Modelling the Survival of Acid-Adapted and Nonadapted Escherichia coli O157:H7 in Burkina: A Western African Traditional Fermented Milk Product

Leticia Donkor; Nicole Sharon Affrifah; Angela Parry-Hanson Kunadu; Samuel Kwofie; Stephen Yeboah; Bernard Kuditchar

doi:10.1155/2023/1011319

Modelling the Survival of Acid-Adapted and Nonadapted Escherichia coli O157:H7 in Burkina: A Western African Traditional Fermented Milk Product

Int J Food Sci. 2023 Nov 20:2023:1011319. doi: 10.1155/2023/1011319. eCollection 2023.

Authors

Leticia Donkor¹, Nicole Sharon Affrifah¹, Angela Parry-Hanson Kunadu², Samuel Kwofie³, Stephen Yeboah², Bernard Kuditchar⁴

Affiliations

¹ Department of Food Process Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, P. O. Box LG 77, Legon, Accra, Ghana.
² Department of Nutrition and Food Science, College of Basic and Applied Sciences, University of Ghana, P. O. Box LG 134, Legon, Accra, Ghana.
³ Department of Biomedical Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, PMB, Legon, Accra, Ghana.
⁴ Department of Computer Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, P. O. Box LG 1181, Legon, Accra, Ghana.

Abstract

Burkina, a traditional fermented dairy product, is consumed in most parts of West Africa, including Ghana. Studies on the microflora of Burkina have indicated the presence of Escherichia coli and other pathogenic organisms. Thus, predicting the survival of E. coli in the product will inform the best manufacturing and handling practices. This study investigated the combined effect of storage temperature and time on the survival of acid-adapted and acid-non-adapted E. coli O157:H7 in Burkina. Samples were pasteurised and inoculated with acid-adapted or acid-non-adapted E. coli O157:H7. They were stored at 5, 15, and 30°C for 0, 2, 4, 6, 8, 10, 12, 14, 18, and 48 h, and the bacteria colonies were enumerated. Growth rate (survival versus time) models were developed using MATLAB software. Observed data were fitted to the Baranyi model using the DMFit curve fitting software. The E. coli O157:H7 strain appeared inherently tolerant to acid, with storage time having the most significant effect on the response parameter, survival (log CFU/mL). A negative correlation was observed for the primary models (survival versus time), which accounted for 79-97% of the relationship (p < 0.05). Although E. coli survived, its growth was inhibited over time regardless of acid adaptation.