Sulfhydryl analysis: II. Free sulfhydryl content of heated doughs from 2 wheat cultivars and effect of potassium bromate

The combined effects of heat and potassium bromate (KBrO3) on the free sulfhydryl content of doughs prepared from two Australian commercial wheat flours were investigated. Flour derived from the cultivar Janz was not responsive to KBrO3 in baking, whereas flour from the cultivar Oxley was responsive. Heating of dough samples with or without KBrO3 caused a large decline in free sulfhydryls for both samples. Doughs prepared from each sample showed a significant loss of KBrO3 during the heating protocol. Mixing alone caused a nearly 50% decline in the level of KBrO3 from the quantity added. Results of this investigation indicate that although KBrO3 had reacted during the period of heating, it was not directly linked to the decrease in free sulfhydryls.