Food · Thickeners & gelling agents

Kudzu Starch

葛粉 (Kuzuko)

Also known as: Kuzu Starch, Pueraria Root Starch

At a glance

CategoryFood
INCI namePueraria Lobata Root Extract (for cosmetic uses, distinct from starch)
Japanese labeling nameプエラリアミリフィカ根エキス (different species) / クズ根エキス (cosmetic)
Common Japanese notations葛粉, クズコ
OriginPlant-derived (Pueraria lobata root starch)
Typical functionsGelling agent, Thickener
Regulatory status in JapanFood ingredient regulated under the Food Sanitation Act. The related root is also a Kampo material (葛根, kakkon).

Kudzu starch — kuzuko — is the traditional starch extracted from Pueraria lobata roots through a labor-intensive crushing, washing, and settling process. It is the defining gelling agent for kuzu-mochi, kuzu-kiri, and kuzu-yu (a thick hot starch drink sometimes prepared in cold-season recovery contexts). Several Japanese regions have historical production, including the area around the town of Yoshino in Nara.

Classification

Tags below link to other ingredients sharing the same attribute, so you can pivot from one ingredient to its peers.

Used in (typical product categories)

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

  • Traditional confectionery (kuzu-mochi, kuzu-kiri)
  • Culinary thickening (kuzu-yu, sauce-making)
  • Traditional Kampo preparations

What it is

Kuzuko is extracted by crushing Pueraria lobata roots, washing the starch fraction out of the fibrous material with water, allowing the starch to settle, and then drying and milling the final product. The traditional process yields a fine-grained starch with distinctive gelling and texture properties.

Note: Some specific regional kuzuko brands (including those associated with the Yoshino area) may fall under geographical indication or trademark protection. Generic "kudzu starch" or "kuzuko" terminology is used on cosmetic and ingredient labels without regional designations.

Typical uses in Japanese products

In food, kuzuko is the thickener for kuzu-mochi, the base for kuzu-kiri cold noodle-style dessert, and the central ingredient in kuzu-yu. It is also used in sauce-thickening applications.

In Kampo, the related root preparation 葛根 (kakkon) is a traditional medicinal material used in specific formulations, separately regulated from food use.

Regulatory classification in Japan

Food regulation under Food Sanitation Act. Kampo applications under the Pharmaceutical and Medical Device Act.

Regulatory classification in other markets

EUFood use established. Cosmetic use of Pueraria extracts should be verified against CosIng.
USAFood and supplement uses established.
ChinaWidely used in Chinese food and traditional medicine under various names.
KoreaSimilar uses exist in Korean cuisine.

Example products

Example finished products will be added after verification. Regional brands with GI or trademark protection are handled as descriptive production-region notes.

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

References

  1. MAFF food classification — kuzuko

Last updated: 2026-04-22. Ingredient entries are reviewed at least annually against current regulatory listings.

Explore more Japan-market resources

Related tools for overseas buyers, formulators, and sourcing teams.