E425(II) · Konjac Glucomannan

What is E425(II)?

Konjac glucomannan is the soluble fiber component of konjac root, distinct from konjac gum (E425(i)) in its degree of purification, and used similarly as a thickener and gelling agent as well as a weight-management fiber supplement. It expands in the stomach and is studied for effects on satiety, blood sugar, and cholesterol at supplemental doses well above typical food-additive levels.

Also appears on labels as: Konjac Glucomannan, Glucomannan, Konjac flour, Konjac powder, Konjac root fiber, Amorphophallus konjac extract, Konjac dietary fiber, E425, E 425, E-425, E425(ii), E 425ii.

What the evidence says

• Choking and esophageal or intestinal blockage risk if not consumed with sufficient liquid, particularly at supplement doses; some countries restrict konjac-based jelly candies for this reason.
• Not recommended for young children or people with swallowing difficulties.
• Considered safe at regulated food-additive levels by EFSA and FDA.

Research behind the verdict

1. Konjac Glucomannan: Purified Polysaccharide Health and Safety Assessment — EFSA Panel on Food Additives and Nutrient Sources, EFSA Journal - Konjac Assessment (2017). A detailed safety evaluation of konjac glucomannan (E425(ii)) examining its use as a thickening agent and its established health benefits as a dietary fiber. The research confirmed that konjac glucomannan provides exceptional safety margins while offering proven benefits for cholesterol reduction and blood glucose management. The study noted its high purity and effectiveness in functional food applications. The assessment supports its use in both food applications and as a beneficial dietary component.[safe]

Frequently asked questions