Effect of the application of physical elicitors during the post-harvest in mint and rosemary essential oils

In recent decades the predictions of climate change have focused on scenarios describing emissions of gases produced by greenhouse effect and potential usage patterns for resources, technological innovations and demography. Degradation of the planet will have direct impact on the distribution and conservation of biodiversity. For example, one of the main consequences of temperature increase has been the displacement of vegetable and animal species all around the world to higher altitudes and latitudes, in response to changing environmental conditions to which they were adapted. In this way, emerges the possibility of applying new post-harvest treatments which are environmentally friendly and also allow increasing the content of secondary metabolites, which are the main component of essential oils. In this study we evaluated the effect of UV-B radiation applied in young leaves and stems from plants harvested in fresh and dry of Rosemary (Rosmarinus officinalis L.) and Mint (Mentha spicata L.). These were radiated with Philips TL 40W/12 RS luminaire using different doses of UV-B radiation; Treatment 1 (T1) 0.05 Wh m(-2) and Treatment 2 (T2) 0.075 Wh m(-2). The effect of the treatments was established based on the variation in the production and the essential oil antioxidant capacity. The extraction was carried out by the Randall method. By applying 0.075 Wh m(-2) we got an increase of 9.48% in the production of rosemary essential oil compared to the control; while applying 0.05Wh m(-2) produced a raise of nearly 23,75 % in the production of mint essential oil compared to the control. These results are consistent with previous studies where there was a successful use of UV-B radiation as a promoter of secondary metabolites in aromatic plants obtaining increases of about 35% in the production compared to control plants.