ABSTRACT
Using heating to reduce the bacterial level of foods is widespread [1]. Thermal processing aims to reduce contamination so that the food will not cause a health hazard during its shelf life. The classical method of thermal preservation is canning, in which food is placed in the package, which is then sealed and sterilized. Each part of the material must be processed to a level prescribed to ensure product safety. Heat transfer to cans is slow, however. The commonest method of providing heat is the use of condensing steam. Heat must then be transferred within the can, either by thermal conduction (if the food is a solid or a very viscous liquid) or by convection if the food is a less viscous liquid. This can lead to overcooking of some or all of the material. As a result, canned food has a taste and texture significantly different than unprocessed foods.
