Enrichment of sponge cake with tomato pomace powder and pomegranate peel extract and evaluation of its physical, textural and sensorial properties

Pomegranate peel could have medicinal or industrial applications, however, is consideredan agro-industrial residue.The present study aimed to investigate the replacement  effect of pomegranate  peel extract (PPE) with water (0-12%)  and tomato pomace powder (TPP) with cake flour (0-10%) on the physicochemical (moisture content, dough density, acidity, and color), phytochemical (total phenolic content and antioxidant capacity), textural, and sensory properties of sponge cake based on combined (mixture-mixture) design. The obtained results showed that replacing TPP with cake flour increased dough density. Replacing TPP with cake flour and PPE with water darkened the color of the crumb. The moisture content of the samples decreased with the replacement of TPP and PPE. Increasing the level of TPP and PPE resulted in increased total phenol and antioxidant capacity. Substitution of PPE and TPP increased the acidity of samples on 1st day of baking. However, PPE decreased the acidity of samples compared to the control ones during storage time (7th day). The energy and hardness of samples with the incorporation of TPP up to 6% increased but at high levels (>6%) decreased. The results of the sensory evaluation showed that incorporation of TPP and PPE decreased the overall acceptability score of samples (p<0.05). However, the overall acceptance of all samples was higher than the acceptable limit (>3.7). According to the sensory results, replacing 6% TPP with cake flour with 7% PPE instead of water in sponge cake formulation produced a high nutritional value product with the same sensory characteristics as the control ones.