agar Dried extracts from various seaweeds, including Gelidium and Gracilaria spp. It is a partially soluble non‐starch polysaccharide, composed of galactose units. It swells with water to form a gel, and is used in soups, jellies, ice‐cream, and meat products. It is also used as the basis of bacteriological culture media, as an adhesive, for sizing silk, and as a stabilizer for emulsions. Also called agar‐agar, Macassar gum, vegetable gelatine.

agar Complex substance extracted from seaweed; its powder forms a ‘solid’ gel in solution. It is used as a thickening agent in foods; as an adhesive; as a medium for growing bacteria, mould, yeast and other microorganisms; as a medium for tissue culture; and as a gel for electrophoresis.

a·gar / ˈäˌgär; ˈāˌgär/ (also a·gar-a·gar / ˈägär ˈäˌgär; ˈāgär ˈāˌgär/ ) • n. a gelatinous substance obtained from various kinds of red seaweed and used in biological culture media and as a thickener in foods.

agar A complex polysaccharide obtained from certain types of seaweed. When heated with water and subsequently cooled to about 45°C, agar readily forms a gel (jelly); an agar gel supplemented with nutrients is used widely as a medium for the culture of bacteria and other micro-organisms.

agar An extract of certain species of red seaweeds that is used as a gelling agent in microbiological culture media, foodstuffs, medicines, and cosmetic creams and jellies. Nutrient agar consists of a broth made from beef extract or blood that is gelled with agar and used for the cultivation of bacteria, fungi, and some algae.