CHANGES IN THE CONTENT OF LACTOSE AND FREE AMINO ACIDS DURING THE RIPENING OF UNSALTED CHEESE

This study investigated the changes in lactose content and free amino acid (FAA) levels during the ripening of cow’s milk cheese produced without salt treatment. Two cheese variants were prepared from pasteurised cow’s milk (3.8% fat): one coagulated with chymosin only (DLKP) and one with chymosin supplemented with a microbial starter culture (DLK-SP). Cheese samples were stored at 14–15 °C and analysed on days 1, 3 (or 5) and 7 of ripening for moisture, pH, titratable acidity, lactose and free amino acids. In the chymosin-only variant (DLKP), lactose decreased from 5 and 7, and FAA levels fell over the same period, reflecting limited proteolytic activity in the absence of a defined starter culture. The starter-supplemented variant (DLK-SP) exhibited an accelerated pattern: lactose declined on day 1 to day 3 and fell below the detection limit by day 7, while FAA levels were high, rising on days 1, 3 and 7. The pH of DLK-SP dropped accompanied by an increase in titratable acidity. The results demonstrate that in the absence of salt, the addition of a microbial starter culture stimulates both lactose catabolism and proteolysis from the earliest stages of ripening. The FAA content in the starter-supplemented unsalted cheese (DLK-SP) was higher than in any of the salted variants, indicating that the omission of salt with starter inoculation, creates conditions highly favourable for the enzymatic degradation of caseins and the release of flavour precursors. These findings suggest that unsalted cheese produced with a starter culture develops flavour and aroma compounds more rapidly than its salted counterparts.