Effect of cysteine addition on the volatiles of extruded wheat flour

The sulfur-containing amino acid cysteine was added at concentrations ranging from 0% to 1.0% to wheat flour and extruded in a corotating twin screw extruder. A total of 18 sulfur-containing compounds was tentatively identified along with 4 pyrazines and 1 furan. The fact that most of the sulfur-containing compounds were thiazoles indicated that these compounds may be formed due to thermal degradation of cysteine. The increase in concentration of cysteine in the wheat flour did effect the concentration of most volatiles, including non-sulfur-containing volatiles; however, the addition of cysteine over the 0.5% level did not seem to greatly increase volatile production.