Size Analysis of Barley Starch Granules by Sedimentation/Steric Field Flow Fractionation

In the present work the relatively new technique of sedimentation/steric field-flow fractionation (Sd/StFFF) was used for the size analysis of the large, medium and small starch granules of barley grain. The experimental parameters varied were the time from the preparation of the starch sample dispersion — in order to study the disintegration or the aggregation of the starch granules — and the concentration of the sample — in order to study the sample overloading effect on the measured size of the starch granules. A bimodal or trimodal size distribution curve, depending on the experimental conditions used, was found by Sd/StFFF, and the number and weight average diameters of the starch granules were calculated. Finally, the experimental results are compared with those obtained by scanning electron microscopy and light scattering, and useful conclusions concerning the destruction or the aggregation of the starch granules, as well as the sample overloading effect on the granule's size, measured by Sd/StFFF, are extracted.