- Glucomannan is a water-soluble polysaccharide classified as a hemicellulose, composed of a linear backbone of β-(1→4)-linked D-mannose and D-glucose units in an approximate molar ratio of 1.6:1, with occasional acetyl substitutions. This structure gives glucomannan exceptional hydrophilic properties and the ability to form highly viscous solutions even at low concentrations.
- It is considered one of the most effective natural dietary fibers, renowned for its swelling capacity and ability to absorb large amounts of water—sometimes up to 50 times its weight.
- The primary commercial source of glucomannan is the konjac plant (Amorphophallus konjac), a tuber native to East and Southeast Asia. Konjac glucomannan (KGM) has been traditionally consumed in Japan, China, and other parts of Asia for centuries, particularly in foods like konnyaku (a jelly-like product) and shirataki noodles. Beyond konjac, glucomannan is also found in certain legumes and other plants, though in much smaller amounts. Its abundance in konjac roots, combined with its unique functional properties, makes konjac the dominant industrial source.
- From a nutritional and health perspective, glucomannan is valued as a dietary fiber with multiple physiological benefits. Because humans lack the enzymes to hydrolyze its β-(1→4) bonds, glucomannan passes through the small intestine undigested and undergoes fermentation in the colon by gut microbiota, producing beneficial short-chain fatty acids (SCFAs). Its high viscosity slows gastric emptying and nutrient absorption, promoting satiety and aiding in weight management. Clinical studies have shown that glucomannan supplementation may help reduce cholesterol, regulate blood glucose, and support bowel regularity, making it useful for managing obesity, diabetes, and cardiovascular risk.
- In the food industry, glucomannan is widely used as a thickener, gelling agent, stabilizer, and fat replacer. It is incorporated into low-calorie foods, gluten-free products, and functional foods aimed at promoting satiety and digestive health. Its ability to form thermally stable gels, especially when combined with other hydrocolloids such as xanthan gum or carrageenan, broadens its applications in confectionery, bakery, and plant-based meat alternatives. In Asia, its traditional uses remain strong, while in Western markets it has gained popularity as a functional supplement and ingredient in health foods.
- Glucomannan also has applications in pharmaceuticals, cosmetics, and biotechnology. In drug delivery, its gel-forming and bioadhesive properties are explored for sustained-release formulations. In cosmetics, glucomannan is included in skincare products as a moisturizer and texture enhancer. Its biodegradability and biocompatibility make it suitable for emerging uses in biomedical materials, wound dressings, and encapsulation systems for probiotics or bioactive compounds.
