Pub Date : 2026-04-02Epub Date: 2026-01-13DOI: 10.1016/j.ijfoodmicro.2026.111635
Xiaoyun Zhang , Hui Qiu , Qingrong Yue , Esa Abiso Godana , Jun Li , Yuanyuan Xie , Lina Zhao , Hongyin Zhang
Our previous study demonstrated that Bacillus amyloliquefaciens is a potential biocontrol agent for postharvest management of tomato soft rot caused by Pectobacterium carotovorum subsp. brasiliense (Pcb). In this study, the application of B. amyloliquefaciens significantly reduced the natural decay of tomato fruits, as well as alleviating quality deterioration. However, the relative mechanisms especially the molecular mechanisms involved need a comprehensive exploration. In this study, we investigated the colonization capacity of B. amyloliquefaciens on fruits and the induced defense response of tomato fruits, with particular emphasis on transcriptome-wide gene expression alterations profiled through RNA sequencing. The results demonstrated that B. amyloliquefaciens exhibited robust biofilm formation enabling rapid wound colonization that competitively suppressed Pcb through nutrient and spatial resource sequestration. Additionally, B. amyloliquefaciens significantly elevated defensive enzyme (polyphenol oxidase and phenylalanine ammonia-lyase) activities and resistant secondary metabolite accumulation (total phenols, flavonoids and lignin) in tomato fruits. More importantly, B. amyloliquefaciens up-regulated important genes participating in plant-pathogen interaction, MAPK cascades, plant hormone transduction, secondary metabolite synthesis, and sulfur metabolism in fruits. These coordinated mechanisms collectively enhanced systemic defense ability, thus strengthening the disease resistance of fruits against pathogens. This research provides valuable insights for establishing novel strategy to manage postharvest diseases of tomato fruits.
{"title":"Unlocking the mechanisms involved in the control of Bacillus amyloliquefaciens against postharvest soft rot of tomato fruits","authors":"Xiaoyun Zhang , Hui Qiu , Qingrong Yue , Esa Abiso Godana , Jun Li , Yuanyuan Xie , Lina Zhao , Hongyin Zhang","doi":"10.1016/j.ijfoodmicro.2026.111635","DOIUrl":"10.1016/j.ijfoodmicro.2026.111635","url":null,"abstract":"<div><div>Our previous study demonstrated that <em>Bacillus amyloliquefaciens</em> is a potential biocontrol agent for postharvest management of tomato soft rot caused by <em>Pectobacterium carotovorum</em> subsp. <em>brasiliense</em> (<em>Pcb</em>). In this study, the application of <em>B. amyloliquefaciens</em> significantly reduced the natural decay of tomato fruits, as well as alleviating quality deterioration. However, the relative mechanisms especially the molecular mechanisms involved need a comprehensive exploration. In this study, we investigated the colonization capacity of <em>B. amyloliquefaciens</em> on fruits and the induced defense response of tomato fruits, with particular emphasis on transcriptome-wide gene expression alterations profiled through RNA sequencing. The results demonstrated that <em>B. amyloliquefaciens</em> exhibited robust biofilm formation enabling rapid wound colonization that competitively suppressed <em>Pcb</em> through nutrient and spatial resource sequestration. Additionally, <em>B. amyloliquefaciens</em> significantly elevated defensive enzyme (polyphenol oxidase and phenylalanine ammonia-lyase) activities and resistant secondary metabolite accumulation (total phenols, flavonoids and lignin) in tomato fruits. More importantly, <em>B. amyloliquefaciens</em> up-regulated important genes participating in plant-pathogen interaction, MAPK cascades, plant hormone transduction, secondary metabolite synthesis, and sulfur metabolism in fruits. These coordinated mechanisms collectively enhanced systemic defense ability, thus strengthening the disease resistance of fruits against pathogens. This research provides valuable insights for establishing novel strategy to manage postharvest diseases of tomato fruits.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111635"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976035","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}
Pub Date : 2026-04-02Epub Date: 2026-01-14DOI: 10.1016/j.ijfoodmicro.2026.111638
Csaba Varga
Antimicrobial-resistant and multidrug-resistant Campylobacter spp. poses a human health risk. A total of 1694 isolates from market hogs (1599 Campylobacter coli and 95 C. jejuni) and 965 isolates from sows (918 C. coli and 47 C. jejuni) that were isolated at US slaughter plants from 2013 to 2021 and tested for antimicrobial resistance were included in the analysis. Multidrug resistance (MDR) (resistance ≥ antimicrobial classes) was highest in C. coli isolates from market hogs (29.6%). C. jejuni isolates from both sources had lower MDR rates (8.4% for market hogs and 6.4% for sows). Isolates based on their MDR profiles were grouped into clusters by using an unsupervised machine learning algorithm. A large MDR cluster (n = 653) of C. coli isolates of market hogs was identified that included isolates that showed high resistance to lincosamides (99%), tetracyclines (89%), and macrolides (72%), moderate resistance to quinolones (25%), and low resistance to aminoglycosides (2%). A multivariable logistic regression model was constructed to assess the impact of predictor variables, sampling source (market hogs vs. sows), Campylobacter species (C. coli vs. C. jejuni), and year of sampling, on the likelihood of multidrug resistance (MDR) as the outcome. Higher odds of MDR were found in C. coli compared to C. jejuni isolates (OR = 4.00, 95% 2.24–7.92), in market hogs compared to sows (OR = 2.46, 95% CI: 1.99–3.06), and in 2014 compared to 2013 (OR = 1.51, 95% CI: 1.07–2.14). Production-type-specific antimicrobial stewardship strategies are needed to mitigate the health burden of multidrug-resistant Campylobacter spp.
