Study on optimization of extraction technique of pericarp essential oil in Litsea Cubeba (Lour) Pers

Litsea cubeba is an important aromatic oil plant. Litsea cubeba pericarp essential oil has various physiological activities such as antibacterial activity, antioxidant capacity, etc., and is widely used. Its main ingredient is citral, which is the raw material for the synthesis of many precious spices. For the purpose of increasing yield, researchers have conducted many studies on the extraction of essential oil from pericarp of Litsea cubeba . But the extraction process still has room for optimization。In this study, Litsea cubeba fruits were subjected to an optimized method of hydrodistillation to increase the yield and biological activity of pericarp essential oils. Three-factor and three-level orthogonal experimental design was performed (fruit preservation time, distillation voltage and fruit microwave pretreatment time) to optimize the process. According to the results of orthogonal experiments, the highest yield of essential oil can be obtained after the fruit has been preserved for 9 days without microwave pretreatment and the distillation voltage is 220 V. The extracted essential oils were analyzed by gas chromatography-mass spectrometry (GC–MS), which indicated that their main components were 2,6-Octadienal, 3,7-dimethyl-, (E)-, 2,6-Octadienal, 3,7-dimethyl-, (Z)-, 1-Heptanol and 1-Octanol. GC–MS results showed that the relative content of citral in the extracted essential oil was the highest after the fruit was preserved for nine days without microwave pretreatment and the distillation voltage was 150 V. Changes in the process will not significantly affect the main component types of essential oils, but will significantly affect the relative content of the same components.