Effect of dehulling method on the chemical composition of the lipid constituents of the kernels and oils of Ricinodendron heudelotii seeds

Abstract : The aim of this study was to characterize the lipids present in the oil and kernels of Ricinodendron heudelotii seeds. Two dehulling methods were used to extract kernels from their husks: a heat treatment and a manual mechanical dehulling technique. Oil from kernels obtained by traditional heat treatment of seeds had a kinematic viscosity of 169 ± 0.5 mPa.s, and an iodine value of 175.6 ± 1.1 g/100 g oil. The oil from kernels isolated by mechanical dehulling had a kinematic viscosity of 128 ± 0.11 mPa.s and an iodine value of 195.2 ± 2.0 g/100 g oil. Determination of the minor compound profile of the oil revealed a total tocopherol content of 135.0 ± 0.4 mg oil from kernels isolated by traditional heat treatment. The oil obtained from kernels isolated by manual mechanical dehulling had a total tocopherol content of 178.3 ± 0.4 mg/100 g. An analysis of the fatty-acid profile of the oil from kernels isolated by traditional heat treatment revealed the presence of α-eleostearic acid (50.5% ±0.1), linoleic acid (24.0% ±0.0), β-eleostearic (8.4% ±0.0) and catalpic acid (0.40% ±0.1). By contrast, the fatty acid composition of oil from kernels isolated by manual mechanical dehulling was of α-eleostearic acid (60.1% ±0.2), linoleic acid (22.8% ±0.1). Ricinodendron heudelotii oil has a very high level (84.4 ± 0.4%) of polyunsaturated fatty acids (CLnA). Some analysis of the triglycerides present in the oil revealed the potential isomerization of α-eleostearic acid to form β-eleostearic acid and catalpic acid