Predictions and measurements of freezing point depressions of foods under high pressure

摘要

To predict the depression of freezing point for food under high pressure, the suitable conditions of pressure and food have been displayed by assuming foods as psuedo-binary systems. The cryoscopic constants of water increased with rising pressure, indicating the value of 2.22 K·(mol/kg){sup}(-1) at 196MPa, about 20% greater than that at atmospheric pressure (1.86K·(mol/kg){sup}(-1)) Freezing point depressions for glucose solutions of 10, 20 and 30% were predicted by using these constants, and compared with observed data. Predicted values coincided with those observed in the all concentrations at atmospheric pressure and 49MPa, and in the concentrations not more than 20% at 98MPa. Freezing point depressions were demonstrated to be able to determine under proposed conditions.