Physico-chemical evaluation of traditionally cultivatedaromatic rice varities in Sabah

The physicochemical characteristics such as physical (grain appearance, size and shape, and 1000-grains weight (TGW)), chemical (grains aromatic, amylose content (AC), and alkali spread value (ASV) were studied for 10 traditionally cultivated aromatic rice varieties from Sabah. The purpose of this study was to identify the physical and chemical characteristics of the traditionally cultivated aromatic rice varieties in Sabah. The method used to evaluate the physical characteristics were observing the physical appearance, measuring the grain size using 10 grains of de hulled rice and weighing the grains with 1000-grains weight method. As for the chemical characteristics, it was evaluated using grains aromatic score test to evaluate the aroma using 1 - 4 scale with 1, 2, 3 and 4 corresponding to absence of aroma, slight aroma, moderate aroma, and strong aroma respectively. Amylose content analysis was conducted using the spectrophotometer method while for alkali spread value analysis was evaluated by soaking the dehulled grains into weak alkali solution. Among these aromatic rice varieties, the result obtained showed that LIB ratio range from 2.23-4.35 with long and slender shape; TGW obtained in this study was varied between 20.20g to 33.54g with Batangan had the heaviest weight. Durak B was found to have the highest score in grain aromatic test with score of 4 (strong aromatic scent) whereas AC ranged between 9.61-26.55% with Kinandong Patong was the highest in AC and Pantat Ayam was the lowest. The ASV of these traditionally cultivated aromatic rice varieties are ranged between low and intermediate. Galigis, Surakat, Baliung, and Kinandong Patong, belong to the low range while Pantat Ayam, Kambiring, and TQR2 range in intermediate scale. The result obtained showed that there are some traditionally cultivated aromatic rice varieties such as Durak B with excellent grains quality characteristics. Durak B is recommended to be used in plant breeding. It has strong aroma which is useful in genetic tagging for development of superior aromatic variety. This new traits can be used in breeding program to produce better quality of rice grains.