Agar-Agar

Definition

Agar or agar-agar is a dry extract of red marine algae (seaweeds), which contains soluble fiber ^[1,2]. It is used as a food additive and supplement. Agar-agar in Malay means “jelly.”

Composition

Agar is a mixture of indigestible polysaccharides agarose and agaropectin, which are composed of galactose molecules, some of which contain sulfur ^[3].

Properties

Agar-agar is insoluble in cold but soluble in boiling water. When boiled, agar becomes liquid and when cooled it forms a clear, gel-like substance ^[1]. Agar’s melting temperature is 85-95 °C (185-203 °F) and gelling temperature (when cooled down) is 30-40 °C (86-104 °F) ^[3].

Calories

Agar-agar is indigestible, but large intestinal bacteria can break it down (ferment) to absorbable nutrients, mainly short-chain fatty acids (SCFAs), which can probably provide up to 2 kilocalories per gram ^[2].

Origin and Uses in Foods

Agar-agar is produced mainly in Japan, South America and Mediterranean countries.

Agar as a food additive is used as a thickener or “vegetable gelatin” or “vegetarian gelatin substitute.” It is used in pie fillings, meringues, ices, doughnut glaze, cream shells, sherbets, cream cheeses, canned and cured meats, sauces, noodles, baked products, soups, yogurts, cakes, ice creams, puddings, jelly candies and Japanese desserts, such as mitsumame and mizuyokan ^[1].

Agar powder and agar flakes are available in stores.

A Japanese word for agar is kanten. On the food products in the EU, agar is labeled with an E-number E406.

Agar Supplements

Agar is available over-the-counter as a soluble fiber supplement or bulk-forming laxative in the form of powder and capsules.

Possible Agar Health Benefits

There is INSUFFICIENT EVIDENCE about beneficial effects of agar on the following conditions ^[4].

In Japan, agar, as part of “kanten diet plan” is used to promote weight loss, since it supposedly has a satiating effect.
Agar capsules are sold as laxatives, because of its supposed bulk-forming properties.
Agar has been also used to lower blood cholesterol and glucose levels in individuals with diabetes mellitus.

Agar Safety and Side Effects

Agar, as a food additive is Generally Recognized as Safe (GRAS) by the US Food and Drug Administration (FDA) ^[5]. Agar may cause mild diarrhea and, theoretically, when ingested with insufficient fluid, esophageal or bowel obstruction ^[4]. Allergy to agar is possible.

Do not take agar if you have trouble swallowing or bowel obstruction or if you are pregnant. There is insufficient reliable information about safety of agar during pregnancy ^[4].