Foods may be considered as mixtures of the following major components: water, protein, fat, carbohydrate and ash (i.e. non-combustible solids such as minerals etc). Some foods may contain a significant volume fraction of ice and/or air (porosity). Temperature is the most critical processing condition in solid and liquid phases although pressure can be significant too e.g. high pressure processing (HPP). The temperature-dependent thermal conductivities of the major food components were measured for by the thermal conductivity model. This study only considers models which are functions of the composition of the food and thermal conductivities of the major food components only, and do not involve any parameters which must be measured experimentally. For first approximations, one of two approaches.