Keeping an eye on alginate: innovations and opportunities for sustainable production and diverse applications

Abstract

Alginate is a biocompatible, biodegradable, brown seaweed polysaccharide with diverse techno-functional properties. However, growing environmental concerns are driving the need for more sustainable alginate extraction methods. Novel methods such as ultrasound-assisted extraction, microwave-assisted extraction and subcritical water extraction among others, have attracted significant attention by improving polysaccharide yields and addressing current production bottlenecks i.e., extraction time, solvent consumption and energy demand. These technologies used individually or in combination with novel solvents (food grade solvents, ionic liquids, deep eutectic solvents), offer promising environmentally friendly and food-grade alternatives. Large-scale optimised methods utilising these innovative methods remain underexplored. In addition, pre-treatment strategies utilising green protocols could improve alginate yields and properties. This narrative review aims to examine conventional alginate processing alongside emerging technologies and solvents to enhance extraction efficiency and functional properties. It explores the advantages as well as disadvantages of these approaches such as cost and scalability. Challenges for future uses of alginates are also discussed i.e., mechanical and biological. By deepening our understanding of these properties future research could unlock innovative applications, with cultivated meat offering a novel and promising direction.