A Box-Behnken experimental design for microwave assisted extraction optimization of pectin from citron peel

Microwave assisted extraction technique was employed to extract pectin from citron peel. Box-Behnken design was applied to investigate the influence of irradiation time, microwave power and pH on the yield and DE of pectin. The finding indicated that the optimal conditions for the maximum yield of pectin (30.71%) were achieved at irradiation time of 3 min, microwave power of 700 W and pH of 1.5. DE of pectin ranged from 45.08 to 72.19% demonstrating that extracted pectin was classified as high methoxyl pectin. The emulsifier activity of extracted pectin under optimal conditions was 40.7%. Besides, the emulsions were 86.7 and 86.6% stable at 4°C and, 79.5 and 79.2 at 23°C after 1 and 30 days, respectively. The flow behavior of pectin solutions indicated that solutions in low (0.1, 0.5 and 1.0 %w/v) and high (2.0 %w/v) concentrations had Newtonian and pseudoplastic behaviors, respectively.