Abstract
In this research, attempts were made to use rice bran lipase (RBL) from bran to optimize the fatty acid profile of existing commercial sunflower oil by either replacing or incorporating n-3 fatty acids from marine source that can be a value addition to the superior usability of rice bran. Preliminary assay of crude lipase with the substrate 4-nitrophenyl palmitate (4-NPP) showed specific activity of 0.04 U/mg. Subsequently a 9.45-fold purification (specific activity of 0.37 U/mg) was achieved through ammonium sulfate precipitation followed by fast protein liquid chromatography (FPLC) and reverse-phase high performance liquid chromatography (RP-HPLC) method of purifications. The SDS-PAGE and in-gel overlay staining of purified RBL with 4-methylumbelliferyl (4-MU) butyrate showed a single band of 33 kDa. Purified RBL showed a specificity for natural oils having long chain unsaturated fatty acids with a maximum specific activity (0.452 U/mg) in case of rice bran oil. Immobilized RBL was used to blend fish oil free fatty acids (FFA) with sunflower oil (SO) at varying ratios (v/v). Clinically desirable novel structured lipid (SL) were obtained with n-6:n-3 ratios (v/v) of 5.6:1 and 3.6:1 Thus, the current study offers better nutritional desirability to the existing nutrition profile of commercial sunflower oil and further can be exploited to modify other triglycerides to optimize the n-6:n-3 ratio.