engleski

Thermophysical properties of frozen dairy desserts

The knowledge of thermophysical properties of food, especially the temperatures of phase transitions, is necessary for defining the freezing process parameters as well as storage conditions of frozen food. In this work the investigations were carried out with several dairy desserts prepared by mixing and cooking of whey proteins, sugar, eggs, flour and several types of carboxymethilcelulose. Desserts were frozen quickly as well as slowly. Their thermophysical properties were determined before freezing and after 90 days of storage at -10 şC and -20 şC. The temperatures of phase transitions were determined by differential thermal analysis (DTA), while the specific heat and enthalpy were calculated by the application of several mathematical equations. The results have shown that thermophysical properties of investigated food depend, as on the mass fraction of solid matter, so on its composition. It was mentioned that the kind of hydrocolloid, freezing process and storage conditions of frozen desserts has a significant influence on their thermophysical properties.

Thermophisical properties; dairy deserts

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