Hydrolysis of wheat starch and its effect on the Falling Number procedure: experimental observations

Abstract

The underlying mechanisms of starch hydrolysis in cereal grains, as measured by the Falling Number procedure, were studied. Wheat starch, spiked with barley malt α-amylase, was used as a model experimental system. A non-invasive and real-time monitoring system was developed to simultaneously record the sample temperature and stirrer velocity profiles, which are critical parameters that affect Falling Number readings. Experimental results show that the repeatability of the Falling Number procedure can be improved by slowing the heating rate, which is accomplished by increasing the quantity of sample components (ie starch and water) while maintaining the same proportion as currently specified in standard methodology. Among the tested range of heating rates, the best repeatability of Falling Number readings was obtained with 8.4 g starch and 30.0 g water. The experimental findings of this study also serve as basic information for the development of mathematical models on the hydrolysis of starch. © 1999 Society of Chemical Industry