Comparison of microwave-assisted hydrodistillation and solvent-less microwave extraction of essential oil from dry and fresh Citruslimon (Eureka variety) peel

Abstract

This study investigated the effectiveness of microwave-assisted hydrodistillation (MAHD) and solvent-less microwave extraction (SLME) for extracting essential oil (EO) from lemon peels in comparison with conventional hydrodistillation (HD) in terms of extraction time, extraction yield, physical properties, chemical composition, operation cost, and antioxidant activity. The results showed that MAHD and SLME methods required an extraction time of 15 minutes while the required extraction time in HD was 120 minutes. There were no significant differences among physical properties (refractive index, specific gravity, and color) of extracted EOs by the three methods. Gas chromatography analysis did not indicate any noticeable change in the composition of EOs extracted by microwave-assisted extraction methods (MAHD and SLME) and HD method. DPPHº analysis of the extracted EOs indicated that microwave irradiation did not adversely influence antioxidant activity of the extracted EOs. The results of this study introduced MAHD and SLME as rapid, economical, and environmentally friendly extraction methods.

Keywords:

• Essential oil
• hydrodistillation
• lemon
• microwave-assisted hydrodistillation
• solvent-less microwave extraction

Acknowledgments

This research project was financially supported by Shiraz University. We also like to thank Mohsen Hamedpour-Darabi for his native English editing service.