{"title":"Modeling multidrug resistance in Campylobacter coli and Campylobacter jejuni isolated from swine at U.S. slaughter plants","authors":"Csaba Varga","doi":"10.1016/j.ijfoodmicro.2026.111638","DOIUrl":"10.1016/j.ijfoodmicro.2026.111638","url":null,"abstract":"<div><div>Antimicrobial-resistant and multidrug-resistant <em>Campylobacter</em> spp. poses a human health risk. A total of 1694 isolates from market hogs (1599 <em>Campylobacter coli</em> and 95 <em>C. jejuni</em>) and 965 isolates from sows (918 <em>C. coli</em> and 47 <em>C. jejuni</em>) that were isolated at US slaughter plants from 2013 to 2021 and tested for antimicrobial resistance were included in the analysis. Multidrug resistance (MDR) (resistance ≥ antimicrobial classes) was highest in <em>C. coli</em> isolates from market hogs (29.6%). <em>C. jejuni</em> isolates from both sources had lower MDR rates (8.4% for market hogs and 6.4% for sows). Isolates based on their MDR profiles were grouped into clusters by using an unsupervised machine learning algorithm. A large MDR cluster (<em>n</em> = 653) of <em>C. coli</em> isolates of market hogs was identified that included isolates that showed high resistance to lincosamides (99%), tetracyclines (89%), and macrolides (72%), moderate resistance to quinolones (25%), and low resistance to aminoglycosides (2%). A multivariable logistic regression model was constructed to assess the impact of predictor variables, sampling source (market hogs vs. sows), <em>Campylobacter</em> species (<em>C. coli</em> vs. <em>C. jejuni</em>), and year of sampling, on the likelihood of multidrug resistance (MDR) as the outcome. Higher odds of MDR were found in <em>C. coli</em> compared to <em>C. jejuni</em> isolates (OR = 4.00, 95% 2.24–7.92), in market hogs compared to sows (OR = 2.46, 95% CI: 1.99–3.06), and in 2014 compared to 2013 (OR = 1.51, 95% CI: 1.07–2.14). Production-type-specific antimicrobial stewardship strategies are needed to mitigate the health burden of multidrug-resistant <em>Campylobacter</em> spp.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111638"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976039","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}
Pub Date : 2026-04-02Epub Date: 2026-01-10DOI: 10.1016/j.ijfoodmicro.2026.111637
Veronica Moscone, Davide Porcellato
Spoilage of dairy products by psychrotrophic bacteria poses a significant challenge to the food industry, compromising product quality and increasing food waste. Among these microorganisms, Pseudomonas species are particularly problematic due to their production of heat-resistant extracellular enzymes that degrade milk proteins and alter milk functionality. However, the mechanisms underlying strain-specific differences in AprX production and activity, and how these differences influence casein degradation and acid-induced gelation, remain insufficiently understood. In this study, we investigated how diverse Pseudomonas strains with varying proteolytic capabilities impact milk quality, specifically through their effects on casein degradation and coagulation properties. During growth in milk, the strains displayed distinct preferences for degrading either κ-casein or β-casein. κ-Casein degradation correlated with earlier and stronger acid gelation, accompanied by rapid gel development, while β-casein degradation was associated with earlier rennet coagulation. Genomic analysis of the aprX-lipA2 operon revealed variability in operon structure and gene expression that did not consistently predict proteolytic activity across strains. Proteomic and AprX sequence analyses indicated that factors such as gene regulation and secretion system efficiency critically influence strain-specific spoilage potential. Overall, these findings clarify how differences in AprX expression and proteolytic behaviour among Pseudomonas strains influence both acid and rennet coagulation, highlighting the broader impact of strain-level variability on milk functionality during refrigerated storage.
