Evaluation of freezing pressed curd for delayed ripening of semi-hard ovine cheese

Production of cheese from sheep's milk is subject to the seasonal lactation. The objective was to test various conditions of pressed curd freezing to ensure a more consistent supply of ovine cheese. The processing variables evaluated were packaging conditions (polyethylene bags, vacuum-packaging in barrier film, and CO2 atmosphere in barrier film), freezing rate (1.4, 4.8, and 10.2cm/h), and storage time (4 and 10 months at - 23°C). Vacuum-packaging altered the external appearance of cheese. The freezing rate of 10.2cm/h cracked some units. Composition, moisture loss, water activity, lipolysis, and proteolysis were followed both in curds and aged cheese. No differences in moisture loss were observed in 60 d aged cheese from frozen curds. Proteolysis increased in all curds and cheese. Water activity decreased in all cheeses. No significant changes in the main components of cheese or in lipolytic activity were observed. All of the groups behaved similarly despite the freezing process.