Products
Agar (synonym: agar-agar) is available as a pure substance in pharmacies, drugstores, and large grocery stores, among other places. It is found in numerous processed products. Agar was discovered in the 17th century and originated in Japan. It is generally more expensive than gelatin.
Structure and properties
Agar is composed of the polysaccharides of various red algae, mainly , for example, and . It is obtained by extracting the algae with boiling water. The extract is hot filtered, concentrated and dried. Agar is present as powder or broad, crumpled ribbons or flakes. It is colorless to pale yellow, translucent, somewhat tough and difficult to break. It is more brittle after drying. Pure agar has a mucilaginous taste. The gel formed is odorless and tasteless.
Ingredients
The main components are agarose and agaropectin. The agarose is responsible for the gelling ability.
Effects
Agar has gelling, stabilizing, clarifying, emulsifying and viscosity-increasing (thickening) properties. What is special about agar is the heat stability of the gels formed. The gel melts at about 85°C and solidifies at about 40°C. Gelatin, on the other hand, melts at body temperature.
Areas of application
- In the food industry and in the kitchen, for example for sauces, desserts, confectionery and dairy products.
- As a gelling agent for jams.
- For vegetarian cooking as an alternative to animal gelatin, as a vegetable gelling agent.
- For the treatment of constipation (paragar).
- As a pharmaceutical excipient, for example, as a base or as a disintegrant.
- For the preparation of agar plates and agar culture media.
Dosage
As a gelling agent, sprinkle the agar into the liquid and boil for two minutes, stirring frequently. Subsequently, continue to process or allow to cool. One teaspoon gels about 500 ml of liquid – so comparatively small amounts starting at about 1% are necessary. Agar dissolves in hot water. It is therefore not suitable for cold dishes.
Undesirable effects
Agar is generally considered safe and tolerable (GRAS).
