Effect of Oil Extraction Process on the Fatty Acid Composition of Groundnut Oil

Groundnut ( Arachis hypogaea L.) is one of the important oilseed crops in the world, which is utilized for cooking and in confectionery, and is a rich source of valuable antioxidants like vitamin E and plant sterols especially β-sitosterol. In this study, we attempted to study the differences in fatty acid composition in commercially available refined groundnut oil (CRGNO), hexane extracted crude groundnut oil (HCGNO) and cold pressed groundnut oil (CPGNO).The ratio of unsaturated fatty acid to fatty acids was 5.47 ± 3.09, 5.91 ± 2.96, and 5.34 ± 3.11 for CPGNO, CRGNO and HCGNO respectively. Oleic acid (C18:1n9cis) and Linoleic acids (C18:2n6cis) were the major unsaturated fatty acidsand Palmitic acid (C16:0)was the highest saturated fatty acid identified in all the three GNO oils.The total unsaturated fatty acid content was high in all the three oils (86.23 ± 0.23% in CRGNO, 85.12 ± 0.26% in HCGNO and 84.74 ± 0.17% in CPGNO).A lower percentage of saturated fatty acids was observed in all the three oils i.e., 15.93 ± 5.95%, 15.48 ± 6.00% and 14.58 ± 5.68% in HCGNO, CPGNO and CRGNO respectively. From the fatty acid analysis of the three oils, it was observed that there was minor variation in the Oleic acid (C18:1n9cis) and Linoleic acids (C18:2n6cis) content and no significant difference in other fatty acids composition among the three samples. Cold pressed and hexane extracted crude GNO had higher essential fatty acid content (linoleic acid (C18:2n6cis) compared to refined GNO, indicating the effect of oil extraction on the fatty acid composition.