Calculation of Heat Capacity in Meat During Its Freezing Considering Phase Change

Abstract

As a consequence of insufficient study of water phase change in meat accompanied by water crystallization, its modeling is currently based on the empirical dependence of the frozen water portion on temperature. Such model does not allow answering a number of questions such as of metrological order, and also of physicochemical interpretation of processes occurring in meat during water crystallization. In this paper, we propose an approach to modeling the phase change process of meat during its freezing on the basis of the phonon theory of Debye crystallization, which allows to obtain physically justified dependences of heat capacity on temperature in the phase change region. The obtained dependences may serve as a simple method for calculating the heat capacity of meat in the temperature range of 113 K to the cryoscopic temperature of the given meat type, or as a basis for the analysis and correction of factors affecting the meat freezing in the temperature range of the phase change.

A calculation model for the heat capacity of beef with different moisture during freezing taking into account free water crystallization

“…The development of a model for free water crystallization in beef is based in this study on the publication [19], in which the authors (being also the authors of the present paper) showed the possibility to use the Debye concept by the example of NOR beef. The dependence has the following form:…”

“…The most important characteristic of the crystallization process is the cryoscopic temperature Т kr . Methods for measuring this parameter are given in [15,19]. For beef, the temperature, when free water is finally frozen out, is 243 ±0.25 К (-30.15 ±0.25 °C), which corresponds to the end of free water phase transition in beef.…”

“…For beef, the temperature, when free water is finally frozen out, is 243 ±0.25 К (-30.15 ±0.25 °C), which corresponds to the end of free water phase transition in beef. The above mentioned paper [19] presents dependence (2) by the results of the experimental study of a decrease in heat capacity of a frozen sample lower than the temperature of the end of phase transition. с fr.b.…”

“…The method of heat capacity determination proposed in the work [19] in correspondence with the concept of heat capacity by Debye can be used for analysis of the association of obtained dependency (1) parameters with indicators of the freezing regime and different meat initial moisture.…”

“…The studies appeared that noticed the significance of the effect of physico-chemical processes occurred in meat in a range of the subcryoscopic temperatures (T kr ± 0.5 К) on its consumer properties [18]. For such investigations of meat refrigeration in a narrow range of the subcryoscopic temperatures, higher frequency of temperature measurement using the DSC method is necessary [16,17,19].The use of the differential scanning calorimetry method allows minimizing discreteness for specific heat capacity calculation. Dependence of beef specific heat capacity measured using a low-temperature adiabatic vacuum calorimeter [8] Specific heat capacity kJ/kg⋅K Temperature, K At present, however, there is no method that enables predicting the character of meat heat capacity dependence on a temperature in a range of the phase transition temperatures.…”