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E425 Konjac (konjac glucomannan)

E425Thickeners & gumsOrigin: Plant
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The short answer
Konjac (E425) is a strong fiber from the konjac plant, used in shirataki noodles and as a thickener. It is approved, except in jelly mini-cups, which are banned because they are a choking hazard.
Use in moderation

Safe in small amounts; may bother some people or raise blood sugar.

E-numberE425
Comes fromPlant
What it doesThickeners & gums
Glycemic index—
Daily limitNot set
Also calledKonjac, Konjac gum

Rules by country

🇺🇸 US FDAApproved with limits
🇪🇺 European UnionApproved with limits
🇨🇦 Health CanadaApproved with limits
CaliforniaNo extra rules

Konjac is an approved thickener. Both the FDA and the EU ban it in jelly mini-cups, because those sweets do not dissolve in the mouth and have choked children. Noodles, capsules and ordinary gels are a different use.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

A little konjac glucomannan holds a lot of water and makes a clear, bouncy gel. Japanese cooking uses the corm as konnyaku. Low-calorie noodles are mostly water set with this fiber.

Where it comes from: Konjac flour is milled from the corm of the konjac plant. Glucomannan is the soluble fiber washed out of that flour. E425 covers both the gum and the glucomannan.

Why it’s in food

  • Sets shirataki noodles
  • Thickens vegan gels
  • Adds fiber to drinks
  • Firms surimi

Often found in

Shirataki noodlesKonnyaku cakesVegan jellyFiber drinksSurimiCapsules

Also listed as: Konjac, Konjac gum, Konjac glucomannan, Konnyaku, E425i, E425ii

Health & gut impact

ChokingConcern

Mini-cup jellies made with konjac do not melt in the mouth. After choking deaths, the US and the EU banned that sweet.

FDA import alert on konjac mini-cup jelly; EU jelly mini-cup ban

FiberBenefit

Glucomannan is a viscous fiber. It can blunt a glucose rise and it can also swell in the throat if a capsule is taken without enough water.

EFSA assessment of glucomannan

Konjac as noodles, not as a sweet

For your pantry
Pantry staple

Shirataki noodles

Rinse them well; they are konjac and water.

Shop shirataki Opens your country’s Amazon store
Pantry staple

Konjac flour

For a home gel. Keep it away from mini-cup candy recipes.

Shop konjac flour Opens your country’s Amazon store
Pantry staple

Agar flakes

A seaweed gel that sets differently.

Shop agar Opens your country’s Amazon store

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What can I use instead?

Agar-agar

Ratio: Different texture

Best for: A brittle gel

Xanthan gum

Ratio: Much less by weight

Best for: Sauces

Related

More thickeners & gums:

Agar-Agar E406Agar-agar (E406) is a seaweed gel that sets firmer than gelatin. It's safe, vegan, gluten-free, keto and kosher, and is the easiest plant swap for gelatin.Generally safeCarrageenan E407Carrageenan (E407) is a seaweed thickener in plant milks and deli meats. It's approved, but some studies link it to gut inflammation, so people with IBD often avoid it.Use in moderationCassia gum E427Cassia gum (E427) is a seed thickener, not cinnamon. Europe allows it in limited foods. In the US it is mainly a pet-food ingredient. Specs are strict because early batches carried impurities.Use in moderationCellulose Gum (CMC) E466Cellulose gum (E466, CMC) is a thickener made from wood or cotton fiber. It's approved everywhere and fine for most diets, but studies in mice and a small human trial suggest it can disturb gut bacteria.Use in moderation

Common questions

Are konjac noodles banned?

No. The ban is on firm jelly mini-cups that can choke a child. Noodles and ordinary konjac foods are allowed.

Is Konjac safe?

Use in moderation (67/100). Konjac is an approved thickener. Both the FDA and the EU ban it in jelly mini-cups, because those sweets do not dissolve in the mouth and have choked children. Noodles, capsules and ordinary gels are a different use.

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Scientific sources & regulatory citations
  • EFSA OpenFoodTox: E425
  • FDA import alert on konjac mini-cup jelly; EU jelly mini-cup ban
  • EFSA assessment of glucomannan

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