ABSTRACT
The aim of this overview was to collect knowledge on the physicochemical conversions that come into action when light interacts with essential oils and their components. Stability of essential oils depends on various external factors such as oxygen availability, temperature, and light irradiation, given that ultraviolet and visible light are capable of initiating and accelerating degradation processes. Photochemical reaction pathways comprise photooxidation—polymerization and double-bond isomerization, for instance—and can lead to loss of organoleptic properties like odor and flavor, resinification, changes of biological activity, and even potentially dangerous effects, such as photoallergic skin responses, phototoxicity, and phototumorigenicity.
