Study on the extraction of antioxidative phlorotannins from brown algae (Sargassum mccrulei) using microwave assited maceration

Abstract

The conditions for the extraction of antioxidative phlorotannins from brown algae Sargassitm 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 : I - 50 ; 1 (w/w); maceration time 1 - 5 minutes; pH 5 - 8; number of macerations I - 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 limes 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 FeSOy g DW. ANOVA analysis showed a strong non-linear correlation between the phlorotannin/polyphenol content and the antioxidant activities.