Proteolytic and Textural Parameters of Oil-Ripened Semi-Hard Goat Cheese

The proteolytic and textural properties of semi-hard goat cheese ripened in a 50:50 mixture of extra virgin olive oil and refined sunflower oil were investigated. Five batches were divided into three groups: group 1 (control; 60 days air-ripened), group 2 (10 days air and 50 days oil-ripened), and group 3 (20 days air and 40 days oil-ripened). Samples were taken on days 0, 10, 20, 30, 45, and 60 to evaluate proteolysis (water-soluble nitrogen (WSN), trichloroacetic acid-soluble nitrogen (TCA-SN), residual caseins), texture (hardness, fracturability, strain at fracture, cohesiveness), moisture in non-fat substances (MNFS), and salt in moisture (S/M). Oil-ripening preserved MNFS and intensified proteolysis, reflected in the highest WSN and TCA-SN (23.10%; 11.50% total nitrogen (TN), respectively) and lowest residual α-casein (72.24%) in group 2 (p < 0.01). Due to air-ripening, control cheese had the highest S/M (5.20%) and lowest MNFS (47.94%), resulting in the slowest proteolysis as evidenced by the highest values of all residual caseins (p < 0.01). Textural changes mirrored proteolysis and moisture dynamics: the control cheese was the hardest (50.25 N) and most fracture-resistant (45.50 N), while oil-ripened cheeses, especially group 2, were softer (27.18 N) and more cohesive (0.12; p < 0.01). In group 3, prolonged air-ripening led to higher water loss (MNFS: 55.40%) and elevated S/M (3.53%) compared to group 2, resulting in moderate proteolysis. These results demonstrate that oil as a ripening medium can be used to modulate development of cheese texture and quality. PRACTICAL APPLICATIONS: Artisanal cheese plays a vital role in the modern diet, helping preserve tradition and promote economic development, especially in resource-limited areas like islands. Preserving cheese in oil extends its consumption to seasons without goat's milk production. The effects of such ripening conditions and the optimal time for immersion in oil are largely unexplored. This study's findings could interest dairy scientists and cheese makers, particularly as sustainability and food waste prevention gain importance, alongside the rising popularity of traditional cheese.