Dietary inclusion of enzyme- or probiotic-treated date palm leaves enhances the textural and sensory properties of cheese produced from sheep milk

This study evaluated the effects of including date palm leaves (DPL) in the diets of lactating Farafra ewes on milk yield, fatty acid composition, and the quality of white soft cheese produced from their milk. The leaves were ensiled either untreated, with fibrolytic enzymes (ENZ), or with multi-species probiotics (MSP). Diets included DPL at 50% or 100% of the forage portion. Ensiling DPL with ENZ or MSP significantly increased milk yield (linear effect, p < 0.01) and enhanced milk components, including total solids, fat, lactose, and energy content (p < 0.001), with MSP diets producing higher solids-not-fat and lactose (p < 0.001) than ENZ. Both treatments improved milk fatty acid profiles by increasing polyunsaturated and conjugated linoleic acids and elevating the unsaturated-to-saturated fatty acid ratio, while reducing the atherogenicity index (p < 0.001). Cheese produced from milk of ewes fed treated DPL exhibited signs of accelerated ripening during 28 days of storage, as evidenced by increased titratable acidity, soluble nitrogen, and total volatile fatty acids, along with decreased pH. Moisture decreased significantly (p < 0.001), whereas acidity increased markedly (p < 0.001) during storage across all treatments, and total volatile fatty acids also increased (p < 0.001), reaching the highest values in MSP100 cheeses at the end of storage. Total and soluble nitrogen contents also increased over storage (p < 0.001), indicating enhanced proteolysis. Sensory scores for flavor, texture, and appearance improved significantly in ENZ and MSP groups (p ≤ 0.011), with higher overall acceptability observed in ENZ50 cheese, followed by MSP50 (p < 0.001). Textural analysis showed marked increases in hardness, cohesiveness, springiness, gumminess, and chewiness during storage (p < 0.001). Cheeses from the MSP50 group exhibited superior texture attributes, including hardness, cohesiveness, gumminess, and chewiness values compared to other treatments (p < 0.01). The interaction between treatment and storage time was significant for most parameters (p < 0.01), confirming the dynamic influence of diet and ripening duration. In conclusion, feeding lactating ewes with DPL ensiled with fibrolytic enzymes or MSP improved milk yield, fatty acid composition, and the sensory and textural qualities of white soft cheese. The results highlight treated DPL as a promising feed option for sustainable dairy production.