A total characterisation of Moringa oleifera Malawi seed oil

The oil from the seeds of Moringa oleifera Malawi was produced using three different ways. Cold pressure (CP), extraction with n-hexane (H) and extraction with a mixture of chloroform:methanol (50:50) (CM). The oil produced ranged from 25.1 (CP) to 41.4% (CM). The density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, sterols, tocopherols (by HPLC), peroxide value, E 1% 1cm at 232 nm and 270 nm and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially oleic (up to 67.80%), The dominant saturated acid was behenic (up to 6.81%) and stearic (up to 5.86%). The oil was also found to contain high levels of β-sitosterol (up to 47.10%), campesterol (up to 23.83%) and stigmasterol (up to 17.40%). α- γ- and δ-tocopherols were detected up to levels of 226.9, 71.47 and 216.57 mglkg respectively. The induction period (at 120°C) of Moringa oleifera seed oil was reduced from 49% to 74% after degumming. Moringa oil showed high stability to oxidative rancidity. Compared to olive oil, Moringa oleifera seed oil showed higher stability, lower degree of unsaturation and similar fatty acid composition (apart from C18:2 and C18:3).