Evaluation of antioxidant activity of carotenoid extract from shrimp processing byproducts by in vitro assays and in membrane model system

► Shrimp carotenoid extract has strong radical-scavenging activity. ► Astaxanthin-rich fraction of extract has stronger antioxidant activity than ester-rich fraction. ► Astaxanthin-rich fraction has stronger NO-scavenging activity than α-tocopherol. ► Shrimp carotenoid extract protects thermal oxidation of phospholipid liposome. ► Shrimp carotenoid extract protects PL liposome against singlet oxygen oxidation.