Extraction and characterisation of lemon grass oil.

Abstract

Essential oils are present in several plants, including lemon myrtle; lemon grass leaves and stems, eucalyptus leaves, Cedar wood, bay leaf, cinnamon, eucalyptus leaves rose wood. Pure essential oils are mixtures of more than 200 components, normally mixtures of terpenes or phenylpropaaic derivatives, in which the chemical and structural differences between compounds are minimal. They can be essentially classified into two groups: volatile fraction: Essential oil constituting of 90-95% of the oil in weight, containing the monoterpene and sesquiterpene hydrocarbons as well as their oxygenated derivatives along with aliphatic aldehydes, alcohols, and esters while non-volatile residue comprises 1-10% of the oil, containing hydrocarbons, fatty acids, sterols, carotenoids, waxes, and flavonoids. Essential oils present in lemon grass is used for flavourings in cooking, used in the perfumery-industry, pharmaceuticals since it has medicinal importances, preservative since it has anti-microbial properties, This study involved isolation of essential oil from samples of lemon grass grown in Wakiso, using hydro distillation and solvent extraction by hexane, determining the physiochemical properties of the oil which were ph, iodine value, peroxide value, acid value, density and saponification value, comparison with correlation charts, functional groups present determined using FT-IR in the fingerprint region, finding possible applications of lemon grass essential oil in Uganda. The results obtained from the analysis of the physiochemical properties were analysed using Microsoft excel and Anova two extraction methods indicated that the percentage yield of oil extracted is higher on solvent extraction than-as compared to hydro distillation.