Generation of Flavor-Active Compounds by Electrochemical Oxidation of (R)-Limonene

Terpenes may be converted by electrochemical oxidation to various oxidized products with appealing aroma properties. In this study, (R)-limonene was anodically oxidized in the presence of ethanol, and the resulting mixture exhibited a pleasing fruity, herbal, citrus-like, and resinous odor. The aroma-active compounds were purified by means of preparative high-performance liquid chromatography, and their structures were elucidated by means of gas chromatography (GC)-mass spectrometry and nuclear magnetic resonance spectroscopy. In addition, the odor of the isolated compounds was determined by means of GC-olfactometry. Seventeen compounds were isolated, and for only four of them, analytical data had been reported previously in the literature. Furthermore, only for two of the compounds, an odor description had been available in the literature.