(554a) Thermophysical Properties of Processed Meat and Poultry Products

Data on thermophysical properties are essential for modeling and evaluation of food processing operations involving heat transfer when safety, quality and energy cost are considered. Thermophysical properties of various meat and poultry emulsions were evaluated at 4 temperatures (20, 40, 60 and 80^oC). Thermal conductivities (0.26 W/mK to 0.48 W/mK) increase linearly with the temperature from 20 until 60oC. From 60-80^oC, it remained stable for most product except the bologna. Curves of thermal conductivities as a function temperatures could roughly be grouped in two categories; products containing meat particles and emulsions. Densities decreased slightly as a function of temperature from 20 to 40^oC. A transition phase was observed from 40 to 60^oC. It was followed by a decrease from 60 to 80^oC. There was a decrease of about 50 kg/m³ between the density of a raw product at room temperature (at maximum 1070 kg/m³) and the product heated to 80^oC (at minimum 970kg/m³) due to the gelation or setting of the structure. After a transition period from 10-30^oC, the heat capacity increased linearly from 30 until 80^oC. Values ranged from 2850-3380 J/kg^oC. Densities and the heat capacities were strongly influenced by the carbohydrate content (i.e. as the carbohydrate content increased the density decreased). The salt proportion negatively affected the thermal conductivity and diffusivity. As the water content increased the thermal conductivity and diffusivity increased. The density, heat capacity, thermal conductivity, and diffusivity were not affected by the salt proportion due to the limited amount incorporated in products.