Protein Hydrolysates Prepared from the Viscera of Skipjack Tuna ( Katsuwonus pelmamis ): Antioxidative Activity and Functional Properties

摘要

Protein hydrolysates from skipjack tuna viscera prepared using Alcalase 2.4 L (VPH) with different degree of hydrolysis (DH: 10%, 20% and 30%) were prepared and determined for their antioxidative activity. VPH with 20% DH had the highest DPPH, ABTS radical scavenging activities and ferrous chelating activity (P<0.05). However, ferric reducing antioxidant activity of hydrolysates increased as DH increased (P<0.05). When VPH with 20% DH was determined for its pH and thermal stability, ABTS radical scavenging activity remained constant or slightly decreased in a wide pH range (2-11) and during heating (100oC) for 180 min. Functional properties of VPH (20% DH) at different concentrations were also investigated. The emulsifying and foaming properties were governed by its concentrations used. Hydrolysis by Alcalase at 20% DH increased protein solubility to above 91% over a wide pH range (3-9). Therefore, VPH could be used as a food additive possessing both antioxidant activity and functional properties.