Abstract
In order to clarify the mechanical properties of cooked rice, a uniaxial compression test on cooked rice grains of several varieties, Koshihikari (new and old), Nihonbare and California Komachi, was carried out, and the force-deformation curves were converted to stress-strain curves based on the compressed area of the cooked rice grains. The force-deformation curves showed that new Koshihikari had a greater breaking force than that of old Koshihikari, this being different from the result obtained from a sensory evaluation. The breaking stress calculated according to the compressed area of a cooked rice grain for new Koshihikari, however, showed a significantly lower value than that for old Koshihikari, Nihonbare and California Komachi. The behavior of the stress-strain curve for a cooked rice grain was influenced by the deformation velocity, indicating that cooked rice grain was a viscoelastic material.
