Sustainable Recovery of Astaxanthin from Crustacean By-Products Using Green Extraction Technologies

The seafood processing industry generates large amounts of crustacean by-products, including shells, heads, and appendages, which are often discarded despite containing valuable bioactive compounds. Among them, astaxanthin (ASX), a carotenoid with remarkable antioxidant properties, has attracted considerable attention for applications in functional foods, nutraceuticals, and dietary supplements. The recovery of ASX from seafood residues represents an attractive strategy within the framework of circular economy and sustainable food production.

In this study, crustacean by-products from seven species were investigated as alternative natural sources of astaxanthin. Green extraction approaches based on ultrasound-assisted extraction (UAE) and natural deep eutectic solvents (NaDES) were evaluated and compared with conventional organic solvent extraction. Extraction conditions were optimized to maximize ASX recovery while minimizing solvent consumption, extraction time, and environmental impact.

Among conventional solvents, acetone provided the highest extraction efficiency, being 1.7-fold higher in comparison to other solvents such as acetonitrile. UAE significantly reduced extraction time from 30 to 10 min while maintaining comparable yields. Furthermore, hydrophobic NaDES formulations based on naturally derived components showed promising extraction performance, demonstrating their potential as environmentally friendly alternatives to traditional organic solvents (exhibiting similar yields than with acetoner, 50 mg total ASX/kg dry sample).

Chromatographic analysis revealed substantial differences in astaxanthin content among the studied species, with Penaeus kerathurus showing the highest levels (55.5 mg total ASX/kg dry sample). Besides free astaxanthin, a complex profile of esterified forms was observed, highlighting the richness of these marine by-products as sources of high-value carotenoids.

Overall, the results demonstrate that crustacean processing residues can be efficiently transformed into valuable sources of natural astaxanthin through sustainable extraction technologies. The combination of UAE and NaDES constitutes a promising approach for the development of greener recovery processes, contributing to waste valorization, resource efficiency improved, and the implementation of circular economy principles in the seafood sector.