Green in the deep blue: deep eutectic solvents as versatile systems for the processing of marine biomass

Abstract

Deep eutectic solvents (DES) consist of a mixture of compounds, which when combined, present a melting point lower than that of each individual compound. They are an emerging class of alternative solvents notable for their versatility and green credentials. Moreover, they can be synthesized with renewable, non-toxic and biocompatible components and can be reused over several cycles. Over the past decade, they have been increasingly used to extract biopolymers and small molecules from marine biomass and to synthesize biomaterials from marine-origin compounds. Herein, a general overview of the use of DES for processing marine biomass is provided. First, the relevant properties of DES for processing marine biomass, and use as extraction media and as functional adjuvantsare described. Then, the current state of the art concerning the progress made on their use for processing crustacean, fish by-products and seaweeds for the extraction of polysaccharides, proteins, and pigments, as well as their use to create functional materials is explained. The issues concerning DES properties, extract purification, toxicity and biodegradation are also stated. Finally, the future perspectives of DES are discussed. Despite some presentedchallenges, DES are promising systems for the processing of marine biomass with high future potential.

Keywords

• ‘green alternative solvents’
• ‘functional adjuvants’
• marine biomacromolecules