Effects of rough rice storage conditions on gelatinization and retrogradation properties of rice flours

Changes in gelatinization and retrogradation properties of two rice cultiva rs, Bengal and Kaybonnet, during rough rice storage were studied using diff erential scanning calorimetry (DSC). The storage variables included two sto rage moisture contents (12 and 14%), three storage temperatures (4, 21, and 38 degrees C), and four storage durations (0, 3, 9, and 16 weeks). Rough r ice cultivar, storage temperature, moisture content, and duration affected (P < 0.05) the enthalpies and temperatures of gelatinization and retrograda tion of rice flour. Bengal had a higher gelatinization enthalpy (P < 0.005) but lower gelatinization temperatures (P < 0.0001) than the long-grain Kay bonnet. Rice stored at 38 degrees C exhibited higher gelatinization enthalp y and temperatures (P < 0.05) than those stored at 4 or 21 degrees C. Stora ge duration affected the gelatinization and retrogradation properties throu gh a higher order, rather than a linear, relationship.