Abstract:

The oil in Fructus Arctii (the dried fruits of Arctium lappa L.) was extracted with ultrasonic-microwave synergistic extraction (UMSE) method and the extraction parameters were optimized. The possible extraction mechanisms were made according to the scanning electron micrograph (SEM) of fructus arctii. The optimum extraction conditions for UMSE were that fructus arctii were treated with microwave (303 W) for 213 s with solvent-to-material ratio at 10.1:1 (ml/g), and the yield was 19.334% under such conditions. The crack of cell wall and the disruption of tissue structure was caused by cavitation effect and mechanical effect of ultrasound and thermal effect of microwave, and could be the mechanisms for the high oil yield of UMSE. Compared with other extraction techniques, UMSE exhibited higher yield and shorter extraction time.

Key words: Fructus Arctii oil, ultrasonic-microwave synergistic extraction, Box-Behnken experimental design, scanning electron micrograph