Essential and toxic elements in sustainable and underutilized seafood species and derived semi-industrial ready-to-eat products

Blue whiting (Micromesistius poutassou), pouting (Trisopterus luscus) and common dab (Limanda limanda) are underutilized fish species attractive in terms of sustainability. However, there is limited information about their nutritional characteristics as well as potential presence of environmental contaminants. Specimens caught in European waters were characterised for their content of essential and toxic elements. The three species, along with common carp and blue mussels, relevant for sustainable production too, were employed as raw materials for the development of semi-industrial ready-to-eat products. Calcium, copper, iodine, iron, selenium, zinc, cadmium, lead, mercury, and nickel were determined by ICP-MS, whereas methylmercury was determined by HPLCICP-MS. These two techniques were also used to determine arsenic and inorganic arsenic, respectively, in blue mussel and derived products. Differences in element contents were related to the biology and ecology of the examined species. Intake of nutrients and exposure to contaminants were assessed in relation to the relevant DRVs and HBGVs, respectively. All the species were found to be valuable dietary sources of selenium. Pouting was rich in iodine and mussels were good sources of iodine and iron. These two species had comparatively higher levels of mercury and lead, respectively. However, the levels of contaminants were generally of no concern in both raw materials and products. Iodine bioaccessibility was studied in blue whiting, a species with an intermediate iodine content, and found to be 98%. Selenium:mercury molar ratios were assessed and found to be favourable. The semi-industrial products were found to be good sources of selenium and many of them provided appreciable amounts of calcium, iron, copper and zinc.

Automated summary

Blue whiting, pouting, and common dab are underutilized fish species with high sustainability potential. They were found to be valuable dietary sources of selenium, with pouting rich in iodine and mussels good sources of iodine and iron. Despite comparatively higher levels of mercury and lead in some species, the contaminants were generally of no concern in both raw materials and products. The semi-industrial products were good sources of selenium and provided appreciable amounts of calcium, iron, copper, and zinc.