Effect of tomato seed supplementation on chemical and nutritional properties of tarhana

Tomato paste waste materials are rich in bioactive food ingredients and have a low economic value. In this research, the potential use of tomato seeds, a part of tomato waste materials, in tarhana was studied. During the production of tarhana, wheat flour of tarhana was partially (15, 25 and 35%) substituted with tomato seed meal. Protein, oil, dietary fiber, ash, mineral contents (Mg, Ca, K, P, Mn, Zn, Fe, Cu), amino acid compositions, total phenolic contents, antioxidant activity values, color values and sensory properties of tarhanas were analyzed. It was found that the protein, oil, insoluble dietary fiber, total dietary fiber, ash, mineral and total phenolic contents, and antioxidant activity values of tarhanas increased by increasing the amount of tomato seed meal in the formulation (P < 0.05). Substitution of tomato seed instead of wheat flour also increased lysine, phenylalanine, threonine, serine, alanine, glycine, histidine, aspartic acid, arginine and tyrosine contents of tarhanas significantly (P < 0.05). The results of color analysis showed that higher substitution levels of tomato seed instead of wheat flour decreased L values significantly (P < 0.05). Although all of the tarhana samples received sensory scores higher than the mid of hedonic scale, C (control) tarhana and tarhana having 15% of tomato seed received the best liking scores (P < 0.05).