The objectives of this project are to develop expressions for the thermal properties of protein, fat, and carbohydrate food components during freezing. These food components are considered to be the building blocks of food materials. The specific objectives are to: 1) to identify standard materials for use in food freezing studies which represent the basic food components; 2) to construct phase diagrams for these materials; 3) to develop relationships between temperature and unfrozen moisture content for each test material; and, 4) to develop thermal property relationships for these materials during freezing. The first task is to identify protein, fat, and carbohydrate based test materials which represent the basic components of foods. Then, phase diagrams will be formulated from phase transition temperatures determined for different concentrations of these materials from differential scanning calorimetry experiments. The expressions for the thermal properties will be based on thermodynamic relationships between temperature and moisture content formulated from these phase diagrams. The building block concept represents a novel approach to the investigation of the freezing process, and it has great future potential for the expanded practical use of mathematical food freezing models which require knowledge of the thermal properties. First of all, use of this concept eliminates the need for freezing point depression data to be available for different food products, and secondly, it could result in simplified thermal property relationships which would facilitate the use of complex multi-dimensional freezing models.
