The interaction of microwaves with the food molecules creates different volumetric heating effect. This research was aimed to study the influence of food composition type on the microwave heating time in relation to the inactivation of Salmonella enterica serovar Enteritidis and Shiga-toxigenic Escherichia coli (STEC) O157. Different food composition types, i.e. carbohydrate, protein and fats, were inoculated with 106 CFU/mL of bacteria cocktail and microwave heated. Food sampling was performed to enumerate the remaining surviving bacteria. The outcome of the research showed that fat food material had the shortest thermal inactivation time (<50s) compared to carbohydrate and protein food materials due to low specific heat of fat. In addition, S. enterica serovar Enteritidis exhibit a consistent inactivation profile compared to STEC O157. Both foodborne pathogens showed no signs of thermal resistance towards microwave heating as they were fully thermal inactivated at 60s of microwave heating for all food compositions. This study could provide an insight for further studies on the interaction of microwaves with mixture food compositions and other foodborne pathogens microwave heating inactivation profile in relation to microwave heating time.
- Bacterial inactivation
- Food composition
- Microwave heating
- Salmonella enterica serovar Enteritidis
- STEC O157