Sustainable food protein extraction from biomass using deep eutectic solvents: A review

The increasing universal demand for eco-friendly and value-added proteins requires novel and environmental friendly extraction methods. Deep eutectic solvents (DES) are gaining recognition as a promising class of green solvents because of their biodegradable nature, low toxicity, and tuneable physicochemical features. This review critically investigates the advances in DES as an environmental friendly substitute for protein extraction from various biomass sources, including plant, animal, microbial, and algal origins. Key topics discussed include the composition, varieties, and protein interactions, emphasizing structural and functional mechanisms like hydrogen bonding, electrostatic interactions, and van der Waals forces that contribute to protein structure preservation and functionality. The influence of physicochemical parameters-such as viscosity, polarity, melting point, and pH-on protein stability and extraction efficiency is thoroughly assessed. Refinement technologies, including ultrasonic-assisted and solid-liquid extractions, are assessed in conjunction with real world applications in valorizing agricultural and industrial by-products. The review discusses challenges as well, such as the high viscosity of some DES formulations, constraints in mass transfer, potential toxicity and obstacles in separation and scalability for industrial use. Additionally, it underscores the potential of DES-extracted proteins in food packaging and other bio-based applications. By incorporating structural analysis, sustainability considerations, and application-focused discussions, this review offers a new and detailed understanding to guide future research and industrial adoption of DES for sustainable protein extraction.