Syneresis rate of cow's, ewe's, and goat's curd. Effect of thermal treatment and ultrafiltration.

The influences of ultrafiltration (UF), the intensity of heat treatment (70 degrees C for 5 or 30 min) applied to milk prior to UF processing, and species on the syneresis rate of curd from cow's, ewe's, and goat's milk were analyzed. The influence of the species was significant (P < 0.05) in the syneresis rate. The syneresis rate depended significantly on the intensity of the heat treatment applied before UF and the degree of concentration; these two parameters showed significant (P < 0.05) differences in the syneresis rate depending on the species studied. These results could indicate a possible difference in the structure of the curd formed. The differences in the curd structure could be due to the different relative composition of the retentates of the different species as well as the possible effect of the UF process on the physicochemical composition of milk.