Effects of Catechin for preventing black spot forming in cultured whiteleg shrimp (Litopenaeus vannamei) during frozen storage

Effects of catechin for preventing black spots forming in whiteleg shrimp (Litopenaeus vannamei) were evaluated. For processing whole shrimp، catechin was used at a concentration of 0. 2 and 0. 3 % for 15 minutes. Sodium metabisulfite was used at a concentration of 3 % for 10 minutes as control samples. Without antioxidant shrimp were used as control samples too. Treatments quality was evaluated by Sensory analysis and chemical experiments during 6 months being kept in frozen storage. pH، total volatile basic nitrogen and trimethylamine factors in 0. 3 % catechin treatments showed significant differences During the storage period (P0. 05). TMA، FFA and TVB-N factors in Sodium metabisulfite treatments showed significant differences compared to other treatments (P0. 05). PV، TBARS، FFA، pH and TVB-N factors in 0. 2 and 0. 3 % catechin treatments showed no significant difference during the storage period compared to Sodium metabisulfite treatments (P>0. 05). But they showed significant differences compared to without antioxidant treatments.