What Is Algin? Uses and Sources

Algins (alginates) are natural polysaccharides extracted from the cell walls of brown algae (Phaeophyceae), such as kelp and wracks.

Chemical Structure

Linear copolymers of β-D-mannuronic acid (M) and α-L-guluronic acid (G) arranged in blocks (MM, GG, MG). The M/G ratio determines gel strength and flexibility.

Key Properties

• Water-soluble, forming viscous solutions
• Forms gels with calcium ions (cold-setting, heat-stable)
• Film-forming, stabilizing, thickening
• Biocompatible, non-toxic, biodegradable

Major Applications

• Food: Thickener, stabilizer, emulsifier in ice cream, sauces, dressings, spherification (molecular gastronomy)
• Pharmaceuticals: Controlled-release tablets, wound dressings (calcium alginate), antacid raft-forming agents (Gaviscon)
• Cosmetics: Thickener, moisture-retentive masks, texture modifier
• Industrial: Textile printing, paper coating, welding fluxes
• Dietary Fiber: Soluble fiber supplement

Global production relies on sustainable wild harvest and aquaculture of species like Laminaria, Macrocystis, and Ascophyllum.