Effect of using kiwi fruit and heart of date palm slurries as a novel acceleration ripening enzyme source on the physicochemical, textural, and sensorial properties of Ras cheese.

Ras cheese, a hard cheese typically consumed in the Middle East after a 6-month ripening period, is a rich source of casein. Microbial enzymes are commonly used to develop its distinct flavor, but plant-based enzymes offer a cost-effective alternative. Kiwi fruit and heart of date palm slurries contain substantial levels of protease activity, measured at 77.18 and 53.50 units per 100 g of edible portion, respectively. This study explored the use of kiwi fruit and heart of date palm slurry as novel ripening agents at concentrations of 10, 15, and 20 mL/kg cheese curd. Samples were analyzed when fresh and at 30-day intervals over a 90-day period for ripening indices, as well as physicochemical, rheological, microbiological, and sensory properties. Results showed that both plant slurries accelerated ripening and enhanced functional characteristics, especially at higher concentrations. At the optimal levels (15 and 20 mL/kg of cheese curd, respectively), the treatment resulted in a 25.8 % increase in soluble nitrogen, a 30.4 % rise in free fatty acids, and a reduction in ripening time by approximately 30 %. Sensory qualities of all treated samples improved over time. These findings highlight the potential of kiwi and date palm as innovative, natural additives in dairy processing, offering a sustainable approach to enhancing cheese maturation and product development.