Effets de différents traitements de correction sur les aptitudes à la coagulation des laits de chèvre, de brebis et de vache chauffés

Abstract

The effects of calcium addition, acidification, protein concentration by ultrafiltration and 24 h storage at 25 °C have been studied in cow's milk, goal's milk and ewe's milk heated at 80 °C during 1 and 10 min. Among the three types of milk, cow's milk is the one whose renneting properties were the most strongly impaired by heating. Technological treatments which were applied after heating, especially acidification, had marked relative effects in that milk. But they were unable to restore a gelification kinetic compatible with a cheesemaking process, when milk was heated at 80 °C for 10 min. Goat's milk was characterized by the best ability to recover coagulating properties close to that of fresh milk, even after heating for 10 min at 80 °C. Excepted for whey draining capacity, ewe's milk underwent few changes due to heat treatment. After the most severe heat treatment, the strong decrease of whey draining capacity of ewe's milk could never be compensated by any of the technological treatements tested, as it never exceeded 10% of the volume obtained for fresh milk.