Leaves, cuticles and green stems as untapped feedstocks for natural hydrogels: Extraction, functionalization and applications

Leaves, green stems and cuticles are underutilized. They can be useful to make natural hydrogels for a sustainable bioeconomy. They are different parts of plants like fruit peels or the sticky stuff from seeds. Leaves, green stems and cuticles have their special mix of chemicals like cellulose, hemicellulose, pectin, cutin and mucilage. These chemicals help leaves, green stems and cuticles to hold water. Leaf cuticles have an ability to control moisture. They also have phenolics and secondary metabolites. The article explains how to extract and separate the hydrogel from leaves, green stems, etc. All the methods in detail including the extraction and fractionation strategies are explained. Overall, valorization of leaves, cuticles, and green stems offers a promising pathway toward circular bioeconomy-driven hydrogel technologies.