Ripening of ovine milk cheeses: effects of plant rennet, pasteurization, and addition of starter on lipolysis

The influences of type of rennet (from animal sources or from flowers of Cynara cardunculus), pasteurization (or not) of the milk, and addition (or not) of starter cultures prior to cheesemaking, on the release of major fatty acid residues of ovine milk cheese were evaluated throughout the ripening period. The long-chain saturated (C16:0 and C18:0) and unsaturated (C18:1, C18:2 and C18:3) free fatty acids (FFA) were the most abundant types at all stages of ripening. The overall concentrations of FFA released by 68 days of ripening were 6517 and 7802 mg kg−1 cheese for ovine milk cheeses manufactured from the same batch of raw milk and ripened under the same conditions without deliberate addition of a starter culture, using plant or animal rennet, respectively; therefore, such plant rennet appears to be a good substitute for animal rennet from a lipolytic point of view. The overall concentrations of FFA in fresh cheese were 3538, 3002 and 3283 mg kg−1 cheese for raw milk without addition of a starter culture, pasteurized milk without addition of a starter culture, and pasteurized milk with addition of a starter culture, respectively; these values increased to 6517, 8115 and 4847 mg kg−1 cheese by 68 days, of which 1791, 3887 and 1649 mg kg−1 cheese were accounted for by short-chain FFA.