Pub Date : 2025-04-23DOI: 10.1016/j.ijfoodmicro.2025.111220
Yuxin Gan , Jinxi Cui , Aoxuan Nie , Yuxia Yang , Xiuhong Zhao
This study investigated the impact of L. paracasei C5 on the generation of flavor compounds in bread through metagenomics and flavouromics. Metagenomic profiling revealed that L. paracasei C5 facilitated carbohydrate, amino acid, and lipid metabolism in the dough. Correlative analyses between specific microbial species and flavor compounds demonstrated a positive association between L. paracasei and key flavor compounds in bread, such as 2-nonenal,(E)-, 2-octenal,(E)-, benzeneacetaldehyde, and hexanoic acid, ethyl ester. A predictive network outlining the metabolic pathways responsible for L. paracasei C5 sourdough bread flavor compounds was established, elucidating the microbial annotation of pertinent genes and enzymes. The findings underscored the synergistic role of L. paracasei and S. cerevisiae in enhancing the activity of encoded enzymes involved in carbohydrate degradation, acetyl-CoA synthesis, succinate conversion, acyl-CoA production, transaminases, alcohol dehydrogenase, and carboxylesterases. These results offer novel insights into the mechanisms by which L. paracasei C5 augments bread flavor.
{"title":"Revealing the influence of Lacticaseibacillus paracasei C5 on the flavor formation of bread dough by metagenomics and flavouromics","authors":"Yuxin Gan , Jinxi Cui , Aoxuan Nie , Yuxia Yang , Xiuhong Zhao","doi":"10.1016/j.ijfoodmicro.2025.111220","DOIUrl":"10.1016/j.ijfoodmicro.2025.111220","url":null,"abstract":"<div><div>This study investigated the impact of <em>L. paracasei</em> C5 on the generation of flavor compounds in bread through metagenomics and flavouromics. Metagenomic profiling revealed that <em>L. paracasei</em> C5 facilitated carbohydrate, amino acid, and lipid metabolism in the dough. Correlative analyses between specific microbial species and flavor compounds demonstrated a positive association between <em>L. paracasei</em> and key flavor compounds in bread, such as 2-nonenal,(E)-, 2-octenal,(E)-, benzeneacetaldehyde, and hexanoic acid, ethyl ester. A predictive network outlining the metabolic pathways responsible for <em>L. paracasei</em> C5 sourdough bread flavor compounds was established, elucidating the microbial annotation of pertinent genes and enzymes. The findings underscored the synergistic role of <em>L. paracasei</em> and <em>S. cerevisiae</em> in enhancing the activity of encoded enzymes involved in carbohydrate degradation, acetyl-CoA synthesis, succinate conversion, acyl-CoA production, transaminases, alcohol dehydrogenase, and carboxylesterases. These results offer novel insights into the mechanisms by which <em>L. paracasei</em> C5 augments bread flavor.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"437 ","pages":"Article 111220"},"PeriodicalIF":5.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869122","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 : 2025-04-23DOI: 10.1016/j.ijfoodmicro.2025.111219
Xingguang Chen , Wenzhe Li , Jiyang Chu , Ziqiang Chen , Lifang Zou , Lei Wang , Ran Qiu , Jian Lu , Dianhui Wu
Carbendazim (CBZ) is a broad-spectrum fungicide commonly used in agriculture, but its residue can contaminate beer ingredients, potentially affecting Saccharomyces cerevisiae and beer quality. In this work, the effect of CBZ on Saccharomyces cerevisiae Saflager S-189 (S-189) and beer quality was investigated. The results demonstrated that S-189 was inhibited at concentrations equal to or exceeding 150 μg/kg of CBZ, reducing its growth rate, cell number, viability, and damaging cell structure. The CBZ disrupted multiple metabolic pathways in S-189, including amino acid biosynthesis, tRNA biosynthesis, and ABC transporters, and negatively affected energy metabolism, antioxidant activity, nutrient transport, and fermentation performance. Compared with the control group, the fermentation degree, alcohol content, and total acidity of beer fermented with 300 μg/kg CBZ-contaminated wort decreased, while the true concentration, pH, turbidity, and alcohol-ester ratio increased. Furthermore, CBZ changed the content of key flavor substances in beer, which affected the flavor quality of beer.
