**4. Future Perspectives**

Further studies are required to determine the consumer demand for agri-food productbased EOs; however, a balance must be struck between matching customer expectations and maximizing industrial production efficiency in accordance with Green Chemistry. On the other hand, reality simulation models are required in order to determine the composition of essential oils based on the environmental conditions surrounding plants; these models should aim to manage these variables and thus obtain high yield oils with the appropriate chemical composition for specific functions in the agri-food sector. In addition, the use of PEOs as food preservatives should be investigated further to determine the optimum application regarding the effective dose, the time of exposure, and the number of treatments. Regarding the herbicidal effect of PEOs, further future studies are recommended in order to characterize the allelochemical substances of many EOs against various weeds. In the same context, additional investigations are also needed to encapsulate EOs to maximize their biological activities and to examine the application of single active ingredients for several purposes.
