Eugenol Enrichment of Clove Bud Essential Oil Using Different Microwave-assisted Distillation Methods

• Published in: FOOD SCIENCE AND TECHNOLOGY RESEARCH Vol. 23; no. 3; pp. 385 - 394
• Main Authors: Golmakani, Mohammad-Taghi, Zare, Mahdieh, Razzaghi, Saeedeh
• Format: Journal Article
• Language: English
• Published: Tsukuba Japanese Society for Food Science and Technology 2017; The Japanese Society for Food Science and Technology; Japan Science and Technology Agency
• Subjects: Acetic acid; antioxidant activity; Antioxidants; Chemical composition; clove bud; Distillation; essential oil; Essential oils; Eugenol; eugenol enrichment; Extraction; Hydrolysis; microwave-assisted extraction
• ISSN: 1344-6606; 1881-3984
• DOI: 10.3136/fstr.23.385

Clove bud (Syzygium aromaticum) essential oils (EOs) were extracted by hydro-distillation (HD), steam-distillation (SD), microwave-assisted hydro-distillation (MAHD), and microwave-assisted steam-distillation (MASD) methods. A comparison was made between microwave-assisted extraction and conventional extraction methods in terms of extraction kinetic, chemical composition, eugenol enrichment and antioxidant activity. Significant differences were observed between the ultimate EO yields of HD-based methods (12.98 – 13.94%) and those of SD-based methods (11.54 – 12.71%). Nonetheless, chemical compositions of the four extracted EOs were similar, but significant differences occurred among the quantity of compounds in the EOs. The ratio of eugenol per eugenyl acetate in HD-based methods (8.36 – 11.90%) was higher than those of SD-based methods (5.28 – 5.81%). These differences result from the hydrolysis of eugenyl acetate to eugenol in HD-based methods. Although, there was no significant difference between antioxidant activity of EOs extracted by microwave-assisted extraction methods and conventional-based methods but, accordingly, there were significant differences between HD-based methods and SD-based methods.