Abstract

• The present study focused on the extraction of essential oil from yacon leaf and its physicochemical properties as well as antimicrobial activity. Types of organic phytochemical constituents in yacon leaf were determined. The essential oil (0.283 %) was extracted by steam distillation using a Clevenger apparatus. The antimicrobial activity of essential oil was also assessed by agar well diffusion method. The oil was found to show low activities on all tested microorganisms, namely Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus pumilus, Candida albicans and Escherechia coil. The essential oil of yacon leaf analyzed by gas chromatography-mass spectroscopy (GC-MS) indicated the presence of 3- carene,1-methyl-3-(1-methyl ethyl) benzene, γ-terpinene, D-limonene, caryophyllene,1-methylene-2β-hydroxymethyl-3,3-dimethyl -4β - (3 methyl but -2-enyl) cyclohexaneand 1-formyl-2, 2-dimethyl-3-trans- (3-methylbut-2-enyl)-6-methylene cyclohexane in the essential oil. Some physicochemical properties such as specific gravity (0.936), total acid number (2.805 mg KOH/g) and ester value of essential oil (57 mg KOH/g) were also determined. The present study thus confirmed the presence of essential oil containing mono and sesquiterpenes and the phenolic compounds in yacon leaf, which can be beneficial to human health as a drug or a food.