A review of innovative extraction technologies for protein recovery from plant-based by-products: A step toward...

The increasing global emphasis on sustainability in food production has heightened interest in valorizing plant-based by-products, including oilseed meals, fruit pomace, cereal bran, and legume hulls. Although these residues contain valuable proteins, their commercial use remains limited due to shortcomings associated with traditional extraction techniques. Conventional methods are typically energy-intensive, environmentally polluting, chemically dependent, and often detrimental to the functionality of extracted proteins. To address these challenges, innovative extraction technologies have emerged, such as Ultrasound-Assisted Extraction (UAE), Enzyme-Assisted Extraction (EAE), Supercritical Fluid Extraction (SFE), Microwave-Assisted Extraction (MAE), Natural Deep Eutectic Solvents (DES), Pulsed Electric Fields (PEF), High Hydrostatic Pressure (HHP), and Membrane Filtration. These modern methods significantly improve extraction efficiency, protein quality, and environmental sustainability. Moreover, these advanced technologies align closely with circular economy principles by converting waste streams into high-value ingredients suitable for food, nutraceutical, and cosmetic applications. Despite these advantages, current research faces gaps, including operational complexity, challenges in managing protein-membrane interactions, and a lack of standardized optimization protocols. The review identifies critical future directions-such as combining extraction methods (hybrid approaches), developing advanced antifouling membrane solutions, and applying machine learning for process optimization-to further enhance the economic feasibility and sustainability of protein extraction processes.