Other Uses, and Utilization of Vetiver: Vetiver Oil

摘要

Vetiver, a native of India is known for its perfumery and medicinal value since ancient times, much before the world became familiar with rose scents. The annual world trade in vetiver oil is estimated to be around 250 tons, with Haiti, Indonesia (Java), China, India, Brazil, Japan being the main producers, and USA, Europe, India, and Japan being the main consumers. It is a gift of India to modern world, and finds its greatest use in modern perfume creations. The essential oil distilled from the roots of vetiver, is one of the most complex mixtures of sesquiterpene alcohols and hydrocarbons, and also one of the most viscous oils with an extremely slow rate of volatility. Slow evaporation rate of vetiver oil coupled with its pleasant aroma makes it a perfume by itself. Its high solubility in alcohol that improves its miscibility with other perfumery material, makes it unique perfume resource, for which no synthetic substitute is yet available. The essential oil produced in different countries possesses distinct odor note-Reunion (Bourbon) and Haitian oil with roseate note is highly regarded in perfumery industry, but the vetiver (khus) oil obtained from wild 'Khus' roots in India is considered to be the best for its balsamic woody note. Washed fresh or soaked semidried roots when distilled by hydro-distillation / steam distillation produce an amber or dark brown oil with a viscous texture. When the oil is distilled using traditional copper vessel in conventional slow fire stills, the oil produced is of dark green color. Normally 15-18 month old roots, harvested during December - January are most suitable to realize high concentration and good quality of essential oil. Depending upon the biotype, cultural practice, age of roots and mode and duration of distillation, vetiver roots may give a yield of about 0.3 to 2 % essential oil on fresh root weight basis. Under ideal steam distillation conditions the economic distillation of essential oil is realized within 15-18 hrs, but low temperature wood-fired distillers may require over 24 hrs. Lately, molecular extraction by liquid carbon dioxide is gaining preference over hydro-distillation methods to realize high-grade essential oil. Chemical composition of vetiver oil is extremely complex, mainly comprising of sesquiterpenes and sesquiterpene derivatives, of which vetiverols, their carbonyl compounds and esters, are the main constituents, and their relative abundance normally establishes the oil quality. Three carbonyl compounds, α- vetivone, β - vetivone and khusimone, are considered the primary odor - influencing components; β -vetivone has the better odor, and is considered the most important, while its major isomer nordihydro β-vetivone has a strong, rich, woody-peppery note. The oil and its constituents are used extensively for blending oriental type of perfumes and floral compounds, as well as in other cosmetic and aromatherapy applications. It is very persistent and one of the finest fixatives known. Vetiver oil is a main ingredient in 36% of all western quality perfumes and 20 % of all men's fragrances. Dried roots are used as sachets / stuffing material to prepare ventilating screens that provide cool air effect and pleasant aroma when moistened.