Variation in Minnesota HRS wheats: Starch granule size distribution

The functional properties of wheat (Triticum aestivum L.) starch, which are responsible for the unique characteristics of many foods, can be in part explained by variations in starch granule sizes. This study characterizes the variation in starch morphology in Minnesota Hard Red Spring wheats and examines the interdependence of the granule size distribution on selected mixing and pasting properties. Starch granule sizes were measured using an automated microscopic imaging instrument in both wheat-meal and flour, and these data were correlated with their respective mixing and pasting properties. Quantitative image analysis showed significant differences (Tukey HSD, P<0.025) in the mean percentage of wheat-meal large starch granules (> 10 μm in diameter) among five varieties commonly grown in Minnesota. The proportion of large starch granules also correlated significantly with the pasting properties of wheat-meal and flour, whereas the proportion of starch granules below 10 μm in diameter correlated significantly to the wheat-meal and flour mixing properties.