Quantification of Anethole in Fennel and Anise Essential Oils using Gas Chromatography and 1H-NMR-Spectroscopy
Abstract
Nine essential oils from fennel (seeds and herbs) and anise (seeds) from different origins were analysed for density, refractive index and for a complete composition through GC-MS and 1H-NMR-spectroscopy. Anethole was the main compound identified in fennel and anise essential oils. Anethole content varied between 30 – 90% in fennel oils and between 80 – 99% in anise oils; anethole is often used as flavouring substance in foods with a good antimicrobial activity also. A positive correlation was found between anethole content determined by GC-MS and 1H-NMR (r = 0.8567 for fennel oils and r = 0.6986 for anise oils). The results showed different levels of anethole in oils (values ranged between 30.66 % and 99.24 %). Electronic nose was a very good and rapid method for discrimination of essential oils based on PCA (Principal Component Analysis) with discrimination index above 90 for both essential oils.a) Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
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