Food · Fermented foods

Konnyaku Flour (Refined Konjac Powder)

こんにゃく精粉 (Konnyaku Seiko)

Also known as: Konnyaku flour, Konjac powder, Refined konjac flour, Glucomannan flour, Amorphophallus konjac corm flour, 蒟蒻精粉

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At a glance

Category	Food
Japanese labeling name	こんにゃく精粉
Common Japanese notations	こんにゃく精粉, 蒟蒻精粉, コンニャク粉, グルコマンナン粉
Origin	Refined powder from the corm of Amorphophallus konjac (こんにゃくいも); principal modern domestic regions Gunma (the dominant production prefecture, accounting for over 90% of Japan's domestic konnyaku-imo cultivation), Tochigi, Hiroshima; significant Chinese imports for industrial konnyaku-flour applications
Typical functions	Konnyaku and shirataki production — the dominant volume application (block konnyaku, ito-konnyaku, shirataki noodles), Glucomannan dietary fiber supplement (FFC functional food category), Diet-food positioning (very low calorie, high satiety), Vegan and gluten-free alternative noodle (rice/pasta substitute) ingredient, Industrial gel-forming ingredient for processed foods (texturizer, stabilizer)
Regulatory status in Japan	Konnyaku follows standard food labeling. The konnyaku-imo to konnyaku-seiko ratio and origin (domestic Gunma vs Chinese import) are key positioning factors. Glucomannan content typically 60-80% in refined seiko flour. Multiple FFC (Foods with Function Claims) registrations exist for glucomannan-positioned products targeting cholesterol moderation and bowel function. Konnyaku is not a designated allergen. Konnyaku jelly products carry choking-hazard precautions following established consumer safety guidelines.

Konnyaku flour (こんにゃく精粉, refined konjac powder) is the industrial ingredient form of konnyaku — the refined, glucomannan-concentrated powder extracted from the corm of Amorphophallus konjac. Konnyaku has been a Japanese staple for over a thousand years, but the modern industrial supply chain is dominated by Gunma Prefecture (over 90% of domestic konnyaku-imo cultivation) for premium retail and by Chinese imports for volume processed-food applications. The OEM applications are diverse: as the foundation of block konnyaku, shirataki, and ito-konnyaku retail products (a large volume Japanese retail category); as the source of glucomannan dietary fiber for FFC functional food supplements (cholesterol moderation and bowel function claims); as a diet-food ingredient (very low calorie ~7 kcal/100g, high satiety); and as a gel-forming and texturizing ingredient for processed-food applications. Glucomannan content in refined seiko is typically 60-80%, with higher purity grades for supplement applications.

Classification

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Product applications

Functions

Flavoring

Regulatory tags

Culinary ingredient

Origin

Plant-derived

Used in (typical product categories)

Finished-product categories that commonly include this ingredient in Japanese-market formulations.

Konnyaku-seiko refined flour (industrial ingredient supply)
Block konnyaku (板こんにゃく — major retail format)
Shirataki / ito-konnyaku noodles (糸こんにゃく)
Sashimi-konnyaku (premium gift retail)
Glucomannan supplements (capsules, powder, drinks)
Konnyaku jelly / konjac jelly (snack and dessert category)

What it is

Konnyaku (Amorphophallus konjac) is a perennial corm-producing plant native to East Asia, cultivated in Japan for at least 1,000 years. The harvested corm contains approximately 3% glucomannan (a unique water-soluble polysaccharide) and is processed through drying, milling, and refining to yield konnyaku-seiko (refined flour) at 60-80% glucomannan concentration. Higher-purity grades (90%+ glucomannan) are produced for supplement applications.

Industrial supply: Gunma Prefecture is overwhelmingly dominant in domestic Japan production (over 90% share, with Shimonita-cho as the most established konnyaku-imo town), with Tochigi and Hiroshima providing additional supply. Premium domestic Japan-origin konnyaku is positioned for premium retail (sashimi-konnyaku, traditional regional varieties). Volume processed-food applications (industrial konnyaku for ready-meals, jelly, supplements) increasingly use Chinese-imported konnyaku flour at lower price positioning.

Nutritionally, finished konnyaku is very low calorie (approximately 7 kcal per 100g for block konnyaku) due to the indigestible glucomannan content. Dietary fiber content is approximately 3.0g per 100g of finished konnyaku. The unique value proposition is satiety with minimal caloric load.

Typical uses in Japanese products

Konnyaku and shirataki production — block konnyaku, ito-konnyaku, shirataki noodles, and sashimi-konnyaku are the dominant retail applications. Major branded suppliers include Mannan Life, Hagoromo Foods, and regional Gunma producers.

Glucomannan dietary fiber supplements — capsule, powder, and drink formats for FFC-positioned cholesterol moderation and bowel function products. Multiple SKUs hold FFC registration.