{"title":"Strain-specific effects of bacterial proteolytic activity on acid and rennet coagulation of milk","authors":"Veronica Moscone, Davide Porcellato","doi":"10.1016/j.ijfoodmicro.2026.111637","DOIUrl":"10.1016/j.ijfoodmicro.2026.111637","url":null,"abstract":"<div><div>Spoilage of dairy products by psychrotrophic bacteria poses a significant challenge to the food industry, compromising product quality and increasing food waste. Among these microorganisms, <em>Pseudomonas</em> species are particularly problematic due to their production of heat-resistant extracellular enzymes that degrade milk proteins and alter milk functionality. However, the mechanisms underlying strain-specific differences in AprX production and activity, and how these differences influence casein degradation and acid-induced gelation, remain insufficiently understood. In this study, we investigated how diverse <em>Pseudomonas</em> strains with varying proteolytic capabilities impact milk quality, specifically through their effects on casein degradation and coagulation properties. During growth in milk, the strains displayed distinct preferences for degrading either κ-casein or β-casein. κ-Casein degradation correlated with earlier and stronger acid gelation, accompanied by rapid gel development, while β-casein degradation was associated with earlier rennet coagulation. Genomic analysis of the <em>aprX-lipA2</em> operon revealed variability in operon structure and gene expression that did not consistently predict proteolytic activity across strains. Proteomic and AprX sequence analyses indicated that factors such as gene regulation and secretion system efficiency critically influence strain-specific spoilage potential. Overall, these findings clarify how differences in AprX expression and proteolytic behaviour among <em>Pseudomonas</em> strains influence both acid and rennet coagulation, highlighting the broader impact of strain-level variability on milk functionality during refrigerated storage.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111637"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976045","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}
Pub Date : 2026-04-02Epub Date: 2026-01-23DOI: 10.1016/j.ijfoodmicro.2026.111661
Hao Zhou , Lijun Yan , Boyang Xu , Ling Zhang , Ruijuan Wang , Qin Chen , Xingjiang Li
Pit mud serves as a habitat for functional bacteria involved in Baijiu fermentation. While pH is recognized as a key driver of bacterial succession in pit mud, the underlying pattern remains insufficiently characterized. This study systematically investigated the relationship between pH and bacterial communities in pit mud by integrating dataset analysis with pH gradient experiments. The results revealed strong correlations between pH and the key bacterial families, which occurred not only across the time dimension but also in relation to spatial heterogeneity or artificial disturbance. Along the pH gradient, heterogeneous selection may govern bacterial succession. As pH increased, the appearance of Oscillospiraceae signaled the onset of bacterial succession, while the near disappearance of Lactobacillaceae indicated enhanced stability. Six representative genera were further studied, revealing distinct genomic features that changed consistently with pH. During bacterial succession, the abundance of Lactobacillus declined, which predominantly carries genes associated with lactate and acetate metabolism. In contrast, the abundance of Caproicibacterium, which possesses a complete gene cluster for reverse β-oxidation, increased. The pH gradient experiments confirmed that pH influences bacterial assembly mainly through heterogeneous selection, which appeared to be facilitated both by the lactate-utilizing ability of Caproicibacterium and the pH-mediated suppression of Lactobacillus. These findings advance the theoretical understanding of pit mud aging and contribute to the optimization of Baijiu fermentation.
{"title":"Heterogeneous selection driven by pH determines the successional pattern of bacterial communities in pit mud used for Baijiu fermentation","authors":"Hao Zhou , Lijun Yan , Boyang Xu , Ling Zhang , Ruijuan Wang , Qin Chen , Xingjiang Li","doi":"10.1016/j.ijfoodmicro.2026.111661","DOIUrl":"10.1016/j.ijfoodmicro.2026.111661","url":null,"abstract":"<div><div>Pit mud serves as a habitat for functional bacteria involved in Baijiu fermentation. While pH is recognized as a key driver of bacterial succession in pit mud, the underlying pattern remains insufficiently characterized. This study systematically investigated the relationship between pH and bacterial communities in pit mud by integrating dataset analysis with pH gradient experiments. The results revealed strong correlations between pH and the key bacterial families, which occurred not only across the time dimension but also in relation to spatial heterogeneity or artificial disturbance. Along the pH gradient, heterogeneous selection may govern bacterial succession. As pH increased, the appearance of <em>Oscillospiraceae</em> signaled the onset of bacterial succession, while the near disappearance of <em>Lactobacillaceae</em> indicated enhanced stability. Six representative genera were further studied, revealing distinct genomic features that changed consistently with pH. During bacterial succession, the abundance of <em>Lactobacillus</em> declined, which predominantly carries genes associated with lactate and acetate metabolism. In contrast, the abundance of <em>Caproicibacterium</em>, which possesses a complete gene cluster for reverse β-oxidation, increased. The pH gradient experiments confirmed that pH influences bacterial assembly mainly through heterogeneous selection, which appeared to be facilitated both by the lactate-utilizing ability of <em>Caproicibacterium</em> and the pH-mediated suppression of <em>Lactobacillus</em>. These findings advance the theoretical understanding of pit mud aging and contribute to the optimization of Baijiu fermentation.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111661"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146062840","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}
Pub Date : 2026-04-02Epub Date: 2026-01-07DOI: 10.1016/j.ijfoodmicro.2026.111622
Jun Liu , Xiaoxiao Huang , Yanrong Wang , Yingji Wang , Rongrong Luo , Xiaolin Lu , Ketao Cao , Jun Xing , Yixian Tu , Wenxin Zheng
Antibiotic resistance genes (ARGs) are emerging contaminants threatening public health, yet their transmission risk via mare milk products remains understudied. Using metagenomics, we analyzed lactic acid bacteria (LAB)-inoculated fermented, naturally fermented, raw, and pasteurized mare milk to investigate the effect of LAB inoculation on the distribution and transmission pathways of ARGs in mare milk. The results showed that naturally fermented, raw, and pasteurized mare milk had the highest number of pathogens, relative abundance of ARGs, and relative abundance of mobile genetic elements (MGEs), while LAB inoculation significantly reduced these (p < 0.05). Bacillota was the dominant microbial group in different samples. Compared to naturally fermented and raw mare milk, LAB-inoculated fermentation significantly altered microbial community structure (p < 0.05). This not only reduced or eliminated certain harmful bacteria but also decreased the abundance of total ARGs and multiple ARG subtypes by reducing host bacteria and MGEs. Microbes and MGEs jointly drove ARG transmission, with microbes being key. Transposon, Bacteroidota, and Pseudomonadota are the major MGEs and microbial taxa for ARG transmission. LAB inoculation can effectively inhibit the spread of 11 ARG types, including β-lactam and multidrug resistance, by weakening the co-occurrence network among microbes, ARGs, and MGEs. This study enhances understanding of resistance genes in diverse equine dairy products, elucidates the impact of LAB fermentation on ARG distribution and transmission pathways in mare milk, and provides valuable data references and theoretical guidance for safer equine dairy processing.
