Composition Of Peppermint Oil Research Articles

A Scent of Peppermint—A Microwave Spectroscopy Analysis on the Composition of Peppermint Oil

Essential oils have a vast number of applications in different areas of our daily life. Detailed chiral analysis and structural characterization of their constituents remains an important subject in analytical chemistry. Here, we report on a broadband rotational spectroscopy study of peppermint oil in the frequency range 2–8 GHz. We focus on an unambiguous determination of the excess enantiomers of the oil constituents menthone and isomenthone in the oil by applying chirality-sensitive rotational spectroscopy, the so-called microwave three-wave mixing (M3WM) technique. Additionally, a new menthol conformer, not previously characterized, was experimentally observed, and the gas-phase structures of the two conformers of menthol and menthone were determined experimentally based on the assignment of their 13C-isotopologues in natural abundance.

Integrated Nutrient Management on Biomass, Oil Yields and Essential Oil Composition of Peppermint (Mentha piperita L.) and Residual Fertility in a Hilly Soil

A field experiment was conducted to study the influence of combined use of farm yard manure and inorganic fertilizers on biomass and essential oil yields, chemical and microbial biomass carbon and nitrogen of soil grown with peppermint (Mentha piperita) in a hilly region, Bageshwar, India. Combined application of both farm yard manure and inorganic fertilizers increased the biomass and oil yields of peppermint compared to sole inorganic fertilizers treatments. The treatments receiving both farm yard manure and inorganic fertilizers improved the soil organic carbon and total N from initial value of 3.9 to 7.0 g kg-1 soil and 0.27 to 0.58 g kg-1 soil, respectively. A significant improvement has been noticed in soil respiration, soil microbial biomass carbon and nitrogen compared to inorganic fertilizer alone. Moreover, different proportions of inorganic fertilizers with farm yard manure had significant variation on available major soil nutrients. A significant correlation coefficient (r= 0.41* to 0.98**) was observed between yields and soil properties. The quality of essential oil was good and acceptable for the market.

Modification of yield and composition of essential oils by distillation time

Altering the distillation times of economically important essential oils such as peppermint (Mentha×piperita L.), lemongrass (Cymbopogon flexuosus Steud.), and palmarosa (Cymbopogon martinii Roxb.) oils may allow producers to increase the production, engineer the composition, and decrease the energy required for distillation. Experiments were conducted to model essential oil yield and oil composition of peppermint, lemongrass, and palmarosa oils as a function of the length of the steam distillation time (DT). Maximum essential oil yields of peppermint, lemongrass, and palmarosa were achieved at a DT of 20min; further increases in DT did not increase oil yields. In lemongrass and palmarosa experiments, DTs of 240min led to 25–40% reductions in oil yield compared to yields at 20–160min. This study demonstrated that DT can be used as a tool for obtaining essential oils with specific targeted composition from peppermint, lemongrass, and palmarosa. Secondly, the study found that the optimum length of the DT for maximum essential oil yields of peppermint, lemongrass, and palmarosa was much shorter than the time usually used by researchers and processors. Shorter DT may save producers and processors energy costs and other resources. This study also suggests that comparison of data on oil composition must take into consideration the length of the DT.

Variations in composition of peppermint oil in relation to production areas

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.

Environmental Effects on Peppermint (Mentha piperita L.). I. Effect of Daylength, Photon Flux Density, Night Temperature and Day Temperature on the Yield and Composition of Peppermint Oil

Long days (16 h light), high photon flux density (1200 �Em-2 s-1.) and high night temperature (20°C) resulted in the highest oil yield. : Daylength, night temperature, day temperature and photon flux density were important interacting factors determining oil composition. The photosynthate model proposed by Burbott and Loomis (Plant Physiol., 1967, <B.42, 20-8) explained the effect of environmental factors with respect to pulegone, menthone and menthofuran. Factors favouring the maintenance of high levels of photosynthate resulted in high concentrations of menthone and low concentrations of pulegone and menthofuran. The photosynthate model does not explain the effect of environmental factors on several other monoterpenes.

The effect of irrigation and nitrogen on the yield and composition of peppermint oil (Mentha piperita L.)

Peppermint was harvested twice during the growing season. Harvest 1 was conducted on 16 February 1979, and the subsequent regrowth was harvested on 25 April 1979. High peppermint oil yields were associated with high rates of nitrogen fertilizer (100, 200 and 300 kg nitrogen/ha), and high levels of irrigation (50 mm per week) throughout the last half of the growing season. The composition of oil extracted from herb at the commercial harvest date was not significantly affected by either nitrogen or irrigation treatments. The oil yield from regrowth within the same growing season was significantly affected by irrigation and nitrogen treatments applied prior to the first harvest. When 300 kg nitrogen/ha and 50 mm of irrigation weekly (during the last half of the growing season) were applied, the oil yields from regrowth approached the commercial yield obtained from one harvest. Oil from regrowth contained high levels of menthol, menthyl acetate, menthofuran and limonene, and low levels of menthone and cineole. The possibility of obtaining two commercial harvests of peppermint per season, under southern Tasmanian conditions, is discussed