A micro‐method for the estimation of oil content and fatty acid composition in seeds with special reference to cyclopropenoic acids

Abstract

AbstractA micro‐method is described for the routine estimation of oil content and fatty acid composition in seeds containing cyclopropenoic fatty acids (CPEFA) by determination of the total and component long‐chain fatty acids. The oil was transmethylated without prior extraction using 1.17% sodium methoxide in methanol at 80°C for 45 min. The resultant fatty acid methyl esters were separated and measured by gas‐liquid chromatography using a glass capillary column coated with Carbowax 20 M at 170°C. The method was shown to be applicable to a wide range of seeds including cottonseed (Gossypium hirsutum), kapok (Ceiba pentandra), paka (Urena lobata), baobab (Adansonia grandidieri and A. suarezensis). Individual seeds can be used with this method which needs only 50 to 150 mg for analysis. Results obtained with this micro‐method were reproducible and good recoveries of oil and individual fatty acids were observed. The micro‐method was compared for the determination of CPEFA (malvalic plus sterculic acids) to the nuclear magnetic resonance quantitation and gas‐liquid chromography after derivatisation of CPEFA in more stable compounds.