Pub Date : 2026-01-12DOI: 10.1016/j.ijfoodmicro.2026.111634
Denes do Rosario , Juliana X. Bissoli , Pedro H.A. Martins , Brenno A.S. Jacinto , Eniale M. Oliveira , Carlos A. Conte-Junior , Patrícia C. Bernardes
This study aimed to isolate, promote molecular identification (ITS1, ITS4, α-tubulin, and β-tubulin), and model the growth of Aspergillus westerdijkiae, Penicillium verrucosum, Penicillium citrinum, and Penicillium nalgiovense from the microbiota of the traditional Brazilian dry-cured loin “Socol”. Growth (μmax and lag phase) occurred under environmental conditions of temperatures between 15 and 35 °C and water activities between 0.83 and 0.97. A. westerdijkiae grew three times faster (0.50 mm/h) than the other fungi and was favored by higher temperatures. P. nalgiovense was slightly affected by temperature. P. verrucosum was favored at lower temperatures. This entire scenario was observed during the simulated start of production, a critical point for fungal colonization of dry-cured meat products. While producing dry-cured meat products in tropical countries is challenging, refrigeration poses the same risks as in temperate countries. Hence, understanding the microbial dynamics of these products is the key to improving the production chain in terms of consumer safety. Extending the refrigeration time at the beginning of production may be an alternative to increase safety.
{"title":"Growth modeling of autochthonous molds from the traditional Brazilian dry-cured loin “Socol”: Impact of the abiotic conditions","authors":"Denes do Rosario , Juliana X. Bissoli , Pedro H.A. Martins , Brenno A.S. Jacinto , Eniale M. Oliveira , Carlos A. Conte-Junior , Patrícia C. Bernardes","doi":"10.1016/j.ijfoodmicro.2026.111634","DOIUrl":"10.1016/j.ijfoodmicro.2026.111634","url":null,"abstract":"<div><div>This study aimed to isolate, promote molecular identification (ITS1, ITS4, α-tubulin, and β-tubulin), and model the growth of <em>Aspergillus westerdijkiae</em>, <em>Penicillium verrucosum</em>, <em>Penicillium citrinum</em>, and <em>Penicillium nalgiovense</em> from the microbiota of the traditional Brazilian dry-cured loin “Socol”. Growth (μmax and lag phase) occurred under environmental conditions of temperatures between 15 and 35 °C and water activities between 0.83 and 0.97. <em>A. westerdijkiae</em> grew three times faster (0.50 mm/h) than the other fungi and was favored by higher temperatures. <em>P. nalgiovense</em> was slightly affected by temperature. <em>P. verrucosum</em> was favored at lower temperatures. This entire scenario was observed during the simulated start of production, a critical point for fungal colonization of dry-cured meat products. While producing dry-cured meat products in tropical countries is challenging, refrigeration poses the same risks as in temperate countries. Hence, understanding the microbial dynamics of these products is the key to improving the production chain in terms of consumer safety. Extending the refrigeration time at the beginning of production may be an alternative to increase safety.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111634"},"PeriodicalIF":5.2,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146029455","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}
Aspergillus flavus is among the most resilient fungi, causing significant losses in the quantity and quality of agricultural food commodities. It often produces aflatoxin B1 (AFB1), a Class 1 human carcinogen that poses a serious threat to human and animal health. The present study investigated the potential of a chemically characterized essential oil-based formulation, ZTC (a synergistic mixture of Zingiber officinale (ZOEO), Trachyspermum ammi (TAEO), and Coleus aromaticus (CEO)) against the growth and aflatoxin B1 production by the toxigenic species Aspergillus flavus. The ZTC formulation demonstrated in vitro and in situ antifungal effects (0.4 μL/mL) and aflatoxin inhibition (0.3 μL/mL) against A. flavus. At the cellular level, ZTC disrupted ergosterol biosynthesis, compromised membrane integrity, impaired mitochondrial potential, and altered redox homeostasis. Integrated transcriptomic and biochemical analyses indicated coordinated downregulation of glycolysis, the TCA cycle, ATP production, and sterol and fatty acid biosynthesis. This led to energy deficiency, membrane destabilization, induction of oxidative stress, and inhibition of aflatoxin B1 biosynthesis by suppressing gene expression and disrupting key enzymes, thereby reducing AFB1 at sublethal concentrations. The findings highlight the multi-target mechanism of action of the developed formulation, ZTC, against fungal growth and aflatoxin B1 contamination, and recommend it as a promising candidate for eco-friendly and sustainable antifungal agents.
