The effect of incubation time variations on the enrichment of linoleic acid in rice bran oil by solid fermentation method using Aspergillus terreus

Rice bran oil contains unsaturated fatty acids which are very potential to prevent and reduce the risk of hypercholesterolemia. Hypercholesterolemia is a condition of increasing concentration of cholesterol in the blood that exceeds the normal value. This condition can be prevented by consuming unsaturated fatty acids, such as linoleic acid (C18:2). Hypocolesterolemic effects possessed by rice bran oil can reduce blood cholesterol levels thereby reducing the risk of atherosclerosis and coronary heart disease. Rice bran is the most effective substrate for producing that type of fatty acids. Its fermentation using Aspergillus terreus mold is one of the ways to maintain and enrich the unsaturated fatty acid content in rice bran oil. Aspergillus terreus can produce oil that has a higher composition of unsaturated fatty acids compared to another Aspergillus species. This study examines the effect of incubation time of mold inoculum to determine the content of unsaturated fatty acids in fermented bran oil. The fermentation method used is solid fermentation using the modified Bligh-Dyer extraction method. Gas Chromatography/Mass Spectrometry (GC/MS) is an instrument which is used to determine the composition and content of unsaturated fatty acids in rice bran oil. The result showed that the incubation time for the enrichment of linoleic acid in rice bran oil using Aspergillus terreus, which is for 6 days with linoleic acid content of originally 37,758% to 39,780%.