{"title":"Metagenomics insights into the effects of lactic acid bacteria inoculation on the microbial communities and antibiotic resistance genes in mare milk","authors":"Jun Liu , Xiaoxiao Huang , Yanrong Wang , Yingji Wang , Rongrong Luo , Xiaolin Lu , Ketao Cao , Jun Xing , Yixian Tu , Wenxin Zheng","doi":"10.1016/j.ijfoodmicro.2026.111622","DOIUrl":"10.1016/j.ijfoodmicro.2026.111622","url":null,"abstract":"<div><div>Antibiotic resistance genes (ARGs) are emerging contaminants threatening public health, yet their transmission risk via mare milk products remains understudied. Using metagenomics, we analyzed lactic acid bacteria (LAB)-inoculated fermented, naturally fermented, raw, and pasteurized mare milk to investigate the effect of LAB inoculation on the distribution and transmission pathways of ARGs in mare milk. The results showed that naturally fermented, raw, and pasteurized mare milk had the highest number of pathogens, relative abundance of ARGs, and relative abundance of mobile genetic elements (MGEs), while LAB inoculation significantly reduced these (<em>p</em> < 0.05). Bacillota was the dominant microbial group in different samples. Compared to naturally fermented and raw mare milk, LAB-inoculated fermentation significantly altered microbial community structure (<em>p</em> < 0.05). This not only reduced or eliminated certain harmful bacteria but also decreased the abundance of total ARGs and multiple ARG subtypes by reducing host bacteria and MGEs. Microbes and MGEs jointly drove ARG transmission, with microbes being key. Transposon, Bacteroidota, and Pseudomonadota are the major MGEs and microbial taxa for ARG transmission. LAB inoculation can effectively inhibit the spread of 11 ARG types, including β-lactam and multidrug resistance, by weakening the co-occurrence network among microbes, ARGs, and MGEs. This study enhances understanding of resistance genes in diverse equine dairy products, elucidates the impact of LAB fermentation on ARG distribution and transmission pathways in mare milk, and provides valuable data references and theoretical guidance for safer equine dairy processing.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111622"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976036","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}
Hákarl, the traditional Icelandic product obtained from the fermentation of Greenland shark (Somniosus microcephalus), represents a unique food item from both cultural and microbiological perspectives. This study investigated commercial samples of hákarl using an integrated approach, combining physico-chemical analyses, lipid and volatile profiling, metataxonomic sequencing, and microbial isolation. Results confirmed the alkaline nature of the product (pH ∼8) and a water activity (aw) of 0.96, sufficient to sustain an active and diverse microbial community. Lipid profiling revealed the predominance of monounsaturated fatty acids, with differences in PUFA and DHA levels between the analyzed producers, consistent with nutritionally favorable characteristics. Microbiological analysis highlighted bacterial communities dominated by Firmicutes, particularly Bacilli and Clostridia, with significant abundances of Tissierella creatinini and Atopostipes suicloacalis. Culture-dependent methods led to the isolation of Carnobacterium antarcticum cultures, which were subsequently characterized for their enzymatic activities. These findings suggest potential biotechnological applications of the isolates, especially in fermentation and aroma development. Volatile compound analysis identified thirteen VOCs including alcohols, aldehydes, ketones, phenols, sulfur- and nitrogen-containing compounds. Trimethylamine was the predominant metabolite responsible for the strong ammonia-like odor, followed by phenol and sulfur-containing compounds, which also contributed to the sensory profile. Overall, the results provide novel insights into the microbial ecology, physico-chemical traits, and volatile characteristics of hákarl, confirming its variability linked to artisanal production methods. The study emphasizes hákarl's role as a reservoir of pro-technological microorganisms and advances current understanding of the factors influencing its safety, quality, and identity as traditional fermented food.
