SEPARATION OF STARCH AND GLUTEN: V. PROBLEMS IN WHEAT STARCH MANUFACTURE ARISING FROM FLOUR PENTOSANS

Abstract

The voluminous starch sludge or "squeegee" fraction, obtained with all known methods of wheat starch manufacture, consists of strongly hydrated pentosan masses in which starch granules are embedded. The pentosans of the bran and endosperm both contribute to the formation of these heterogeneous complexes. The "squeegee" starch fraction is not abolished by allowing the crude starch slurries to ferment, by exposing them briefly to mildly acid or alkaline solutions, or to C2−C12 monohydric alcohols. The pentosan and protein contents of this low quality starch fraction may be greatly reduced by 24–48 hr. digestion in dilute acid at pH 2.0 before recovering the starch on the centrifuge.