{"title":"The effects of carbendazim on metabolic pathways of Saccharomyces cerevisiae Saflager S-189 and beer characteristics","authors":"Xingguang Chen , Wenzhe Li , Jiyang Chu , Ziqiang Chen , Lifang Zou , Lei Wang , Ran Qiu , Jian Lu , Dianhui Wu","doi":"10.1016/j.ijfoodmicro.2025.111219","DOIUrl":"10.1016/j.ijfoodmicro.2025.111219","url":null,"abstract":"<div><div>Carbendazim (CBZ) is a broad-spectrum fungicide commonly used in agriculture, but its residue can contaminate beer ingredients, potentially affecting <em>Saccharomyces cerevisiae</em> and beer quality. In this work, the effect of CBZ on <em>Saccharomyces cerevisiae</em> Saflager <em>S-189</em> (<em>S-189</em>) and beer quality was investigated. The results demonstrated that <em>S-189</em> was inhibited at concentrations equal to or exceeding 150 μg/kg of CBZ, reducing its growth rate, cell number, viability, and damaging cell structure. The CBZ disrupted multiple metabolic pathways in <em>S-189</em>, including amino acid biosynthesis, tRNA biosynthesis, and ABC transporters, and negatively affected energy metabolism, antioxidant activity, nutrient transport, and fermentation performance. Compared with the control group, the fermentation degree, alcohol content, and total acidity of beer fermented with 300 μg/kg CBZ-contaminated wort decreased, while the true concentration, pH, turbidity, and alcohol-ester ratio increased. Furthermore, CBZ changed the content of key flavor substances in beer, which affected the flavor quality of beer.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"437 ","pages":"Article 111219"},"PeriodicalIF":5.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873560","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 : 2025-04-22DOI: 10.1016/j.ijfoodmicro.2025.111216
Yu Liu , Jincheng Ma , Zhipeng Liu , Shaojin Wang , Long Chen
A significant variation between experimental and predicted log reductions of Salmonella at a constant water activity level has been previously found during a simultaneous hot air assisted radio frequency (HARF) pasteurization and drying of low-moisture foods (LMFs). However, how the dynamic thermal resistance of Salmonella changes with the changing temperature and water activity during HARF is unclear. Thermal inactivation kinetics of Salmonella Enteritidis PT 30 (S. enteritidis PT 30) in walnut shell powder and on in-shell walnuts were investigated under three temperatures and water activities. The dynamic thermal resistance (D-value) of S. enteritidis PT 30 in walnut shell powder and on in-shell walnuts were quantitatively described by modified Bigelow models during simultaneous HARF pasteurization and drying. The survival of S. enteritidis PT 30 was predicted and validated based on the dynamic thermal resistance on in-shell walnuts during HARF pasteurization. The results showed that the D-values of S. enteritidis PT 30 on in-shell walnuts were significantly (P < 0.05) higher than those in walnut shell powder at different temperatures and water activities, indicating a need to determine the thermal resistance parameters based on real-case pasteurization scenarios. The dynamic thermal resistance of S. enteritidis PT 30 in walnut shell powder and on in-shell walnuts first decreased and then increased during the simultaneous HARF pasteurization and drying. The experimental log reduction (2.06 ± 0.08) of S. enteritidis PT 30 on in-shell walnuts was close to the predicted value (2.07) during the simultaneous HARF pasteurization and drying. Predicting microbial survival based on the dynamic thermal resistance of S. enteritidis PT 30 on in-shell walnuts is more accurate and reliable than that based on the static one. The developed model and proposed approach are valuable and crucial for the commercialization of simultaneous RF pasteurization and drying processes of LMFs.
