Identification of the constituent of non-triglyceride components of Jatropha seed oil

Abstract

Vegetable oils are mostly triglyceride of saturated and unsaturated fatty acid, but they also contain a small percentage of non- triglyceride components that belong to wide chemical classes and could contribute to the nutritive value or anti-nutritional value of the vegetable oil. Jatropha oil is non edible because it is considered to contain phorbol ester, a toxin and a tumour promoter that is found in jatropha seeds. This research was carried out with the aim of identifying the content of the volatile component of jatropha oil. Jatropha seeds were extracted with n-hexane using soxhlet extraction method and quality parameters of iodine value, acid value and peroxide value were determined. The Fourier Transform-Infrared spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis were carried out in order to identify the volatile chemical compounds in the oil. The oil yield was 43.17%, and the iodine value, acid value and peroxide values were 100 mgI2 /100 g, 2.39 mgKOH/g, and 8.36 meq/kg respectively. The FT-IR analysis revealed the presence of compounds with the functional groups of alkanes, alkenes, alcohols, esters carboxylic acid, amine and carbonyl. The GC-MS analysis showed the presence of twenty compounds of different chemical classes. It was concluded that jatropha seed oil contains many different types of compounds in addition to triglycerides.