Food additive databaseseasoning, nutrient (fortification)Checked 2026-10-02
L-Leucine L-ロイシン
Existing food additivePermitted in the EU (E641)
- Purpose
- seasoning, nutrient (fortification)
- On the label
- “調味料（アミノ酸）” (seasoning (amino acids)), “L-ロイシン” (L-leucine), “ロイシン” (leucine)
- Name in the List of Existing Food Additives
- L-ロイシン (No. 325)
- Source and production
- A substance whose component is the amino acid L-leucine (containing 98.0 to 102.0% on a dry basis).
In Japan
- One of the amino acids, used as a seasoning and a nutrient fortifier. There are no standards for use.
- When used as a seasoning, it can be labeled with the group name “調味料（アミノ酸）” (seasoning (amino acids)). The short name is “ロイシン” (leucine). When used to fortify nutrition, labeling is exempt (Food Labeling Standards).
Japan's standards for use
There are no standards for use that limit which foods or how much (the general standards for all additives still apply).
This is a summary of the standards for use. See the source list for the exact conditions.
In the EU
- It is on the EU list of food additives (Regulation (EC) No 1333/2008, Annex II) as E641.
- In the EU the only food it can be used in is tablet-form table-top sweeteners, at a maximum of 50 g/kg (Annex II, Part E). Japan has no standards for use.
When it is labeled under a shared name
L-Leucine may be declared on the label in the same way as “調味料（アミノ酸等）”. See Seasoning (amino acids etc.) — e.g. MSG for details.
Sources
- List of Existing Food Additives — Japan Food Chemical Research Foundation (Japanese)
- Standards for use and storage of each additive — Japan Food Chemical Research Foundation (Japanese)
- EU food additive database (Japanese translation) — MAFF (Japanese)
- Regulation (EC) No 1333/2008 on food additives — EUR-Lex
- 第10版食品添加物公定書（2024年、厚生労働省・消費者庁）成分規格・保存基準各条の定義 (Japanese)
- 消費者庁「食品表示基準について」本体（添加物の物質名・簡略名・増粘多糖類・用途名・加工助剤・栄養強化） (Japanese)
- 消費者庁「食品表示基準について」別添 添加物関係（1-1 簡略名、1-4 一括名の範囲、2-1 既存添加物名簿収載品目リスト） (Japanese)
- 食品表示基準（平成27年内閣府令第10号）第3条（「色」「増粘」の文字を含む場合の用途名の省略、加工助剤・栄養強化の表示免除）（e-Gov 法令検索） (Japanese)
- Regulation (EC) No 1333/2008 統合版（2026-08-18）附属書II（EUR-Lex） (Japanese)
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 seasoning, nutrient (fortification)
- Monosodium L-Aspartate
- DL-Alanine
- L-Arginine L-Glutamate
- L-Isoleucine
- L-Glutamic Acid
- L-Theanine
- L-Valine
- L-Histidine Monohydrochloride
- L-Phenylalanine
- L-Lysine L-Aspartate
- L-Lysine Monohydrochloride
- L-Lysine L-Glutamate
- L-Asparagine
- L-Alanine
- L-Arginine
- L-Glutamine
- L-Cystine
- L-Serine
- L-Tyrosine
- L-Histidine
- L-Hydroxyproline
- L-Proline
- L-Lysine