Effects of Olive Pomace Powder Incorporation on Physicochemical, Textural, and Rheological Properties of Sheep Milk Yogurt

The valorization of agro-industrial by-products is a key component of sustainability goals in food production. Olive pomace (OP), a major by-product of olive oil extraction, is characterized by a high content of dietary fiber and bioactive phenolic compounds with antioxidant activity, which contribute to its nutritional and functional potential. The present study investigated the effect of the fortification of sheep milk yogurt with freeze-dried OP (1% w/w), added either before pasteurization (YOPB) or after overnight refrigeration (YOPA). The OP showed considerable antioxidant capacity and was microbiologically safe. Its addition significantly increased the yogurt's total phenolic content, with YOPB displaying the lowest syneresis and the highest water-holding capacity and apparent viscosity. Textural and scanning electron microscopy analyses revealed that the timing of OP addition affected the gel structure, with pre-pasteurization incorporation facilitating a superior integration into the protein network. The microbial viability was preserved, and the sensory evaluation showed no significant differences in consumer acceptance between the control and YOPB. These findings highlight OP's potential as a functional ingredient for dairy fortification, contributing to waste reduction and improving gel structure. The findings obtained provide support for the development of sustainable and functional dairy products enriched with by-products derived from the olive oil industry.