Abstract
The present study focused on variation in the fatty acid (FA) composition of the different lipids in black, red and green rice brans. Total lipids were fractionated using TLC into nine subfractions. The lipids comprised mainly triacylglycerols (TAG: 78.0 - 81.6 wt%), free FA (FFA: 5.6 - 8.8 wt%), and phospholipids (PL: 6.3 - 7.0 wt%). The PL components included phosphatidyl choline (52.6 - 57.2 wt%), phosphatidyl inositol (22.3 - 25.2 wt%) and phosphatidyl ethanolamine (11.4 - 16.4 wt%). Comparison of these cultivars showed no significant differences (P > 0.05) in FA composition of TAG, FFA and PL. FA composition of TAG among the three cultivars was characterized in the rice brans: unsaturated FA were predominantly concentrated at the sn-2 position (97.7 - 98.5 wt%) and saturated FA primarily occupied the sn-1 or sn-3 position (29.8 - 31.8 wt%). Comparison of individual PLs revealed significant differences (P < 0.05) in FA composition. Black and red rice brans were very similar, with green rice bran exhibiting a few differences. The results revealed no significant differences (P > 0.05) in the proportional composition of FA with increased degree of milling.
