Characterization of starch polysaccharides by flow field-flow fractionation-multi-angle laser light scattering-differential refractometer index

The coupling between flow field-flow fractionation (FFF), multi-angle laser light scattering and differential refractometer index provides a promising technique for fractionation of starch polysaccharides in aqueous condition s. Native starches with different amylose/amylopectin levels (0-70%) as wel l as a pure amylose sample were characterized. By applying a sudden drop in the cross-flow-rate, clear separation was achieved between amylose (which elutes first) and amylopectin. Flow FFF produced correct relationships betw een the molecular mass or the gyration radius versus elution volume for the fractionated amylopectin population. The results are also considered in te rms of the macromolecular composition of starches. (C) 2001 Elsevier Scienc e B.V. All rights reserved.