Thermal resistance of selected strains of Salmonella spp. isolated from eggs and sesame seeds

In this study, we investigated the effect of food matrices on the heat tolerance of Salmonella strains and evaluated the impact of sugar and fat on the heat resistance of these strains. We tested ten strains of Salmonella spp. isolated from eggs and ten from sesame seeds. The conducted research revealed that S. Poona 4193 and S. Oranienburg 4182, isolated from sesame seeds, exhibited the lowest average decimal reduction times (D-values) at 60 °C and 65 °C. Conversely, strains of S. Enteritidis 3927 (eggs), and S. Mbandaka 4297 (sesame seeds), demonstrated the highest D-values. In the next stage we examined the effect of different concentrations of sucrose (5%, 10%, 15%) and sesame oil (10%, 25%, 50%) on the tolerance of Salmonella to high temperatures. We then selected specific concentrations of sucrose and oil in the medium for each strain based on the highest D-value obtained. The 4297 strain exhibited the highest D-value with 5% sucrose and 10% oil, 4193 strains with 10% sucrose and 25% oil, 4182 with 10% sucrose and 10% oil, and 3927 strain with 10% sucrose, and 50% oil. Our studies indicated that the heat resistance of Salmonella is highly dependent on the specific strain.