Enzymatic approach for the extraction of bioactive fractions from red, green and brown seaweeds

Abstract

Although several enzymatic approaches have been applied with this intent, the sequential use of enzymes covering both cellulolytic and proteolytic activity has never been performed in seaweeds. Sequential use of these enzymes improved the overall extraction yield by up to 160%, 30% and 80% in the different seaweeds when compared to the control condition (water extraction), use of a carbohydrases’ cocktail alone and use of proteases alone, respectively. Regarding the proximate composition of extracts, it proved to be an efficient approach for the solubilization of carbohydrates (up to 28% in G. vermiculophylla, 66% in P. dioica, 77% in U. rigida and 35% in F. vesiculosus) and protein (up to 55% in G. vermiculophylla, 47% in P. dioica, 52% in U. rigida and 42% in F. vesiculosus). For all biomasses, the combination of enzymes induced a significant increase in antioxidant activity, not only by the increase of phenolic compounds but also by the hydrolysis of protein to peptides. Moreover, extracts from red seaweeds displayed prebiotic activity which can be ascribed to their increased content in oligosaccharides and protein/peptides. Overall, the sequential use of enzymes with different activities demonstrated to be an efficient approach for extracting functional fractions to be used as functional ingredients to improve the nutritional value (e.g. in proteins) and/or to include antioxidant and prebiotic features in the food product.