Impact of Egyptian and Saudi Ziziphus spina-christi L. (Sidr) pulp incorporation on the nutritional, functional, and sensory properties of protein bars.

This study investigated the improvement of the nutritional composition of protein bars by partially replacing glucose syrup with Egyptian Sidr pulp (ES) and Saudi Sidr pulp (SS) at 5%, 10%, and 15% levels. The ES pulp exhibited higher unsaturated fatty acids (67.2%) compared to SS (59.8%), while SS contained more saturated fatty acids (40.2%) than ES (32.8%). ES also showed higher contents of ash (3.84%), protein (8.67%), fiber (5.21%), iron (2.19 mg/100 g), and zinc (1.17 mg/100 g) than SS. Incorporation of Sidr pulp into protein bars significantly (p < 0.05) increased fiber (from 1.91% in control to 4.72% at 15% ES), iron (from 1.07 mg/100 g in control to 2.19 mg/100 g at 15% ES), and zinc (from 0.61 mg/100 g in control to 1.17 mg/100 g at 15% ES), with no substantial changes in protein and fat content. The highest total phenolic content was observed in ES bars (6.42 mg GAE/g), and antioxidant activity increased up to 52.8% in ES bars. Sensory evaluation revealed improved overall acceptability scores, rising from 6.2 (control) to 8.1 (15% ES). Water activity decreased from 0.61 (control) to 0.54 (15% ES), indicating enhanced shelf-life. These findings highlight Sidr pulp as a valuable functional ingredient for developing protein bars with improved nutritional and sensory qualities.