E425I - Konjac gum

At a glance

• What it is: A natural, glucomannan‑rich gum from the konjac plant, used as a thickener, stabiliser, gelling agent, humectant, and carrier.
• E‑number: E425i (Konjac gum). A related additive is E425ii, konjac glucomannan.
• Typical foods: Shirataki/konjac noodles, jelly desserts, sauces, plant‑based meats, bakery fillings, and beverages.
• Diets: Vegan and gluten‑free friendly. Not known as a common allergen.
• Label names: Konjac gum, konjak gum, konjac flour, glucomannan.
• Special note: Jelly mini‑cups containing konjac have been banned in the EU due to a choking hazard.

Why is Konjac gum added to food?

Konjac gum is added to thicken, gel, or stabilise foods so they feel smooth and consistent. It binds water, helps keep ingredients evenly mixed, and can improve the body of sauces, desserts, and drinks. In alkaline conditions with calcium present, it can form firm, heat‑stable gels, which is why it’s popular in jelly products and certain noodles.

What foods contain Konjac gum?

You’re most likely to find konjac gum in:

• Asian‑style shirataki/konjac noodles and rice
• Jelly and gelled desserts
• Sauces, gravies, and dressings
• Plant‑based meat analogues for juiciness and bite
• Bakery fillings and low‑fat spreads
• Fiber‑fortified snacks and beverages

In the European Union, small jelly mini‑cups containing konjac are not allowed because they pose a choking risk, especially to children.¹

What can replace Konjac gum?

Depending on the recipe and texture you want, cooks and manufacturers may swap in:

• Xanthan gum for general thickening and pourable textures
• Guar gum for cold‑process thickening
• Locust bean gum for creamy, elastic gels (often with other gums)
• Gellan gum for clear, brittle or soft gels
• Sodium alginate for spherification and heat‑stable gels with calcium
• Agar for firm, sliceable gels
• Pectin or carrageenan for fruit or dairy‑style gels

How is Konjac gum made?

Konjac gum is obtained from the corms of Amorphophallus konjac. The corms are cleaned, dried, and milled to make konjac flour. The glucomannan is then purified (for example, by washing and selective extraction to remove starches and proteins), dried, and ground into a fine powder that meets identity and purity specifications set in EU law for E425i.²

Is Konjac gum safe to eat?

The European Food Safety Authority (EFSA) reviewed konjac gum (E425i) and concluded there is no safety concern for consumers at reported uses and use levels in foods.³ However, there is a known choking hazard with certain jelly mini‑cups containing konjac, and the European Commission has banned these products in the EU.¹

Does Konjac gum have any benefits?

Konjac gum is rich in glucomannan, a non‑digestible, soluble dietary fiber. It adds minimal calories while helping foods hold moisture and feel fuller in the mouth.³ EFSA has also approved a health claim that glucomannan, taken in the context of an energy‑restricted diet, contributes to weight loss when 3 grams per day are consumed in three 1‑gram doses with water before meals.⁴ This claim applies to the fiber itself under the stated conditions, not to every food that contains small amounts of konjac gum.

Who should avoid Konjac gum?

• Young children and anyone with swallowing difficulties should avoid jelly mini‑cups made with konjac due to choking risk (these are banned in the EU).⁵
• People who have been advised to restrict fiber (for example, during certain medical treatments) should consult their healthcare professional before consuming high‑fiber products.

Myths & facts

• Myth: Konjac gum is a synthetic chemical. Fact: It’s a plant‑derived gum extracted from konjac corms.
• Myth: Konjac gum is unsafe. Fact: EFSA found no safety concern at reported food use levels; the main issue has been choking with specific jelly mini‑cups, which are banned in the EU.
• Myth: Konjac gum adds lots of calories. Fact: It is a soluble fiber and contributes very few calories in typical use.

Konjac gum in branded foods

Konjac gum appears on labels as “konjac gum,” “konjac flour,” “konjak gum,” “glucomannan,” or “E425i.” You’ll commonly see it in shirataki noodles, some gelled desserts, plant‑based meat alternatives, and reduced‑fat sauces or dressings. Formulas change often, so always check the ingredient list if you need to confirm its presence.

References

Footnotes

1. Commission Decision 2002/247/EC on suspending the placing on the market and import of jelly confectionery containing the food additive E 425 konjac — European Commission. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32002D0247 ↩ ↩²

2. Commission Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 (entry for E 425 i, Konjac gum) — European Commission. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩

3. Re‐evaluation of konjac gum (E 425 i) and konjac glucomannan (E 425 ii) as food additives — European Food Safety Authority (EFSA). https://www.efsa.europa.eu/en/efsajournal/pub/4876 ↩ ↩²

4. Scientific Opinion on the substantiation of health claims related to glucomannan and reduction of body weight (Article 13(5)) — EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010.1798 ↩

5. See the “What foods contain Konjac gum?” section and its cited EU decision for details. ↩