{"title":"Novel insights into hákarl: A deep dive into the microbiological and physico-chemical features of Iceland's traditional fermented shark","authors":"Federica Cardinali , Giorgia Rampanti , Paolo Lucci , Ilario Ferrocino , Deborah Pacetti , Benedetta Fanesi , Lama Ismaiel , Vesna Milanović , Cristiana Garofalo , Annalisa Petruzzelli , David Savelli , Claudia Gabucci , Lucia Aquilanti , Andrea Osimani","doi":"10.1016/j.ijfoodmicro.2026.111629","DOIUrl":"10.1016/j.ijfoodmicro.2026.111629","url":null,"abstract":"<div><div><em>Hákarl</em>, the traditional Icelandic product obtained from the fermentation of Greenland shark (<em>Somniosus microcephalus</em>), represents a unique food item from both cultural and microbiological perspectives. This study investigated commercial samples of <em>hákarl</em> using an integrated approach, combining physico-chemical analyses, lipid and volatile profiling, metataxonomic sequencing, and microbial isolation. Results confirmed the alkaline nature of the product (pH ∼8) and a water activity (a<sub>w</sub>) of 0.96, sufficient to sustain an active and diverse microbial community. Lipid profiling revealed the predominance of monounsaturated fatty acids, with differences in PUFA and DHA levels between the analyzed producers, consistent with nutritionally favorable characteristics. Microbiological analysis highlighted bacterial communities dominated by Firmicutes, particularly Bacilli and Clostridia, with significant abundances of <em>Tissierella creatinini</em> and <em>Atopostipes suicloacalis</em>. Culture-dependent methods led to the isolation of <em>Carnobacterium antarcticum</em> cultures, which were subsequently characterized for their enzymatic activities. These findings suggest potential biotechnological applications of the isolates, especially in fermentation and aroma development. Volatile compound analysis identified thirteen VOCs including alcohols, aldehydes, ketones, phenols, sulfur- and nitrogen-containing compounds. Trimethylamine was the predominant metabolite responsible for the strong ammonia-like odor, followed by phenol and sulfur-containing compounds, which also contributed to the sensory profile. Overall, the results provide novel insights into the microbial ecology, physico-chemical traits, and volatile characteristics of <em>hákarl</em>, confirming its variability linked to artisanal production methods. The study emphasizes <em>hákarl</em>'s role as a reservoir of pro-technological microorganisms and advances current understanding of the factors influencing its safety, quality, and identity as traditional fermented food.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111629"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976046","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}
Pub Date : 2026-04-02Epub Date: 2026-01-14DOI: 10.1016/j.ijfoodmicro.2026.111645
R. González-Soñora, A. Ramilo, R. Ríos-Castro, E. Abollo, S. Pascual
Parasite detection in seafood products poses a significant challenge for companies involved in processing and distribution, as inadequate risk management may affect both food safety and the quality of the final product. This issue becomes more complex with the introduction of new commercial formats of seafood products, which increase the difficulty of parasite control within the fish-production value chain. The present study aimed to evaluate the presence of Anisakis spp. in different categories, types, and commercial presentations of seafood products made of Merluccius spp., by applying the official inspection method (the visual scheme), the UNE-EN ISO 23036-1:2021 standard, and molecular (PCR and real-time PCR) approaches. Overall, Anisakis spp. larvae and their DNA traces were detected in 6.94% of commercially frozen or processed hake-based products marketed in Spain. This finding, framed within the high rate of sensitization and allergy to Anisakis spp. in Spain, highlights the need to implement and integrate detection methodologies for inspecting these emerging commercial fish products, enabling a more precise assessment of both food quality and food safety risk. In this context, the careful selection of fish raw materials based on routine surveillance programs and the further adoption of innovative processing technologies becomes essential to minimize risks associated with the presence of Anisakis spp. in seafood.
