Biochemical and physicochemical changes in catfish ( Silurus glanis Linne) muscle as influenced by different freeze–thaw cycles

Freeze–thaw cycles affected the biochemical and physicochemical properties of catfish fillets. When the number of freeze–thaw cycles increased, the activities of α-glucosidase and β- N-acetyl-glucosaminidase increased ( P0.05); however the heme iron content decreased ( P0.05) were found as affected by freeze–thaw cycles. After 3 days of chilled storage (2–4°C), a small non-significant increase in non-heme iron content was observed with a concomitant decrease in heme iron. Thiobarbituric acid-release substance increased significantly ( P