Since food is generally of low thermal conductivity, heating by conventional methods remains relatively slow. Thanks to its volumetric and rapid heating, microwave (MW) technology is successfully used in many applications of food processing. In this chapter, fundamental principles of MW heating are briefly presented. MW drying and MW microbial decontamination are extensively reviewed as innovative methods for food preservation. However, the complex interactions between microwaves and materials to be heated are not yet sufficiently controlled. Moreover, MW heating heterogeneity and thermal runaway are the main drawbacks of this technology. Several methods have been proposed and investigated in the literature to overcome these problems in order to assure the microbiological safety and quality of food products.
Part of the book: Food Preservation and Waste Exploitation
Alternative to conventional processes, many innovative techniques have been studied to preserve the nutritional quality and to protect food from deterioration. This chapter represents the principles and the applications of the instant controlled pressure drop (DIC) process in food drying and decontamination. This process is considered as a highly appropriate HTST-type treatment induced by subjecting the material to saturated steam, during a short time, followed by an instant pressure drop leading to auto evaporation of water, product texturing, and cooling. This effect results in improved drying of foods and in killing of the vegetative bacteria and/or spores with no impact on thermosensitive molecules or on the product quality. A wide range of foods and pharmaceutical products were effectively treated by DIC technology at both laboratory and industrial scales.
Part of the book: Food Preservation and Waste Exploitation