Effect of the ultrasound-assisted preliminary maceration on the efficiency of the essential oil distillation from selected herbal raw materials

• Application of ultrasound-assisted maceration (UAM).
• The effect of UAM on the essential oil yield.
• Analysis of essential oil from peppermint, marjoram, and chamomile.

The objective of the study was the estimation of the ultrasound-assisted preliminary maceration effect on the efficiency of essential oil distillation and on its qualitative and quantitative composition. The experiment included analyses on three herbal materials, i.e. peppermint leaves (Mentha piperita L.), marjoram herb (Origanum majorana L.), and chamomile flowers (Chamomilla recutita (L.) Rauschert). The study showed that the application of preliminary water maceration of raw material, augmented with ultrasounds, had a statistically significant increasing effect on the amount of oil distilled, in the case of mint leaf from 1.32% to 1.46% v/w, and in the case of marjoram herb from 1.13% to 1.27% v/w. In the case of chamomile flowers no significant effect of ultrasound on the amount of oil obtained was observed. Generally, comparing the composition of essential oils obtained in the experiments with the requirements of the relevant standards no unfavourable effect of the distillation augmenting techniques applied was noted. Therefore, it should be expected that the studied distillates of volatile fractions will have the desired biological activity.