{"title":"An accurate approach to predict Salmonella Enteritidis PT 30 survival based on dynamic thermal resistance during hot air assisted radio frequency pasteurization of in-shell walnuts","authors":"Yu Liu , Jincheng Ma , Zhipeng Liu , Shaojin Wang , Long Chen","doi":"10.1016/j.ijfoodmicro.2025.111216","DOIUrl":"10.1016/j.ijfoodmicro.2025.111216","url":null,"abstract":"<div><div>A significant variation between experimental and predicted log reductions of <em>Salmonella</em> at a constant water activity level has been previously found during a simultaneous hot air assisted radio frequency (HARF) pasteurization and drying of low-moisture foods (LMFs). However, how the dynamic thermal resistance of <em>Salmonella</em> changes with the changing temperature and water activity during HARF is unclear. Thermal inactivation kinetics of <em>Salmonella Enteritidis</em> PT 30 (<em>S. enteritidis</em> PT 30) in walnut shell powder and on in-shell walnuts were investigated under three temperatures and water activities. The dynamic thermal resistance (<em>D</em>-value) of <em>S. enteritidis</em> PT 30 in walnut shell powder and on in-shell walnuts were quantitatively described by modified Bigelow models during simultaneous HARF pasteurization and drying. The survival of <em>S. enteritidis</em> PT 30 was predicted and validated based on the dynamic thermal resistance on in-shell walnuts during HARF pasteurization. The results showed that the <em>D</em>-values of <em>S. enteritidis</em> PT 30 on in-shell walnuts were significantly (<em>P</em> < 0.05) higher than those in walnut shell powder at different temperatures and water activities, indicating a need to determine the thermal resistance parameters based on real-case pasteurization scenarios. The dynamic thermal resistance of <em>S. enteritidis</em> PT 30 in walnut shell powder and on in-shell walnuts first decreased and then increased during the simultaneous HARF pasteurization and drying. The experimental log reduction (2.06 ± 0.08) of <em>S. enteritidis</em> PT 30 on in-shell walnuts was close to the predicted value (2.07) during the simultaneous HARF pasteurization and drying. Predicting microbial survival based on the dynamic thermal resistance of <em>S. enteritidis</em> PT 30 on in-shell walnuts is more accurate and reliable than that based on the static one. The developed model and proposed approach are valuable and crucial for the commercialization of simultaneous RF pasteurization and drying processes of LMFs.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"437 ","pages":"Article 111216"},"PeriodicalIF":5.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869124","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 : 2025-04-17DOI: 10.1016/j.ijfoodmicro.2025.111212
Xiujin Chen , Minghui Dai , Li Bai , Jun Wang , Zixin Peng , Yang Qu , Shanshan Chen , Xianli Yang , Yalong Bai , Changyan Zhou , Yujuan Suo
Soaked Auricularia auricula-judae (A. auricula-judae) serves as a significant vehicle for foodbome disease caused by Burkholderia gladiol. This study aimed to develop predictive models that described the effect of temperature on the growth and bongkrekic acid (BA) toxin production of B. gladioli in soaked A. auricula-judae. The experiment involved inoculating soaked A. auricula-judae with B. gladioli and incubating it at 4, 10, 15, 20, 26, 30 and 36 °C. B. gladioli concentration data was used to develop a growth predictive model, while BA measurements were utilized to create a toxin predictive model. Model validation was conducted at 18 °C, 28 °C, and 33 °C. The results indicated that B. gladioli did not grow at 4 °C and 10 °C. The SGompertz model was identified as the most appropriate primary model, while a quadratic polynomial model was derived as a secondary model. The secondary model determined that the minimum temperature (Tmin) required for the growth in soaked A. auricula-judae is 12.9 °C. Furthermore, the minimum detectable concentration of B. gladioli for qualitative BA production in soaked A. auricula-judae was approximately 8 log CFU/g, and a toxin-producing model has been developed to predict the time of BA production. Finally, the validation data obtained at 18, 28, and 33 °C showed RMSE and RE values of 0.30, 0.21, and 0.22 log CFU/g and − 2.2 %, −3.1 %, and − 2.5 %, respectively. This study revealed the growth kinetics of B. gladioli and provides information for the foodborne risk of bongkrekic acid production by B. gladioli on soaked A. auricula-judae.
浸泡过的金针菜（Auricularia auricula-judae）是布克氏菌（Burkholderia gladiol）引起的食源性疾病的重要载体。本研究的目的是建立预测模型，描述温度对浸泡过的杏鲍菇（A. auricula-judae）中杏鲍菇伯克霍尔德氏菌（B. gladioli）的生长和邦克瑞克酸（BA）毒素产生的影响。实验包括将浸泡过的枳壳接种到剑兰中，并在 4、10、15、20、26、30 和 36 °C的温度下进行培养。剑水蚤浓度数据被用来建立生长预测模型，而 BA 测量值被用来建立毒素预测模型。模型在 18 °C、28 °C 和 33 °C下进行验证。结果表明，剑水蚤在 4 °C 和 10 °C 下不生长。SGompertz 模型被确定为最合适的主要模型，而二次多项式模型被确定为次要模型。二级模型确定，浸泡过的 A. auricula-judae 生长所需的最低温度（Tmin）为 12.9 °C。此外，在浸泡过的枳实中产生定性 BA 所需的最低可检测 B. gladioli 浓度约为 8 log CFU/g，并建立了一个毒素产生模型来预测产生 BA 的时间。最后，在 18、28 和 33 °C 温度条件下获得的验证数据显示，RMSE 和 RE 值分别为 0.30、0.21 和 0.22 log CFU/g，以及 - 2.2 %、-3.1 % 和 - 2.5 %。这项研究揭示了剑水蚤的生长动力学，并为剑水蚤在浸泡过的枳实上产生邦克瑞克酸的食源性风险提供了信息。
