{"title":"微生物特征和模拟大肠杆菌ATCC 25922在Amlou中的生存:一种传统的摩洛哥涂抹食物","authors":"Youssef Ezzaky , Mariem Zanzan , Fouad Achemchem , Antonio Valero , Fatima Hamadi","doi":"10.1016/j.mran.2022.100216","DOIUrl":null,"url":null,"abstract":"<div><p>This study was carried out to assess the bacteriological profile and to model the combined effects of physicochemical parameters on <em>Escherichia coli</em> ATCC 25922 levels in <em>Amlou</em>, a typical Moroccan traditional spread food made with argan oil, sweet almonds, and honey or sugar. Microbiological analyses of the samples (<em>n</em><span><span> = 44), collected from different traditional producers, included total viable count (TVC), total </span>coliforms (TC), fecal coliforms (FC), </span><em>E. coli,</em><span> lactic acid bacteria (LAB), yeasts and molds (YM), </span><span><em>Staphylococcus aureus</em><span><em>, Salmonella, and </em><em>Listeria</em></span></span> spp<em>.</em> The results showed that 61% of samples met the Moroccan hygiene standards for vegetable paste spreads, with contamination levels of 4.21, 2.94, 2.38, 1.87, and 1.50 log cfu/g for TVC, YM, TC, FC, and <em>E. coli</em>, respectively. <em>S. aureus</em> was detected in 6.82% of <em>Amlou</em> samples, while <em>Salmonella</em> and <em>Listeria</em> spp. were not detected in any of the analyzed samples. On the other hand, the effects of water activity (a<sub>w</sub><span>) (0.44, 0.50, 0.53), temperature (23, 30 °C), and pH (5.5, 6.5) on the kinetics parameters, inactivation rate (IR, log cfu/g/d), and shoulder period (SP, d) of </span><em>E. coli</em> ATCC 25922, were investigated. The survival curves generated under different conditions were fitted using the Baranyi model. Secondary modeling for the combined effects of a<sub>w</sub>, temperature, and pH on the survival parameters was carried out using a polynomial equation. Finally, the goodness of fit was assessed for the survival kinetics of <em>E. coli</em>. Root mean square error (RMSE) and standard error of prediction (%SEP) obtained were 0.20 and 10.22% for IR and 0.24 and 40.01% for SP. These models can provide an estimate of <em>E. coli</em> inactivation in <em>Amlou</em>. Further studies should consider other factors such as argan oil concentration and amount of protein before being applied to ensure food safety for <em>E. coli</em> control in <em>Amlou</em>.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":null,"pages":null},"PeriodicalIF":3.0000,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Microbiological profile and modeling the survival of Escherichia coli ATCC 25922 in Amlou: A traditional Moroccan spread food\",\"authors\":\"Youssef Ezzaky , Mariem Zanzan , Fouad Achemchem , Antonio Valero , Fatima Hamadi\",\"doi\":\"10.1016/j.mran.2022.100216\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>This study was carried out to assess the bacteriological profile and to model the combined effects of physicochemical parameters on <em>Escherichia coli</em> ATCC 25922 levels in <em>Amlou</em>, a typical Moroccan traditional spread food made with argan oil, sweet almonds, and honey or sugar. Microbiological analyses of the samples (<em>n</em><span><span> = 44), collected from different traditional producers, included total viable count (TVC), total </span>coliforms (TC), fecal coliforms (FC), </span><em>E. coli,</em><span> lactic acid bacteria (LAB), yeasts and molds (YM), </span><span><em>Staphylococcus aureus</em><span><em>, Salmonella, and </em><em>Listeria</em></span></span> spp<em>.</em> The results showed that 61% of samples met the Moroccan hygiene standards for vegetable paste spreads, with contamination levels of 4.21, 2.94, 2.38, 1.87, and 1.50 log cfu/g for TVC, YM, TC, FC, and <em>E. coli</em>, respectively. <em>S. aureus</em> was detected in 6.82% of <em>Amlou</em> samples, while <em>Salmonella</em> and <em>Listeria</em> spp. were not detected in any of the analyzed samples. On the other hand, the effects of water activity (a<sub>w</sub><span>) (0.44, 0.50, 0.53), temperature (23, 30 °C), and pH (5.5, 6.5) on the kinetics parameters, inactivation rate (IR, log cfu/g/d), and shoulder period (SP, d) of </span><em>E. coli</em> ATCC 25922, were