Influence of aqueous yam extract and goat milk casein powder on the characteristics of goat Greek-style yogurt

Abstract

This study proposed the production of goat Greek-style yogurt with added aqueous yam extract and goat milk casein powder. Yam brings health benefits when consumed, as it is rich in fiber and antioxidant compounds that help in the treatment of various diseases such as diabetes and cancer, and goat milk proteins are precursors of bioactive peptides that have antioxidant, anti-hypertensive and anti-glycemic action. Furthermore, yam is rich in starch, which, like casein, are components with a recognized hydrocolloid function. So to verify the influence of aqueous yam extract and goat milk casein powder on the physicochemical, technological, microbiological characteristics, and sensory acceptance of goat Greek-style yogurt, four formulations varying the proportion of milk: aqueous yam extract (100:0; 100:0; 90:10; and 80:20) (v/v) and varying the concentration of goat milk casein powder (0%; 2%; 2%; and 2%) (w/v) in relation to the volume of milk plus aqueous yam extract were prepared. The supplementation of goat milk casein powder enhanced the yield, water holding capacity, viscosity, sensory acceptance, and purchase intention score of goat Greek-style yogurt. Meanwhile, the aqueous yam extract reduced grain concentration in the formulation with the proportion of 80:20 milk: aqueous yam extract, and increased viscosity in the formulation with the proportion of 90:10 milk: aqueous yam extract. The results of this study presented the incorporation of the goat milk casein powder and aqueous yam extract as ingredients of a new goat dairy product with nutritional quality, and added market value owing to its potential functional properties.