Abstract:
Sri Lankan traditional rice varieties (SLTRV) have been known to be associated with higher nutritional and healthcare properties but along with the rice market, cultivation of improved rice varieties is highly dominated at present. Therefore, this comparative study was done to investigate physicochemical parameters and proximate composition of selected traditional and improved rice varieties grown in Sri Lanka. Thirty-nine rice varieties including traditional and improved were cultivated and harvested at Rice Research Station, Ambalantota, Sri lanka. The physicochemical parameters, Gelatinization Temperature (GT) and Amylose Content (AC) and the proximate composition (crude ash, crude fiber, crude protein, crude fat and carbohydrate) were analysed. GT of the samples varied between 66.14 – 71.74°C, where five improved rice varieties H4, At 405, At 362, Bw 272 6b and Ld 408 showed low GT of 66.14°C. AC varied between 17.0 - 31.3 % and only one improved variety (At 405) was found with low AC. The proximate compositions were also independent from each other within varieties. Higher protein contents (>9.0%) were found with the improved varieties of H4, H7 and Bw 272-6b whereas the lowest (5.2 %) was also recorded with the improved variety of At 362 which is a highly cultivated variety in Sri Lanka. Crude fat contents of ≥2.4 % were recorded with five rice varieties namely, Suduru samba, Rath suwandel, Suwandel, Bw 272-6b and Ld 368. The varieties of Beheth heenati, Suwndel, Bw 272-6b and Basmathi 442 showed crude ash content of ≥1.2 %. Carbohydrate content had significant negative correlations with other nutrients except for crude fibre. It can be concluded that there was no significant difference in physicochemical properties and proximate composition in the studied traditional varieties of rice over the improved varieties except for the protein content. Many of the improved varieties contained higher protein content compared to the SLTRV.