investigated. The survival curves generated under different conditions were fitted using the Baranyi model. Secondary modeling for the combined effects of a<sub>w</sub>, temperature, and pH on the survival parameters was carried out using a polynomial equation. Finally, the goodness of fit was assessed for the survival kinetics of <em>E. coli</em>. Root mean square error (RMSE) and standard error of prediction (%SEP) obtained were 0.20 and 10.22% for IR and 0.24 and 40.01% for SP. These models can provide an estimate of <em>E. coli</em> inactivation in <em>Amlou</em>. Further studies should consider other factors such as argan oil concentration and amount of protein before being applied to ensure food safety for <em>E. coli</em> control in <em>Amlou</em>.</p></div>\",\"PeriodicalId\":48593,\"journal\":{\"name\":\"Microbial Risk Analysis\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.0000,\"publicationDate\":\"2022-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microbial Risk Analysis\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2352352222000160\",\"RegionNum\":4,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microbial Risk Analysis","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352352222000160","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Microbiological profile and modeling the survival of Escherichia coli ATCC 25922 in Amlou: A traditional Moroccan spread food
This study was carried out to assess the bacteriological profile and to model the combined effects of physicochemical parameters on Escherichia coli ATCC 25922 levels in Amlou, a typical Moroccan traditional spread food made with argan oil, sweet almonds, and honey or sugar. Microbiological analyses of the samples (n = 44), collected from different traditional producers, included total viable count (TVC), total coliforms (TC), fecal coliforms (FC), E. coli, lactic acid bacteria (LAB), yeasts and molds (YM), Staphylococcus aureus, Salmonella, and Listeria spp. The results showed that 61% of samples met the Moroccan hygiene standards for vegetable paste spreads, with contamination levels of 4.21, 2.94, 2.38, 1.87, and 1.50 log cfu/g for TVC, YM, TC, FC, and E. coli, respectively. S. aureus was detected in 6.82% of Amlou samples, while Salmonella and Listeria spp. were not detected in any of the analyzed samples. On the other hand, the effects of water activity (aw) (0.44, 0.50, 0.53), temperature (23, 30 °C), and pH (5.5, 6.5) on the kinetics parameters, inactivation rate (IR, log cfu/g/d), and shoulder period (SP, d) of E. coli ATCC 25922, were investigated. The survival curves generated under different conditions were fitted using the Baranyi model. Secondary modeling for the combined effects of aw, temperature, and pH on the survival parameters was carried out using a polynomial equation. Finally, the goodness of fit was assessed for the survival kinetics of E. coli. Root mean square error (RMSE) and standard error of prediction (%SEP) obtained were 0.20 and 10.22% for IR and 0.24 and 40.01% for SP. These models can provide an estimate of E. coli inactivation in Amlou. Further studies should consider other factors such as argan oil concentration and amount of protein before being applied to ensure food safety for E. coli control in Amlou.
期刊介绍:
The journal Microbial Risk Analysis accepts articles dealing with the study of risk analysis applied to microbial hazards. Manuscripts should at least cover any of the components of risk assessment (risk characterization, exposure assessment, etc.), risk management and/or risk communication in any microbiology field (clinical, environmental, food, veterinary, etc.). This journal also accepts article dealing with predictive microbiology, quantitative microbial ecology, mathematical modeling, risk studies applied to microbial ecology, quantitative microbiology for epidemiological studies, statistical methods applied to microbiology, and laws and regulatory policies aimed at lessening the risk of microbial hazards. Work focusing on risk studies of viruses, parasites, microbial toxins, antimicrobial resistant organisms, genetically modified organisms (GMOs), and recombinant DNA products are also acceptable.