Ultrasound induced intensification and selective extraction of essential oil from Carum carvi L. seeds

The influence of ultrasonic pre-treatment of Carum carvi L. seeds cultivated in El Hamadia, Bordj Bou Arreridj (Algeria) was investigated for the recovery of essential oil (EO) by means of hydrodistillation. The results indicate that ultrasound treatment engenders a rapid release of essential oil with 80% of EO recovery after only 30 min of extraction for treated seeds versus 90 min for untreated seeds. However, almost similar yields of volatile fraction were obtained with 1.72% versus 1.68%, respectively. A total of 21 components accounting for 99% of total oil were identified using gas chromatography–mass spectrometry (GC–MS). The main constituents for both extracts (treated and untreated seeds) were carvone (5.93 mg/g, 5.73 mg/g) is predominant over limonene (5.47 mg/g, 5.28 mg/g). Therefore, the data report higher carvone/limonene concentration ratio for treated seeds in shorter processing time. In addition, the analysis of essential oil obtained from hydrodistillation of seeds, revealed that 61% of EO was recovered in the liquid phase in treated seeds against 63% of EO in the solid phase from untreated samples.

► Rapid extraction of essential oil by ultrasound assisted extraction.
► Ultrasound increases selectivity of extraction of oxygenated compounds.
► Intensification by ultrasound due to cavitation.
► Selectivity by ultrasound due to solubility and not related to boiling point.