Water unfreezable

Fig. 1.51. Unfreezable water (UFW) in a 0.57 % ovalbumin solution as a function of the freezing temperature with different CPAs (Fig. 4. from [1.36]).

Table 1.13 Tg data, related UFW (unfreezable water, %) 7 and Tc data (7T- and UFW data from [3.6] Tr and Tc data from [1.113]).

Duckworth, R. B. Differential thermal analysis of frozen food systems. I. The determination of unfreezable water. Joum. Food Technol. 6, p. 317-327, 1971... 

As shown in the following table (from [3.6]) the selection of the excipient also defines Tg- and the amount of unfreezable water (UFW) in the glass phase. 

The unfreezable water may have more than a theoretical meaning. Adding more water than the total of the unfreezable to biopolymers, small amounts of freezable water are observed but the freezing point is reduced (see Figs. 16 and 20 in 181 ). So in fish (cod) muscle water freezes at —10 °C 208. Feeney has found a special anti-... 

Table 1.1.1 shows the unfreezable water (UFW) in various foods. The reasons and the consequences are described in Sections 1.1.3 and 1.1.4. In comparing these data with other publications, e.g. [1.3], smaller values may be found. This can depend not only on the different raw materials and the history of the probe until measurement, but also on the methods of measurement. 

The amount of unfreezable water, based on protein content, appears to vary only slightly from one food to another. About 8 to 10 percent of the total water in animal tissue is unavailable for ice formation (Meryman 1966). Egg white, egg yolk, meat, and fish all contain approximately 0.4 g of unfreezable water per g of dry protein. This corre-... 

Table 2 Glass Transition Temperatures (Tg-) and Content of Unfreezable Water (UFW) of Some Excipients at Glass Temperatures 4]...

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