Enzymatic extraction of antioxidant ingredients from Danish seaweeds and characterization of active principles

Abstract

The present study investigated the enzymatic extraction of antioxidant ingredients from four Danish seaweeds viz., Fucus vesiculosus, Fucus serratus, Ascophyllum nodosum and Polysiphonia fucoides. The seaweeds were hydrolyzed with five carbohydrases and three proteases. The antioxidant activities and total phenolic content (TPC) of the resulting extracts were studied. Considerable variation was observed in the antioxidant activities and TPC of different enzymatic hydrolysates. Among the 32 enzymatic extracts studied, F. vesiculosus-Alcalase, F. vesiculosus-Viscozyme, F. serratus-Termamyl, and P. fucoides-Termamyl extracts showed high TPC and antioxidant activities. Fractionation and characterization of these extracts revealed that radical scavenging and reducing power was mainly due to the phenolic fractions, whereas protein and polysaccharide fractions mainly contributed to the iron-chelating activity. The antioxidant activity observed in the liposome model system was due to a combined effect of the various fractions and their antioxidant properties. Gallic, gentisic and chlorogenic acids were the main free phenolics in the phenolic fractions. Fucose rich polysaccharides were obtained when F. vesiculosus and F. serratus were hydrolyzed with Viscozyme and Termamyl, respectively. Thus, enzyme assisted extraction is an effective tool for getting antioxidant with specific properties, which can find application in food and cosmetics.