Valorization of Arapaima gigas processing residues as a sustainable source of collagen, gelatin, chitin and chitosan

Abstract Arapaima gigas is an important source of protein in the diet of the Amazonian population, and the skin and scales, by-products of its processing, are inadequately disposed of, thereby affecting the ecosystem. Such by-products are also rich in proteins and polysaccharides, including collagen, gelatin, chitin, and chitosan, which are widely used across industries for their functional properties and accessibility. This study aimed to assess the feasibility of recovering collagen, gelatin, chitin, and chitosan from Arapaima gigas processing residues. Centesimal and mineral composition analyses, together with Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), were used to characterize the recovered biomolecules and demonstrate their potential for biotechnological applications within a sustainable bioeconomy. This research used pirarucu skin and scales and showed that these residues are a potential source of industrially relevant biomolecules, such as collagen, gelatin, chitin, and chitosan, highlighting their potential as sustainable raw materials for high-value biomaterials and contributing to the development of the Amazonian circular bioeconomy.