserving MAP salad safety and quality during extended shelf-life.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"440 ","pages":"Article 111268"},"PeriodicalIF":5.0,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phage applications for biocontrol of enterohemorrhagic E. coli O157:H7 and other Shiga toxin-producing Escherichia coli","authors":"K. Holzer ,&nbsp;L. Marongiu ,&nbsp;K. Detert ,&nbsp;S. Venturelli ,&nbsp;H. Schmidt ,&nbsp;L.E. Hoelzle","doi":"10.1016/j.ijfoodmicro.2025.111267","DOIUrl":"10.1016/j.ijfoodmicro.2025.111267","url":null,"abstract":"<div><div>Foodborne outbreaks are becoming increasingly common and linked to zoonotic diseases caused by microbial spillover from wild or farm animals. Furthermore, agricultural animals could be considered reservoirs of multidrug-resistant (MDR) microorganisms. <em>Escherichia coli</em> O157:H7, a widespread foodborne pathogen, poses a substantial hazard due to its ubiquitous environmental distribution, MDR phenotypes, and life-threatening pathogenicity. This bacterium produces a potent toxin (Shiga toxin, Stx) encoded by prophages (Stx-phage). In addition to antibiotic resistance, <em>E. coli</em> O157:H7 has been shown to express more Stx upon treatment with antibiotics such as trimethoprim-sulfamethoxazole and metronidazole than controls. The combination of MDR and increased pathogenicity upon antibiotic treatment requires the development of alternatives for treating and preventing <em>E. coli</em> O157:H7 and related bacteria. Bacterial viruses (phages) are gaining popularity in clinical and veterinary settings due to their high antibacterial activities and lack of side effects in animals. Phage application in food production can help reduce the spread of <em>E. coli</em> O157:H7 and other Stx-producing <em>E. coli</em> (STEC), thus decreasing the burden of infection and economic loss due to these foodborne zoonoses. The present review will provide an update on phage utilization in the food industry to reduce the STEC load, with particular focus on O157:H7.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111267"},"PeriodicalIF":5.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Recent insights on the multifaceted roles of wooden tools in cheese-making: A review of their impacts on safety and final traits of traditional cheeses” [Int. J. Food Microbiol. 111179 10.1016/j.ijfoodmicro.2025.111179]","authors":"Silvia Ruta ,&nbsp;Giovanni Belvedere ,&nbsp;Giuseppe Licitra ,&nbsp;Luís Augusto Nero ,&nbsp;Cinzia Caggia ,&nbsp;Cinzia L. Randazzo ,&nbsp;Margherita Caccamo","doi":"10.1016/j.ijfoodmicro.2025.111239","DOIUrl":"10.1016/j.ijfoodmicro.2025.111239","url":null,"abstract":"","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111239"},"PeriodicalIF":5.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143985241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the antifungal mechanism of Artemisia argyi essential oil against Botrytis cinerea, Alternaria alternata, and Penicillium digitatum and its application in extending blueberry shelf life","authors":"Yue-yan Chen ,&nbsp;Yu-dong Zhang ,&nbsp;Li Wang ,&nbsp;Mei-qing Li ,&nbsp;Yu Wang ,&nbsp;Jin Liang ,&nbsp;Dong-liang Wang ,&nbsp;Hai-wei Zhang","doi":"10.1016/j.ijfoodmicro.2025.111262","DOIUrl":"10.1016/j.ijfoodmicro.2025.111262","url":null,"abstract":"<div><div>The trend towards reducing chemical fungicides in the food industry has increased interest in antimicrobial essential oils for food preservation. This study investigates the chemical composition of <em>Artemisia argyi</em> essential oil (AAEO) and its efficacy in inhibiting <em>Botrytis cinerea</em>, <em>Alternaria alternata</em>, and <em>Penicillium digitatum</em>, along with potential antifungal mechanisms involved. GC–MS analysis identified that the main components of AAEO were eucalyptol (19.19 %), L(−)-borneol (6.38 %), camphor (6.17 %), (+)-thujone (5.74 %), terpinen-4-ol (5.55 %), and <em>p</em>-cymene (5.31 %). AAEO demonstrated significant antifungal activity against all three fungi, especially through non-contact exposure. Exposure to AAEO increased AKP, nucleic acid and soluble proteins release, reflecting cell wall and membrane integrity alterations. AAEO also reduced biofilm formation, cell viability, and respiratory activity. SEM images revealed cellular fractures and deformations in the fungal cell walls. The fumigation with AAEO during storage resulted in a significant reduction of both the decay rate (by 24.7 %) and pathogen infestation (by 61.2 %) in blueberries on the 13th day of storage. A 50.8 % reduction in <em>Alternaria alternata</em> incidence was observed in inoculated blueberries by day 4 post-AAEO treatment. Therefore, AAEO is a potent antifungal agent against <em>B. cinerea</em>, <em>A. alternata</em>, and <em>P. digitatum</em>, positioning it a promising option for food preservation.