Newswise — A new study from the Journal of Food Science, published by the Institute of Food Technologists, shows that microwave reheating of hotdogs for 75 seconds at high power may decrease risks from pathogens that cause foodborne illness.
Because of their speed and convenience, microwave ovens are commonly used to cook and reheat food; however, these appliances often provide non-uniform heating, which may produce hot and cold spots within food products being heated. The uneven distribution of heat could lead to the survival of pathogens in contaminated food cooked in microwave ovens.
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
“Microwave oven reheating instructions must be designed specifically for each type of product and consider variations in microwave appliance power, amount of food to be reheated, age of the product and the presence of antimicrobial compounds in the formulation of the food,” says Colorado State University researcher and IFT member expert Patricia Kendall.
To receive a copy of the study, please contact Jeannie Houchins at firstname.lastname@example.org.
The Institute of Food Technologists (IFT) exists to advance the science of food. Our long-range vision is to ensure a safe and abundant food supply contributing to healthier people everywhere. Founded in 1939, IFT is a nonprofit scientific society with 20,000 individual members working in food science, food technology, and related professions in industry, academia, and government. IFT champions the use of sound science across the food value chain through knowledge sharing, education, and advocacy, encouraging the exchange of information, providing both formal and informal educational opportunities, and furthering the advancement of the profession. IFT has offices in Chicago, Illinois, and Washington, D.C. For additional information, please visit ift.org