Abstract
The quality of cooked long, medium and short-grain imported rice was investigated by its amylographic characterisitics. Cooked rice grains were subjectedto amylography, the temperature being programmed from 26°C to 50°C and then held at 50°Cfor 64 minutes. The viscosity of the cooked rice was evaluated from the maximum viscosity of the amylogram. The viscosity at the final stage was also evaluated according to the degree of retrogradation, the oscillatory amplitude showing that the surface of the cooked rice grains was easily crushed. The maximum viscosity, the viscosity at the final stage and the oscillation showed the lowest values with long grain-rice. Long-grain rice was less viscous, the degree of retrogradation was greater and the cooked rice was not as easily crushed as the medium and short-grain rice samples.
The amylographic variates of cooked rice (maximum viscosity, breakdown value, oscillatory amplitude and viscosity at the final stage) were analyzed and compared with the analytical results for the gelatinization temperature, maximum viscosity, minimum viscosity, breakdown value and set back of rice flour. A factor analysis on the quality of cooked rice according to amylographic characteristics was effective for classifying the variety of rice grains.
