Towards the sustainable extraction and purification of non-animal proteins from biomass using alternative solvents

Abstract

Advances towards the development of a sustainable economy must address the exploitation of bio-based products combined with the use of greener solvents and manufacturing processes that can preserve natural resources and the environment. To address the growing demand for proteins, their production must focus on non-animal sources, such as vegetal biomass and respective residues/waste, and on the use of sustainable solvents and processes for their recovery. This review provides an overview of the advances achieved in the separation and purification processes of proteins from vegetable biomass and respective residues using ionic liquids (ILs) and deep eutectic solvents (DESs) as alternative greener solvents. It begins with an overview of the ability of ILs and DESs to stabilize proteins, followed by the assessment of the extraction and separation of biomass-derived proteins assisted by ILs and DESs. Different types of non-animal biomass and respective residues are considered as protein resources, i.e., algae, plants (e.g., aloe vera and holy basil), cereals (e.g., wheat and oat), fruits (e.g., papaya, pineapple, pomegranate, and seabuckthorn berries), and vegetables (e.g., spinach, radish, and ginger). Several IL- and DES-based approaches are discussed, comprising (i) conventional solid–liquid extraction (SLE), (ii) ultrasound-assisted extraction (UAE), (iii) microwave-assisted extraction (MAE), and (iv) aqueous biphasic systems (ABSs). Finally, the economic and environmental challenges of using such alternative solvents in industrial applications are discussed, including technoeconomic analysis and life cycle assessment.