Simultaneous extraction of calcium phosphates and proteins from fish bones. Innovative valorisation of food by-products.

By products of the fish industry can be a source of valuable molecules, with different technological applications. Fish bones, in particular, contain both organic and inorganic phases (collagen, other proteins and calcium phosphate respectively), with uses in cosmetics and biomedicine. Using the most common extraction protocols, only of the two phases can be extracted, while the other one is degraded. Investigation of the organic phase composition by proteomic related procedures followed by LC MS MS analysis, showed that the main extracted proteins were collagen in its different forms (especially alpha 1); some differences were observed between salmon and sea bream and between the methods of extraction. Biocompatibility tests performed on both organic and inorganic extracts (with fibroblast and osteoblast like cellular lines) showed their non toxicity and, hence, their suitability for cosmetic or biomedical applications.