L-Cysteine
The short version
An amino-acid dough conditioner — often derived from animal hair or feathers, creating documented vegan / halal / kosher concerns.
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Where it comes from
Industrially produced largely by acid hydrolysis of human hair (mainly sourced from China) or animal feathers — a fact that creates documented vegan, kosher, and halal concerns. Microbial fermentation variants exist but are less common. The molecule itself is a normal sulfur amino acid present in all proteins.
How it's used
Used as a dough conditioner in industrial bread, pizza dough, and bagels at 10–90 mg/kg. Reduces mixing time and improves crumb texture by partially reducing gluten disulfide bonds. Classified as 'Flour treatment agent' in the EU additive system; placed here under Emulsifier alongside other dough conditioners (DATEM, SSL).
Safety profile
ADI not specified — considered safe as a normal dietary amino acid. The safety concern is sourcing rather than the molecule: animal-sourced material is typically not declared by source on labels, conflicting with religious dietary observance and veganism.
Physical & chemical properties
White crystalline powder, soluble in water. Free thiol group makes it a strong reducing agent on gluten disulfides.
Regulation worldwide
Permitted globally. EU does not require source disclosure on labels — a frequent point of advocacy for vegan and religious dietary groups.
Educational information only. Not medical or dietary advice.