Effect of storage at 4 degrees C on the physicochemical and renneting properties of milk: a comparison of caprine, ovine and bovine milks.

The effects of cold storage at 4 degrees C for 12, 24 and 48 h on the physicochemical characteristics and renneting properties of ewes', goats' and cows' milks were compared. The most important changes were observed in cows' milk. Soluble calcium concentrations were not affected in ewes' milk but were increased by 10% in cows' milk and 7% in goats' milk. More casein was dissociated on cooling cows' (+300%) than goats' (+100%) milk, and there was no change in soluble casein in ewes' milk. The coagulation characteristics of cows' milk were more impaired by cold storage than goats' or ewes' milks. Coagulation times increased by approximately 30% and whey draining capacity decreased by 40% after cows' milk was cooled, but there were no changes with ewes' milk and only a slight decrease in coagulation time with goats' milk. We propose an interpretation of these results based on the physicochemical properties of each type of milk.