In vitro antioxidant activity of enzymatic hydrolysates prepared from abalone (Haliotis discus hannai Ino) viscera

Pacific abalone (Haliotis discus hannai Ino) viscera, which are normally discarded as byproducts, were hydrolyzed with five commercially available proteases, including alkali protease, papain, neutral protease, pepsin, and trypsin. The hydrolysates obtained were fractionated using ultrafiltration membrane bioreactor system. The resulting hydrolysate fractions were investigated for their antioxidant activities, including the scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, the scavenging effect on hydroxyl radical, and the reducing power. Results showed that the hydrolysate fractions were effective antioxidants, and the antioxidant activity of the hydrolysates was related to the enzyme type employed. As byproducts, abalone viscera can be used as a potential source of antioxidant peptides.

Research highlights
► Pacific abalone (Haliotis discus hannai Ino) viscera contain high content of protein.
► The hydrolysates from abalone viscera showed DPPH radical scavenging activities and the reducing power.
► As byproducts, abalone viscera can be used as a potential source of antioxidant peptides.