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111262"},"PeriodicalIF":5.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strawberry preservation using multilayer chitosan films grafted with phenolic acids and loaded with γ-CD-MOFs encapsulated antifungal agents","authors":"Linyun Mou ,&nbsp;Wei Jiang ,&nbsp;Ya Lu ,&nbsp;Jianlong Li ,&nbsp;Ganpeng Li ,&nbsp;Hai Yuan ,&nbsp;Ziyi Jiang ,&nbsp;Lingzhi Zhang ,&nbsp;Tingyin Ming","doi":"10.1016/j.ijfoodmicro.2025.111247","DOIUrl":"10.1016/j.ijfoodmicro.2025.111247","url":null,"abstract":"<div><div>Post-harvest spoilage of strawberries is a pressing issue that requires urgent attention. This study successfully isolated and identified two saprophytic fungi responsible for strawberry rot—<em>Aspergillus tubingensis</em> and <em>Alternaria alternata</em>. Subsequently, the response surface methodology was employed to optimize the concentration ratios of citral, geraniol, and menthol, aiming to maximize their combined effect on inhibiting fungal growth. Molecular docking techniques were employed to investigate the binding targets of these active substances with 14<em>α</em>-demethylase (CYP51). The antifungal agents at optimized concentrations were loaded into <em>γ</em>-cyclodextrin metal-organic frameworks (<em>γ</em>-CD-MOFs) and uniformly dispersed within a multilayer film composed of phenolic acid-grafted modified chitosan. This approach significantly enhanced (<em>P</em> &lt; 0.05) the mechanical properties of chitosan, including fracture tensile strain among others, while also endowed it with dual functionalities of antifungal and antioxidant effects. Additionally, it offered excellent controlled-release characteristics, ensuring a steady and continuous release of active ingredients. Finally, the application of multilayer films to postharvest strawberries significantly reduced the decay rate (<em>P</em> &lt; 0.001) and weight loss (<em>P</em> &lt; 0.05), while also limiting their respiratory intensity. In summary, the multilayer film demonstrates excellent preservation effects on strawberries, thus holding broad application prospects in food preservation.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111247"},"PeriodicalIF":5.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioactive films with essential oils and machine learning for controlling Aspergillus niger growth and fumonisin B2 production in vitro","authors":"Fernando Mateo ,&nbsp;Andrea Tarazona ,&nbsp;Rafael Gavara ,&nbsp;Eva María Mateo","doi":"10.1016/j.ijfoodmicro.2025.111251","DOIUrl":"10.1016/j.ijfoodmicro.2025.111251","url":null,"abstract":"<div><div><em>Aspergillus niger</em> is an important species in the fungal community of many foods and is one of the most significant microorganisms used in biotechnology. Some <em>A. niger</em> strains are capable of producing fumonisin B₂ (FB₂) under certain conditions, but little is known about methods to control them, especially in organic foods. FB₂ is a mycotoxin with high toxicity for humans and animals. Effective strategies to control <em>A. niger</em> and FB₂ in agricultural commodities are needed. In this study, ethylene-vinyl alcohol (EVOH) copolymer films containing <em>Origanum vulgare</em> (ORE), <em>Cinnamomum zeylanicum</em> (CIN) essential oils (EO) or individual EO components such as carvacrol (CAR) cinnamaldehyde (CINHO), citral (CIT), isoeugenol (IEG) and linalool (LIN) were evaluated as antifungal and anti-fumonisin agents against two isolates of <em>A. niger</em> isolated from organic maize grains grown in Spain. Radial colony growth rate (GR), effective doses to reduce or completely inhibit fungal growth by 50, 90, and 100 % (ED₅₀, ED₉₀, and ED₁₀₀), and FB₂ levels were determined in all cultures. Assays were performed under different