Physicochemical Characteristics and Antioxidant Capacity of Traditional Yogurt Fortified with Grape (Vitis vinifera L.) Seed Extract at Different Levels

Abstract

The aim of this study is to obtain the grape seed extract with high antioxidant activity and to investigate the quality characteristics of traditional yogurts fortified with seed extracts at different concentrations. For this aim, batch hot water extraction was conducted and extraction conditions were optimized to produce Vitis vinifera L. grape seed extract using with the highest antioxidant activity. The fortification of yogurts was conducted at 0.1-0.15 and 0.2 g/ 100g extract level and antioxidant, physicochemical, microbial and sensory characteristics of the yogurt samples were analyzed. Results showed that antioxidant activity of fortified yogurts were higher and up to 14 % more antioxidant activity was detected compared to the control samples. Yogurt samples preserved their physicochemical characteristics. Although sample with 0.1 g/100 g extract had highest scores in overall acceptance, the sample containing the highest extract concentration of 0.2 g/100 g, exhibited negative perceptions by panelists in sensorial analysis. In conclusion, grape seed may be used in traditional yogurt production by improving the taste and antioxidant potential. The fortification levels of 0.1-0.15 g/100 g grape seed extract might be more feasible in functional yogurt production and might be more recommended for consumer's appreciation in terms of positive health effects.