• Applied Biological Chemistry
• /
• v.38 no.5
• /
• pp.398-402
• /
• 1995

Hardness and adhessiveness of cooked rice were measured with rice grain and rice block methods by texturemeter. In grain method 3, 4 and 5 grains were arranged and subjected to the texture test with a plastic plunger at 95% strain and 0.5mm/sec speed. The hardness were 7.4kg, 7.5kg and 10.0kg respectively and the coefficient of variation ranged from 37.0% to 25.9%, which was mainly due to the irregular geometry of the grains in each specimen set Adhesiveness could not be measured with this method. A cylindrical rice block($H/D=20mm{\times}15mm$) was made for the texture analysis. The hardness was 2.1 kg with coefficient of variation ranging from 2.8 to 7.0%, and the block method was s more reproducible compared to the grain method. A grooved plastic plunger and platform were designed for the measurement of adhesiveness of cooked rice block. The adhesiveness was 0.68kg sec and the coefficient of the variation was 4.6%.

• Applied Biological Chemistry
• /
• v.38 no.5
• /
• pp.422-424
• /
• 1995

In order to investigate the textural changes of cooked rice in a home electrical rice cooker during warm keeping period, rice was cooked and stored at $73^{\circ}C$ for 42 hours. The time course changes of hardness and adhesiveness of cooked rice were measured with the specimen prepared as a cylindrical rice block(H/D= 15 mm/20 mm). At the initial stage of warm keeping period the hardness was 1.61 kg and it was increased steadily to 1.95 kg up to 12 hours. And it was rapidly dropped to 1.57 kg within 3 hours, and thereafter gradually decreased to 1.44 kg. The adhesiveness was steadily declined with warm keeping period from 0.51 to 0.323kg set The cohesiveness and chewiness were also changed in the similar pattern to that of hardness while the springiness remained unchanged throughout the whole warm keeping period.