Comparison of Extracting Methods for Anthocyanins and Flavonoids of Rhodomyrtus tomentosa and Studies on Their Antioxidant Activity

The anthocyanins and flavonoids of Rhodomyrtus tomentosa were extracted by different methods such as traditional hot water, microwave assisted and ultrasonic assisted methoed, and their antioxidant activity with the three methods were compared, after the anthocyanins and flavonoids identified. The results indicated that microwave assisted extraction was the best method for the extraction of anthocyanins and flavonoids which reached (1 123.9 ± 1.74) mg/100 g DM and (182.01 ± 5.95) mg/100 g DM respectively, and the extraction showed strongest radical scavenging abilities on DPPH and ABTS+•. The efficacy order on extracting anthocyanin for three assisted methods was: microwave assisted extraction > ultrasonic assisted extraction > traditional hot water extraction; The order of flavonoids contents was: microwave assisted extraction > traditional hot water extraction > ultrasonic assisted extraction; The order of eliminating DPPH ability was: microwave assisted extraction > ultrasonic assisted extraction > traditional hot water extraction; The order of eliminating ABTS ability was: microwave assisted extraction > traditional hot water extraction > ultrasonic assisted extraction. Cyanidin-3-O-glucoside, Peonidin-3-O-glucoside and Delphinidin-3-O-glucoside were identified in Rhodomyrtus tomentosa by HPLC-QqQ-MS, the main kind of flavonoids were Scopoletin,(-)-gallocatechin, myricetin-3-O-glucoside, tangeritin and myricetin-3-O-furanoarabinoside. © 2018, Editorial Office of Journal of CIFST. All right reserved.