The global shift toward plant-based proteins is driven by the need for sustainable food systems, improved public health, and enhanced food security. However, traditional extraction methods, such as alkaline extraction–isoelectric precipitation (AE–IEP), often result in protein denaturation, limited functionality, and increased environmental impact. These limitations have prompted efforts to develop more efficient and sustainable technologies.
This study systematically examines peer-reviewed studies comparing conventional techniques (AE–IEP and salt and solvent extraction) with innovative approaches such as ultrasound-assisted extraction (UAE), pulsed electric field (PEF), microwave-assisted extraction (MAE), ionic liquid extraction, and membrane-based purification. Articles were searched in Web of Science and Scopus using the keywords “Plant Protein Extraction” and “Purification.” From 3,761 initial records, duplicates, non-English texts, and studies without methodological detail were excluded. After screening and eligibility checks, 124 full-text articles were assessed, and 72 studies were finally included in the synthesis.
The synthesis of the current literature shows that modern approaches are being applied across a wide range of crops and biological sources, from cereals and legumes to oilseeds, algae, and underutilized plants. Emerging methods consistently improve extraction efficiency, enhance solubility and emulsification properties, and reduce contaminants such as phenolics, anti-nutritional compounds, and toxins. Research also highlights the integration of nanotechnology, enzymatic modification, and microbial or biopolymer-based approaches, which expand functional and therapeutic applications. Studies on protein–polyphenol complexes, bioactive peptides, extracellular vesicles, and enzyme-assisted detoxification further demonstrate how extraction and purification are increasingly linked to health-related benefits, not just yield and purity.
Overall, modern technologies provide substantial improvements in the quality and functionality of plant protein isolates. Yet, challenges remain in balancing yield, purity, and cost, as well as scaling laboratory advances into industrial processes. These advances, when adapted to different plant sources and market needs, hold strong potential for building resilient protein systems that meet both nutritional demands and sustainability goals.
