Contribution of hydrophobic soluble gluten proteins, fractionated by hydrophobic interaction chromatography in highly acetylated agarose, to dough rheological properties

Hydrophobic interaction chromatography with highly acetylated agarose in 1- mL columns was used to fractionate gliadins and acid-soluble glutenins. Pro teins were eluted in two fractions, the first with acetate buffer (pH 3.6) containing 35% propanol, and the second with Tris buffer in 8M urea. The pr oportion of eluted protein in the second fraction was called the surface hy drophobicity index. The study included 20 wheat samples of different baking qualities. Multiple regression analysis using the general linear model com bined with the stepwise technique was used to relate the surface hydrophobi city index of soluble gluten proteins to specific dough rheological charact eristics. Surface hydrophobicity index of gliadins and acetic acid soluble glutenins explained part of the variability of swelling index, extensibilit y, and work of deformation (dough strength) measured with the alveograph, a nd part of the farinograph water absorption variability, but showed no rela tionship to dough mixing characteristics. Hydrophobic soluble gluten protei ns fractionated by hydrophobic interaction chromatography (HIC) explained a part of the variability of dough rheological properties.