Fatty Acid Composition of Oil from Groundnuts and Oyster Nuts Grown in Uganda

This study determined the fatty acid (FA) composition of oil from groundnuts and oyster nuts in Uganda. The FA composition was determined by Gas Chromatography/Mass Spectrometry with FID. Oil from groundnuts contained 39.71 to 55.89% oleic, 20.21 to 35.59% linoleic and 11.91 to 17.16% palmitic acids. Oil from Serenut cultivars contained cis 11-eicosenoic acid (C20.1), cis 11, 14 eicosadienoic acid (C20.2) and cis 11, 14, 17 eicosatrienoic acid (C20.3ω3) which were not detected in traditional cultivars. Oyster nut oil was high in linoleic acid at 41.02 to 44.86% and palmitic acid at 33.58 to 38.11% while oleic acid was low with amounts <10%. The polyunsaturated to saturated FA ratios of oil from groundnuts and oyster nuts were >0.45, the minimum recommended by FAO. The atherogenic (AI) and thrombogenic indices (TI) of <1 and the hypocholesterolemic to hypercholesterolemic index (h/H) of >4 in groundnut oil were favorable for cardiovascular health. Indices for oyster nut oil were ≤1for AI and >1for TI. The h/H was low compared to that of groundnut oil. Results showed little distinction between the FA compositions of oil from traditional and improved groundnuts suggesting that breeding may not have significant effect on major FAs. Oyster nut oil contained saturated and unsaturated FA in a ratio of 1:1. The lipid health indices for groundnut oil were within recommendations while those of oyster nuts were less desirable. Oyster nut oil should therefore be consumed with moderation.