Study on the extraction of antioxidative phlorotannins from brown algae Sargassum mcclurei using microwave assisted maceration
Đặng Xuân Cường
Trần Thị Thanh Vân
Vũ Ngọc Bội
Bùi Minh Lý
Abstract
The conditions for the extraction of antioxidative phlorotannins from brown algae Sargassum mcclurei using microwave assisted maceration with ethanol 96 % were studied. The experimental parameters were varied as follows: microwave power 100 – 800 W; solvent/ material ratio 10: 1 – 50: 1 (w/w); maceration time 1 – 5 minutes; pH 5 – 8; number of macerations 1 - 3 times. The phlorotannin/polyphenol content, the total antioxidant activity, and the reducing power were evaluated. The best results were obtained at microwave power of 100 W, solvent/ material ratio 30: 1 (v/w), maceration time 2 minutes, pH 7, and 3 times of consecutive macerations. Under these conditions, following results were obtained: phlorotannin/polyphenol content 3,88 ± 0,033 mg phloroglucinol/g DW, total antioxidant activity 15,096 ± 0,037 mg acid ascorbic/g DW, and reducing power 5,365 ± 0,028 mg FeSO4/g DW. ANOVA analysis showed a strong non-linear correlation between the phlorotannin/polyphenol content and the antioxidant activities.