Thermal Conductivity of Several Liquid Foods

The thermal conductivity of eight kinds of liquid foods of total solid content between 10 and 60wt% was measured by a transient heat flow method using twin probes at temperatures ranging from 10 to 50°C. The effects of temperature and total solid content on the thermal conductivity of sample solutions were investigated. The thermal conductivity of the samples could be represented as a function of both tem-perature and total solid content. The observed values were compared with values calculated from the three typical structural models for thermal conductivity, i.e., series, parallel, and random heat transfer models. A new model to predict the thermal conductivity of liquid foods, defined as a combination of parallel and random models, was developed, and the observed data agreed well with the values calculated from the new model.