Cereal Chem 56:1 - 5.  |  VIEW ARTICLE
Density Fractionation of Wheat Flours in Nonaqueous Solvents. I. Effect of Flour Moisture Level on Distribution of Solids, Protein, and Ash Among Fractions.

R. L. Clements. Copyright 1979 by the American Association of Cereal Chemists, Inc. 

Moisture in pin-milled hexane-extracted soft and hard wheat flours was adjusted to low, intermediate, and high levels. The flours at each moisture level were then fractionated by sequential flotations at 0 C in a series of Freon TF-hexane mixtures, sp gr 1,350-1.450 at 25 C in 0.010 increments to give 10-12 floating fractions plus residues. Protein was highest (68-75% db) in the first floating fraction from soft wheat flour and maximum (54-64%) in the first or second fraction from hard wheat flour. About 70% of the total solids from soft wheat flour were distributed in two high-density fractions containing 1-4% protein. About 75% of the solids from hard wheat flour were distributed in three to four high-density fractions containing 1-14% protein. Protein was high (up to 23%) in residues. Ash was uniform among floating fractions from both flours, but high (6-23%) in residues. Increasing flour moisture caused high-density components to float off earlier in the solvent sequence, but had little overall effect on fractionation.