Resumen de Modification of the composition of thyme (Thymus vulgaris) essential oil based on the quality of the light
Carlos de Jesús Morales Becerril, María Teresa Beryl Colinas León, Ramón Marcos Soto Hernández, Teresa Martínez Damián, Guillermo Mendoza Castelán
Objective: To identify the changes in the concentration of the main components of thyme (Thymus vulgaris) essential oil in response to five different LED colors. Design/Methodology/Approach: A completely randomized experimental design was used. The design included five treatments (white light; blue light; red light; 75% blue light and 25% red light; and 75% red light and 75% blue light) and 10 repetitions, at a 25 μmol m−2 s−1 luminous intensity, during a 16 h photoperiod. The thyme plants were sown in a pot with a substrate made up of 50% peat, 48% perlite, and 2% vermicompost. Each plant was an experimental unit. The plants were placed in light isolation chambers and subjected to the treatment for 35 days. Results: The concentration of the main molecules in the essential oil recorded considerable changes between treatments: the concentration of thymol (its main component) increased in the white light treatments, as well as in the red light (75%) and blue light (75%) treatments. In addition, the composition of the essential oil resulting from these treatments is different to the composition reported in the references. Study Limitations/Implications: The light intensity used in this experiment was lower than the light intensity required for plant growth; however, it was enough to produce changes in the secondary metabolism. Findings/Conclusions: The changes in the quality of the light modify the composition of the thyme essential oil. Even at a low light intensity (25 µmol m-2 s-1), the changes in the spectrum composition under which the plants grow influence the composition of the essential oil.
