Variations in composition of peppermint oil in relation to production areas

Abstract

Compositional data obtained for peppermint oil fromMentha piperita L. produced in Tasmania as well as oils produced in other major production areas, were analysed by principal coordinate analysis. The 6 variates included in the analysis were the oil compounds limonene, cineole, menthone, menthofuran, menthyl acetate and menthol. In general, Tasmanian oils were characterised by low menthofuran, low limonene, low menthyl acetate and to a lesser extent high menthone, low cineole and high menthol concentrations relative to most major production areas. When the variation in composition of oil samples from within Tasmania was displayed in 3 dimensions (using the first 3 principal coordinates) it was not possible to achieve any pronounced separation of oils produced at different locations within southern Tasmania. Principal coordinates which were based mainly on cineole and menthol concentrations, respectively, did allow a degree of separation between oils produced in southern and northern Tasmania. Generally, oils produced in northern Tasmania had lower cineole and, in some cases, higher menthol than southern Tasmanian oils. Oil extracted from regrowth herb after commercial harvest was distinguished by having very high menthyl acetate, low menthone, high menthol, high menthofuran, low cineole and low limonene concentrations. The effect of some cultural and environmental factors on oil composition is also discussed.