Hydrodistillation
A conventional method of hydrodistillation (HD) was carried out to compare the extraction performances with SFME. The sieved materials (200 g) were placed in a Clevenger apparatus and mixed with deionised water at a ratio of 1:7 (w/v). After 5 h (until no more essential oil was obtained), the essential oil was collected, dried over anhydrous sodium sulphate and stored at 4 °C in the dark until used.