Cereal Chem 39:209 - 219. | VIEW
The Role of Lipids in Oxidation of Doughs.
C. C. Tsen and I. Hlynka. Copyright 1962 by the American Association of Cereal Chemists, Inc.
Results obtained with the thiobarbituric acid method on lipids extracted from flour provide direct evidence that lipid peroxides are formed in dough during mixing in air or oxygen. Doughs mixed in air or oxygen gave a higher absorbance in the TBA test than did control doughs mixed in nitrogen. Addition of lipoxidase in the form of "Wytase" also increased the rate of peroxidation of flour lipids. On the other hand, addition of NDGA or propyl gallate as antioxidants to flour inhibited the peroxidation essentially to the level of doughs mixed in nitrogen. Succinic acid peroxide, t-butyl hydroperoxide, hydrogen peroxide, acetyl peroxide, and methyl ethyl ketone peroxide all increased the structural relaxation constant of dough, indicating a similar improving role for flour lipid peroxides. When sulfhydryl-blocking reagents (PCMB, IAA, HgCl2, and NEMI) and improving agents (iodate and bromate) were incorporated into dough, lipid peroxidation was increased. This suggests that flour lipids compete with sulfhydryl groups for available oxygen in dough. On the basis of these findings a unified hypothesis for the role of lipids in oxidation of doughs is presented and discussed.