13 Thermophysical properties of meat In chilling, freezing, thawing and tempering processes heat has either to be introduced or to be extracted from the meat to change its temperature The rate at which heat can be removed or introduced into the surface of meat is essentially a function of the process being used, for example air blast, plate, immersion, and so on. However, the rate at which heat can flow from within the meat to its surface is a function of the thermophysical prop- erties of the meat. If we continue to refrigerate meat in the form of car casses, quarters or primals, heat flow within, rather than from, the meat will always limit our ability to achieve rapid uniform rates of temperature We are interested in the thermal conductivity, which governs heat flow, and the specific heat, which is a measure of the amount of heat to be removed. Since the specific heat of meat is not constant with temperature it is often better to use the difference in enthalpy between the tempera tures of interest to provide a value for the energy change required Meat is not a homogeneous product and in a carcass the three main com- ponents- fat, lean muscle and bone- have very different properties. In frozen meat the ice content dominates the thermal properties. The basic structure of this chapter is based on the publications of morley (1972a, 1974). Comprehensive reviews of the thermal properties of food can be found in Morley(1972b), Polley et al.(1980), Miles et aL. (1983)and Rahman(1995). Few publications provide data on enthalpy, heat capacity and thermal conductivity of meat over the total temperature range -40 to +30 C that can be encountered in the refrigeration of meat. Two par- ticular publications that do provide such data are, Tocci et al.(1997)on boneless mutton and Lind (1990)on minced lean meat.13 Thermophysical properties of meat In chilling, freezing, thawing and tempering processes heat has either to be introduced or to be extracted from the meat to change its temperature. The rate at which heat can be removed or introduced into the surface of meat is essentially a function of the process being used, for example air blast, plate, immersion, and so on. However, the rate at which heat can flow from within the meat to its surface is a function of the thermophysical prop￾erties of the meat. If we continue to refrigerate meat in the form of car￾casses, quarters or primals, heat flow within, rather than from, the meat will always limit our ability to achieve rapid uniform rates of temperature change. We are interested in the thermal conductivity, which governs heat flow, and the specific heat, which is a measure of the amount of heat to be removed. Since the specific heat of meat is not constant with temperature it is often better to use the difference in enthalpy between the tempera￾tures of interest to provide a value for the energy change required. Meat is not a homogeneous product and in a carcass the three main com￾ponents – fat, lean muscle and bone – have very different properties. In frozen meat the ice content dominates the thermal properties. The basic structure of this chapter is based on the publications of Morley (1972a, 1974). Comprehensive reviews of the thermal properties of food can be found in Morley (1972b), Polley et al. (1980), Miles et al. (1983) and Rahman (1995). Few publications provide data on enthalpy, heat capacity and thermal conductivity of meat over the total temperature range -40 to +30 °C that can be encountered in the refrigeration of meat.Two par￾ticular publications that do provide such data are, Tocci et al. (1997) on boneless mutton and Lind (1990) on minced lean meat