INFLUENCE OF NATIVE LIPIDS ON THE RHEOLOGICAL PROPERTIES OF WHEAT FLOUR DOUGH AND GLUTEN

We report on the viscoelastic properties of dough and gluten (prepared by ultracentrifugation) after the flour lipids had been removed by solvents differing in polarity (chloroform, ethanol and diethylether). The extracted lipids were fractionated by thin layer chromatography. The flours differed in lipid composition after the extraction. Ethanol removed more polar lipids than the other solvents. Removal of lipids (0.6–0.9% on flour weight) altered the viscoelastic properties of dough significantly, whereas those of gluten were only marginally affected. The storage modulus (G′) of dough increased with used solvent polarity. The highest value of G′ was observed for the dough made with the flour where the lipids were removed by ethanol. This was consistent with a marked decrease in the frequency dependence of G′ of dough when the lipids were removed.