One dimensional models for the microwave heating of moist foodstuffs

Microwave ovens are frequently used in domestic situations for the heating of chilled foodstuffs which are generally approximately 80% by weight water. Rapid, internal heating are some of the key benefits over conventional ovens. The food industry utilises these attributes in a number of ways most in particular with the introduction of microwave ready meals and convenience food. It is important that the food properly heated to ensure that is is micro-biologically safe for consumption. One of the principle modes of heating in microwave cooking is through dipole orientation. In the case of foodstuffs there is a large concentration of polar water molecules, when exposed to an electromagnetic field these molecules attempt to align themselves with the field. Domestic microwave ovens typically use an EM frequency of 2.45GHz and so the water attempts to line up with a rapidly changing field. Internal reflections within the oven cavity can lead to standing wave patterns forming in the EM field, and these troughs in the field can lead to so called ”cold spots” in the food. It is in these regions of low temperature that harmful organisms can propagate and survive.