Evaluation of Photostability and Thermal Stability of Selected Commercially Important Essential Oils from Bosnia and Herzegovina

Abstract

Essential oils, composed of various classes of chemical compounds, are susceptible to changes during storage. They can be sensitive to temperature, light and oxygen and therefore it is necessary to consider the influence of these factors on shelf life of essential oils. Commercially valuable essential oils from B&H were selected for determination of chemical composition and impact of light, temperature and available oxygen on alteration. Aliquots of immortelle, silver fir, prickly juniper, lavender, winter savory and chamomile essential oils were exposed to UV-A irradiation as well as to elevated temperature in the presence of atmospheric oxygen and in the presence of inert gas, respectively. Photostability and thermal stability were evaluated by GC-FID and GC-MS analysis, comparing composition before and after the applied regimes. Each oil showed individual response to applied conditions. Silver fir and prickly juniper essential oils were shown to be stable, while immortelle, winter savory, lavender, chamomile, laurel and mint essential oils showed specific chemical changes upon applied stress conditions. Based on the obtained results, optimal way of storage can be suggested for each oil.