Effect of freezing storage on the stability of fat emulsion and proteins in cow's buffalo's, and goat's milks [Egypt]

Cow's, buffalo's, and goat's milk were pasteurized then stored frozen at - 10 C for 10 days. The effect of pasteurization and freezing storage on the stability of fat emulsion and protein systems was studied. Fat emulsion in goat's milk was more stable against pasteurization and freezing than that of cow milk, while that of buffalo's milk had a lower stability. On the other hand, protein stability was lower in goat's milk than in the buffalo's one. Cow's milk was the most stable of them all. This conclusion was based on the ru informant data of buffering capacity equally to of buffering range in all milks. Freezing was more effective on buffering capacity than pasteurization. Freezing storage altered the normal ratio of soluble Ca in all milks and Mg in cow's and goats milks. Soluble Mg was slightly increased in buffalo's milk differing in behaviour from both cow's and goat's milks in which soluble Mg content was obviously decreased by freezing. Freezing had an adverse effect on the clotting ability of casein by rennet. Clotting time was doubled after freezing storage of pasteurized milk. Alcohol stability showed that cow's milk proteins were highly stable, while goats milk proteins were the most sensitive