Origin
In the past, the amino acid cysteine, which occurs in hair and feathers, was obtained from these using sulfuric acid. Today, E 920 is produced on a biotechnological basis with the help of microorganisms. This can also involve genetically modified organisms. Cysteine then appears as an odorless solid.
Usage
E 920 can be used without maximum quantity restrictions for all food products. However, it is almost exclusively utilized for the production of baked goods. E 920 has the property to retain air in dough, meaning that baked goods remain fresh significantly longer due to the addition of cysteine. Old dough can also be made "fresh" again through the addition of E 920. For industrial production, E 920 is very important because by adding it, doughs for automatic production can be adjusted so as to guarantee an exact shape and size.
Risks
The food additive cysteine is considered completely harmless. Therefore, a recommended daily dose (ADI value) has not been given.