Comparative study of physicochemical and thermal properties of the seed oils of three cucurbit species

Abstract

Three indigenous cucurbit seeds from Ivory Coast namely Cucumeropsis mannii Naudin, Citrullus lanatus var. Citroides (Thrumb.) Matsum & Nakai and Cucumis melo var. Agrestis were investigated for the physicochemical properties. Thermal properties of their crude oils extracted by a cold solvent method were also tested. Physicochemical characterization of the seeds showed that they are important sources of proteins, lipids, carbohydrates and mineral elements. C. lanatus seeds had the highest lipid content (46.40%) followed by C. melo seeds (36.50%) and C. mannii seeds (35.70%) on dry weigh bases. Most of the index values and chemical characteristics of extracted seed oils are not significantly different, except for the peroxide value and the color parameters of C. mannii. Linoleic acid, whose values ranged from 54.84% to 70.76%, was the major fatty acid out of all seed oil species. The thermal properties revealed that C. melo seed oil had low transition temperatures followed by C. lanatus seed oil and C. mannii seed oil depending on their fatty acid compositions. These results suggest that these thermal properties could be used in the industrial fractionation and the cucurbit seed oils may be used as edible oils due to their similarity to the commonly used edible oils.