Microstructure of Recombinated Gels of Amylose and Amylopectin Isolated from Rice Starch

쌀전분으로부터 분리한 아밀로오스와 아밀로펙틴 혼합겔의 형태학적 구조

  • Baek, Man-Hee (Department of Food and Nutrition, Chonnam National University) ;
  • Shin, Mal-Shick (Department of Food and Nutrition, Chonnam National University)
  • 백만희 (전남대학교 식품영양학과) ;
  • 신말식 (전남대학교 식품영양학과)
  • Published : 1999.10.31

Abstract

The changes on microstucture of recombinated gels with different ratio of amylose(A) and amylopectin(AP) which were isolated from nonwaxy rice starch were investigated by scanning electron microscope(SEM) and X-ray diffractometer. As the concentration of amylose was above 3%(1.08% of soluble amylose) in the amylose suspension, gel matrix became like a three-dimensional network. The microstructure of amylose gels showed a network including macroporous structure, but the higher the ratio of amylopectin content were, the firmer network were formed. In case of A/AP mixed gels(15%) with different amylose/amylopectin percent ratios ; 0/5, 5/10, 10/5, 15/0%, as the storage time of gels and the percent ratio of amylose content were increased, network was formed harder with thick films. While X-ray diffractograms of waxy rice starch which contained 100% amylopectin showed A type, those of purified amylose and amylopectin showed V type and amorphous patterns, respectively. Amylose(3%) gels added $2{\sim}3%$ amylopectin and A/AP mixed gels(15%) showed peak at $2{\theta}\;=\;17.0^{\circ}$which were shown B type crystallinity similar af retrograded starches. Also as the percent ratio of amylose content in mixed gels was increased, peak intensity wat increased.

Keywords

amylose;amylopectin;gel;scanning electron microscope