Quality optimization

Abstract

The process that is delivered to a canned or packaged food not only inactivates the spoilage micro-organisms, but also cooks the product to an acceptable texture. Canned foods, being convenience foods, are thermally processed to such a degree that they only require reheating prior to consumption. The amount of cooking that a product receives depends on its consistency, the thermal processing conditions and the container or package size. For convection-heating products the internal mixing permits a fairly uniform cook for the whole product; however, for conduction-heating products the heating and, consequently, the degree of cooking vary from the outside to the inside of the food. The product nearest the container wall receives the maximum heat treatment and is consequently the most cooked portion of the food. In general this results in overcooking the outer layers, with a consequent loss of overall quality, especially for products in large-diameter cans. These products are generally perceived as being of lower nutritional value than their fresh or chilled counterparts, which has led to a vast amount of both theoretical and practical work in an attempt to reduce processing conditions. (Holdsworth 1985, 2004).