{"title":"Assessing safety risks associated with Burkholderia gladiolus in soaked Auricularia auricula-judae: One instant predictive model study","authors":"Xiujin Chen , Minghui Dai , Li Bai , Jun Wang , Zixin Peng , Yang Qu , Shanshan Chen , Xianli Yang , Yalong Bai , Changyan Zhou , Yujuan Suo","doi":"10.1016/j.ijfoodmicro.2025.111212","DOIUrl":"10.1016/j.ijfoodmicro.2025.111212","url":null,"abstract":"<div><div>Soaked <em>Auricularia auricula-judae (A. auricula-judae)</em> serves as a significant vehicle for foodbome disease caused by <em>Burkholderia gladiol</em>. This study aimed to develop predictive models that described the effect of temperature on the growth and bongkrekic acid (BA) toxin production of <em>B. gladioli</em> in soaked <em>A. auricula-judae</em>. The experiment involved inoculating soaked <em>A. auricula-judae</em> with <em>B. gladioli</em> and incubating it at 4, 10, 15, 20, 26, 30 and 36 °C. <em>B. gladioli</em> concentration data was used to develop a growth predictive model, while BA measurements were utilized to create a toxin predictive model. Model validation was conducted at 18 °C, 28 °C, and 33 °C. The results indicated that <em>B. gladioli</em> did not grow at 4 °C and 10 °C. The SGompertz model was identified as the most appropriate primary model, while a quadratic polynomial model was derived as a secondary model. The secondary model determined that the minimum temperature (<em>T</em><sub><em>min</em></sub>) required for the growth in soaked <em>A. auricula-judae</em> is 12.9 °C. Furthermore, the minimum detectable concentration of <em>B. gladioli</em> for qualitative BA production in soaked <em>A. auricula-judae</em> was approximately 8 log CFU/g, and a toxin-producing model has been developed to predict the time of BA production. Finally, the validation data obtained at 18, 28, and 33 °C showed RMSE and RE values of 0.30, 0.21, and 0.22 log CFU/g and − 2.2 %, −3.1 %, and − 2.5 %, respectively. This study revealed the growth kinetics of <em>B. gladioli</em> and provides information for the foodborne risk of bongkrekic acid production by <em>B. gladioli</em> on soaked <em>A. auricula-judae</em>.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111212"},"PeriodicalIF":5.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850333","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 : 2025-04-17DOI: 10.1016/j.ijfoodmicro.2025.111213
Ye Htut Zwe , Roshini Devi Mohan , Si Jia Lim , Wai Ching Lai , Kae Hwan Sim , Yu Lee Leyau , Ker Lew , Joachim Mun Choy Chua , Kyaw Thu Aung , Kern Rei Chng , Yuan Sheng Wu , Joanne Sheot Harn Chan , Li Kiang Tan
Staphylococcus aureus is one of the major foodborne pathogens that poses significant public health risk, particularly in ready-to-eat (RTE) food prepared under inadequate hygiene conditions. Staphylococcal food poisoning (SFP) is increasingly prevalent worldwide, yet it is not reportable in Singapore, leaving a knowledge gap regarding the clinical incidence and virulence of local strains. This study examined the genetic diversity, antimicrobial resistance (AMR), and virulence determinants of S. aureus in RTE, and cooked food using both conventional testing and whole-genome sequencing (WGS) tools. We retrospectively analyzed 12178 RTE, and cooked food samples collected in Singapore from 2020 to 2023, detecting S. aureus in 0.19 % (23/12178) of samples. Genotype t4171_ST1155 was most common (4/23), followed by t91_ST2990 (3/23). Immunoassays detected the production of classical staphylococcal enterotoxin (SE) A, B, and C types in 43.5 % (10/23) of the isolates. Additionally, genomic analysis identified three more isolates that contained only non-classical SE genes, which were not detectable through immunoassays. AMR occurrence was highest for tetracycline (21.7 %, 5/23), followed by erythromycin (8.7 %, 2/23), clindamycin, gentamicin, and sulfamethoxazole-trimethoprim (4.3 %, 1/23 each). A minority (30.4 %, 7/23) of isolates possessed the complete icaADBC operon, which is associated with the well-studied matrix component involved in biofilm formation. Our findings indicate a low occurrence of S. aureus in RTE, and cooked foods in Singapore, with a minority carrying AMR and biofilm formation features, though about half are enterotoxigenic. This investigation plays a crucial role in comprehending the food safety landscape in Singapore, enabling the development of effective risk mitigation strategies aimed at improving community food safety.
