(282e) Crustacean Shells Waste Valorization - a Tale of Two Processes

The idea of a circular economy based on reducing waste and recycling products has shaped recent policy efforts since it responds to both environmental and economic challenges. Thus, materials that are currently considered as low-value waste must be treated as a renewable feedstock. However, converting waste into valuable products will not be enough as long as the current downstream processes continue to be economically and environmentally unfavorable. Downstream processes represent up to 80% of the total manufacturing costs, making imperative the development of sustainable technologies for the Green Biorefinery concept.

Fish industry presents a large market value worldwide, with 70% of the caught fish being industrially processed. However, this also leads to a considerable waste production. As one of the most traded food commodities, seafood generates 6-8 M tons of crustacean shells waste, which is rich in valuable compounds like astaxanthin. Yet, these are still neglected. Astaxanthin is a carotenoid with an enhanced antioxidant activity, hence being a natural colorant with dual function – color & health benefits, and several applications.

Lately, there has been an increasing consumers demand for natural ingredients thus, leading to an impetus search for natural colorants to be applied in food, beverages, cosmetics and textile industries. However, replacing the synthetic dyes is a hard task as there is still a limited number of commercially available natural pigments.

In this sense, using shrimp shells waste to extract and purify astaxanthin arises as an excellent solution for these bottlenecks. Thus, it was here developed two distinct processes to obtain this colorant. One is based on a full biorefinery approach whereas the second approach uses a selective and sustainable process based on deep eutectic solvents for the solely isolation of astaxanthin, as this is the highest-added value compound of this biomass. Finally, both processes were analyzed in terms of economic and environmental impacts.

Acknowledgments

This work was funded by the Slovenian Research Agency under research core funding P2-0152; and within the scope of CICECO projects: UIDB/50011/2020 & UIDP/50011/2020 and CESAM: UIDB/50017/2020 & UIDP/50017/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. A. Dias and H. Passos acknowledge FCT for their contracts: CEECIND/02174/2017 and CEECIND/00831/2017, respectively.