Enrichment of Tarhana with Olive Leaf Powder: Evaluation of Physical, Functional, Powder, and Sensory Properties

Olive leaves are a by-product of olive cultivation and remain underutilized despite their significant potential as a rich source of health-promoting and functional components. Similarly, tarhana, a fermented food product, is known for its valuable nutritional properties. This study aimed to combine these two beneficial products by examining the effect of different concentrations of dried olive leaf powder (0, 2.5, 5, 7.5, and 10% by weight) on the physical, functional, powder, and sensory properties of tarhana samples. Results showed that moisture content of the tarhana samples were below 10% (wet basis, wb). The ash content (2.17-2.71%, wb) and water holding capacity (32.50-59.00%) of samples increased significantly with the addition of olive leaf powder (p<0.05). The pH value of the doughs was found to be around 5.5 and decreased during the fermentation. The wettability and solubility times of all samples were found to be less than 25 seconds and 16 seconds, respectively. All tarhana samples exhibited high flowability and low stickiness properties. Formulations containing up to 7.5% olive leaf powder were well-received by consumers.