L-cysteine

Basic Information

Field	Content
Chinese name	L-cysteine
English name	L-cysteine
INS/E number	INS 920
Functional class	Flour treatment agent
Year adopted	1965
Approved by	Australia/New Zealand (FSANZ), European Union (EFSA)

What is it?

L-cysteine (commonly as its hydrochloride) is a sulphur-containing amino acid used mainly as a dough conditioner that develops and relaxes gluten in baked goods.

Source

Natural：毛发/羽毛角蛋白水解，或发酵/酶法生产

Why is it used?

• Relaxes gluten as a dough conditioner
• Shortens fermentation/proofing time
• Improves bread texture and volume
• Used in steamed buns and Asian noodles

Common Foods

• Bread
• Steamed buns
• Asian pastries
• Biscuits
• Instant noodles

Safety

ADI (Acceptable Daily Intake)：Not limited (as amino acid nutrient)

Concerns：

• 少数人可能出现过敏或不耐受

Usage Standard

China：GB 2760《食品安全国家标准 食品添加剂使用标准》

International：

• EU Regulation 1333/2008 Annex II (E 920)
• FDA 21 CFR 172.320 (GRAS)
• Codex GSFA (INS 920)
• FSANZ Food Standards Code (920)

In a nutshell

L-cysteine is a dough conditioner that relaxes gluten and improves baked quality.

Consumer Advice

L-cysteine is an amino acid used in flour processing as a dough conditioner that strengthens the gluten network, making bread softer and easier to shape. Traditionally it is derived from hydrolysed hair or feathers, though fermentation-based vegan versions also exist. It is safe at approved levels, but its source can affect suitability for vegetarians and vegans, so check the labelling where possible.

Dietary Restrictions

• Vegan: ❌
• Halal: ✅
• Kosher: ✅

Allergens

✅ Free from common allergens

Disclaimer

The information provided here is for discussion and educational purposes only. It is not medical advice or an evaluation/rating of any product or ingredient. This information may not apply to you; before using or taking any action, you should contact the manufacturer, vendor, medical, dietary, fitness, or other professionals. If you use any information provided here, you do so at your own risk.