{"title":"Occurrence & characterization of Staphylococcus aureus from ready-to-eat (RTE), and cooked food in Singapore: A retrospective analysis","authors":"Ye Htut Zwe , Roshini Devi Mohan , Si Jia Lim , Wai Ching Lai , Kae Hwan Sim , Yu Lee Leyau , Ker Lew , Joachim Mun Choy Chua , Kyaw Thu Aung , Kern Rei Chng , Yuan Sheng Wu , Joanne Sheot Harn Chan , Li Kiang Tan","doi":"10.1016/j.ijfoodmicro.2025.111213","DOIUrl":"10.1016/j.ijfoodmicro.2025.111213","url":null,"abstract":"<div><div><em>Staphylococcus aureus</em> is one of the major foodborne pathogens that poses significant public health risk, particularly in ready-to-eat (RTE) food prepared under inadequate hygiene conditions. Staphylococcal food poisoning (SFP) is increasingly prevalent worldwide, yet it is not reportable in Singapore, leaving a knowledge gap regarding the clinical incidence and virulence of local strains. This study examined the genetic diversity, antimicrobial resistance (AMR), and virulence determinants of <em>S. aureus</em> in RTE, and cooked food using both conventional testing and whole-genome sequencing (WGS) tools. We retrospectively analyzed 12178 RTE, and cooked food samples collected in Singapore from 2020 to 2023, detecting <em>S. aureus</em> in 0.19 % (23/12178) of samples. Genotype t4171_ST1155 was most common (4/23), followed by t91_ST2990 (3/23). Immunoassays detected the production of classical staphylococcal enterotoxin (SE) A, B, and C types in 43.5 % (10/23) of the isolates. Additionally, genomic analysis identified three more isolates that contained only non-classical SE genes, which were not detectable through immunoassays. AMR occurrence was highest for tetracycline (21.7 %, 5/23), followed by erythromycin (8.7 %, 2/23), clindamycin, gentamicin, and sulfamethoxazole-trimethoprim (4.3 %, 1/23 each). A minority (30.4 %, 7/23) of isolates possessed the complete <em>icaADBC</em> operon, which is associated with the well-studied matrix component involved in biofilm formation. Our findings indicate a low occurrence of <em>S. aureus</em> in RTE, and cooked foods in Singapore, with a minority carrying AMR and biofilm formation features, though about half are enterotoxigenic. This investigation plays a crucial role in comprehending the food safety landscape in Singapore, enabling the development of effective risk mitigation strategies aimed at improving community food safety.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111213"},"PeriodicalIF":5.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855626","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 : 2025-04-17DOI: 10.1016/j.ijfoodmicro.2025.111211
Heba A. Ahmed , Ahmed S. El-tahlawy , Rasha M. El Bayomi , Marwa A. Ahmed , Mona A. Abd Elazeem , Waleed Alahmad , Abd El-Salam E. Hafez
In recent times, chicken-based food items have seen a surge in demand due to their high-quality protein and essential nutrients. However, poultry products remain vulnerable to contamination by Escherichia coli (E. coli), including pathogenic strains that pose significant food safety challenges. This study investigates bacterial contamination in various chicken parts (thigh, breast, skin, gizzard, and liver) collected from five retail outlets and markets with different sanitation standards in Zagazig city, Sharkia Governorate, Egypt. The total Enterobacteriales count ranged from 5.38 to 5.55 log10 CFU/g, with gizzard samples showing the highest bacterial count of 5.55 ± 0.08 log10 CFU/g. Coliform levels were highest in gizzard samples with an average of 5.74 ± 0.10 log10 MPN/g. E. coli was detected in 33 % of the samples, with the highest prevalence in gizzard (12/20; 60 %) and liver (10/20; 50 %). Additionally, 11 out of 33 E. coli isolates (33.3 %) were Extended-Spectrum Beta-Lactamase (ESBL) producers, with liver samples showing the highest incidence (5/33; 15.15 %). E. coli serotyping revealed diverse strains, particularly in gizzard samples. All 25 E. coli isolates carried the phoA and blaTEM genes, while none tested positive for blaSHV. Of the 33 E. coli isolates, 25 were tested for antimicrobial resistance. All tested isolates (100 %) were resistant to ampicillin, while cefotaxime and cefoxitin exhibited complete sensitivity.
{"title":"Prevalence, antimicrobial resistance, and genetic profile of Escherichia coli in retail chicken parts in Zagazig City, Egypt","authors":"Heba A. Ahmed , Ahmed S. El-tahlawy , Rasha M. El Bayomi , Marwa A. Ahmed , Mona A. Abd Elazeem , Waleed Alahmad , Abd El-Salam E. Hafez","doi":"10.1016/j.ijfoodmicro.2025.111211","DOIUrl":"10.1016/j.ijfoodmicro.2025.111211","url":null,"abstract":"<div><div>In recent times, chicken-based food items have seen a surge in demand due to their high-quality protein and essential nutrients. However, poultry products remain vulnerable to contamination by <em>Escherichia coli</em> (<em>E. coli</em>), including pathogenic strains that pose significant food safety challenges. This study investigates bacterial contamination in various chicken parts (thigh, breast, skin, gizzard, and liver) collected from five retail outlets and markets with different sanitation standards in Zagazig city, Sharkia Governorate, Egypt. The total Enterobacteriales count ranged from 5.38 to 5.55 log<sub>10</sub> CFU/g, with gizzard samples showing the highest bacterial count of 5.55 ± 0.08 log<sub>10</sub> CFU/g. Coliform levels were highest in gizzard samples with an average of 5.74 ± 0.10 log<sub>10</sub> MPN/g. <em>E. coli</em> was detected in 33 % of the samples, with the highest prevalence in gizzard (12/20; 60 %) and liver (10/20; 50 %). Additionally, 11 out of 33 <em>E. coli</em> isolates (33.3 %) were Extended-Spectrum Beta-Lactamase (ESBL) producers, with liver samples showing the highest incidence (5/33; 15.15 %). <em>E. coli</em> serotyping revealed diverse strains, particularly in gizzard samples. All 25 <em>E. coli</em> isolates carried the <em>phoA</em> and <em>blaTEM</em> genes, while none tested positive for <em>blaSHV</em>. Of the 33 <em>E. coli</em> isolates, 25 were tested for antimicrobial resistance. All tested isolates (100 %) were resistant to ampicillin, while cefotaxime and cefoxitin exhibited complete sensitivity.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111211"},"PeriodicalIF":5.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847845","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 : 2025-04-16DOI: 10.1016/j.ijfoodmicro.2025.111214
