Thermal Conductivity of Fresh Lamb Meat, Offals and Fat in the Range -40 to +30�C: Measurements and Correlations

Meat Industry Research Institute of New Zealand (Inc.), PO Box 617, Hamilton, New Zealand
Journal of Food Science (Impact Factor: 1.7). 06/2008; 54(3):508 - 515. DOI: 10.1111/j.1365-2621.1989.tb04639.x


The thermal conductivity of fresh lamb meat, offals and fat was measured over the temperature range -40°C to +30°C using a guarded hot plate apparatus. Simple empirical equations were presented for the conductivity of high-moisture (65 to 80%) meat and offals. With independently obtained values of physical parameters, several theoretical models were tested to sec if thermal conductivity could be calculated from composition and temperature. Over a wide range of compositions and temperatures, best predictions (in terms of mean, standard deviation and range of errors) were obtained with Levy's modification to the Maxwell-Eucken equation. Its accuracy was not unduly sensitive to the uncertainties in the values of the physical parameters, the prediction errors remaining in the range ± 10% for all reasonable values of the latter.

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    • "and extended to the negative temperatures. The water activity was measured and modelled by a GAB l of Levy was used for the thermal conductivity due to its suitability in the low temperature ranges (Pham and Willic, 1989). The bound water (X b = 0.14) was calculated from the curves obtained by DSC (Differential Scanning Calorimetry) and the initial freezing temperature ( determined thanks to experiments. "
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    • "Fig. 3 shows that, since k water /k solids is relatively low, the choice of effective thermal conductivity model is not critical for Class I foods. Pham and Willix (1989) performed measurements on the effective thermal conductivity of meat, fat and offal between À40 °C and +30 °C, and compared the results to the predictions of six of the effective thermal conductivity models plotted in Fig. 1. They found that for the unfrozen materials (Class I foods) any of the six models provided satisfactory predictions, consistent with the previous discussion. "
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    • "The model considers the Protein, Fat and Ash content, as a function of the thermal conductivity. Spells [22] model was considered by Pham [23] to obtain the conductivity of various kinds of meat. Comini et al. and Spells models deemed only the moisture content as the main parameter, which influenced the thermal conductivity. "
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