Correlating Traditional Transient Plane Source Thermal Conductivity Testing Results in Monitoring the Fat Content of Milk with Modified Transient Plane Source Technique Results

摘要

The thermal conductivity measurement in the food industry provides insight into the heat transfer properties of foods - important in the design of processing and preservation equipment. In the processing of dairy products the material is heated and cooled. In order to understand accurately the rate and amount of heat involved it is necessary to value the thermal properties of the material. The thermal conductivity of the material is impacted by a number of factors including the density, particle size, composition, etc. The application of thermal conductivity data contributes to refinements in food processing techniques, equipment and optimization of processing conditions, resulting in improved quality and safety of foods. This study applies the modified transient plane source technique to measure the thermal conductivity of milk products, in an effort to confirm the validity of this technique to distinguish between the fat content of different milk products. The thermal conductivity of milk products with fat contents of 0%, 1%, 2% and 3.25% were tested using C-Therm's TCi Thermal Conductivity Analyzer employing the modified transient plane source (MTPS) technique for thermal conductivity measurement and the results compared with previously published data by M. Gustaffson and S. Gustaffson. The data confirms a strong linear correlation between thermal conductivity and fat content and correlates well with results previously published in measuring similar milk samples with the traditional transient plane source (TPS) technique.