water activities (a_w) (0.95–0.99) and temperatures (20–35 °C). Machine learning (ML) models to predict GR and FB₂ production were developed. Fungal isolate, film type, doses, a_w and temperature had significant effects on film efficacy to control <em>A. niger</em> growth and FB₂ production. Optimal GR was found at 0.99 a_w and 35 °C, and optimal FB₂ production occurred at 0.97 a_w and 28 °C. The most effective bioactive film against <em>A. niger</em> and FB₂ production was EVOH-CINHO, followed by EVOH-IEG and EVOH-CAR; the worst film was EVOH-LIN. <em>A. niger</em> growth was inhibited in the treatments with EVOH-CINHO films at a dose of 250 μg/Petri dish incubated at 20 °C and 0.95 a_w and in the treatments with EVOH films supplemented with IEG, CIT, CAR, or LIN at a dose of 1000 μg/dish. Overall, the XGBoost (extreme gradient boosted tree) and support vector machine (SVM) algorithms generated the most accurate models for predicting GR. The former was also the most effective at predicting FB₂ production. This is the first study on the effect of bioactive films supplemented with EO or its main components on <em>A. niger</em> growth and FB₂ production. The EVOH films incorporating CINHO, IEG, or CIT examined in this study are strongly recommended as biodegradable component in packaging material to control <em>A. niger</em> and FB₂ production in fresh foods, including organic foods.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111251"},"PeriodicalIF":5.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Persistence of mcr-1-carrying E. coli in rabbit meat production: Challenges beyond long-term colistin withdrawal","authors":"Marisa Ribeiro-Almeida ,&nbsp;Joana Mourão ,&nbsp;Inês C. Rodrigues ,&nbsp;André Pinto de Carvalho ,&nbsp;Paulo Martins da Costa ,&nbsp;Luísa Peixe ,&nbsp;Patrícia Antunes","doi":"10.1016/j.ijfoodmicro.2025.111248","DOIUrl":"10.1016/j.ijfoodmicro.2025.111248","url":null,"abstract":"<div><div>Colistin, a last-resort antibiotic in human medicine, has been banned in European food animal production to mitigate antimicrobial resistance. This study investigates the long-term effects of the colistin ban on the occurrence and genomic features (WGS) of colistin-resistant, <em>mcr</em>-carrying <em>Escherichia coli</em> across intensive rabbit farms (8 farms, ~600 animals/farm, fecal and farm environmental samples) in the north and center of Portugal.</div><div>Colistin-resistant <em>E. coli</em> was detected in 25 % of groups from three farms in pre-slaughter fecal samples, with <em>mcr-1</em>-positive strains found throughout the lifecycle (does, offspring, and feed) in all fecal samples from one farm. A polyclonal multidrug-resistant (MDR) <em>E. coli</em> population carrying <em>mcr-1</em> persisted over three years, mostly in pre-slaughter rabbits but also in newly arrived younger does (GP). Comparative genomic analysis (cgMLST) revealed four clusters, with closely related strains between rabbit feces and feed (ST1196, ST40) and between feces and GP (ST1196), suggesting external reservoirs, biosecurity concerns, and cross-contamination. WGS also revealed high load and diversity in virulence (EPEC and ExPEC), antibiotic resistance and genes related to metal decreased susceptibility. All <em>mcr-1</em> genes were located on similar IncHI2 multireplicon plasmids, carrying <em>sil</em> + <em>pco</em> (copper) co-located with antibiotic resistance genes, and circulating in global sources. These results highlight that, despite colistin withdrawal, MDR <em>mcr</em>-carrying <em>E. coli</em> clones persist over three years in a single farm, underscoring complex co-selection pressure and biosecurity gaps. The findings underscore food safety risks via the food chain and environmental contamination. Enhanced biosecurity, feed monitoring, and One Health surveillance are essential to mitigate AMR dissemination and safeguard public health.