Structural characteristics of slowly digestible starch and resistant starch isolated from heat-moisture treated waxy potato starch

摘要

The objective of this study was to investigate the structural characteristics of slowly digestible starch (SOS) and resistant starch (RS) fractions isolated from heat-moisture treated waxy potato starch. The waxy potato starch with 25.7% moisture content was heated at 120 degrees C for 5.3 h. Scanning electron micrographs of the cross sections of RS and SDS + RS fractions revealed a growth ring structure. The branch chain-length distribution of debranched amylopectin from the RS fraction had a higher proportion of long chains (DP >= 37) than the SOS + RS fraction. The X-ray diffraction intensities of RS and SOS +RS fractions were increased compared to the control. The SOS + RS fraction showed a lower gelatinization enthalpy than the control while the RS fraction had a higher value than the SDS + RS fraction. In this study we showed the RS fraction is composed mainly of crystalline structure and the SOS fraction consists of weak crystallites and amorphous regions. (C) 2015 Elsevier Ltd. All rights reserved.