ABSTRACT
The stability of vitamin E during 297 days of storage of wheat flour and whole wheat flour ground on a stone mill or a roller mill, respectively, were studied. One day after milling, the total content of vitamin E, expressed in vitamin E equivalents (α-TE), was 18.7 α-TE and 10.8 α-TE for stone-milled and roller-milled wheat flour, respectively. The difference in total vitamin E content was primarily due to the absence of the germ and bran fractions in the roller-milled flour. The total loss of vitamin E during storage was 24% for stone-milled wheat flour but 50% for roller-milled wheat flour. These results indicate that vitamin E, which is present in high amounts in wheat germ, functions as an antioxidant in the stone-milled wheat flour. Hexanal formation showed that lipid oxidation in roller-milled flour occurred just after milling, whereas the formation of hexanal in the germ fraction displayed a lack period of 22 days, confirming that vitamin E functions as an effective antioxidant in the wheat germ. Results showed no significant difference in total loss of vitamin E for stone-milled and roller-milled whole wheat flour. Total loss after 297 days of storage for both milling methods was ≈32%.
