CHICAGO – A new study from the Journal of Food Science shows that microwave reheating of hotdogs for 75 seconds at high power may decrease risks from pathogens that cause foodborne illness.
Most studies on the effectiveness of microwave oven heating of foods and its control of pathogens have been based solely on heating frozen meals and cooking meat, chicken or fish. With regard to chilled leftovers and ready-to-eat meats, such as frankfurters and deli meats, limited or no information is available about the effectiveness of microwave ovens increasing microbial safety.
Researchers evaluated different power and time combinations of microwave oven heating for inactivation of Listeria monocytogenes on inoculated and stored frankfurters. The frankfurters were formulated with and without antimicrobials, inoculated with Listeria monocytogene and stored under different conditions. The findings are as follows:
- The highest reductions of Listeria monocytogenes contamination were obtained when frankfurters were reheated at high power for 75 seconds. Standing time after treatment may also play a role in obtaining a more uniform distribution of heat, by conduction, after the microwave power is off and can improve microbial destruction in food.
- Frankfurters that were formulated with antimicrobials, which inhibited growth of the pathogen during product storage, displayed a decrease in Listeria monocytogenes counts after microwave treatments at high power for 60-75 seconds, regardless of storage time or packaging condition.
- Frankfurters that were formulated without antimicrobials and in which counts of Listeria monocytogenes steadily increased during product storage, treatments of medium power for 60 or 75 seconds and high power for 30 or 45 seconds were consistently ineffective in decreasing pathogen numbers. The effectiveness of the 75 second-high power treatment depended on the contamination level of the pathogen on the frankfurters, which in turn, was related to the length of product storage and packaging condition.
