The invention uses rapid heating to effect a material property change in a biomaterial. The biomaterial is heated to a predetermined real temperature, whereas the biomaterial's total thermal treatment is described by an equivalent temperature and an equivalent time defining a point above a minimum gel set temperature line, above a reduction in bacteria line, below a water loss line, and below a maximum gel set temperature line. According to one aspect of the invention, the biomaterial is heated by exposing the biomaterial to a relatively uniform electric field. The material is heated to a predetermined temperature for a predetermined time in order to achieve a food product characterized by a preselected refrigerated shelf life of from about two weeks to about forty-two weeks. The food product may be packaged prior to the microwave exposure so as to sterilize the packaging and decrease product loss. According to another aspect of the invention, the material is heated to a predetermined real temperature T.sub.1 from time A to time B and a real temperature T.sub.2 from time B to time C. According to another aspect of the invention, the material is heated to a predetermined real temperature from time A to time B to attain a material property at shear stress level S.sub.1 and heated to a predetermined real temperature from time B to time C to attain at least one additional material property at shear stress level S.sub.2. According to another aspect of the invention, the material is moved at a predetermined rate R.sub.1 from time A to time B and a predetermined rate R.sub.2 from time B to time C. The material is preferably stationary (i.e. R.sub.2=0) from time B to time C. According to another aspect of the invention, multiple microwave cavities are used to effect the material property change in the biomaterial. The material is passed through a second microwave cavity that is sequentially arranged or concurrently arranged with the first microwave cavity.