Fresh and frozen stored fillets of Atlantic mackerel (Scomber scombrus)– effect on oxidation and sensory quality of canned mackerel fillets

Abstract

Atlantic mackerel caught off the West Coast of Norway were filleted and frozen in 20 kg blocks at landing. The fillets were canned with tomato sauce when fresh and after 1, 3, 6, 9 and 12 months of frozen storage. The quality of the fillets before and after canning were sensory evaluated and analysed for free fatty acids (FFA), peroxide value (PV) and thiobarbituric acid (TBARS). FFA increased during 12 months of frozen storage. Canning did not affect the FFA content. PV and TBARS increased during the first 6 months of frozen storage followed by a decrease over the next three months. PV values in canned fillets were below the initial PV of fresh fillets. Sensory analyses of the raw fillets demonstrated that elasticity, texture firmness and odour intensity decreased throughout 6 months’ storage. A significant difference was detected in canned fillets in odour, texture and taste for frozen fillets stored for 1 and 12 months, and for fillets stored for 6 and 12 months. Lipid spoilage and fish quality loss caused by storage have been satisfactorily assessed by classical biochemical damage indicators (FFA, PV, TBARS) and by sensory assessment. After six months of frozen storage, the peroxide values had increased in the raw material but were low for all the canned products. It is concluded that 12 months’ storage of mackerel at commercial temperatures results in an acceptable end product, although the quality is not as good as after shorter storage.