Cereal Chem 43:602 - 622.  |  VIEW ARTICLE

Extraction of Flour by Mixtures of Butanol-1 and Water.

A. H. Bloksma. Copyright 1966 by the American Association of Cereal Chemists, Inc. 

Flour, when suspended in aqueous butanol-1, reversibly absorbs or loses water. When the solvent contains 17.5% water (by weight), the equilibrium water content of the flour is 48% (d.b.) and rises very rapidly with increasing water content of the solvent. A flour was extracted stepwise with various butanol-1-water mixtures. With increasing water content, the extracted lipids increased from 1.16 to 1.37%. Likewise, the extracted nonlipids increased from 0.06 to 0.27% and larger amounts were extracted by percolation. Gluten development was retarded when the extract contained more than 10% water; further increases in water content resulted in greater retardation. When gluten development was retarded, gluten yield could be increased by increasing the mixing time or the rest period between mixing and washing. After 15 min. of mixing and 60 min. of rest, gluten yields were normal in all cases. The retardation of gluten development and the loss of baking quality after extraction with butanol-1 containing more than 10% water may be due to the extraction of carbohydrates, more particularly water-soluble pentosans, rather than lipid constituents. This suggestion is supported by the decrease of water absorption of the flour with increasing water content of the solvent.