EFFECT OF CYSTEINE ADDITION ON THE VOLATILE COMPOUNDS RELEASED AT THEDIE DURING TWIN-SCREW EXTRUSION OF WHEAT-FLOUR

Numerous sulfur-containing volatile compounds were released from an ex truder when cysteine was added to wheat flour before extrusion. The vo latiles released were collected in a specially designed cryogenic appa ratus at the die of the twin-screw extruder Five concentrations of cys teine were used (0 to 10 g/kg). Among the identified sulfur-containing compounds, meat-like flavor compounds, such as 2,4-dimethyl-3-thiazol ine, 2-methylthiazolidine, 3,5-dimethyl-1,2,4-trithiolane, and 2,4,6-t rimethyl-perhydro-1,3,5-dithiazine, were collected in the highest amou nts. Several nonsulfur containing compounds such as methylpyrazine, 2, 6-dimethylpyrazine, and 2-acetyl furan were also found in the condensa te The total amount of volatiles collected increased when more cystein e was added to the flour, brit only a small fraction of added cysteine formed flavor volatiles in both the condensate and extrudate.