Oil Extraction from Millet Seed – Chemical Evaluation of Extracted Oil

ABSTRACT: The object of this study is to extract the oil from millets and evaluate the chemical properties of the extracted oil. Commercial millet oil was obtained by cold solvent extraction adopting soxhlet procedure. Quantitative and qualitative tests concerned with the non-saponifiable matter, fatty acid composition, phosphorus content representing total phospholipids, refractive index, peroxide, saponification, acid and iodine values were carried out on the extracted oil. The extracted non-saponifiable matter was fractionated into a number of chemical classes of compounds on TLC plates. The major two fractions; sterols and tocopherols were separated and extracted with ether. Gama tocopherol and β-sitosterol were the predominant tocopherol and sterol present in the millet oil. Prepared fatty acid methyl esters of the oil sample showed that linoleic (64.8 %), followed by oleic (24.2 %) and palmitic (6.1%) acids were the predominant fatty acids, in respective decreasing order. The oil contains considerable quantities of tocopherols which act both as vitamin E and antioxidant. The oil content of the seed depending on the types of extraction is low (4-7%) but due to its nature, being high in both linoleic acid and tocopherol, the purified oil might be employed as an ingredients in food formulation.   Keywords: Chemical Evaluation, Fatty Acid Composition, Millet Oil, Non- Saponifiable Matter, Oil Extraction.