Comparison of volatile compounds profile and antioxydant activity of Allium sativum essential oils extracted using hydrodistillation, ultrasound-assisted and sono-hydrodistillation processes

Abstract

Objective: This work aims to evaluate the impact of the use of ultrasound during essential oils extraction from garlic bulbs. Material and methods: The essential oils were extracted by Conventional Hydrodistillation method (HD), Ultrasound-Assisted hydro-distillation (US-HD) and Sono-hydrodistillation (SHD) and compared using yield profile, chemical composition and antioxidant activity. Results: Higher performances were obtained when the direct application of ultrasound were used. Indeed, SHD allowed a higher yield after only 30 min of extraction time against 70 min and 90 min for the US-HD and the HD respectively. Among the total identified compounds by GC/MS, Sulphur compounds were found to be the most abundant with qualitative similarities for the three processes. Essential oils showed a potential DPPH radical scavenging activity with IC50 values of 0.96, 1.17 and 1.23 respectively for the three HD, US-HD and SHD processes. Conclusion: The use of ultrasound for the extraction of essential oil from garlic reduced extraction time without causing significant changes in volatile composition and antioxidant activity.