Effect of Storage Life of Rice Bran on the Quality of Oil

Rice is one of the staple food in Bangladesh.The most important milling by-product of rice is 'rice bran' which is an excellent source of edible oil.Due to the poor storage facility in the rice milling industry, the quality of rice bran gets deteriorates rapidly.This study examines the deterioration level of rice bran during the storage period in average room temperature (31°C).Raw, partially parboiled and parboiled rice bran was collected right after milling.Oil is extracted by 'hexane solvent extraction' method from the 1st day of storage period for one week with the interval.Free fatty acid level, lipase activity, Iodine value and the pH value was determined from the collected rice bran oil.The preliminary result of this study showed that the deterioration level is rapidly increased during the 1 week of storage and the maximum deterioration level was found in raw rice bran.The free fatty acid (FFA) level, the degree of unsaturation and pH was respectively 17.25%, 92g Iodine/100ml oil and 3.10, whereas in parboiled rice bran it was respectively 4.23%, 101.1gIodine/100ml oil and 6.23.Since the parboiled rice bran undergoes through a traditional stabilization method of parboiling and drying before milling, it might be a reason for the lower level of deterioration.The oil collected right after milling also showed a lower lipase activity.This study can be concluded by considering that, the less the storage time the better is the quality of the oil.