Quality Evaluation, Nutrition Values, and Shelf-life Stability of Bakery Products Supplemented With Dried Olive Mill Wastewater

Olive mill wastewater (OMWW) is a by-product generated in large quantities during olive oil production. This study explored the benefits of incorporating dried OMWW into wheat dough and bakery products such as wheat bread and biscuits. The study investigated the effect of dried OMWW as a source of bioactive compound on dough rheological properties and properties of selected bakery products (quality, nutritional value, and shelf-life). It was detected that dried OMWW has a high concentration of total phenol (TP) 5.75 g GAE/L especially the oleuropein bioactive compound 235.2 mg/ 100g. The addition of OMWW (up to 3%) led to a decrease in water absorption and dough development time, while increasing dough softness and elasticity compared to the control. Bread volume increased with 3% OMWW supplementation. Scores for color, appearance, and overall acceptability of both bread and biscuits (without addition of lemon) decreased significantly (p < 0.05) compared to the control. The tenderness of OMWW-supplemented products improved significantly (p < 0.05) over 7 days of storage at 25 °C. Oxidative stability of biscuits also improved with 3% OMWW supplementation after 3 weeks at 25°C, as evidenced by a significant (p<0.05) reduction in thiobarbituric acid (TBA) values, though TBHQ (200 ppm) supplemented controls had the lowest TBA values overall. Additionally, OMWW supplementation increased the total phenol content and nutritional value of the bakery products. The study suggests that food industries should consider using dried OMWW in bakery products to create functional foods with enhanced nutritional profiles and extended shelf lives.