Effects of ultrasonic and enzymatic pretreatments on the yield and antioxidant properties of basil oil

Abstract

This main purpose of this study was to investigate the effects of pretreating with ultrasonic, Viscozyme L and combination of ultrasound and Viscozyme L on the quality of basil (Ocimum basilicum L.) essential oil. Basil leaves were treated at different sonication duration (30-120 minutes), different sonication temperature (30-50oC) or different enzymatic incubation time (30-120 minutes) before running hydrodistillation. The obtained results showed that combination of ultrasonic and Viscozyme L treatments increased oil yield, antioxidant capacity, chemical compositions and antimicrobial activities of essential oil. The maximum oil yields of the basil ultrasound-assisted hydrodistillation (UAHD) was 0.261 ± 0.016 (%) and the enzyme Viscozyme L-assisted hydrodistillation (EAHD) was 0.359 ± 0.003 (%), corresponding to 90 and 120 minutes of treatments. Interestingly applying both ultrasound and Viscozyme L (CAHD) treatments gave the highest yield, at 0.446 ± 0.009 (%) as compared to the others. Meanwhile, the strongest antioxidant capacities were recorded from 90 min UAHD,120 min EAHD and 120 min CAHD oil samples with values of 60.2 ± 2.4 (%), 52.7 ± 2.5 (%) and 25.5 ± 0.2 (%), respectively. Key words: Antioxidant, Basil oil, GCMS, hydrodistillation, oil yield, Ultrasound, Viscozyme L.