LAUSR

The processing of fishery products generates a substantial amount of by-products, which can be utilized to promote a circular economy. The objective of the present study was to extract and characterize native collagen and total lipid extract from the fish skin and bones of crevalle jack (Caranx hippos). Physicochemical, structural, and morphological properties were evaluated for collagens. Chemical composition and functional properties were evaluated for lipid extracts. Native type I collagens were obtained by acid extraction, yielding approximately 2.64–6.16% (d.b.). The elemental chemical analysis showed its purity. The stability of the triple helix of collagen was verified through characteristic bands in the FTIR and UV spectra, the peaks at 2θ, around 7.5° and 19.5° obtained by XRD, and the bands of SDS-PAGE. Collagens show isoelectric points of 4.94 (skin) and 4.90 (bone), thermal stabilities of 53.40 °C (skin) and 46.88 °C (bone), and the percentage surface porosities of 41.28 (skin) and 38.84 (bone), all of which demonstrate their potential as a raw material in the biomedical field. The total lipids obtained were extracted using the Soxhlet and Folch methods. The extracts show EPA (1.26–3.16%) and DHA (3.94–9.78%) contents, with inhibition percentages of 32.7% (ABTS), 19.6% (DPPH), and 70.83% (β-carotene). These results highlight the potential of total lipid extract for nutraceutical and food applications.