Preparation and characterization of the hydrolysates from Porphyra haitanensis

The extraction yields, DPPH radical scavenging activity, amino acid compositions, protein solubility and emulsion activity of extracts from Porphyra haitanensis treated by means of cellulose and papain were investigated.It was found that the extraction yields of laver with papain hydrolysis were higher than those with cellulose.The solid yield of laver could be increased using papain combined with cellulose, while the protein yield didn’t change. A high positive correlation between DPPH radical scavenging activity and protein content in the laver extracts was observed, probably due to the increase of amino acids with antioxidant activity. On the other hand, the protein extracted from laver using papain combined with cellulose, was solved about 100% irrespective of pH.Moreover, the emulsion activity of laver extracts was the highest at pH9, but the emulsion stability was the lowest at pH7.