Extraction and Enrichment of Protein from Red and Green Macroalgae

Macroalgae, in particular red and green species, are gaining interest as protein-rich foods for human consumption and sources of proteinaceous biofunctional peptide ingredients. During protein extraction the starting raw material, the cell disruption method utilized and the reagents employed have a major effect on the yield of protein recovered. A method is described herein for extraction and semi-purification of food-grade aqueous and alkaline soluble proteins from red and green macroalgae. Dried milled macroalgae are disrupted by osmotic shock with subsequent removal of aqueous soluble proteins by centrifugation. Alkaline soluble proteins are removed following consecutive treatment of the resultant pellet with an alkaline solution. Aqueous and alkaline soluble proteins are then enriched from the crude extracts by isoelectric precipitation.