Agar is a natural macromolecular polysaccharide produced by scientific processing and extraction from marine red algae such as Gracilaria and Asparagus. It features high gel strength, strong coagulation power, low syneresis, and good stability. Agar ranges in color from white to yellowish, with a gelatinous texture, odorless or with a slight characteristic odor. As a hydrophilic colloid, agar is insoluble in cold water, soluble in boiling water, and slowly soluble in hot water.
Agar can form a fairly stable gel even at a concentration below 1%, making it a usable raw material for the food industry, chemical industry, and medical research. It possesses physical and chemical properties such as gelling, stability, and the ability to form complexes with certain substances. It can be used as a thickener, gelling agent, suspending agent, emulsifier, preservative, and stabilizer.