L-cysteine

L-Cysteine (CAS 52-90-4), also designated E920 in food applications, is a sulfur-containing amino acid sourced through fermentation or protein hydrolysis. In food and pharmaceutical manufacturing, it functions primarily as a dough conditioner and antioxidant.

It serves as a precursor in flavor and nutrient synthesis. In commercial baking, E920 reduces mixing time and improves dough extensibility, making it a standard processing aid in bread, crackers, and pizza bases.

Pharmaceutical and nutraceutical manufacturers use this amino acid as a building block for glutathione synthesis and in amino acid infusion formulations. Personal care formulators incorporate it into hair treatment products.

It is used in keratin-based straightening and conditioning systems where it modifies disulfide bonds in hair protein. In flavor production, Cys reacts with sugars under heat to generate meat-like and savory Maillard compounds.

This chemical qualifies under FEMA 3263 for use in reaction flavor systems. The product is supplied as a white crystalline powder, available in both free base and hydrochloride monohydrate forms.

Recognized grades include USP, Ph.Eur., FCC, and food-grade. The hydrochloride salt is the most commercially prevalent form due to its stability and ease of handling in industrial settings.

Bulk supply is standard for industrial food and pharma applications. Smaller quantities are available for specialty formulation, ensuring compliance with BP, EP, and ACS standards where required.