Application of Non-Thermal Plasma for Milk Sterilization: A Review

Milk is an optimal liquid medium for the growth of microbial contaminants due to the high nutritional content. Therefore, the sterilization process is needed to make the milk save to be consumed as well as to extend the milk’s shelf life by inactivating microorganisms. A non-thermal plasma system has been utilized as a new alternative sterilization method for food products. Non-thermal plasma generates free radicals, reactive oxygen species (ROS), and reactive nitrogen species (RNS) that contribute to bacterial cells inactivation. This review focused on the factors that affect the non-thermal plasma efficacy to microbial inactivation during the development of milk cold sterilization. The plasma effectiveness in inactivating bacteria could be affected by the attributes of plasma treatment time, the applied voltage, working gas and the type of plasma system. The non-thermal plasma system successfully applied to reduce the number of total bacteria in milk and prolong the shelf-life.