{"title":"Systematic investigation of aflatoxigenic Aspergillus flavus inhibition: Integrating essential oils-based formulation with mathematical modeling and transcriptomic analysis","authors":"Prem Pratap Singh , Ritu Singh , Praveen Kumar Verma , Bhanu Prakash","doi":"10.1016/j.ijfoodmicro.2026.111632","DOIUrl":"10.1016/j.ijfoodmicro.2026.111632","url":null,"abstract":"<div><div><em>Aspergillus flavus</em> is among the most resilient fungi, causing significant losses in the quantity and quality of agricultural food commodities. It often produces aflatoxin B<sub>1</sub> (AFB<sub>1</sub>), a Class 1 human carcinogen that poses a serious threat to human and animal health. The present study investigated the potential of a chemically characterized essential oil-based formulation, ZTC (a synergistic mixture of <em>Zingiber officinale</em> (ZOEO), <em>Trachyspermum ammi</em> (TAEO), and <em>Coleus aromaticus</em> (CEO)) against the growth and aflatoxin B<sub>1</sub> production by the toxigenic species <em>Aspergillus flavus</em>. The ZTC formulation demonstrated in vitro and in situ antifungal effects (0.4 μL/mL) and aflatoxin inhibition (0.3 μL/mL) against <em>A. flavus</em>. At the cellular level, ZTC disrupted ergosterol biosynthesis, compromised membrane integrity, impaired mitochondrial potential, and altered redox homeostasis. Integrated transcriptomic and biochemical analyses indicated coordinated downregulation of glycolysis, the TCA cycle, ATP production, and sterol and fatty acid biosynthesis. This led to energy deficiency, membrane destabilization, induction of oxidative stress, and inhibition of aflatoxin B<sub>1</sub> biosynthesis by suppressing gene expression and disrupting key enzymes, thereby reducing AFB<sub>1</sub> at sublethal concentrations. The findings highlight the multi-target mechanism of action of the developed formulation, ZTC, against fungal growth and aflatoxin B1 contamination, and recommend it as a promising candidate for eco-friendly and sustainable antifungal agents.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111632"},"PeriodicalIF":5.2,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146010228","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 : 2026-01-12DOI: 10.1016/j.ijfoodmicro.2026.111633
Chenggang Song , Aoran Xue , Zhi-Jun Zhang , Lan Yang , Bao-Qi Zhang , Mingzhe Zhang , Yingqian Liu , Jianchun Qin
Mycotoxins, toxic secondary metabolites produced by pathogenic fungi contaminating agricultural commodities, represent a significant threat to food safety and human health. Notably, Aspergillus flavus and its associated aflatoxins are primary food contaminants requiring rigorous prevention and control strategies. This study elucidates the mechanism by which neocryptolepine, a natural antifungal compound, inhibits A. flavus growth and aflatoxin B1 accumulation in corn. Neocryptolepine effectively impedes the vegetative growth of A. flavus filaments and spores, disrupting cellular integrity by interfering with cell wall component synthesis. Furthermore, neocryptolepine treatment induces mitochondrial dysfunction in A. flavus cells, leading to disruptions in energy metabolism and reactive oxygen species homeostasis. Transcriptomic sequencing revealed that neocryptolepine downregulates the expression of aflatoxin biosynthetic gene clusters, such as aflJ, and related global regulatory factors, thereby suppressing aflatoxin biosynthesis. Importantly, the drug protected corn kernels from A. flavus infection without affecting their germination capacity. These findings suggest that neocryptolepine holds promise as a potential eco-friendly mycotoxin inhibitor for application in agricultural and food production.
