Inactivation of Salmonella during microwave cooking.

Sixty meat loaves were experimentally infected with a strain of Salmonella serovar mbandaka to give approximately 10(7) cells/g. Thirty contaminated loaves were cooked in a microwave oven for 4 min, and 30 other samples for 3 min 30 s, both followed by a standing time of 2 min. No viable experimental contaminants were recovered from both core and surface samples of the 30 loaves cooked for 4 min. Loaves cooked for the short time were often Salmonella positive. These results point out that infection hazard linked to microwave cooked food can be avoided by following adequate procedures concerning exposure time, temperature and post-heating holding time. A standardization of microwave ovens for domestic use is desirable, making it easier to give users correct instructions based on careful and strict experimentations approved by Public Health Authorities.