Study of the stability of Ricinodendron heudelotii oil: Effects of solar radiation on the chemical composition of the oil

The native crude oil of Ricinodendron heudelotii mainly consists of triglycerides formed typically with polyunsaturated fatty acids (84%). Fatty acids with three conjugated double bonds (Conjugated Linolenic Acids, CLnA) contain more than 60% of α-eleostearic acid (C18:3 9c, 11 t, 13 t). The heat-treating process using the traditional hulling method of seeds for kernel consumption results in the isomerization of α-eleostearic acid into β-eleostearic and catalpic acid. In order to gather information about the transformation of these conjugated polyunsaturated fatty acids, a study to investigate the effects of solar radiation on the native oil was conducted. Changes in the chemical composition of fatty acids in the oil, especially conjugated polyunsaturated fatty acids, were monitored by GC (Gas Chromatography). Analysis of fatty acid profiles of treated and untreated oils showed the isomerization of α-eleostearic acid under the effect of solar radiation, whether natural or artificial. This isomerization involves the conversion of α-eleostearic acid into its isomers β-eleostearic acid (C18:3 9 t, 11 t, 13 t) and catalpic acid (C18:3 9 t, 11 t, 13c) with a ratio of 5:1 in the triglycerides of the oil. Our findings highlight the significant influence of solar radiation on composition and isomerization of the fatty acids of Ricinodendron heudelotii oil, and emphasize as well as its potential use in the industrial production of some CLnA isomers. [Display omitted] •CLnA isomerization in Ricinodendron heudelotii oil under natural or artificial solar radiations.•Isomerization of α-eleostearic acid into β-eleostearic acid and catalpic acid.•The ratio of β-eleostearic acid to catalpic acid formed is about 5:1.