Chemical composition and stability of the hydrosols obtained during essential oil production. I. The case of Melissa officinalis L. and Asarum canadense L.

Abstract

chemical composition of the oils and hydrosols obtained from either wild or cultivated plantations was determined by GC-FID and GC/MS analyses. The components obtained from the hydrosols are mainly monoterpenic alcohols, aldehydes and ketones and as such the composition of the hydrosols are very different of the corresponding oils: the oil with the most important fraction of hydrocarbon compounds, the composition of the two phases is the most different. It appears that the composition of hydrosols undergoes important change over a two-year period of storage at normal temperature. In both cases, a complex equilibrium involving nerol, geraniol, linalool, linalool oxides and several diols is not achieved. The same kind of behaviour involving several menthadienols is working with citral. Also, it is observed that phenylpropanoid molecules partly disappear during the same time.