Plant Amorphophallus is a genus herb that has been used in traditional Chinese medicine (TCM) and food for centuries in Asia. They are perennial herb growing with underground stem which is called corm. Amorphophallus konjac is the one of the most widely used among total 170 species. In tropical and subtropical Asia, it is also known as Konjac, Konjak, Konjaku, devils’ tongue, elephant yam etc. It is usually used to make flour and jelly because of its large starchy rhizome. It’s also a good substitute for gelatin.
The soluble fiber extracted from corms of Konjac commonly known as glucomannan is used as food additive and in dietary supplements. It's water soluble and fermentable composing of mannose and glucose combined by beta-1, 4 glucosidic linkages in ratio of around 1.6:1 (Drugs.com). It's bearing the highest viscosity which is about ten times the viscosity of cornstarch and making it the most popular food thickener. Unlike the cornstarch, the glucomannan is a soluble fiber, which does not contain starch and sugar. It also has little or no calories. Its molecular weight ranges from 200,000 to 2,000,000 Da. The characteristic hygroscopic properties giving it the ability of absorbing up to 50 times of its weight of water and make the dry form of glucomannan swells into a viscous gel in water (Drugs.com). This makes it a good candidate food for the purpose of weight loss. Another attractive aspect is the prebiotic activity of konjac glucomannan, it can help maintain digestive regularity (etc.).