Agar is a jelly-like substance that is obtained from algae. It was first discovered in the late 1650s by Mino Tarozaemon, from Japan, where it was first called kanten. Derived from the polysaccharide agarose, agar forms the supporting structure of the cell walls of specific species of algae and are released by boiling. These algae are known as agarophytes, which belong to the Rhodophyta phylum, also known as red algae. Agar is essentially the result of mixing two components: a heterogeneous mixture of smaller molecules called agaropectin and the linear polysaccharide agarose.
Throughout history and well into modern times, agar has been primarily used in Asia as an ingredient in desserts and also as a solid substrate to contain culture media for microbiological work. Agar can be utilized as an appetite suppressant, a laxative, a thickener for soups, a vegetarian substitute for gelatin in fruit preserves, ice cream, and other desserts, as a particular agent in brewing, and also for sizing fabrics and paper.