"A practical supplier guide to konjac glucomannan powder (CAS 37220-17-0). Covers what the material is, how it thickens and gels, its food, vegan-meat, pharma and cosmetic uses, the specs buyers should verify, and handling notes."
-Deshangchemical-chemechemi
Konjac Glucomannan (CAS 37220-17-0): The Food-Grade Fibre Behind Konnyaku, Vegan Meat, and Slow-Release Tablets
Konjac glucomannan, usually shortened to KGM or just called konjac gum, is a high-molecular-weight water-soluble dietary fibre pulled from the tuber of Amorphophallus konjac. If you have eaten konnyaku jelly, a shirataki noodle, or a vegan "fish" fillet that holds together without egg or gluten, you have already met it. Under the number CAS 37220-17-0 it ships as a fine off-white to cream powder, and depending on grade it lands in food plants, nutraceutical lines, and pharmaceutical workshops.
What the material actually is
KGM is a non-ionic polysaccharide built from mannose and glucose units in roughly a 1.6:1 ratio, joined by beta-glycosidic bonds. That structure explains how it behaves in water: a small amount swells into a thick, tacky paste, and under the right conditions it firms into a rubbery gel. The gel is thermally stable, which matters for products that get cooked or retorted after forming.
Viscosity is the spec buyers argue about most. A 1% solution of good food-grade KGM can read well past 10,000 mPa·s, and some pharma grades go higher. Because viscosity drops fast once the powder is sheared or held in acid, the way you hydrate it changes the number you measure.
How it thickens and gels
On its own KGM forms a weak, stringy gel. The trick most formulators use is alkali. Add a little calcium hydroxide, sodium carbonate, or potassium carbonate and the gel firms into the elastic block people know as konnyaku — which is why konnyaku kits ship with a small sachet of food-grade lime. Without alkali you still get a strong thickener, useful in soups, sauces, and vegan dairy where you do not want a set gel at all.
In food
The food side is where KGM shows up most. As a thickener and stabilizer it carries the E-number E425 in Europe. You will find it in instant noodles (to keep the broth clingy), reformed hams, vegetarian jellyfish, and gluten-free bakery where it holds the moisture that flour would normally provide. The same swelling property is what puts it in weight-management products: the fibre drinks water in the stomach and the user feels full. Buyers building a flavour system often reach for ethyl maltol (CAS 4940-11-8) to round off the taste, and for acid-balanced drinks citric acid anhydrous (CAS 77-92-9) is the usual acidulant.
In vegan meat
This is the application that has grown fastest in the last few years. KGM gives plant-based "seafood" and "poultry" a chewy, fibrous bite that soy or pea protein cannot reach alone. Combined with methylcellulose or starches it mimics the snap of squid or the strand of a chicken strip. Formulators who want a softer mouthfeel sometimes blend it with sodium lauroylsarcosinate (CAS 137-16-6) in rinse-off systems, though in food the more common partners are starches and alginates.
In pharma and cosmetics
Pharmacists have used KGM for decades as a tablet binder and as a matrix for sustained-release tablets. Because it swells in the gut, a KGM matrix slows drug release and smooths the dissolution curve. It is also a bulk-laxative raw material and a cholesterol-management supplement, sold as glucomannan capsules and sachets. For skin-facing products the same gentle film-forming behaviour is why it appears in cosmetics next to materials like squalane (CAS 111-01-3) and kojic acid (CAS 501-30-4), where it carries actives and adds slip.
Specs to check before you buy
| Parameter | What to confirm |
|---|---|
| Viscosity | Measured at 1% w/v, 25°C, Brookfield. Confirm spindle and shear history. |
| Particle size | Finer powder hydrates faster but dusts more; coarser is easier in dry blends. |
| pH of 1% solution | Food and pharma grades sit near neutral, around 5.0–7.0. |
| Loss on drying | Keep under the agreed limit or the powder clumps in storage. |
| Microbial load | Total plate count, yeast, mould, and coliforms must meet the grade. |
| Heavy metals & residual alkali | Critical if the batch was gel-grade processed with lime. |
| Allergen statement | Needed for clean-label food lines (gluten, soy, etc.). |
Storage and handling
KGM is hygroscopic. Keep it in a sealed bag away from humidity, and weigh it in a low-dust area because the fine powder drifts. Hydrate it in cold water with agitation, then heat if the process needs it; dumping it into hot water without mixing makes lumps that are hard to break.
Why the source matters
Viscosity and microbial limits vary sharply between lots, and a cheap off-spec batch can ruin a gel line. Working with a supplier who holds batch certificates, offers food and pharma grades, and ships consistent viscosity is what keeps a production run stable. If your line also uses cosmetic peptides such as GHK-Cu (CAS 49557-75-7), consolidating from one source can simplify the paperwork.
Bottom line
Konjac glucomannan is one of those quiet ingredients that does a lot of visible work: it sets konnyaku, binds vegan meat, thickens gluten-free bread, and carries actives in tablets and creams. If you formulate foods, supplements, or topical products and have not tested it yet, it is worth a bench trial — start at 0.5–1.0% and adjust from the viscosity you measure, not the number printed on the bag.
