Extraction of Protein from Four Different Seaweeds Using Three Different Physical Pre-Treatment Strategies

Seaweeds are a rich source of protein and can contain up to 47% on the dry weight basis. It ischallenging to extract proteins from the raw biomass of seaweed due to resilient cell-wall complexes.Four species of macroalgae were used in this study-two brown,Fucus vesiculosusandAlaria esculenta,and two red,Palmaria palmataandChondrus crispus. Three treatments were applied individually tothe macroalgal species: (I) high-pressure processing (HPP); (II) laboratory autoclave processing and(III) a classical sonication and salting out method. The protein, ash and lipid contents of the resultingextracts were estimated. Yields of protein recovered ranged from 3.2% forFucus vesiculosuspre-treatedwith high pressure processing to 28.9% protein recovered forChondrus crispustreated with the classicalmethod. The yields of protein recovered using the classical, HPP and autoclave pre-treatmentsapplied toFucus vesiculosuswere 35.1, 23.7% and 24.3%, respectively; yields fromAlaria esculentawere 18.2%, 15.0% and 17.1% respectively; yields fromPalmaria palmatawere 12.5%, 14.9% and 21.5%respectively, and finally, yields fromChondrus crispuswere 35.2%, 16.1% and 21.9%, respectively.These results demonstrate that while macroalgal proteins may be extracted using either physical orenzymatic methods, the specific extraction procedure should be tailored to individual species