The results indicated that antioxidative activities of carotenoids in carotenoproteins of Pacific white shrimp shell were in the concentration-dependent manner. Thus, carotenoids were capable of scavenging radicals and having the reducing power to a greater extent when higher concentrations were used. This result was in accordance with Sowmya and Sachindra (2012) who reported that carotenoid extracted from shrimp processing discards showed antioxidant activity. Crude extract rich in astaxanthin showed the strong antioxidant activity as indicated by radical scavenging, reducing activity and metal chelating activity, comparable to that of the known antioxidants α-tocopherol and TBHQ (Sowmya & Sachindra, 2012).