Innovative approaches in leaf protein extraction: advancements, challenges, and applications in sustainable food formulation and design.

The growing demand for sustainable protein sources has recognized leaf protein as a promising alternative, valued for its rich nutritional profile and environmental benefits. Extracted from various plant leaves, leaf proteins are high in essential amino acids and offer potential for multiple food applications. Their extraction also supports circular economy principles by converting agricultural by-products into valuable resources. Recent advances in extraction technologies, such as enzymatic hydrolysis, ultrasound-assisted extraction, and membrane filtration, have improved protein yield, purity, and functionality. These techniques aim to overcome traditional challenges, particularly removing chlorophyll and anti-nutritional factors that affect flavor, color, and overall consumer acceptance. However, despite notable progress, significant hurdles remain in scaling up extraction for commercial use. Low protein yields, high processing costs, and the persistence of undesirable sensory attributes, such as green color and earthy flavors, limit wider adoption. This review provides a comprehensive analysis of recent advancements in leaf protein extraction, highlights key technological and commercial barriers, and explores potential food applications. Synthesizing current research identifies opportunities for innovation to improve extraction efficiency, enhance product quality, and promote the use of leaf proteins in sustainable food systems. Future developments could significantly contribute to addressing global protein demands sustainably.