PROPERTIES OF WAXY AND ISOGENIC NONWAXY RICES DIFFERING IN STARCH GELATINIZATION TEMPERATURE

The samples selected for this study were two crops of 12 waxy varieties and two pairs of isogenic nonwaxy lines differing essentially in starch gelatinization temperature alone. Gelatinization temperature differences were related to physical properties of the raw rice and starch, but not to those of the cooked rice. Waxy samples of low and high gelatinization temperatures gave similar eating quality scores of cooked rice, although the samples differed in the alkali digestibility and cooking time of milled rice, amylopectin intrinsic viscosity, and x-ray crystallite size and/or degree of order, ease of acid and α-amylase corrosion, hot water absorption, and solubility of the starch granules. Many properties, such as starch crystallinity and gelatinization temperature, and intrinsic viscosity of starch fractions, were modified by environment. © 1969, American Chemical Society. All rights reserved.