Diet food retail — konnyaku rice (replacing white rice with shirataki-style konnyaku), konnyaku pasta (Zenpasta and similar brands), low-calorie konnyaku jelly products, and konnyaku-based meal-replacement formulations.

Vegan and gluten-free alternative noodles — shirataki has emerged as a global vegan/keto/gluten-free pasta alternative, with significant export presence (Miracle Noodle, House Foods Tofu Shirataki, etc.).

Industrial texturizer and gel-forming ingredient — konjac glucomannan is used as a thickener, stabilizer, and gel-former in commercial food applications including alternative meat products, jelly products, and gluten-free baking.

For OEM: konnyaku-seiko refined flour ingredient supply (specifying glucomannan content grade), domestic Gunma origin block konnyaku and shirataki retail OEM, glucomannan supplement OEM with FFC pathway support, konnyaku-rice and konnyaku-noodle diet food retail OEM, vegan/gluten-free alternative noodle export OEM, and industrial gel-forming and texturizer ingredient supply.

Regulatory classification in Japan

Standard food labeling. Origin disclosure (Gunma domestic vs Chinese import) is significant for premium positioning.

Glucomannan content disclosure: typical refined seiko 60-80%, premium supplement grade 90%+.

FFC (Foods with Function Claims): multiple registrations exist for glucomannan-positioned products supporting cholesterol moderation and bowel function. Pre-approved health claims framework available.

Konnyaku is not a designated allergen.

Konnyaku jelly choking hazard: small one-bite konnyaku jelly products (popular in 1990s) caused multiple choking incidents and now carry mandatory consumer safety warnings. OEM jelly products must follow established sizing and labeling guidelines.

Premium GI: 'Shimonita-konnyaku' has Gunma regional protection.

Regulatory classification in other markets

EU	Imported as konjac. Konjac is approved as a food ingredient. Konjac jelly products specifically have been the subject of EU choking-hazard regulations — small, gel-cup formats are restricted. Block konnyaku and shirataki are unrestricted.
USA	Imported under FDA standard food procedures. Konjac jelly choking hazard rules apply (FDA import alerts have been issued for small-cup konjac jelly products historically). Shirataki has established US market position as keto/diet noodle.
China	China is itself a major konjac producer. Japanese-origin konnyaku positioned as premium specialty.
Korea	Korea has growing konjac (gonyak) market. Japanese-origin konnyaku positioned as specialty import.

Example products

Example finished products will be added after verification of glucomannan grade, origin (Gunma domestic / Chinese import), product format, and target market.

All brand names and product names referenced anywhere on this site are the property of their respective owners. Example entries are provided for informational purposes only and do not imply endorsement.

Related ingredients

Used in similar product applications

Other ingredients commonly used in the same finished-product families.

Sharing similar functions

Ingredients that overlap on functional benefit tags.

From the same origin

Other ingredients that share an origin classification.

FAQ for OEM buyers

Q. What's the difference between food-grade konnyaku-seiko and supplement-grade konjac glucomannan?

Food-grade konnyaku-seiko (refined flour) is typically 60-80% glucomannan, with the balance being other plant components from the corm. This grade is suitable for konnyaku, shirataki, and ito-konnyaku production where the gel-forming and textural properties are the key requirements. Supplement-grade konjac glucomannan is 90%+ purified glucomannan, produced through additional refining steps. This grade is used for capsule, powder, and drink-format supplements where high glucomannan dose with minimal other matter is required for FFC functional positioning. Pricing differs significantly — supplement-grade is 3-5× the food-grade price. For OEM positioning: standard konnyaku and shirataki retail OEM uses food-grade seiko; FFC supplement OEM and high-end functional food formulations use supplement-grade glucomannan.

Sources · Last reviewed: 2026-04-28

Editorial — Japan konjac glucomannan grade reference
FFC supplement specification examples

Q. How does the choking-hazard issue affect konnyaku-jelly OEM in Japan and export markets?

The konnyaku-jelly choking-hazard issue arose in the 1990s-2000s when small one-bite konnyaku jelly products (mini-cup format) caused multiple fatal choking incidents in Japan, particularly affecting young children and elderly. Regulatory and industry response established safety guidelines: mini-cup format products now carry mandatory consumer warnings; product sizing has shifted toward larger cup or bag-pack formats that are eaten with a spoon; and major retailers have moved away from the original small-cup format. Export markets: the EU has restricted small-cup konjac jelly products; the US FDA has issued import alerts on certain formats. For OEM: konnyaku-jelly product development should follow established Japanese sizing guidelines (avoid the original small-cup format), include appropriate consumer warnings on packaging, and target adult consumer formats. Block konnyaku, shirataki, and bag-pack konjac jelly products do not face the same restrictions and remain established categories.