{"title":"The mechanisms of neocryptolepine inhibiting Aspergillus flavus growth and aflatoxin B1 accumulation in corn","authors":"Chenggang Song , Aoran Xue , Zhi-Jun Zhang , Lan Yang , Bao-Qi Zhang , Mingzhe Zhang , Yingqian Liu , Jianchun Qin","doi":"10.1016/j.ijfoodmicro.2026.111633","DOIUrl":"10.1016/j.ijfoodmicro.2026.111633","url":null,"abstract":"<div><div>Mycotoxins, toxic secondary metabolites produced by pathogenic fungi contaminating agricultural commodities, represent a significant threat to food safety and human health. Notably, <em>Aspergillus flavus</em> and its associated aflatoxins are primary food contaminants requiring rigorous prevention and control strategies. This study elucidates the mechanism by which neocryptolepine, a natural antifungal compound, inhibits <em>A. flavus</em> growth and aflatoxin B1 accumulation in corn. Neocryptolepine effectively impedes the vegetative growth of <em>A. flavus</em> filaments and spores, disrupting cellular integrity by interfering with cell wall component synthesis. Furthermore, neocryptolepine treatment induces mitochondrial dysfunction in <em>A. flavus</em> cells, leading to disruptions in energy metabolism and reactive oxygen species homeostasis. Transcriptomic sequencing revealed that neocryptolepine downregulates the expression of aflatoxin biosynthetic gene clusters, such as <em>aflJ</em>, and related global regulatory factors, thereby suppressing aflatoxin biosynthesis. Importantly, the drug protected corn kernels from <em>A. flavus</em> infection without affecting their germination capacity. These findings suggest that neocryptolepine holds promise as a potential eco-friendly mycotoxin inhibitor for application in agricultural and food production.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111633"},"PeriodicalIF":5.2,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976047","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 : 2026-01-10DOI: 10.1016/j.ijfoodmicro.2026.111636
Lihan Wu , Yuqi Zhang , Xuan Chen, Qingfen Zhang, Shihua Wang
Aspergillus flavus is a typical filamentous fungus that poses risk to both humans and animals, as well as for crops. The secondary metabolite aflatoxin B1 produced by A. flavus is also one of the most carcinogenic and toxic natural pollutants discovered so far. Lysine benzoylation (Kbz), which participates in various life activities in different organisms, is an important post-translational modification of proteins. Cystathionine β-synthase (CBS) is a key enzyme in the maintenance of the homocysteine balance in organisms. However, the basic mechanism of CBS in the life activities of A. flavus is still unclear. By knocking out the cbs gene, it was found that compared to the wild-type and complementary strains, the cbs deficient strains had lower growth diameter, spore yield and seed colonization, while the number of sclerotia was increased, and toxin accumulation was increased by TLC. We then validated these results through RT-PCR. We also found the existence of a benzoyl site K109 on CBS by immunoprecipitation. Mutation at K109 abolishes benzoylation, resulting in reduced CBS enzymatic activity, which We found that the phenotype of point mutations is consistent with that of knockout strains. In addition, we found that benzoyltransferase GcnE catalyzes the benzoylation of CBS protein and affects enzyme activity. These results not only give theoretical support for the research of cystathionine β-synthase and benzoyl modification, but also provides fresh ideas for the prevention and control of pathogenic fungus A. flavus.
{"title":"The development and virulence of Aspergillus flavus regulated by benzoylation of CBS protein","authors":"Lihan Wu , Yuqi Zhang , Xuan Chen, Qingfen Zhang, Shihua Wang","doi":"10.1016/j.ijfoodmicro.2026.111636","DOIUrl":"10.1016/j.ijfoodmicro.2026.111636","url":null,"abstract":"<div><div><em>Aspergillus flavus</em> is a typical filamentous fungus that poses risk to both humans and animals, as well as for crops. The secondary metabolite aflatoxin B1 produced by <em>A. flavus</em> is also one of the most carcinogenic and toxic natural pollutants discovered so far. Lysine benzoylation (Kbz), which participates in various life activities in different organisms, is an important post-translational modification of proteins. Cystathionine β-synthase (CBS) is a key enzyme in the maintenance of the homocysteine balance in organisms. However, the basic mechanism of CBS in the life activities of <em>A. flavus</em> is still unclear. By knocking out the <em>cbs</em> gene, it was found that compared to the wild-type and complementary strains, the <em>cbs</em> deficient strains had lower growth diameter, spore yield and seed colonization, while the number of sclerotia was increased, and toxin accumulation was increased by TLC. We then validated these results through RT-PCR. We also found the existence of a benzoyl site K109 on CBS by immunoprecipitation. Mutation at K109 abolishes benzoylation, resulting in reduced CBS enzymatic activity, which We found that the phenotype of point mutations is consistent with that of knockout strains. In addition, we found that benzoyltransferase GcnE catalyzes the benzoylation of CBS protein and affects enzyme activity. These results not only give theoretical support for the research of cystathionine β-synthase and benzoyl modification, but also provides fresh ideas for the prevention and control of pathogenic fungus <em>A. flavus</em>.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"450 ","pages":"Article 111636"},"PeriodicalIF":5.2,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018466","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 : 2026-01-10DOI: 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":"2026-01-10","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}
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":"2026-01-10","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 : 2026-01-09DOI: 10.1016/j.ijfoodmicro.2026.111624
Dong Zhang , Xinrui Xie , Changlian Yu , Yuwei Liu , Li Yang , Chang Su , Xingzhong Zhang , Hongjun Li , Jie Tang
This study systematically investigated the effects of liquid smoke on the microbial community, flavor compounds, and metabolites in Sichuan fermented sausages. High-throughput sequencing, comprehensive two-dimensional gas chromatography–mass spectrometry, and metabolomics were employed. The results showed that the addition of liquid smoke (XH group) partially altered the composition of the microbial community: the relative abundance of Latilactobacillus decreased, while that of Staphylococcus and Lactococcus increased. The fungal composition also shifted. The predominant fungi in the XH group were Apiotrichum, Yarrowia, and Fusicolla, whereas in the control group (H group, without liquid smoke), they were Apiotrichum, Yarrowia, and Kurtzmaniella. Both groups developed favorable flavors during fermentation; however, unique compounds such as 2,4-Di-tert-butylphenol were detected exclusively in the XH group. Metabolomic analysis revealed that while the levels of some secondary metabolites decreased in the XH group, those of other metabolites with important functional roles or positive contributions to taste were enhanced. In conclusion, the addition of liquid smoke did not completely reshape the overall microbial structure. Instead, it influenced metabolic outcomes by modulating the abundance of dominant species, thereby leading to certain variations in flavor and metabolite profiles. Notably, the addition of 0.08 % liquid smoke enriched the flavor profile of Sichuan fermented sausages without significantly affecting their overall acceptability, demonstrating its potential for application in their production.
{"title":"New insights into the characteristic flavor formation of Sichuan fermented sausages driven by liquid smoke addition: An integrated study based on microbiomics, flavoromics, and untargeted metabolomics","authors":"Dong Zhang , Xinrui Xie , Changlian Yu , Yuwei Liu , Li Yang , Chang Su , Xingzhong Zhang , Hongjun Li , Jie Tang","doi":"10.1016/j.ijfoodmicro.2026.111624","DOIUrl":"10.1016/j.ijfoodmicro.2026.111624","url":null,"abstract":"<div><div>This study systematically investigated the effects of liquid smoke on the microbial community, flavor compounds, and metabolites in Sichuan fermented sausages. High-throughput sequencing, comprehensive two-dimensional gas chromatography–mass spectrometry, and metabolomics were employed. The results showed that the addition of liquid smoke (XH group) partially altered the composition of the microbial community: the relative abundance of <em>Latilactobacillus</em> decreased, while that of <em>Staphylococcus</em> and <em>Lactococcus</em> increased. The fungal composition also shifted. The predominant fungi in the XH group were <em>Apiotrichum</em>, <em>Yarrowia</em>, and <em>Fusicolla</em>, whereas in the control group (H group, without liquid smoke), they were <em>Apiotrichum</em>, <em>Yarrowia</em>, and <em>Kurtzmaniella</em>. Both groups developed favorable flavors during