Effects of Bleaching on Tocopherols in Wheat Flour

In sophisticated areas, milled wheat flour is artificially aged and bleached, and chlorine dioxide is now preferred as the bleaching agent. Using the paper chromatography method, Moore et al. (1957) observed that 80% of the tocopherols in flour were destroyed when 30 parts per million (ppm) of chlorine dioxide were used to bleach. Later, they confirmed this result by hemolysis tests and rat assays (Moore et al., 1958). 

In similar studies Frazer et al. (1956a, b) noted a drop in the a-tocopherol content of flour from 1.5 mg % to 0.2 mg %. They considered this loss to be of no nutritional import since even whole wheat bread will supply only a small percentage of the 15 mg % of tocopherol required by man daily (Sebrell and Harris, 1954). Mason and Jones (1958) noted that the total tocopherol content of Australian whole wheat dropped from 2.3 to 1.55 mg % in milling, and to 0.72 mg % after chlorine dioxide bleaching. 

flour bleached with chlorine dioxide contains little or no tocopherol. On the other hand, no measurable loss occurs when similar white flour is bleached using ascorbic acid or potassium bromate (Moore et al., 1957). 

Rothe et al. (1958) noted a 50% reduction in the tocopherol content of white and of whole grain flours, and a 25% loss in wheat germ, during 

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