Developing and Optimizing mackerel filleting

Summary

With the support of RFF West and with Pelagia as an industrial partner the main goal was to reveal how season, handling and processing parameters influence the quality and storage stability of frozen mackerel fillets. The project was divided into 3 parts. Part 1 quantified the quality parameters of the existing fillet products in Asia. Part 2 examined the quality variation of mackerel fillets as a result of season and final thaw temperature at filleting. Part 3 examined the storage stability of the fillets, the effect of the glazing and the addition of an antioxidant. China-fillet had consistent quality, while the Norwegian fillets were characterized by large variation within batch, probably due to manual fillet production and glazing. For color, texture, gaping and blood spots, the quality of the Norwegian September filet was similar to the quality of China-fillets. The results indicate that thawing can have an effect on fillet quality. This should be investigated with several fish and under more controlled (automated) fillet production. The results indicate that the shelf life of Norwegian mackerel fillet is 4–8 months at approximately -20 °C frozen storage. The firmness of fillets seemed to increase with storage, but the fillets were soft compared with previous studies (with whole fish). The results showed no clear antioxidative effect of 2% rosemary extract.