Nutritional enrichment of cereal foods: feasibility study and characterisation of biscuits fortified with seabass by-products

Abstract

Industrial fish processing generates large amounts of fish by-products. Therefore, this research aimed to explore alternatives that allow better exploitation of these by-products and promote sustainability and a circular economy. To achieve this, the possibility of producing and using fish meal (FM) and fish protein hydrolysates (FPH) from seabass was studied for the nutritional fortification of biscuits. The results showed that the heat applied in the production of FPH was a factor that negatively affected the lipidic fraction, reducing the proportion of polyunsaturated fatty acids but also producing a product with darker shades. The incorporation of FM and FPH into the biscuits produced nutritional enrichment, especially in protein and polyunsaturated fatty acids, but also caused colour changes, which were more intense due to the increase of Maillard reaction, and changes in sensory perception, where higher intensities of colour and toasted flavour were perceived (especially when including FPH), but also fish flavours. Scanning electron microscopy made possible the visualisation of differences in the internal structure, which could be related to differences found in instrumental texture measurements. In conclusion, this research demonstrated that using fish by-products to enrich biscuits is possible from a nutritional perspective. However, other techniques such as the use of antioxidant substances to preserve the fish's fatty acid profile or the combination of enzymes to reduce fish flavours should be considered for future research.