Alginic acid

Alginic acid (CAS 9005-32-7), also known commercially as Kelacid and approved as E400, is a natural polysaccharide extracted from brown seaweed. It functions as a thickener, gelling agent, and stabilizer across food, pharmaceutical, and industrial manufacturing processes.

In food production, E400 thickens and stabilizes products such as salad dressings, desserts, and bakery fillings where controlled viscosity and water retention are critical. Pharmaceutical manufacturers use it as a binder and disintegrant in tablet formulations.

It also serves as a viscosity modifier in topical preparations and antacid products. Textile processors apply alginic acid as a print paste thickener for reactive dye printing, where its resistance to dye interaction ensures clean color definition on fabric.

In paper manufacturing, it improves surface sizing and coating uniformity, directly affecting print quality and sheet strength. Alginic acid is supplied as a white to pale yellow powder in varying particle size distributions to suit different requirements.

Standard grades include food-grade (FCC compliant) and pharmaceutical-grade (USP/BP) specifications. Technical grade is available for textile and industrial applications where pharmaceutical compliance is not required.