Abstract
Aqueous extracts of orange peel and pulp with high total phenolic contents (TPC) (25.94 and 11.38 mg GAE/g extracts, respectively) were employed in the formulation of functional carrot juice and functional juices were treated using thermosonication process. In accordance with Box-Behnken design, 17 runs with 3 variables and 3 levels was applied for the optimization of the carrot juice with peel (CJPL) and pulp (CJPP) extracts. Overlaid contour plots prediction showed that the optimal conditions for CJPL were 125 mL juice volume, 6.50 min ultrasound process time and 52.78 degrees C ultrasound process temperature for maximum TPC (30.25 mg GAE/100 mL) and DPPH scavenging activity (61.22%). Sample CJPP has maximum TPC (28.94 mg GAE/100 mL) and DPPH activity (55.87%) under optimal ultrasound process conditions of 125 mL juice volume, 5.04 min and 59.99 degrees C ultrasound process time and temperature, respectively. Optimization of thermosonication showed significant improvements in the quality of functional carrot juice.