Oranges are the most produced citrus fruit on the planet, with around 50% of all citrus fruits produced being an orange or related to an orange such as a clementine or mandarin. When you squeeze orange peel a liquid sprays out – this is the essential oil which is locked in the skin. Sweet orange essential oil has a very sweet smelling scent, compared to its cousin the bitter orange. Orange essential oils have antibacterial qualities. Orange essential oils is mainly made up of something called d-limonene, which is a compound commonly found in the peel of citrus fruits. D-limonene has been shown to be an excellent antibacterial agent.