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111248"},"PeriodicalIF":5.0,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning-driven hyperspectral imaging for real-time monitoring and growth modeling of psychrophilic spoilage bacteria in chilled beef","authors":"Guanglei Wang ,&nbsp;Xiuwei Yan ,&nbsp;Yingjie Feng ,&nbsp;Yue Chen ,&nbsp;Jiarui Cui ,&nbsp;Sijia Liu ,&nbsp;Songlei Wang","doi":"10.1016/j.ijfoodmicro.2025.111254","DOIUrl":"10.1016/j.ijfoodmicro.2025.111254","url":null,"abstract":"<div><div>Owing to the unsound cold chain system in China, chilled beef's quality would be affected by psychrophilic bacteria, resulting in quality deterioration and corruption, which leads to food safety problems. In this study, the growth of <em>Pseudomonas</em> and <em>Lactobacillus</em> in chilled beef was modeled by plate counting method and hyperspectral imaging, while the colony number of each dominant psychrophilic bacteria in chilled beef was determined using a traditional microbiological method. For the spectral data, the competitive adaptive reweighted sampling (CARS) algorithm, variable combination penalty analysis algorithm, successive projection algorithm and iteratively retained information variable were utilized to extract the characteristic wavelengths, and the partial least squares regression (PLSR), Energy Valley Algorithm Optimised Time Convolution Network combined with Multihead Attention Mechanism and stochastic configuration neural network (SCN) were used to predict the content of <em>Pseudomonas</em> and <em>Lactobacillus</em> in chilled beef. For <em>Lactobacillus</em>, the results showed that the prediction based on the Gaussian filtering-PLSR model achieved the optimal modeling (R_c² = 0.7381, R_p² = 0.7101, RMSEC = 0.5802 log₁₀CFU/g, RMSEP = 0.7934 log₁₀CFU/g). For <em>Pseudomonas</em>, the best prediction results were achieved (R_c² = 0.9415, R_p² = 0.8636, RMSEC = 0.7050 log₁₀CFU/g, RMSEP = 1.0546 log₁₀CFU/g) based on the CARS-SCN model. Finally, the growth of <em>Pseudomonas</em> and <em>Lactobacillus</em> was fitted using the Baranyi model, Huang model, and Gompertz model. Rapid nondestructive detection of bacterial content was realized from the hyperspectral data of chilled beef.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111254"},"PeriodicalIF":5.0,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of spore-forming bacteria in plant-based raw materials used for plant-based milk alternatives","authors":"Anne Gleissle ,&nbsp;Herbert Schmidt ,&nbsp;Jörg Hinrichs","doi":"10.1016/j.ijfoodmicro.2025.111255","DOIUrl":"10.1016/j.ijfoodmicro.2025.111255","url":null,"abstract":"<div><div>Plant-based milk alternatives can be produced from a variety of raw materials. The microbial load of the used raw materials can vary greatly, affecting the heating parameters necessary for reducing the microbial load. In this study, plant-based raw materials for producing oat-, almond-, pea-, and rice-based drinks were examined for their microbial load. In this context, flours, flakes, protein isolates, and syrups were tested. The microbiological tests included i) the mesophilic viable cell count (mVCC), ii) the thermophilic viable cell count (tVCC), iii) the mesophilic spore count (mSC), and iv) the thermophilic spore count (tSC). Pure cultures were isolated from each sample, and bacterial species were identified using 16S rRNA gene analysis.</div><div>The plant-based raw materials (oat, almond, pea and rice) showed wide variations in the viable cell and spore count, ranging from 1 to 8.5 log₁₀ CFU/g. Most of the raw materials contained a high proportion of spores in the viable cell count. Despite previous ultra-high temperature treatment (UHT treatment), the oat and rice syrups showed spore levels of 1 to 4 log₁₀ CFU/g.</div><div>In total, 435 bacterial isolates were classified with the most frequent species belonging to the genus <em>Bacillus</em>. Among these, <em>B. licheniformis</em>, <em>B. subtilis,</em> and <em>B. tequilensis</em> were the most prevalent. However, other species such as <em>B. cereus</em>, <em>B. amyloliquefaciens</em>, <em>P. etheri,</em> and <em>G. stearothermophilus</em> were also present.</div><div>Based on the initial spore load of the raw materials, the required effect of the heat treatment <em>B*</em> can be calculated to ensure a commercially sterile plant-based drink. For an average mesophilic bacterial load of oat flours with 5 log₁₀ CFU/g, a 12 log₁₀ reduction is required and for a higher contamination with 9 log₁₀ CFU/g a 16 log₁₀ reduction is already necessary.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"439 ","pages":"Article 111255"},"PeriodicalIF":5.0,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}