Improvement of a method for chain-length distribution analysis of wheat amylopectin

For the chain-length distribution analysis of wheat amylopectin using high-performance anion-exchange chromatography (HPAEC) under alkaline conditions, the reduction of amylopectin isoamylolyzate with sodium borohydride facilitated obtaining reproducible chromatograms without both alkaline degradation and epimerization of maltooligosaccharides in aqueous NaOH solution. In a comparison of the chromatograms of isoamylolyzates of wheat starch and its fractionated amylopectin, reproducible results were also obtained. The improved method presented here, based on the use of starch isoamylolyzates reduced with sodium borohydride, is available for performing automated analysis of the chain-length distribution of wheat amylopectin by HPAEC equipped with an autosampler.