conventional food treatment processes utilized for food preservation generally involve heat treatment and usually result in some degree of thermal damage . a process has been developed for the non - thermal treatment of liquid food products which results in a significant reduction in the microbial population , thus reducing spoilage and extending shelf life . the novel process involves the rapid application of electromagnetic energy , such as microwave or radio frequency energy , and the simultaneous removal of any thermal energy which may be generated by the process through the use of circulating cooling medium and an efficient heat exchanger .