Impact of Different Milk Types and Storage Period on the Quality Characteristics of Malatya Cheese

In this study, Malatya cheeses were produced using cow's milk, sheep's milk, and a cow-sheep milk mixture (1:1), were stored in brine solutions, and samples from both the cheeses and their brines were collected and analyzed at 0, 30, 90, and 180 days of storage to investigate the impact of the milk type and storage time on the cheese characteristics. Cheese made from cow's milk exhibited a lower fat content (14.5%), whereas cheese made from sheep's milk had a lower protein content (17.5%). During storage, salt and ash contents increased. Water-soluble nitrogen (WSN) and trichloroacetic acid-soluble nitrogen (TCASN) levels decreased during the first 90 days of storage, followed by a subsequent increase. Cow's milk cheese demonstrated higher ripening extension index (REI) values, indicating early-stage proteolysis, whereas sheep milk cheese showed higher ripening depth index (RDI) values, reflecting more advanced ripening. The total concentration of volatile compounds in the headspace increased over time, rising from 576.7-1060.2 to 5795.1-7360.1 mu g/kg dry matter by day 180 of storage, with acids being the dominant volatile group in both quantity and diversity. Free fatty acids (FFAs) were the predominant volatiles and branched-chain acids and alcohols associated with proteolysis were particularly notable in cow's milk cheeses. Additionally, the transfer of proteins and volatile compounds into the brine increased throughout the storage period. Overall, storage time significantly influenced the cheese characteristics, while milk type also played a role, albeit to a lesser extent.