Rheological characteristics and texture attributes of glutinous rice cakes (mochi)

The interrelationships between rheological characteristics and sensory attributes of commercial glutinous rice cake (mochi) have been investigated by using creep test, dynamic oscillatory measurements, texture profile analysis (TPA) and sensory evaluation. The water content of the mochi varied depending upon the addition of sugar. When no sugar was added, the water content could be as high as 55%. As sugar being added, the water content could be as low as 18%. Both water and sugar acted as plasticizer to soften the mochi. The mochi exhibited shear modulus (G′) from 0.32 to 2.98 kPa with complex viscosity (η∗) from 0.06 to 0.51 kPa s. From TPA, the products yielded hardness from 60 to 270 gf. The creep data fitted well in the modified 4-element model with the coefficient of determination (R2) not less than 0.99. The interrelationships among the rheological properties have been discussed. Thirty-five panelists conducted a descriptive sensory evaluation on the mochi. The results from intensity test significantly correlated with the rheological characteristics. Nevertheless, the preference test did not show similar results.