圧力処理炊飯米の老化の特徴 [in Japanese] Characteristic of Retrogradation of Pressure-Treated Cooked Rice [in Japanese]
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We researched into the characteristic of retrogradation of cooked rice treated by pressure after soaking. By β-amylase pullulanase (BAP method), the degree of gelatinization of the nonpressure treated rice immediately after cooking was 95.7% and 79.1% after 5 days. On the other hand, the degree of gelatinization of the pressure-treated rice immediately after cooking was 98.4% and 92.9% after 5 days. Retrograded rice was scanned by a Differential Scanning Calorimeter (DSC) .ΔH was 14.3 mJ/mg to the cooked rice immediately after cooking, and 10.4 mJ/mg to the rice treated by pressure. Furthermore, with the storage time ΔH in the rice came closer to ΔH in the rice flour with water. But in this case, d H in the pressure-treated cooked rice was more lower than d H in the nonpressure-treated cooked rice. The results of Near Infrared Reflectance (NIR) analysis were as follows: The first principal component score (coefficient of determination 90.5%) correlated to its storage term (R<SUP>2</SUP>=0.775). A difference between the pressure-treated and the nonpressure-treated ricewas observed by plotting the first and the fourth (c.d. 0.5%) principal component scores. With a value calculated by d H and a value measured by the BAP method as a purpose variable and the first through the fourth principal component scores as explanation variables, the multiple correlation analysis was calculated by the addition and reduction method. The fourth principal component score (R<SUP>2</SUP>=0.513)was primarily obtained, then the first principal component score (R<SUP>2</SUP>=0.818), and then the third principal component score (R<SUP>2</SUP>=0.865) significantly appeared. When the retrograded rice was heated with a microwave, the degree of gelatinization of nonpressure-treated cooked rice was 93.1 to 96.8%, but that of pressure-treated cooked rice was 100%. Even after 30 days, the retrogradation pressure treated rice showed a high degree of gelatinization by micro-wave heating.
- Journal of Applied Glycoscience
Journal of Applied Glycoscience 46(1), 31-38, 1999-03-31
The Japanese Society of Applied Glycoscience