海产品中的寄生虫检测对参与加工和分销的公司构成了重大挑战，因为风险管理不足可能影响食品安全和最终产品的质量。随着海鲜产品新商业模式的引入，这一问题变得更加复杂，这增加了在鱼类生产价值链中控制寄生虫的难度。本研究采用官方检验方法（目测法）、UNE-EN ISO 23036-1:2021标准和分子（PCR和实时荧光定量PCR）方法，对不同种类、类型和商业产品中异尖藻的存在情况进行了评估。总体而言，在西班牙销售的商业冷冻或加工鳕鱼产品中，6.94%检测到异尖线虫幼虫及其DNA痕迹。这一发现，在西班牙对异尖线虫的高致敏率和过敏率的框架内，强调了实施和整合检测这些新兴商业鱼类产品的检测方法的必要性，从而能够更精确地评估食品质量和食品安全风险。在这种情况下，根据常规监测计划仔细选择鱼类原料，并进一步采用创新的加工技术，对于最小化与海产品中异尖线虫存在相关的风险至关重要。
{"title":"Detection of Anisakis spp. (Nematoda, Anisakidae) in frozen and processed hake products marketed in Spain","authors":"R. González-Soñora, A. Ramilo, R. Ríos-Castro, E. Abollo, S. Pascual","doi":"10.1016/j.ijfoodmicro.2026.111645","DOIUrl":"10.1016/j.ijfoodmicro.2026.111645","url":null,"abstract":"<div><div>Parasite detection in seafood products poses a significant challenge for companies involved in processing and distribution, as inadequate risk management may affect both food safety and the quality of the final product. This issue becomes more complex with the introduction of new commercial formats of seafood products, which increase the difficulty of parasite control within the fish-production value chain. The present study aimed to evaluate the presence of <em>Anisakis</em> spp. in different categories, types, and commercial presentations of seafood products made of <em>Merluccius</em> spp., by applying the official inspection method (the visual scheme), the UNE-EN ISO 23036-1:2021 standard, and molecular (PCR and real-time PCR) approaches. Overall, <em>Anisakis</em> spp. larvae and their DNA traces were detected in 6.94% of commercially frozen or processed hake-based products marketed in Spain. This finding, framed within the high rate of sensitization and allergy to <em>Anisakis</em> spp. in Spain, highlights the need to implement and integrate detection methodologies for inspecting these emerging commercial fish products, enabling a more precise assessment of both food quality and food safety risk. In this context, the careful selection of fish raw materials based on routine surveillance programs and the further adoption of innovative processing technologies becomes essential to minimize risks associated with the presence of <em>Anisakis</em> spp. in seafood.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111645"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976048","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}
This study investigated interactions and competition between the starter culture Penicillium nalgiovense and the toxigenic fungus Aspergillus westerdijkiae, focusing on their effects on processing parameters and on ochratoxin A (OTA) production on the dry-fermented salami surface during ripening. The influence of Lactococcus lactis, incorporated into the meat matrix, was also assessed. Salami was produced in accordance with official technical standards in a controlled environment. Half of the meat batter was inoculated with L. lactis. Following stuffing, salami was treated with one of three inoculum solutions: (A) P. nalgiovense, (B) P. nalgiovense plus A. westerdijkiae, or (C) A. westerdijkiae alone. Samples ripened for 20 days under industry-standard conditions. At days 0, 4, 8, 12, 16, and 20, pH, water activity, total bacterial counts in the meat, total fungal counts on the casing, and OTA concentrations in both matrices were measured. A. westerdijkiae rapidly colonised and dominated the casing surface by day 4, even in the presence of P. nalgiovense, and reached peak growth between days 8 and 12. OTA concentrations increased significantly after day 12, reaching 69 μg/g in the casing and 16 μg/g in the meat by day 20. Indicating that the surface provides more favorable conditions for toxin production, so removing casing could reduce the exposure to the toxin. The addition of L. lactis accelerated early acidification and temporarily reduced bacterial load but did not significantly affect fungal growth or OTA biosynthesis. These findings demonstrate that, under favorable environmental conditions, toxigenic fungi represent a significant food safety risk during salami ripening. Starter cultures alone are insufficient to prevent mycotoxin contamination in dry-cured meat products.
本研究研究了发酵剂青霉（Penicillium nalgiovense）和产毒真菌西曲霉（Aspergillus westerdijkiae）之间的相互作用和竞争，重点研究了它们对干燥发酵腊肠成熟过程中加工参数和表面赭曲霉毒素A （OTA）产生的影响。还评估了加入肉类基质中的乳酸乳球菌的影响。萨拉米香肠是在受控环境下按照官方技术标准生产的。一半的肉糊接种乳酸乳杆菌。填充后，用三种接种溶液中的一种处理腊肠：(A) P. nalgiovense, (B) P. nalgiovense加A. westerdijkiae，或(C)单独A. westerdijkiae。样品在工业标准条件下成熟20天。在第0、4、8、12、16和20天，测量pH、水活度、肉中细菌总数、肠衣上真菌总数和两种基质中的OTA浓度。即使在有P. nalgiovense存在的情况下，A. westerdijkiae在第4天迅速定殖并占主导地位，并在第8至12天达到生长高峰。第12天时，OTA浓度显著升高，第20天时，肠衣中OTA浓度达到69 μg/g，肉中OTA浓度达到16 μg/g。这表明地表为毒素的产生提供了更有利的条件，因此去除套管可以减少毒素的暴露。乳酸乳杆菌的添加加速了早期酸化，暂时降低了细菌负荷，但对真菌生长和OTA生物合成没有显著影响。这些发现表明，在有利的环境条件下，产毒真菌在腊肠成熟过程中代表着重大的食品安全风险。发酵剂本身不足以防止干腌肉制品中的霉菌毒素污染。
