ABSTRACT
The general objective of food processing is to protect and preserve food, to destroy microorganisms, to inactivate enzymes, to destroy inhibitors and toxic substances, to augment digestibility, to maintain or improve organoleptic properties, and to produce more desirable physical functions and aesthetic characteristics. However, the pursuit of the primary effect in processing often results in unwanted secondary effects, the so-called processing damage. The key variables that influence protein quality during processing and that can be controlled in the manufacture of a good product are temperature, moisture content, pH, composition of food product, and composition of gaseous phase. These are essentially household operations that are sometimes also used in the food industry but generally under better-controlled conditions. During the ordinary household cooking of fish and meat, there is no loss of protein quality and no diminution of the essential amino acid content, in spite of some losses in the extractable substances that contain practically no essential amino acids.
