CALCULATION OF INITIAL FREEZING-POINT, EFFECTIVE MOLECULAR-WEIGHT ANDUNFREEZABLE WATER OF FOOD MATERIALS FROM COMPOSITION AND THERMAL-CONDUCTIVITY DATA

A procedure was developed for simultaneous determination of the effect ive molecular weight, unfreezable water, and initial freezing point of foods based on composition and thermal conductivity data. Freezing pr operties were determined by trial and error and optimized by minimizin g the difference between calculated and reported values of thermal con ductivity. The procedure involved determination of the ice fraction at several temperature levels. Corresponding thermal conductivity values at each temperature level were then calculated. Results showed that c alculated values of effective molecular weight, unfreezable water, and initial freezing point for various types of meat and fish are compara ble to those published. The parallel-perpendicular model was found an excellent predictor of thermal conductivity of frozen meat and fish wi th muscle fibers oriented toward the direction of the heat flow.