What is konjac mannan? Konjac mannan, also known as glucomannan is a water-soluble, fermentable polysaccharide that can serve as a dietary fiber. It is derived from the konjac root (Amorphophallus konjac), a plant native to tropical eastern Asia frequently used as a gelling agent in many foods, usually comprising more than half of Amorphophallus konjac. Specifically, it is used to make flour, jelly, and yam. In Japan, konjac appears in dishes such as the konyaku, a mixture of water, limewater, and flavoring frequently added to meals like gyudon, and ito konyaku, noodle-like strips of konjac added to foods such as sukiyaki and oden.The Chinese use the konjac plant to make tofu and the devil’s taro.
Konjac mannan is composed of common sugar monomers mannose and glucose in a ratio of 1.6:1, forming a straight-chain polymer through the glucosidic linkages between the monomers. When immersed in water under acidic conditions, it swells to form a viscous gel which can easily be denatured through intense heat, mechanical agitation, or enzymes from intestinal organisms such as bacteria from the Clostridium genera. Such factors help in effectively dissolving the polysaccharide into mannose and glucose to be used for practical applications.
Aside from its uses in many foods, glucomannan has been used as a possible treatment for common digestive problems such as constipation. Studies have shown that it can function as a laxative because of its swelling in the presence of water, as well as promote the presence of probiotic bacteria such as those under the Lactobacillus and Bifidobacterium genera, anddecrease the presence of potentially harmful microorganisms such as E. coli and Clostridium perfringens.
Konjac mannan has also been proven to be effective for patients dealing with either a high level of cholesterol or obesity issues. It possesses the characteristics of a hemicellulose, a heteropolymer present in plants that can easily be hydrolyzed and links microfibrils throughout the cell. In this context, glucomannan binds the cholesterol in the body and brings it to the liver to undergo either recycling or waste disposal. The decrease in cholesterol level also decreases the low density lipoprotein (LDL) content of the body, which otherwise can cause heart problems. It specifically contributes to lowering the LDL level of the body by inhibiting the active transport of cholesterol and the absorption of bile acids in the digestive tract.The ability to swell through absorption of water slows down digestion, which makes it an appetite suppressant.
Konjac mannan has also shown potential in the treatment of several illnesses. Dy (1992) investigated the possible role of konjac powder in inhibiting lung cancer in mice and observed that it greatly inhibited the growth of cancer cells. Kawamoto et al (2007) conducted a separate test showing the reduction of scratching and skin sensitivity in mice fed with glucomannan, although through pulverized glucomannan, implying a possible size of dosage for it to be effective. Other tests suggest that it can also help in efficiently delivering drugs throughout the body and in reducing thyroid hormone levels, occurrences of allergic rhinitis, and growth of Propionibacterium acnes, one of the causes of acne.
We hope this gave you a better view of what konjac mannan is.