Responses of E. coli O157:H7, L. monocytogenes 1/2 c and Salmonella enteritidis to pH, aw and temperature stress combinations

This study compared the responses of Escherichia coli O157:H7, Listeria monocytogenes 1/2 c and Salmonella enteritidis toward different combinations of physicochemical stresses (pH: 3–8; aw: 0.93–0.99; temperature: 3–62 °C). Results showed that L. monocytogenes generally had lower inactivation rates and was able to exhibit growth in most number of tested combinations, including those with very high and very low factor settings. Temperature introduced the greatest variation in the measured growth and death parameters but the contributions of both pH and aw in all temperature ranges were also noted. The results of this study may be applied in the selection of appropriate pathogens in the evaluation of safety of foods that are preserved using individual or combined physicochemical factor control.