Abstract

Dried and fresh peels of Citrus limon were subjected to microwave‐assisted hydrodistillation (MAHD) and solvent‐free microwave extraction (SFME), respectively. A comparison was made between MAHD and SFME with the conventional hydrodistillation (HD) method in terms of extraction kinetic, chemical composition, and antioxidant activity. Higher yield results from higher extraction rates by microwaves and could be due to a synergy of two transfer phenomena: mass and heat acting in the same way. Gas chromatography/mass spectrometry (GC/MS) analysis did not indicate any noticeable differences between the constituents of essential oils obtained by MAHD and SFME, in comparison with HD. Antioxidant analysis of the extracted essential oils indicated that microwave irradiation did not have adverse effects on the radical scavenging activity of the extracted essential oils. The results of this study suggest that MAHD and SFME can be termed as green technologies because of their less energy requirements per ml of essential oil extraction.

Conventional essential oil extraction methods have some disadvantages such as low extraction efficiency and degradation of volatile compounds. These shortcomings have led to consideration of the use of novel methods for essential oil extraction from fresh and dry samples using microwave‐assisted extraction methods, which increase the yield of essential oils, maintain their qualities, and use less energy.