Novel thermal and non-thermal food processing technologies

Consumers’ demand for increased quality characteristics of foods has led to the development of new and less aggressive processing technologies, which allow greater retention of food natural features. Thermal processing operations, such as blanching, pasteurization and sterilization are commonly applied in the food industries in order to attain safety standards of the products. However, these traditional heat-based methods may lead to undesirable sensorial and nutritional changes, such as color degradation, softening of tissues, vitamin losses and development of unpleasant cooked flavors. Aiming at preservation, low temperature processes such as chilling and freezing also inevitably affect quality characteristics. Alternatively, non-thermal methods, or less severe thermal methods, have been replacing traditional processing technologies. They constitute challenging processes aiming at reducing pernicious effects of thermal methods, while preserving quality and nutritional attributes of foods, and yielding safe and less-perishable product with extended shelf-life. This chapter provides an overview of traditional and novel thermal and non-thermal processing technologies such as ohmic and dielectric heating, high pressure processes, ultrasounds, UV-C radiation and ozone based treatments, which reveal promising applications in food industry. The impact of those treatments on food safety aspects from a microbiological point of view and on quality characteristics will be discussed.