Free amino acids of brown rice in relation to specific gravity grade

비중선별(比重選別) 현미중(玄米中) 유리 Amino산 함량

  • Park, H. (Institute of Plant Environment O.R.D.) ;
  • Chun, J.K. (College of Agriculture, Seoul National University) ;
  • Cho, I.H. (Dept. of Chem., Chun Pook Univ.)
  • 박훈 (농촌진흥청 식물환경연구소) ;
  • 전재근 (서울대학교 농과대학) ;
  • 조인호 (전북대학교 문리과대학)
  • Published : 1972.04.12


The contents of free amino acids in deembryod brown rice of two varieties were investigated by amino acid autoanalizer in relation to specific gravity grade. The analytical methods of free amino acid were also discussed. 1) The lower the specific gravity of the unhulled rice the higher the content of total free amino acids in the deembryod brown rice, and the similar trend appears to hold on each amino acids. 2) Main free amino acids were serine+asparagine, glutamic acid, aspartic acid, alanine and valine, and maximum values of them were 7.3, 5.1, 4.0, 3.4, 0.9mg/100g rice, respectively. They consist about 85% of total free amino acids in most cases. 3) The contents of soluble nitrogen and free amino acids appear to be lower in high protein variety (IR 667) than in low protein variety (Jinhung). The percentage of free amino acid nitrogen to soluble nitrogen, however, appears to be higher in high protein variety (IR 667). 4) Alanine was much lower than aspartic acid in IR 667 having Indica blood while alanine appears to be higher than aspartic acid in Jinhung (Japonica rice) suggesting varietal difference in amino acid metabolism. 5) Threonine peak was overlaped with glutamine, and serine was with asparagine in this study.