Non-Thermal and Minimal Food Processing Technologies: Principles, Techniques Applications in Modern Preservation

Food processing exists to solve one basic problem: raw food left to itself will spoil. Microorganisms multiply, indigenous enzymes keep on working, chemical reactions like oxidation and browning proceed unchecked, degrading safety, quality and nutritional value. For most of the twentieth century this problem was solved largely by heat. The principle of heating food to a temperature high enough to kill pathogenic and spoilage microorganisms and to inactivate deteriorative enzymes underlies pasteurization, sterilization, blanching, canning and retorting. Thermal processing is a reliable, well-understood and inexpensive process and remains the backbone of the global food supply.Heat, however, is destructive of more than micro-organisms. Vitamin C, thiamine and folate are heat-labile; proteins denature and lose functional properties such as gelling and emulsification; pigments like chlorophyll and anthocyanins degrade; and volatile aroma compounds are lost or changed into cooked, caramelized notes, which are very different from the fresh product.