Differently processed Sri Lankan traditional rice as a source of oleic, linoleic, and other fatty acids

Renewed interest in Sri Lankan traditional rice has led to demonstrate their nutritional and health potential. However, much data is not available on the constituent fatty acids or the effect of processing of rice on fatty acids which are vital in maintaining immunity and many metabolic functions.

To assess the fatty acid profiles of traditional rice subjected to different processing methods Methods: Six traditional rice varieties; Goda heenati, Batapola el, Dik wee, Dahanala, Unakola samba, and Hangimuththan were processed as raw under milled (unpolished), raw polished (4%), and parboiled under milled. Fat was extracted from cooked and uncooked rice flour of differently processed rice varieties. Extracted fat was hydrolysed, methylated, and subjected to gas chromatography mass spectrophotometry.

Irrespective of processing, the major fatty acid contents of fat of uncooked and cooked rice flour remained as oleic > linoleic> palmitic> stearic acid. Monounsaturated fatty acid, oleic was the most abundant fatty acid found in all differently processed uncooked (35.7-47.6% fat) and cooked rice flour (34.8-44.7% fat). Essential fatty acid, linoleic (18:2) content in the fat of uncooked and cooked rice ranged from 17.9-32% and 18.6-32% respectively. Saturated palmitic acid (C-16) and stearic acid in uncooked and cooked ranged from 13.5-21.5% and 18.2-22.4% and 1.5- 3% and 1.1-3.2%respectively. Consumption of two cups of these traditional rice varieties will provide approximately 4-10% of RDA of linoleic acid.

Raw unpolished traditional rice varieties provide the highest amounts of monounsaturated oleic acid and polyunsaturated linoleic acid followed by parboiled and raw polished rice.