2004 Volume 99 Issue 6 Pages 457-466
The structure of amylopectins in 70%-polished rice endosperm of fourteen cultivars, including nine varieties for sake brewing, was characterized by a high-performance anion-exchange chromatography system equipped with a pulsed amperometric detector (HPAEC-PAD) after hydrolysiswith isoamylase. It was found that starch isoamylolyzates of the rice suitable for sake brewing were plentiful in shortish chains around DP 7-9, while the longish chains were poor in Yamadanishiki and Hattannishiki 1, and the middle chains were poor in Gohyakumangoku, Okuhomare, and Hattannishiki 1, compared with those of Koshihikari. Correlation analysis using all rice samples showed positive correlations between the shortish (DP: 6-9) chains and water absorption, or digestibility, whereas negative correlations existed between the longish (DP: 35-41) chains and digestibility. Also, there were positive correlations between the longish (DP: 43-51) chains and the DSC parameters (peak temperature, conclusion temperature, and heat of transition), but negative ones between the shortish (DP: 7-11) chains and these DSC parameters. The RVA parameters showed rather high correlations with the distribution ratio of some amylopectin side chains, but they were not much higher than those observed in the case of digestibility or DSC parameters.
