The global seafood sector generates substantial volumes of by-products, such as fish viscera, heads, skins, frames, and crustacean shells. These materials are often treated as waste, contributing to environmental pressure and economic loss, despite being rich in compounds with functional value. Their valorisation represents an opportunity to reduce waste generation, enhance resource efficiency, and support the transition toward more sustainable and circular production systems.

In this context, the present study focused on the recovery of high-value bioactive compounds from marine processing side streams, including omega-3 polyunsaturated fatty acids, protein hydrolysates, and natural antioxidant molecules. Particular attention was given to crustacean by-products, which are notable for their high content of carotenoids and peptides with recognised nutraceutical and pharmaceutical potential, expanding the range of compounds that can be sustainably produced from seafood by-products.

The extraction of astaxanthin and peptide fractions was carried out using green extraction techniques, specifically Supercritical Fluid Extraction (SFE) and enzymatic hydrolysis, respectively. These techniques preserve the quality of the recovered compounds while limiting solvent use and environmental impact. The antioxidant activity, assessed through radical scavenging (DPPH) assays, confirmed their high bioactive properties, supporting their potential use as functional ingredients for nutraceutical, feed, food, and cosmeceutical applications.

The results demonstrate a basis for scalable and transferable valorisation pathways, supporting the development of high-value bio-based products derived from seafood by-products. By shifting from disposal to resource utilisation, this work strengthens circularity, reduces environmental pressure, and contributes to a more sustainable, efficient, and competitive seafood sector.