Selection of Origanum vulgare plants for essential oil, carvacrol, total phenols and antioxidant potential

In the summer of 2005, individual plant selection was performed on different oregano populations started at Applied Plant Research (PPO-WUR) in Lelystad, The Netherlands. Selection was focused on erect growing, healthy, leafy but flowering, productive plants. Samples of these visually selected plants were analyzed for essential oil content and its main components (such as carvacrol). Some of the selected plants were also screened for phenolic components and antioxidant activity. This paper describes the selection process and presents the mean levels (from 79 selected plants with a complete data set) of the essential oil and its different components, the ethanol-soluble and cell wall-bound phenolic compounds, and the antioxidative activity of the extracts. The correlations between these parameters are presented. The results suggest that under the present experimental conditions, it is difficult to achieve the objective of single selection for high essential oil/carvacrol and high phenol content/antioxidant activity