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.

쌀전분으로부터 분리한 아밀로오스와 아밀로펙틴이겔을 형성할 수 있는 최저농도로 아밀로오스와 아밀로펙틴 혼합겔을 제조하여 주사전자현미경과 X-선 회절기를 이용하여 겔 구조를 관찰하였다. 겔을 형성할 수 있는 최저농도인 용해성 아밀로오스 1.08% 농도에 아밀로펙틴을 $1.5%{\sim}7%$ 첨가하면 겔 그물망구조가 잘 형성되었고, 아밀로펙틴을 2%와 3% 첨가한 겔은 저장에 따라 $2{\theta}\;=\;17.0^{\circ}$에서 피크가 커졌다. 15% 아밀로오스/아밀로펙틴 혼합겔을 저장했을 때 아밀로오스 함량이 높을수록 단단하고 안정된 그물망구조를 이루었으며 생전분에서의 겔형성 양상과는 달리 아밀로오스와 아밀로펙틴이 함께 겔메트릭스를 이루는데 참여하는 것으로 생각되었고, 아밀로오스 함량이 증가할수록 $2{\theta}\;=\;17.0^{\circ}$에서 피크의 크기와 결정강도는 커졌다.

Keywords