Zengbo Wang , Junwu Cai , Bailiang Li , Huizi Tan
Soy protein is a multimeric globular protein that is less likely to be metabolized and utilized by lactic acid bacteria (LAB) during fermentation compared to milk-derived proteins. Little genetic information is available regarding LAB-mediated hydrolysis of soy protein. In this study, we sequenced the genomes of 46 Lactobacillus helveticus (L. helveticus) strains to analyze genetic-level factors affecting soy protein hydrolytic activity. The analysis revealed that the soy protein hydrolysis capability of these L. helveticus strains showed no correlation with their isolation sources, geographic origins, extracellular protease genes, peptide transporter genes, or peptidase gene distribution. Through genome-wide association analysis (GWAS), we identified two significantly associated missense SNPs (SNP-482062 and SNP-1780770) linked to soy protein hydrolysis activity. These two SNPs changed the local tertiary structure of amino acid permease and ornithine decarboxylase, respectively. Enzymatic assays confirmed that the mutations significantly affected enzyme activity, thereby validating their critical role in soy protein hydrolysis. This study elucidates the genetic basis for differential soy protein hydrolysis capacity among L. helveticus strains, offering practical guidance for selecting highly proteolytic strains to develop soy-based fermented dairy alternatives.
{"title":"Exploring the genetic information of Lactobacillus helveticus strains hydrolyzing soy protein using genome-wide association analysis","authors":"Zengbo Wang , Junwu Cai , Bailiang Li , Huizi Tan","doi":"10.1016/j.ijfoodmicro.2025.111214","DOIUrl":"10.1016/j.ijfoodmicro.2025.111214","url":null,"abstract":"<div><div>Soy protein is a multimeric globular protein that is less likely to be metabolized and utilized by lactic acid bacteria (LAB) during fermentation compared to milk-derived proteins. Little genetic information is available regarding LAB-mediated hydrolysis of soy protein. In this study, we sequenced the genomes of 46 <em>Lactobacillus helveticus</em> (<em>L. helveticus</em>) strains to analyze genetic-level factors affecting soy protein hydrolytic activity. The analysis revealed that the soy protein hydrolysis capability of these L. <em>helveticus</em> strains showed no correlation with their isolation sources, geographic origins, extracellular protease genes, peptide transporter genes, or peptidase gene distribution. Through genome-wide association analysis (GWAS), we identified two significantly associated missense SNPs (SNP-482062 and SNP-1780770) linked to soy protein hydrolysis activity. These two SNPs changed the local tertiary structure of amino acid permease and ornithine decarboxylase, respectively. Enzymatic assays confirmed that the mutations significantly affected enzyme activity, thereby validating their critical role in soy protein hydrolysis. This study elucidates the genetic basis for differential soy protein hydrolysis capacity among L. <em>helveticus</em> strains, offering practical guidance for selecting highly proteolytic strains to develop soy-based fermented dairy alternatives.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111214"},"PeriodicalIF":5.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855624","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 preliminarily evaluated the effect of different combinations of two Pseudomonas species (P. fragi, P. lundensis, P. fluorescens, and P. putida) on the protein degradation capacity of meat and bacteria growth rules. Then P. fragi and P. putida, with the co-spoilage potential, were inoculated on pork to determine the ability of spoilage, and the potential spoilage genes further were revealed by whole genome sequencing. Results showed that, in the P. fragi + P. putida and P. fragi + P. fluorescens group, the diameter of Raw-pork Juice Agar (RJA) decomposition zone was significantly higher than that in the single-inoculated group, respectively. Furthermore, the results in situ showed that P. fragi and P. putida grew rapidly after co-culture, in which μmax was significantly higher than that in the single-inoculated group. In addition, at the end of storage, the pH and TVB-N values of pork after co-culture were significantly higher than those of the single-inoculated group, and the texture of pork was softer. Simultaneously, the contents of volatile organic compounds including 1-Octen-3-ol, 2-Nonanone, and Hexanal, were significantly increased after co-culture. Moreover, the genes of P. fragi and P. putida, identified by whole genome sequencing, related to amino acid metabolism, carbohydrate metabolism, and motor chemotaxis may be the primary reasons involved in the co-spoilage of pork. In conclusion, this study demonstrated that P. fragi and P. putida had a synergistic interaction to accelerate the spoilage of pork, which could provide a better understanding of co-spoilage of different Pseudomonas spp.
