Essential oil obtained from Chrysanthemum indicum var. aromaticum leaf using solvent-less microwave irradiation-induced hydrodistillation and extraction in situ

Abstract

Chrysanthemum indicum var. aromaticum is a new variety in the family Compositae and is an aromatic plant resource with high economic value that was first discovered in Shennongjia, Hubei, China. In this work, an improved technique for collecting essential oil from leaves using solvent-less microwave irradiation-induced hydrodistillation and extraction in situ was developed. We extensively investigated a few of the variables that could impact essential oil yield using Pareto analysis and Box‒Behnken design response surface analysis. The highest yield of the essential oil under optimal circumstances was 7.22 ± 0.31 mL/kg DW. The results of GC‒MS analysis showed that C. indicum var. aromaticum leaf essential oil mainly contained terpenes, and the main abundant components were myrtene acetate (21.72%) and cis-sabinol (19.23%). And the first-order kinetic model demonstrated a better fit for the SLMHD. SLMHD (microwave irradiation power 540 W) for 30 min gives a higher yield of essential oil than conventional HD (heating power 450 W) for 180 min, i.e., the emission of CO2, the main greenhouse gas, is reduced from 1080 g for 180 min in conventional HD (heating power 450 W) to 216 g in SLMHD. It can be shown that for the same power consumption, SLMHD can indeed obtain more essential oil. The operator's working hours can be significantly reduced because of the quicker response time, which can help cut labor expenses. Taking all these points into account, further development of the approach could yield good economic benefits.