{"title":"Microbial competitiveness and risk of ochratoxin A in salami: in situ evaluation along maturation","authors":"Andrieli Stefanello , Alessandra Marcon Gasperini , Dâmaris Cristine Landgraf , Antoine Thiollet , Marina Venturini Copetti , Esther Garcia-Cela","doi":"10.1016/j.ijfoodmicro.2026.111646","DOIUrl":"10.1016/j.ijfoodmicro.2026.111646","url":null,"abstract":"<div><div>This study investigated interactions and competition between the starter culture <em>Penicillium nalgiovense</em> and the toxigenic fungus <em>Aspergillus westerdijkiae</em>, focusing on their effects on processing parameters and on ochratoxin A (OTA) production on the dry-fermented salami surface during ripening. The influence of <em>Lactococcus lactis</em>, incorporated into the meat matrix, was also assessed. Salami was produced in accordance with official technical standards in a controlled environment. Half of the meat batter was inoculated with <em>L. lactis</em>. Following stuffing, salami was treated with one of three inoculum solutions: (A) <em>P. nalgiovense</em>, (B) <em>P. nalgiovense</em> plus <em>A. westerdijkiae</em>, or (C) <em>A. westerdijkiae</em> alone. Samples ripened for 20 days under industry-standard conditions. At days 0, 4, 8, 12, 16, and 20, pH, water activity, total bacterial counts in the meat, total fungal counts on the casing, and OTA concentrations in both matrices were measured. <em>A. westerdijkiae</em> rapidly colonised and dominated the casing surface by day 4, even in the presence of <em>P. nalgiovense</em>, and reached peak growth between days 8 and 12. OTA concentrations increased significantly after day 12, reaching 69 μg/g in the casing and 16 μg/g in the meat by day 20. Indicating that the surface provides more favorable conditions for toxin production, so removing casing could reduce the exposure to the toxin. The addition of L. <em>lactis</em> accelerated early acidification and temporarily reduced bacterial load but did not significantly affect fungal growth or OTA biosynthesis. These findings demonstrate that, under favorable environmental conditions, toxigenic fungi represent a significant food safety risk during salami ripening. Starter cultures alone are insufficient to prevent mycotoxin contamination in dry-cured meat products.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111646"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036087","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}
Pub Date : 2026-04-02Epub Date: 2026-01-22DOI: 10.1016/j.ijfoodmicro.2026.111653
Furkan Erdem, Onay Dogan, Hami Alpas
High Hydrostatic Pressure (HHP) is a non-thermal preservation method that enhances microbial safety while maintaining nutritional and sensory attributes. In this study, the inactivation of Escherichia coli O157:H7 in tomato juice was quantified using the Geeraerd primary model, fitted within a Bayesian framework for all pressure–time combinations. Models that would be expected to perform best were pooled and trialed from the primary fits using a regression model. A global (primary–secondary) quadratic secondary model was then applied to describe the dependence of and residual colonies () on pressure, incorporating random effects for each pressure level. Results showed a monotonic increase of with pressure, with the strongest inactivation observed at 450 MPa, while residual populations declined consistently across the pressure domain. Posterior predictive checks confirmed that the Full Geeraerd model provided an accurate description of inactivation kinetics, and that the quadratic secondary structure adequately captured pressure dependence. These findings demonstrate that HHP substantially accelerates microbial inactivation, and that a two-stage Bayesian modeling framework combining primary and secondary models can provide robust predictions to support the optimization of non-thermal food preservation processes.
{"title":"Modeling the inactivation of E. coli O157:H7 (ATCC 43888) in high hydrostatic pressure treated tomato juice","authors":"Furkan Erdem, Onay Dogan, Hami Alpas","doi":"10.1016/j.ijfoodmicro.2026.111653","DOIUrl":"10.1016/j.ijfoodmicro.2026.111653","url":null,"abstract":"<div><div>High Hydrostatic Pressure (HHP) is a non-thermal preservation method that enhances microbial safety while maintaining nutritional and sensory attributes. In this study, the inactivation of <em>Escherichia coli</em> O157:H7 in tomato juice was quantified using the Geeraerd primary model, fitted within a Bayesian framework for all pressure–time combinations. Models that would be expected to perform best were pooled and trialed from the primary fits using a regression model. A global (primary–secondary) quadratic secondary model was then applied to describe the dependence of <span><math><mrow><msub><mrow><mo>log</mo></mrow><mrow><mn>10</mn></mrow></msub><msub><mrow><mi>k</mi></mrow><mrow><mtext>max</mtext></mrow></msub></mrow></math></span> and residual colonies (<span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>R</mi><mi>e</mi><mi>s</mi></mrow></msub></math></span>) on pressure, incorporating random effects for each pressure level. Results showed a monotonic increase of <span><math><msub><mrow><mi>k</mi></mrow><mrow><mtext>max</mtext></mrow></msub></math></span> with pressure, with the strongest inactivation observed at 450 MPa, while residual populations declined consistently across the pressure domain. Posterior predictive checks confirmed that the Full Geeraerd model provided an accurate description of inactivation kinetics, and that the quadratic secondary structure adequately captured pressure dependence. These findings demonstrate that HHP substantially accelerates microbial inactivation, and that a two-stage Bayesian modeling framework combining primary and secondary models can provide robust predictions to support the optimization of non-thermal food preservation processes.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111653"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036089","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}
