Effects of steaming on health-valuable nutrients from fortified farmed fish: Gilthead seabream (Sparus aurata) and common carp (Cyprinus carpio) as case studies.

Fish fortification with iodine-rich macroalgae (Laminaria digitata) and Selenium-rich yeast is expected to promote nutritional added value of this crucial food item, contributing to a healthy and balanced diet for consumers. However, it is not known if steaming can affect these nutrient levels in fortified fish. The present study evaluates the effect of steaming on nutrients contents in fortified farmed gilthead seabream (Sparus aurata) and common carp (Cyprinus carpio). Fortified seabream presented enhanced I, Se and Fe contents, whereas fortified carp presented enhanced I, Se and Zn contents. Steaming resulted in increased I and Se contents in fortified seabream, and increased Fe and Zn levels in fortified carp, with higher elements true retention values (TRVs >90%). The consumption of 150 g of steamed fortified seabream contributes to a significant daily intake (DI) of I (up to 12%) and Se (up to >100%). On the other hand, steamed fortified carp contributes to 19-23% of I DI and 30%-71% of Se DI. These results demonstrate that steaming is a healthy cooking method, maintaining the enhanced nutritional quality of fortified fish. Moreover, the present fortification strategy is a promising solution to develop high-quality farmed fish products to overcome nutritional deficiencies.

Enriched feeds with iodine and selenium from natural and sustainable sources to modulate farmed gilthead seabream (Sparus aurata) and common carp (Cyprinus carpio) fillets elemental nutritional value.

Developing tailor-made fortified farmed fish is a promising solution to overcome nutritional deficiencies and increase consumer confidence in these products. This study evaluated the supplementation of three fortified diets with I-rich seaweed and selenised-yeast on essential and toxic elements levels in gilthead seabream (Sparus aurata) and common carp (Cyprinus carpio). Fortified diets resulted in increased I, Se and Fe in fish muscle. Biofortified seabream and carp revealed lower Cu and Br. The reduction of fishmeal and fish oil in fortified diets resulted in lower Hg and Cd in seabream muscle. Contrarily, fortified diets increased As and Hg in carp fillets. The consumption of 150 g of fortified seabream enabled a significantly higher contribution to the daily recommended intake (DRI) of I (10%) and Se (76%) than non-fortified fish, whereas fortified carp fulfilled 23% of I DRI and 91% of Se DRI. Moreover, the exposure to Pb decreased with the consumption of biofortified seabream (23-82% BMDL01) and carp (26-92% BMDL01). These results support the strategy of developing eco-innovative biofortified farmed fish using sustainable, natural, safe and high-quality ingredients in feeds, to enable consumers to overcome nutritional deficiencies without significantly increased feed costs.