Advancing sustainable closed-loop solutions: Supercritical carbon dioxide technology for aquatic biological waste valorization

• A critical review of ScCO₂-related articles from 2021 to 2025. • A summary of the extraction of bioactive compounds, including lipids and collagen/gelatin. • An overview of process-related mathematical modeling. • A tour d'horizon of the applications combining ScCO₂ with other technologies. The issue of aquatic food waste has drawn significant attention. As a waste rich in valuable nutrients, reusing it can protect the environment while generating economic benefits. Supercritical, subcritical liquid, and gaseous CO₂ treatments have the advantages of being non-toxic, easy to recycle and not producing harmful byproducts. This review summarizes the utilization of supercritical carbon dioxide (ScCO 2 ) for the reuse of aquatic waste, including fish and algae, through extraction and fractionation to obtain omega-3, phospholipids, carotenoids, collagen, and other bioactive compounds, as well as its combination with other technologies to enhance efficiency. Additionally, it discusses the thermodynamic and kinetic modeling of the processes and their economic feasibility. Given the advantages of ScCO 2 technology, it has the potential to see broader adoption in the aquatic food industry.