Varietal Variations in Physicochemical Characteristics and Amylopectin Structure of Grain in Glutinous Rice

  • Choi, Hae-Chune (Rice Research Div., National Yeongnam Agricultural Experiment Station, R.D.A.) ;
  • Hong, Ha-Cheol (Rice Breeding Div., National Crop Experiment Station, R.D.A) ;
  • Kim, Yeon-Gyu (Rice Breeding Div., National Crop Experiment Station, R.D.A) ;
  • Nahm, Baek-Hie (Colleg of Natural Science, Myeongji Univ)
  • Published : 1999.09.01

Abstract

Thirty-eight glutinous rice varieties were classified into nine groups on the scatter diagram by the upper two principal components (56% contribution to the total information) based on eleven physicochemical characteristics including the viscograms and physical properties of cooked rice. The first principal component was the factor mainly associated with the viscogram characteristics of rice flour emulsion and the second was the factor chiefly related to the physical properties of cooked rice and water absorbability of rice grain. Indica glutinous rices were clearly distinguished from japonica ones by the first principal component score. Javanica glutinous rices were widely distributed on the intermediate zone between indica and japonica or on several japonica rice groups. Significant positive or negative correlations were found among water absorption rates of rice grain, physical properties of cooked rice, and viscogram characteristics of rice flour. Especially in japonica glutinous rices, the breakdown and setback viscosities of rice flour were closely associated with the alkali digestion value of milled rice and the stickiness of cooked rice. The frequency ratio of short glucose chains (A-chain) to intermediate glucose chains (B-chain), the ratio of B- chains to long glucose chains (C-chain) and the relative frequency of A- or B-chain fractions representing the amylopection structure of rice starch was closely associated with the breakdown and setback viscosities of rice flour.

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