Thermal conductivity of food materials at elevated temperatures

In order to expand the available information on thermal conductivity of foods, within the framework of COST Action 93, a collaborative study was organised. In the first step, typical food components (apple pulp, meat, olive oil, sodium caseinate, starch, tomato paste) were used as standards for measurements, and in the second step, standardised glass beads were used for calibration experiments. The results have demonstrated that it is rather difficult to come up with reliable accurate information. Problems are to some extent related to the measuring procedures, in particular the variability in contact between heat source and test material and/or contact between test material and thermal sensors. Further problems arise for products which are not stable throughout the duration of the experiment.