Various rheological methods to measure the hardness of instant cooked rice by a texture analyzer were investigated and compared. Specifically, instant white rice samples with a wide range of hardness were subjected to four different rheological tests with disk, cylinder, rod, and cone probe whose results were inter-correlated. All the measurements demonstrated that the hardness of instant rice was reduced with increasing moisture content and showed negatively linear relationships. Out of the four tests applied in this study, the highest coefficient of correlation (R2 = 0.9268) was observed distinctly in the cone probe test, where both compressive and shear forces can be applied to deform individual rice grains. However, the cylinder probe test had the lowest coefficient of correlation (R2 = 0.7247) because it may be ineffective in causing direct deformation of individual rice grains. Furthermore, when the hardness values (N) were converted to stress (Pa), highly linear correlations (R2 ≈ 0.99) were observed between the tests with similar probe geometry and force application.

Abstract
 서 론
 재료 및 방법
  재료
  밥의 경도 측정
  밥의 수분 함량 측정
  통계 처리
 결과 및 고찰
 요 약
 References

• 김희수(세종대학교 식품생명공학과) | Heesu Kim (Department of Food Science & Biotechnology, Sejong University)
• 오임경(세종대학교 식품생명공학과) | Im Kyung Oh (Department of Food Science & Biotechnology, Sejong University)
• 양선경(세종대학교 식품생명공학과) | Seonkyeong Yang (Department of Food Science & Biotechnology, Sejong University)
• 이수용(세종대학교 식품생명공학과) | Suyong Lee (Department of Food Science & Biotechnology, Sejong University) Corresponding author