Publication no. C-1999-0727-02R |  VIEW ARTICLE

Annealing of Long-Term Stored Rice Grains Improves Gelatinization Properties.

Aijiro Yamamoto (1,2) and Kiyoka Shirakawa (3). (1) Professor, Division of Food and Nutritional Science, Graduate School of Nutrition, Koshien University l0-1, Momijigaoka, Takarazuka 665-0006, Japan. (2) Corresponding author. E-mail: <yamamoto@koshien.ac.jp> Phone: 0797-87-5111. Fax: 0797-87-5666. (3) Student of master course, Division of Food and Nutritional Science, Graduate School of Nutrition, Koshien University, l0-1, Momijigaoka, Takarazuka 665-0006, Japan. Cereal Chem. 76(5):646-649. Accepted June 17, 1999. Copyright 1999 American Association of Cereal Chemists, Inc.

We found new characteristics of annealing (or warm water treatment) in this rheological study. Japonica rice grains from long-term storage at an ambient temperature for 10-24 years showed gelatinization properties analogous to that of indica rice but recovered properties similar to that of newly harvested rice after annealing at 55°C for 24 hr. Annealing signifcantly augmented the enthalpy from differential scanning calorimetry of raw and treated rice. This treatment also strengthened peak heights of the A pattern of rice in the X-ray diffraction intensity diagram. Annealing of long-term stored rice grains showed reverse effects to that of newly havested rice and purified starches. This effect of annealing on long-term stored rice might be useful for industrial purposes.