Food additive databaseflavoringChecked 2026-10-02

trans-2-Methyl-2-butenal trans－2－メチル－2－ブテナール

Designated additiveEU: flavoring substance (FL 05.095)

Purpose: flavoring
On the label: “香料” (flavoring) (written under a group name; the substance name is often not written)
Name in the List of Designated Additives: trans－2－メチル－2－ブテナール (No. 426)

In Japan

A type of aldehyde designated as a flavoring. Under the standards for use, it cannot be used for any purpose other than adding aroma.
When used as a flavoring, the label can say the group name “香料” (flavoring), so the substance name does not usually appear in the ingredient list.

Japan's standards for use

Must not be used for any purpose other than flavoring.

This is a summary of the standards for use. See the source list for the exact conditions.

In the EU

In the EU, flavoring substances are covered by the flavorings regulation (Regulation (EC) No 1334/2008), not by the list of food additives. It is on the Union list of flavoring substances (Annex I) as FL 05.095.
In the Union list it carries footnote 1, which marks substances awaiting completion of evaluation by the European Food Safety Authority (EFSA) (English name 2-Methylcrotonaldehyde).

When it is labeled under a shared name

trans-2-Methyl-2-butenal may be declared on the label in the same way as “香料”. See Flavoring for details.

Sources

Checked 2026-10-02. Rules and evaluations change over time. This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.

This page lists facts stated in laws and in evaluations by public bodies; it is not a safety verdict. Additives used in Japan are approved by the government, which sets the foods and amounts they can be used in. The ADI is a guide to the amount that is considered safe to take every day over a lifetime.

Other substances used as flavoring

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