Cereal Chem 41:111 - 121.  |  VIEW ARTICLE

Storage Stability of Hydroxyethylated Flour and Starch.

J. C. Rankin, J. G. Rall, C. R. Russell, and C. E. Rist. Copyright 1964 by the American Association of Cereal Chemists, Inc. 

The effect of storage in closed containers at room temperature on the properties of hydroxyethylated wheat flour, high-amylose starch, and normal corn starch was investigated. The stability of these products for a year was determined by periodic testing of their paste viscosity, clarity, and pH, as well as moisture, nitrogen, sugar, and ethylene oxide contents. Appropriate test data were correlated with such preparative factors as degree of substitution, alkali catalyst concentration, pH, and moisture content. Correlations showed that the hydroxyethylated products were completely stable in a pH range of 4 to 10. Products stored at pH values above 10 had varying degrees of instability. From the viscosity values at various time intervals, a general equation of the point-slope type was developed which permits the relative stability of various samples to be judged from their slope factor, termed index of change, and their initial viscosity. The variations in paste viscosity indicated that changes were taking place in the modified starch and protein constituents. Increasing substitution of ethylene oxide and lowering moisture content were effective stabilizing influences.