THE EFFECTS OF SULFUR CONTENT ON THE PROPERTIES OF WHEAT GLUTEN

Abstract

Two wheat samples were obtained from fertilizer test plots located on sulfur-deficient soils; one from a plot on which sulfur had been consistently used as a fertilizer for about 25 years and the other from a non-fertilized plot. The levels of sulfur in the two samples were respectively 0.18 and 0.10%. The difference decreased in the flours and decreased further in the glutens, but was still highly significant. There was a much larger proportion of non-gluten nitrogen in the sulfur-deficient sample. The gluten from this sample contained smaller amounts of cystine and methionine, a lower content of sulfhydryl and disulfide groups, and dispersions of the gluten in 8% sodium salicylate yielded lower values for relative and intrinsic viscosity. There was no difference in the content of sulfhydryl groups of the flour, nor in sedimentation behavior of the dispersed gluten. The addition of bisulfite to the dispersions eliminated the differences in intrinsic and relative viscosity values. The results all support the conclusion that the differences in quality of the two samples were related to the difference in the number of potential disulfide linkages.