{"title":"Effect of co-inoculation of Pseudomonas fragi and Pseudomonas putida on the spoilage of chilled pork after the screening of a variety of different combinations of two Pseudomonas species","authors":"Guangru Shang, Cong Zhou, Bingjie Zhang, Yuping Zhang, Shuang Teng, Keping Ye","doi":"10.1016/j.ijfoodmicro.2025.111215","DOIUrl":"10.1016/j.ijfoodmicro.2025.111215","url":null,"abstract":"<div><div>This study preliminarily evaluated the effect of different combinations of two <em>Pseudomonas</em> species (<em>P. fragi</em>, <em>P. lundensis</em>, <em>P. fluorescens</em>, and <em>P. putida</em>) on the protein degradation capacity of meat and bacteria growth rules. Then <em>P. fragi</em> and <em>P. putida</em>, with the co-spoilage potential, were inoculated on pork to determine the ability of spoilage, and the potential spoilage genes further were revealed by whole genome sequencing. Results showed that, in the <em>P. fragi</em> + <em>P. putida</em> and <em>P. fragi</em> + <em>P. fluorescens</em> group, the diameter of Raw-pork Juice Agar (RJA) decomposition zone was significantly higher than that in the single-inoculated group, respectively. Furthermore, the results in situ showed that <em>P. fragi</em> and <em>P. putida</em> grew rapidly after co-culture, in which μ<sub>max</sub> was significantly higher than that in the single-inoculated group. In addition, at the end of storage, the pH and TVB-N values of pork after co-culture were significantly higher than those of the single-inoculated group, and the texture of pork was softer. Simultaneously, the contents of volatile organic compounds including 1-Octen-3-ol, 2-Nonanone, and Hexanal, were significantly increased after co-culture. Moreover, the genes of <em>P. fragi</em> and <em>P. putida</em>, identified by whole genome sequencing, related to amino acid metabolism, carbohydrate metabolism, and motor chemotaxis may be the primary reasons involved in the co-spoilage of pork. In conclusion, this study demonstrated that <em>P. fragi</em> and <em>P. putida</em> had a synergistic interaction to accelerate the spoilage of pork, which could provide a better understanding of co-spoilage of different <em>Pseudomonas</em> spp.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111215"},"PeriodicalIF":5.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844957","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 : 2025-04-15DOI: 10.1016/j.ijfoodmicro.2025.111202
Bowen Liu , Xinyuan Miao , Qing Li , Chen Xu , Xilong Kang , Lei Chen , Fan Wang , Xinan Jiao , Chuang Meng , Zhiming Pan
A semiquantitative risk assessment method based on the Delphi–analytic hierarchy process (AHP) can serve as a proactive tool for the prevention and control of Salmonella infections in poultry farms. This method can facilitate early warning to minimize the risk of transmission of Salmonella to chicken meat and eggs. In this study, an expert panel comprising 22 members was established. After two rounds of evaluation, a risk assessment system consisting of 10 primary indicators and 73 secondary indicators was finalized. The expert participation rate (100 %), authority coefficient (1.0), and Kendall's W value (0.222 for the first round and 0.316 for the second round) met the required standards. Moreover, the system exhibited high reliability and validity. Based on the AHP, the top three weighted primary indicators were “seedstock management” (0.2769), “feeding and management” (0.1429), and “cleaning, disinfection and harmless disposal” (0.1429). The combined weight of the secondary indicators ranged from 0.00009 to 0.03027. In total, 6423 samples, including dead embryos and environmental samples, were collected from a poultry farm. By isolating Salmonella, assessing antimicrobial resistance, and performing whole-genome sequencing, the key risk points for contamination were identified. The implementation of targeted control measures based on the risk assessment model resulted in significant improvements. In particular, the overall antibody positivity rate decreased from 65.9 % to 8 %, the isolation rate of Salmonella from dead embryos decreased from 47.5 % to 3.75 %, and the isolation rate of Salmonella from the production environment of the hatchery workshop decreased from 10.1 % to 0.9 %. Moreover, notable improvements were observed in production metrics. Overall, our established risk assessment model is suitable for environments with low Salmonella isolation rates and can effectively facilitate the prevention and control of Salmonella in poultry farms.
