Composition and variation of fatty acids among groundnut cultivars in Uganda
Groundnuts (Arachis hypogaea L.) contain approximately 44-56% oil made up of fatty acids. Oleic and linoleic acids comprise about 80% of fatty acids in groundnuts. Groundnuts with >80% oleic are beneficial health-wise and also improve groundnut quality, flavour, and extended shelf-life, which is beneficial to traders. In Uganda, however, little is known about the fatty acids content of commercially available cultivars. This study was undertaken to determine the fatty acid composition of the most recently released commercially available groundnut cultivars in Uganda. Eleven groundnut genotypes were profiled for different fatty acids using gas chromatography (GC). Data were recorded in percentages from chromatographs and totaled up to about 100%. Oleic to linoleic ratios (O/L) and iodine values were calculated from fatty acid data. Groundnut genotypes tested differed significantly (P<0.05) in oleic, linoleic, palmitic, behenic, gadoleic, arachidic and palmitoleic acids. Oleic acid was highest in Lot 197 line, and linoleic acid was lowest in the same line. Oleic acid was lowest in Serenut 7 (43.19%) and linoleic acid was highest in the same line (33.45%). The lowest iodine value was observed in 197 (84.14); and the highest in Serenut 9T (96.59). Significant correlations (P<0.001) were observed between most of the fatty acids, except between arachidic versus gadoleic, stearic and gamma linoleic.
Key Words: Arachis hypogaea, gas chromatography, linoleic, oleic