Beta Vulgaris root as a natural food colouring in doughnut: Dough rheological properties and bioactive composition

Summary In the present study, the influence of Beta vulgaris root powder (BVP) incorporated at 0%, 5%, 7.5%, 10% and 12.5% levels on the empirical and fundamental rheological characteristics; dough texture properties; nutritional and bioactive components in the doughnut were carried out. The addition of BVP, decreased the WAC (58.4%–51.2%), DDT (6.19–1.31 min), extensibility (148–95 mm), and springiness (4.56–3.24 N) and viscosity parameters to varying extent. The frequency sweep test indicated that both the dynamic moduli increased and G' was higher than G" at all levels indicating the solid elastic structure of the dough. The dimensional characteristics of the doughnuts indicated a decrease in volume (103.3–85 mL) and an increase in weight (35.8–46.7 g) and compression force (11.6–14.5 N). The sensory studies indicated that 10% BVP incorporated doughnut was highly acceptable with higher dietary fibre content. The higher retention of betacyanin (17.88 mg 100 g −1 ), betaxanthin (12.9 mg 100 g −1 ), betanin (6.61 mg 100 g −1 ), TPC (25.74 mg GAE 100 g −1 ), TFC (77.08 mg QE 100 g −1 ) and TAC (28.76 mMTE 100 g −1 ) was observed.