Abstract
The present investigation aimed at finding out the effect of different degumming processes and on the use of some nontraditional alkaline material for refining of rice bran oil. Attempt was made to treat crude rice bran oil with H2O, and H3PO4 for degumming followed by with alum or H2O for dewaxing. After removal of the gums and waxes the oil was neutralized with commonly used NaOH, and some nontraditional neutralizing agents like Na2CO3 and NaHCO3. Finally the oil was bleached traditionally using earth and charcoal and deodorized. The RBD oil was characterized by determining their color, peroxide value, content of unsaponifiable matter, and free fatty acids. Among the different processes tried degumming with 0.2 %, w/w, H3PO4 followed by dewaxing with 2.0 %, w/w, H2O; bleaching with tonsil earth (1.5 %, w/w) and charcoal (0.5 %, w/w) and finally deodorization at 220°C temperature and 2-4 mm Hg pressure resulted best quality oil in terms of the measured parameters. The characteristics of refined rice bran oil could be as content of FFA and UM 0.2 (%, w/w), 2.6 (%, w/w) respectively; color 10.9Y, 2.0R (in 2.54 cm Lovibond Tintometer cell); PV 3.3 (meq/kg). The oil yield is 78-85 % (by weight).