{"title":"Development and application of a risk assessment tool for preventing the introduction and transmission of Salmonella in poultry farms: Based on the Delphi–analytic hierarchy process","authors":"Bowen Liu , Xinyuan Miao , Qing Li , Chen Xu , Xilong Kang , Lei Chen , Fan Wang , Xinan Jiao , Chuang Meng , Zhiming Pan","doi":"10.1016/j.ijfoodmicro.2025.111202","DOIUrl":"10.1016/j.ijfoodmicro.2025.111202","url":null,"abstract":"<div><div>A semiquantitative risk assessment method based on the Delphi–analytic hierarchy process (AHP) can serve as a proactive tool for the prevention and control of <em>Salmonella</em> infections in poultry farms. This method can facilitate early warning to minimize the risk of transmission of <em>Salmonella</em> to chicken meat and eggs. In this study, an expert panel comprising 22 members was established. After two rounds of evaluation, a risk assessment system consisting of 10 primary indicators and 73 secondary indicators was finalized. The expert participation rate (100 %), authority coefficient (1.0), and Kendall's W value (0.222 for the first round and 0.316 for the second round) met the required standards. Moreover, the system exhibited high reliability and validity. Based on the AHP, the top three weighted primary indicators were “seedstock management” (0.2769), “feeding and management” (0.1429), and “cleaning, disinfection and harmless disposal” (0.1429). The combined weight of the secondary indicators ranged from 0.00009 to 0.03027. In total, 6423 samples, including dead embryos and environmental samples, were collected from a poultry farm. By isolating <em>Salmonella</em>, assessing antimicrobial resistance, and performing whole-genome sequencing, the key risk points for contamination were identified. The implementation of targeted control measures based on the risk assessment model resulted in significant improvements. In particular, the overall antibody positivity rate decreased from 65.9 % to 8 %, the isolation rate of <em>Salmonella</em> from dead embryos decreased from 47.5 % to 3.75 %, and the isolation rate of <em>Salmonella</em> from the production environment of the hatchery workshop decreased from 10.1 % to 0.9 %. Moreover, notable improvements were observed in production metrics. Overall, our established risk assessment model is suitable for environments with low <em>Salmonella</em> isolation rates and can effectively facilitate the prevention and control of <em>Salmonella</em> in poultry farms.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111202"},"PeriodicalIF":5.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851587","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}
Fermented food matrices with probiotic cultures capable to enrich the content of riboflavin in the final product, and capable to deliver metabolically active strains, is an appealing alternative to prevent the issues associated with this vitamin deficiency. In this work two riboflavin-overproducing B. longum subsp. infantis strains, IPLA60015 and IPLA60012, were investigated for the elaboration of fermented drinks based on dairy and almond drink matrices. Dairy fermented products showed the highest riboflavin concentrations upon one month of refrigerated storage. The concentration of vitamin in milks fermented with a single riboflavin overproducing bifidobacterial culture, was higher than that obtained in co-culture with several yogurt starters, or that present in commercial yogurts. Besides, following simulated in vitro digestion of the biofortified products, between 59.8 and 84.6 % of the riboflavin present in the fermented foods were detected, the highest recovery occurring in the fermented dairy matrix fermented with strain IPLA60012. These results set the ground to facilitate the incorporation of novel riboflavin producing bifidobacterial cultures into fermented matrices.
{"title":"Biofortification of fermented foods with riboflavin-overproducing Bifidobacterium longum subsp. infantis strains","authors":"Héctor Tamés , Isabel Cuesta , Lorena Ruiz , Patricia Ruas-Madiedo","doi":"10.1016/j.ijfoodmicro.2025.111210","DOIUrl":"10.1016/j.ijfoodmicro.2025.111210","url":null,"abstract":"<div><div>Fermented food matrices with probiotic cultures capable to enrich the content of riboflavin in the final product, and capable to deliver metabolically active strains, is an appealing alternative to prevent the issues associated with this vitamin deficiency. In this work two riboflavin-overproducing <em>B. longum</em> subsp. <em>infantis</em> strains, IPLA60015 and IPLA60012, were investigated for the elaboration of fermented drinks based on dairy and almond drink matrices. Dairy fermented products showed the highest riboflavin concentrations upon one month of refrigerated storage. The concentration of vitamin in milks fermented with a single riboflavin overproducing bifidobacterial culture, was higher than that obtained in co-culture with several yogurt starters, or that present in commercial yogurts. Besides, following simulated <em>in vitro</em> digestion of the biofortified products, between 59.8 and 84.6 % of the riboflavin present in the fermented foods were detected, the highest recovery occurring in the fermented dairy matrix fermented with strain IPLA60012. These results set the ground to facilitate the incorporation of novel riboflavin producing bifidobacterial cultures into fermented matrices.</div></div>","PeriodicalId":14095,"journal":{"name":"International journal of food microbiology","volume":"436 ","pages":"Article 111210"},"PeriodicalIF":5.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844333","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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