Optimization of Ultrasonic-Assisted Enzymatic Extraction of Anthocyanins from Purple Sweet Potato by Response Surface Methodology

The ultrasonic-assisted enzymatic extraction of anthocyanins from purple sweet potato was optimized by BoxBehnken experimental design and response surface methodology to increase the yield of anthocyanins. The optimum extraction conditions were obtained as follows: in a solvent made up of 0.1% hydrochloride and ethanol(50:50, V/V) at 51 ℃, hydrolysis with 54 U/mL cellulase for 33 min at a ultrasonic power of 100 W. The yield of anthocyanins was up to(3.581 ± 0.016)‰ under these conditions. Compared with the traditional solvent extraction method, the extraction duration was shortened and the yield of anthocyanins was increased by 2.73 folds using this method, and by 32.4% and 17.8%, respectively, compared with microwave-assisted method and ultrasonic-assisted method.