Enzymatic extraction of rice-bran protein from Tarom variety and its functional effects on Physico-Chemical properties of low-fat yogurt

In this study hydrolyzed protein was obtained from rice bran of Tarom cultivar by using flavourzyme enzyme for 2 hours and at pH 8. The chemical composition of rice bran and hydrolyzed protein was measured. Degree of protein hydrolysis of rice bran was calculated to be 18.53% after 2 hours of treatment. The water absorption of rice bran and its hydrolyzed protein was calculated to be 2.56 ± 0.9 ml/g and 5.48 ± 1.0 ml/g, respectively. The solubility of hydrolyzed and non-hydrolyzed proteins was 84.09 ± 3.2 and 65.17 ± 4.5, respectively. The emulsifying capacity and emulsifying stability of hydrolyzed protein were calculated to be 9.12 m2 /g and 71.38 min, using the flavourzyme enzyme, respectively. These parameters for non-hydrolyzed protein were 1.55 m2/g and 29.77 min, respectively. Hydrolyzed protein was added to yoghurt at 0, 1, 1.5 and 2% levels, and the physicochemical properties of yogurt were measured. Increasing the concentration of hydrolyzed proteins in yogurt formulation resulted in increased viscosity. By increasing the amount of hydrolyzed protein in the formulation of yogurt, acidity significantly increased and the pH decreased to a significant extent. Using 1.5% of the hydrolyzed protein in low fat yogurt formulation is recommended.