The natural amino acid cysteine (L-cysteine) containing sulphur is found in many foodstuffs and used in selected improvers. The effect is based on the partial solution of disulphide bonds in the dough which are responsible for the firmness of the gluten. The reaction already takes place during the mixing process and reduces the mixing resistance and the dough development time. The following effects are achieved in the dough and the baked goods:
- more plastic and smoother dough properties
- optimized machinability (no shrinking of the dough pieces)
- enhancement of the crust crack behaviour
- increase in the volume of the baked goods
- more tender and shorter crumb texture
While the ascorbic acid stabilizes the dough texture, the extensibility of the gluten network is improved at the same time by the use of L-cysteine. Here, L-cysteine does not cancel out the effect of the ascorbic acid, as both substances have an effect at different points of the gluten network. But cysteine and ascorbic acid can be used parallel despite opposite effects. The process depicted in the following illustration shows the effect of cysteine. Here, in the dough, single disulphide bonds are reduced into thiol groups, which causes a targeted dough relaxation.