fermentation; however, unique compounds such as 2,4-Di-tert-butylphenol were detected exclusively in the XH group. Metabolomic analysis revealed that while the levels of some secondary metabolites decreased in the XH group, those of other metabolites with important functional roles or positive contributions to taste were enhanced. In conclusion, the addition of liquid smoke did not completely reshape the overall microbial structure. Instead, it influenced metabolic outcomes by modulating the abundance of dominant species, thereby leading to certain variations in flavor and metabolite profiles. Notably, the addition of 0.08 % liquid smoke enriched the flavor profile of Sichuan fermented sausages without significantly affecting their overall acceptability, demonstrating its potential for application in their production.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"449 ","pages":"Article 111624"},"PeriodicalIF":5.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922788","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 : 2026-01-09DOI: 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":"2026-01-09","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}
Pub Date : 2026-01-08DOI: 10.1016/j.ijfoodmicro.2026.111627
Fei Ren, Bin Tan
Acetobacter species are important in food fermentation. But, the properties and functional characteristics of many strains have not been fully known. This study identified a strain of Acetobacter indonesiensis SZAI to investigate its characteristics in whole-grain fermentation and its functional properties in enhancing immunity. The strain has a genome size of 14,306,769 bp with 10,716 genes (GC 43.50%). It has large amount of glycosyl transferases and glycoside hydrolases. Volatile compounds analysis of SZAI-fermented whole cereals (wheat, oats, millet, rice, barley) showed that they were very different from those of the control strain. 3-methyl-1-butanol, ethyl valerate, and ethyl acetate were among the most important compounds that made the flavors different. Microbial strain SZAI significantly increased neutrophils counts (59.6, 58.3, 57.0 vs. 42.6, corresponding to 1.40, 1.37, and 1.33 fold, respectively), and upregulated TNF-α expression levels (2.06, 1.96, 1.84 vs. 1.00, corresponding to 2.06, 1.96, and 1.84 fold, respectively) in zebrafish, thereby confirming its immune-enhancing properties. These results show that Acetobacter indonesiensis SZAI has the potential to ferment cereals and enhance the immune system, which suggests that it could be useful in functional fermented foods in the future.
醋酸杆菌在食品发酵中起着重要的作用。但是，许多菌株的性质和功能特征还不完全清楚。本研究鉴定了一株印尼醋酸杆菌SZAI，研究其在全谷物发酵中的特性及其增强免疫功能。该菌株基因组大小为14,306,769 bp，共有10,716个基因（GC 43.50%）。它具有大量的糖基转移酶和糖苷水解酶。稻谷发酵杂粮（小麦、燕麦、小米、大米、大麦）挥发性成分分析结果表明，稻谷发酵杂粮的挥发性成分与对照菌株有很大差异。3-甲基-1-丁醇、戊酸乙酯和乙酸乙酯是使风味不同的最重要的化合物。微生物菌株SZAI显著增加斑马鱼中性粒细胞计数（59.6、58.3、57.0 vs. 42.6，分别对应1.40、1.37、1.33倍），上调TNF-α表达水平（2.06、1.96、1.84 vs. 1.00，分别对应2.06、1.96、1.84倍），证实了其免疫增强特性。这些结果表明，印尼醋酸杆菌SZAI具有发酵谷物和增强免疫系统的潜力，这表明它在未来的功能发酵食品中可能是有用的。
{"title":"An acetic acid bacterium—Acetobacter indonesiensis SZAI and its role in fermented whole cereal volatile compounds and functional characteristics","authors":"Fei Ren, Bin Tan","doi":"10.1016/j.ijfoodmicro.2026.111627","DOIUrl":"10.1016/j.ijfoodmicro.2026.111627","url":null,"abstract":"<div><div><em>Acetobacter</em> species are important in food fermentation. But, the properties and functional characteristics of many strains have not been fully known. This study identified a strain of <em>Acetobacter indonesiensis</em> SZAI to investigate its characteristics in whole-grain fermentation and its functional properties in enhancing immunity. The strain has a genome size of 14,306,769 bp with 10,716 genes (GC 43.50%). It has large amount of glycosyl transferases and glycoside hydrolases. Volatile compounds analysis of SZAI-fermented whole cereals (wheat, oats, millet, rice, barley) showed that they were very different from those of the control strain. 3-methyl-1-butanol, ethyl valerate, and ethyl acetate were among the most important compounds that made the flavors different. Microbial strain SZAI significantly increased neutrophils counts (59.6, 58.3, 57.0 vs. 42.6, corresponding to 1.40, 1.37, and 1.33 fold, respectively), and upregulated TNF-α expression levels (2.06, 1.96, 1.84 vs. 1.00, corresponding to 2.06, 1.96, and 1.84 fold, respectively) in zebrafish, thereby confirming its immune-enhancing properties. These results show that <em>Acetobacter indonesiensis</em> SZAI has the potential to ferment cereals and enhance the immune system, which suggests that it could be useful in functional fermented foods in the future.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"449 ","pages":"Article 111627"},"PeriodicalIF":5.2,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922786","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 : 2026-01-07DOI: 10.1016/j.ijfoodmicro.2026.111628
