Green Extraction Strategies for Sea Urchin Waste Valorization

Area of Science:

• Marine Biology
• Biotechnology
• Green Chemistry

Background:

• Paracentrotus lividus, or purple sea urchin, is a valuable food source in Europe, particularly Italy.
• Sea urchin processing generates significant waste, primarily the test and spines, after gonad harvesting.
• Existing by-product valorization focuses on collagen, leaving carbonate-rich materials underutilized.

Purpose of the Study:

• To develop a green extraction strategy for high-value compounds from purple sea urchin waste.
• To selectively extract polyunsaturated fatty acids and carotenoids using supercritical CO2.
• To isolate and characterize polyhydroxynaphthoquinones (PHNQ) and assess their antioxidant properties.

Main Methods:

• Supercritical CO2 extraction was employed to selectively isolate fatty acids and carotenoids.
• Solvent-based extraction was used on the remaining powder to obtain PHNQ.
• Antioxidant activity was measured using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay.

Main Results:

• Fatty acids and carotenoids were successfully extracted and identified based on supercritical CO2 parameters.
• Polyhydroxynaphthoquinones, including Spinochrome A and Spinochrome B, were obtained from the residual material.
• The extracts exhibited significant antioxidant activity, confirming their potential value.

Conclusions:

• Selective and successive extraction methods effectively valorize purple sea urchin waste.
• Supercritical CO2 and solvent-based techniques offer a feasible approach to target added-value compounds.
• This strategy promotes a circular economy model for seafood processing by-products.