Browsing by Author "Cullwick, Thomas David Cartwright"

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    Freezing rate studies in blocks of meat of simple shape : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, New Zealand
    (Massey University, 1967) Cullwick, Thomas David Cartwright
    In view of the large quantities of foodstuff now being preserved in the frozen state, it is important to be able to predict the freezing time of a product under specified freezing conditions. An accurate knowledge of the freezing time of a product permits a precise termination to be made to the freezing process and the subsequent improvement possible in plant utilization is significant when large quantities of foodstuff have to be frozen in a given freezing plant. The freezing rate of a foodstuff must be high enough to prevent loss of quality as a result of microbiological and enzymic changes, but a loss of quality may still occur as a result of the nature of ice crystal formation during freezing. Mazur (27) proposed a quantitative relationship between the size and location of the ice crystals and the freezing rate and he considered that high freezing rates gave a high product quality. With these factors in mind the freezing rates obtained during the freezing of a product under different conditions were determined. The freezing times and freezing rates of a product can be found by experiment. This involves making temperature measurements with suitably located thermocouples, and the product is frozen when a specified centre temperature is reached. To eliminate the necessity for making experimental studies it is desirable to develop a calculation method which will accurately predict the freezing rate and freezing time of a product. [From Introduction]