Seren Oguz , Carlos Marquez , Fabio Santi , Lotta Kuuliala , Mariem Somrani , Frank Devlieghere
Ensuring food safety in the transition towards more sustainable packaging is critical, particularly given the persistent threat of Listeria monocytogenes in refrigerated modified atmosphere packaging (MAP). Although combining high CO2 and low O2 in refrigeration has been an effective strategy for controlling this pathogen, very little information is available on the effect of the presence of O2 on the growth of L.monocytogenes. This presence during storage is very difficult to avoid when switching to more gas permeable packaging materials. To better refine food safety strategies, extensive quantitative data under controlled conditions are needed to clarify the role of O2 and its interactions with key stressors (CO2, temperature, and pH). Thus, this study aims to analyze the individual effect of O2 and its combined effect with these key factors on L.monocytogenes behavior in a liquid medium under well-controlled atmospheres (60/0/40, 60/20/20, 60/2/38, 0/20/80, 0/0/100–CO2/O2/N2%) at different pH values (7.7, 6.2) and temperatures (4, 7 °C) through a gas-washing bottle incubation system (GBIS). Despite earlier reports suggesting no effect, O2 increased growth in CO2-free environment, which was more pronounced at 7 °C than at 4 °C. Moreover, lowering the pH from 7.7 to 6.2 enhanced the observed growth-increasing effect of O2. Most importantly, 60% CO2 (pH = 6.2) suppressed the effect of O2; even 20% O2 decreased maximum growth rate in the presence of CO2. Overall, this study shows a complex interaction between stress factors influencing the effect of O2 on L.monocytogenes growth.
{"title":"CO2 and pH influence the effect of O2 on the growth of Listeria monocytogenes at refrigeration conditions","authors":"Seren Oguz , Carlos Marquez , Fabio Santi , Lotta Kuuliala , Mariem Somrani , Frank Devlieghere","doi":"10.1016/j.ijfoodmicro.2026.111628","DOIUrl":"10.1016/j.ijfoodmicro.2026.111628","url":null,"abstract":"<div><div>Ensuring food safety in the transition towards more sustainable packaging is critical, particularly given the persistent threat of <em>Listeria monocytogenes</em> in refrigerated modified atmosphere packaging (MAP). Although combining high CO<sub>2</sub> and low O<sub>2</sub> in refrigeration has been an effective strategy for controlling this pathogen, very little information is available on the effect of the presence of O<sub>2</sub> on the growth of <em>L.</em> <em>monocytogenes</em>. This presence during storage is very difficult to avoid when switching to more gas permeable packaging materials. To better refine food safety strategies, extensive quantitative data under controlled conditions are needed to clarify the role of O<sub>2</sub> and its interactions with key stressors (CO<sub>2</sub>, temperature, and pH). Thus, this study aims to analyze the individual effect of O<sub>2</sub> and its combined effect with these key factors on <em>L.</em> <em>monocytogenes</em> behavior in a liquid medium under well-controlled atmospheres (60/0/40, 60/20/20, 60/2/38, 0/20/80, 0/0/100–CO<sub>2</sub>/O<sub>2</sub>/N<sub>2</sub>%) at different pH values (7.7, 6.2) and temperatures (4, 7 °C) through a gas-washing bottle incubation system (GBIS). Despite earlier reports suggesting no effect, O<sub>2</sub> increased growth in CO<sub>2</sub>-free environment, which was more pronounced at 7 °C than at 4 °C. Moreover, lowering the pH from 7.7 to 6.2 enhanced the observed growth-increasing effect of O<sub>2</sub>. Most importantly, 60% CO<sub>2</sub> (pH = 6.2) suppressed the effect of O<sub>2</sub>; even 20% O<sub>2</sub> decreased maximum growth rate in the presence of CO<sub>2</sub>. Overall, this study shows a complex interaction between stress factors influencing the effect of O<sub>2</sub> on <em>L.</em> <em>monocytogenes</em> growth.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"449 ","pages":"Article 111628"},"PeriodicalIF":5.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922714","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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