Ultrasound pretreatment impact on Prangos ferulacea Lindl. and Satureja macrosiphonia Bornm. essential oil extraction and comparing their physicochemical and biological properties

The aim of this study was to investigate the impact of ultrasonic pretreatment (US + HD) of Prangos ferulacea Lindl. and Satureja macrosiphonia Bornm. leaves prior to hydrodistillation (HD). The two plants differed in their secretory structures, internal and external structures, respectively. Extraction kinetics, chemical composition, physical and biological properties of the essential oils was evaluated. Although applying ultrasound pretreatment resulted in a faster extraction process, no significant difference was observed between the yields. Similar main components in essential oils including p-cymene, limonene, (E)-beta-ocimene, terpinolene, and 2,3,6-trimethylbenzaldehyde for P. ferulacea and cis-sabinene hydrate, linalool, borneol, and terpinene-4-ol for S. macrosiphonia were observed, regardless of applying sonication or not. However, a selective extraction of limonene (P. ferulacea) and linalool (S. macrosiphonia) was a direct result of 15 min indirect sonicatin of plant materials prior to hydrodistillation. Ultrasonic pretreatment not only had no adverse effect on biological properties of extracted essential oils but also in case of pre-treated P. ferulacea improved antioxidant activity. Generally, this study indicates that ultrasonic pretreatment of plant materials resulted in accelerating the essential oil extraction process and producing an essential oil with superior characteristics. (C) 2016 Elsevier B.V. All rights reserved.