Effect of washing with or without antioxidants on quality retention of mackerel fillets during refrigerated and frozen storage

Unwashed fillets from stage I rigor mackerel deteriorated extensively compared to unwashed fillets from stage III mackerel; this was likely related to the greater amount of blood contaminating the fillet surface of the fresher fish. Washing improved the quality of fillets from rigor fish but not stage III fish, which was attributed to the greater amount of blood removal from the fresher fish by washing. Having antioxidants in the washing solution doubled the shelf life of fillets compared to water-washed fillets. Filleting in an antioxidant solution slightly but significantly improved quality compared to cutting in air and rinsing with antioxidant solution 1 min after filleting with frozen but not refrigerated samples. Improvements with antioxidants were seen with fillets from stage I but not stage III mackerel. The pro-oxidative activity in extracts prepared from fillet surface tissue using linoleic acid as substrate was stimulated by lipid hydroperoxides. The heme proteins present in tissue extracts had the potential to account for much of the lipid oxidation observed.