Optimization of Ultrasonic Extraction of Polyphenol from Taro (Colocasia esculenta)Peels and Its Evaluation of Antioxidant Activity

In order to utilize taro(Colocasia esculenta) efficiently,the taro peels were used as raw material to extract by ultrasound-assisted. On the basis of single factor experiment,orthogonal experiment was used to optimize the extraction conditions of polyphenols in taro peels and its antioxidant activity in vitro was preliminarily evaluated. The results showed that the optimum extraction process was as follows:Ultrasonic power 400 W,ethanol concentration 45%,solid-liquid ratio 1:55 g/mL,ultrasonic time 35 min. The polyphenol content in the taro peels extracted under this condition was(23.61±0.36) mg/g. Antioxidant activity experiments showed that the polyphenols extracted from taro peels had reduction ability,and the 20.0 μg/mL taro peels polyphenol had a reduction ability of 0.4431±0.0027. The IC₅₀ values of DPPH and ABTS scavenging activities were (5.6647±0.2545) and (36.3630±2.4013) μg/mL. The results indicated that polyphenols from taro peels exhibited positive antioxidant capacity.