“…Such essential oils (EOs) can be produced from all parts of plants (buds, gums, blossoms, flowers, leaves, stems, twigs, seeds, fruits, roots, wood or bark), depending upon the producing species. EOs are stored in several secretory structures such as epidermic cells, secretory hairs, secretory ducts, secretory cavities, glandular trichomes, or resin adducts [15,16,17,18,19]. EOs are generally hydrophobic liquids and soluble in alcohol, nonpolar or weakly polar solvents, waxes, and oils.…”