A dielectric barrier discharge plasma was used for surface treatment of lemon peel, followed
by steam distillation, to enhance essential oil extraction. The effects of plasma surface
treatment of lemon peel on essential oil yield and composition were investigated. The yield of
essential oil was improved by plasma treatment.
Limonene, g-terpinene, and b-pinene were identified
from the extracted essential oil; the concentrations
of these compounds were significantly decreased by
O2, N2, and air plasma treatments, and slightly
decreased by Ar plasma treatment. Microscopic
observations showed that the lemon peel surface
was damaged by discharge, and that some oil bled
from the oil glands. It was concluded that essential
oil extraction was enhanced by small defects
generated on the lemon peel by the plasma
discharge.