Physicochemical properties of iodine and selenium biofortified Sparus aurata and Cyprinus carpio during frozen storage

Fish biofortification with natural ingredients like iodine-rich macroalgae and selenized-yeast is an excellent strategy to enhance the nutritional quality of farmed fish. This study aimed to assess the effect of frozen storage during 12-months on physicochemical quality of biofortified seabream (Sparus aurata) and carp (Cyprinus carpio). Frozen storage reduced iodine content in biofortified seabream fillets (17%), as well as selenium content in biofortified carp fillets (24%). Yet, biofortified fillets still presented enhanced iodine and selenium contents at the end of the storage period. Increased lipid oxidation (3.45 mg MDA kg-1 for seabream and 2.41 mg MDA kg-1 for carp) and decreased water holding capacity (23-29% for seabream and 14-23% for carp) was observed during storage, whereas major changes in colour and texture occurred after 45 days (seabream) and 225 days (carp) of storage. In general, biofortified fish fillets maintained their nutritional value and quality after 360 days of frozen storage.

Highlights: In general, the quality parameters of fish fillets during frozen storage were not relevantly affected by the biofortification strategies; Frozen storage led to increased lipid oxidation of gilthead seabream and common carp fish fillets; Decreased I and Br contents were observed in biofortified seabream fillets during frozen storage; Decreased Se and As contents were observed in biofortified carp fillets during frozen storage; Overall, biofortified fillets maintained acceptable conditions for consumption after 360 days of frozen storage.