Kinetic Studies on Hydration and Cooking of Rice

쌀의 수화 및 취반특성에 관한 속도론적 연구

  • Cho, Eun-Kyung (Department of Food Engineering, Yon Sei University) ;
  • Pyun, Yu-Ryang (Department of Food Engineering, Yon Sei University) ;
  • Kim, Sung-Kon (Food Grain Technology Lab., Korea Institute of Science and Technology) ;
  • Yu, Ju-Hyun (Department of Food Engineering, Yon Sei University)
  • 조은경 (연세대학교 공과대학 식품공학과) ;
  • 변유량 (연세대학교 공과대학 식품공학과) ;
  • 김성곤 (한국과학기술연구소 곡류공학연구실) ;
  • 유주현 (연세대학교 공과대학 식품공학과)
  • Published : 1980.12.30


The hydration and cooking rate of two rice varieties, Akibare (Japonica) and Milyang 23 (Indica), were investigated in terms of mathematical rate equations. The hydration rate at temperatures of $10{\sim}40^{\circ}C$ was examined by weighing method. The absorption of liquid water by rice grain was directly proportional to the square root of the hydration time. The diffusion coefficient was given by the Arrhenius relation : $D=3.151{\times}10^{-3}\exp\;(-4000/RT)$ for Akibare and $D=5.853{\times}10^{-3}\exp\;(-5700/RT)$ for Milyang 23. Milyang 23 was cooked at a faster rate than Akibare. The activation energies for cooking were in the range of 18 000 cal/mole at $90{\sim}100^{\circ}C$ and 9,000cal/mole at $100{\sim}120^{\circ}C$. However, Milyang 23 showed slightly higher activation energy of cooking at $90{\sim}100^{\circ}C$. Adhesiveness and amylograph viscosities at all reference points for Milyang 23 were higher than those for Akibare.