Effect of heat treatment on the rennet clotting time of goat and cow milk

The effect of heat treatment (70, 80 and 95 degrees C, for 1, 3 and 10 min) on the rennet clotting time (RCT) has been evaluated in cow milk (Bruna It aliana) and in the milks of five goat breeds (Saanen, Camosciata, Ionica, G arganica and Maltese). The RCT of raw cow milk ranked at an intermediate le vel compared to that of raw milk of goat breeds examined. With respect to t he raw milks, the RCTs of cow milk became progressively longer as a functio n of both heating temperature and time, while all the goat milks' RCTs decr eased. Significant (P < 0.05 or < 0.001) decreases have been registered in the RCTs of the Camosciata, Ionica, Garganica and Maltese goat milks even a fter mild heating (to 70 degrees C for 1 min), while significant (P < 0.05) variations have been observed in the Saanen goat milk only with intense he ating (95 degrees C for 1, 3 and 10 min). (C) 2000 Elsevier Science Ltd. Al l rights reserved.