Increasing the frequency of microwave sterilization for packaged meals
Destroying microbes in prepackaged meals containing solid and semi-solid food serves as an alternative to conventional retort methods.
Low-acid, high-moisture, shelf-stable, ready-to-eat prepackaged foods are conventionally treated with pressurized steam or high-temperature water at 120°C or higher to inactivate Clostridium botulism spores, stemming their germination and the potential production of a deadly toxin inside the sealed container.
Steam or high-temperature water processes take 30 to 120 minutes to treat the product, depending on the size of the container. However, the prolonged exposure time required with conventional retorting methods causes thermal degradation resulting in a poor-quality product, says Dr. Juming Tang, a professor and distinguished chair of food engineering in the Department of Biological System Engineering at Washington State University (WSU).