Pub Date : 2026-04-02Epub Date: 2026-01-09DOI: 10.1016/j.ijfoodmicro.2026.111625
Mei Yang , Guo-ping Wu , Shi-wei Bao , Yang Zhou , Jie-ting Geng , Chan Zhong
Certain Listeria species, particularly L. monocytogenes, can colonize refrigerated meat surfaces and form biofilms, both threatening product safety and shortening shelf-life. This study developed a shikonin-loaded gelatin-based film (GEL-SKN film). Fourier transform infrared spectroscopy confirmed non-covalent interactions between SKN and gelatin, while scanning electron microscopy revealed uniform dispersion of SKN in the gelatin matrix. These interactions improved SKN dispersion and increased the tensile strength of film to 34.26 MPa. GEL-SKN films exhibited strong antibacterial activity against Listeria monocytogenes, Listeria ivanovii, and Listeria seeligeri at 4 °C and 25 °C. At both temperature, the Listeria count treated with GEL-SKN film (1.88–2.97 log10 CFU/mL) was significantly lower than that in GEL film (3.23–3.84 log10 CFU/mL). Transmission electron microscopy and biochemical leakage assays demonstrated that SKN disrupted the Listeria cell membranes integrity, leading to the leakage of nucleic acids and proteins. The films also showed potent antioxidant activity, with DPPH and ABTS radical scavenging rates of 73.34 %–74.33 % and 88.03 %–88.18 %, respectively. In simulated preservation tests on refrigerated beef (stored at 4 °C for 7 days), GEL-SKN films maintained the pH of beef within the fresh range (5.84–6.01), inhibited lipid oxidation (0.69–0.76 mg MDA/kg), reduced the accumulation of total volatile basic nitrogen (12.25–15.40 mg/100 g), and decreased Listeria counts by 1.04–1.11 log10 CFU/g. Consequently, the sensory acceptability period of refrigerated beef was extended from 3 days to 7 days. These results demonstrate that GEL-SKN films integrate antibacterial and antioxidant functionalities, thereby providing an effective and sustainable strategy to improve microbial safety and oxidative stability of refrigerated meat products.
{"title":"Shikonin-loaded bioactive gelatin films with antibacterial activity against Listeria species and antioxidant properties to extend the shelf-life of raw refrigerated beef","authors":"Mei Yang , Guo-ping Wu , Shi-wei Bao , Yang Zhou , Jie-ting Geng , Chan Zhong","doi":"10.1016/j.ijfoodmicro.2026.111625","DOIUrl":"10.1016/j.ijfoodmicro.2026.111625","url":null,"abstract":"<div><div>Certain <em>Listeria</em> species, particularly L. <em>monocytogenes</em>, can colonize refrigerated meat surfaces and form biofilms, both threatening product safety and shortening shelf-life. This study developed a shikonin-loaded gelatin-based film (GEL-SKN film). Fourier transform infrared spectroscopy confirmed non-covalent interactions between SKN and gelatin, while scanning electron microscopy revealed uniform dispersion of SKN in the gelatin matrix. These interactions improved SKN dispersion and increased the tensile strength of film to 34.26 MPa. GEL-SKN films exhibited strong antibacterial activity against <em>Listeria monocytogenes</em>, <em>Listeria ivanovii</em>, and <em>Listeria seeligeri</em> at 4 °C and 25 °C. At both temperature, the <em>Listeria</em> count treated with GEL-SKN film (1.88–2.97 log<sub>10</sub> CFU/mL) was significantly lower than that in GEL film (3.23–3.84 log<sub>10</sub> CFU/mL). Transmission electron microscopy and biochemical leakage assays demonstrated that SKN disrupted the <em>Listeria</em> cell membranes integrity, leading to the leakage of nucleic acids and proteins. The films also showed potent antioxidant activity, with DPPH and ABTS radical scavenging rates of 73.34 %–74.33 % and 88.03 %–88.18 %, respectively. In simulated preservation tests on refrigerated beef (stored at 4 °C for 7 days), GEL-SKN films maintained the pH of beef within the fresh range (5.84–6.01), inhibited lipid oxidation (0.69–0.76 mg MDA/kg), reduced the accumulation of total volatile basic nitrogen (12.25–15.40 mg/100 g), and decreased <em>Listeria</em> counts by 1.04–1.11 log<sub>10</sub> CFU/g. Consequently, the sensory acceptability period of refrigerated beef was extended from 3 days to 7 days. These results demonstrate that GEL-SKN films integrate antibacterial and antioxidant functionalities, thereby providing an effective and sustainable strategy to improve microbial safety and oxidative stability of refrigerated meat products.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111625"},"PeriodicalIF":5.2,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976022","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}
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