The use of 1,1-diphenyl-2-picrylhydrazyl for detecting free radicals in wheat flour dough

1,1-Diphenyl-2-picrylhydrazyl (DPPH) was added to wheat flour dough to detect the formation of free radicals during mixing. The decolorisation of DPPH, i.e. the scavenging of radicals, was observed in patent flour dough. The rate of decolorisation was decreased by first removing free lipids and then bound lipids from the flour. The lipid fraction from the flour and especially the free fatty acid fraction strongly decolorised DPPH. The decolorisation of DPPH also increased with an increase in the concentration of oxidised linoleic acid. In this study, the results lead to the assumption that free radicals of oxidised lipid formed during mixing of dough cause at least to some extent a change in the rheological properties of dough.