Quality Variations of Khao Dawk Mali 105 (KDML 105) Rice in the Tung Kula Rong Hai Region of Thailand

Abstract

We investigated the quality variations of Khao Dawk Mali 105 (KDML 105) rice produced from three different locations in Tung Kula Rong Hai, the biggest area producing KDML 105 in Thailand. The grain qualities of this rice were evaluated for chemical, physical and morphological properties. A scanning electron microscope (SEM) was used to study the shape and surface details of rice starches. In general, grain size and cooking properties were not significantly different (p>0.05) among the three locations. On the other hand, there were some differences in chemical, texture and pasting properties. The results showed that the 2-acetyl-1-pyrroline (2-AP) content of the rice from one area (5.47 ppm) was significantly higher than those of the two other areas. Pasting temperature, cohesiveness and gumminess were slightly different (p<0.05) in the rice samples. Starch granule size at the outer and center layers of the endosperm of milled rice grain was also found to be significantly different at different growth sites. Capillary electrophoretic patterns of prolamin were found to be identical among analyzed samples. This study has added valuable information about the effects of growth conditions on qualities of Thai rice.