Measurement and prediction of thermal properties of food during freezing and thawing. A review with particular reference to meat and dough

A literature review on the mathematical modelling of thermal properties and measuring methods is presented. Some measured values of the thermal properties of three different food products are presented. These are unproven white bread dough, minced lean meat and minced lean meat mixed with lard, starch, salt and spices. The thermal properties of these three products are also calculated and compared with measured properties to check the validity of some of the existing formulas currently used for these product types. The importance of the temperature steps when using stepwise differential scanning calorimetry to measure the specific heat and enthalpies is discussed. The results show that there are formulas available for calculating accurately the apparent specific heat and the enthalpy change of these three very different food products. The calculations of the thermal conductivity, specific heat and ice content did not agree as well with the measured values, especially in the phase transition region. The apparent specific heat measurements showed the importance of selecting small enough temperature steps.