Cereal Chem 67:78-80   |  VIEW ARTICLE

Factors Affecting the Viscosity of Flour-Water Extracts.

A. M. Moore and R. C. Hoseney. Copyright 1990 by the American Association of Cereal Chemists, Inc. 

Allowing flour and water to remain together for periods of time increases the viscosity of the water-soluble extract. On the other hand, if the extract is held after centrifugation, the viscosity of the extract decreases. This could be explained by the action of an endopentosanase; however, such enzymes have not been demonstrated to occur in flour. If the phenomenon were caused by an enzyme, it should have a well-defined pH optimum. No pH optimum was found. Instead, the loss of viscosity appeared to be more rapid at low pH. We concluded that there was no significant endopentosanase activity. The increase in viscosity of a flour-water mixture as a function of time resulted from increased solubility. The more rapid decrease in viscosity of the centrifuged extract at low pH was speculated to result from hydrolysis of the arabinose side chains followed by precipitation of the xylan chains.