algin A salt (usually the sodium salt) of alginic acid, a complex polysaccharide present in the cell walls and between the cells in brown seaweeds (Phaeophyta). When extracted from the seaweed and mixed with water, many algins make very thick, viscous solutions. They have a number of commercial uses (e.g. as stabilizers in ice-cream and other foods, and as suspending agents in paints and pharmaceutical preparations).

algin (alginic acid) A complex polysaccharide occurring in the cell walls of the brown algae (Phaeophyta). Algin strongly absorbs water to form a viscous gel. It is produced commercially from a variety of species of Laminaria and from Macrocystis pyrifera in the form of alginates, which are used mainly as stabilizers and texturing agents in the food industry.