Size analysis of barley starch granules by sedimentation/steric field flowfractionation

In the present work the relatively new technique of sedimentation/steric fi eld-flow fractionation (Sd/StFFF) was used for the size analysis of the lar ge, medium and small starch granules of barley grain. The experimental para meters varied were the time from the preparation of the starch sample dispe rsion - in order to study the disintegration or the aggregation of the star ch granules - and the concentration of the sample in order to study the sam ple overloading effect on the measured size of the starch granules. A bimod al or trimodal size distribution curve, depending on the experimental condi tions used, was found by Sd/StFFF, and the number and weight average diamet ers of the starch granules were calculated. Finally, the experimental resul ts are compared with those obtained by scanning electron microscopy and lig ht scattering, and useful conclusions concerning the destruction or the agg regation of the starch granules, as well as the sample overloading effect o n the granule's size, measured by Sd/StFFF, are extracted.