Identification of Linalool Glycosides in Green Coffee Beans (Coffea arabica)

One of the most valuable raw materials in the coffee industry is green coffee, especially the Coffea arabica variety, which is preferred by roasters and coffee makers. This study aimed to identify flavor precursors in green coffee beans using various analytical techniques, including counter-current chromatography, liquid chromatography, and methods such as high-resolution gas chromatography coupled with mass spectrometry, high-performance liquid chromatography-electrospray mass spectrometry, and one- and two-dimensional nuclear magnetic resonance spectrometry (NMR). Ten flavor precursors were discovered in this study, including two linalool oxides (furanoid E-Z) disaccharides, linalool, and 4-vinyl guaiacol. The intact glycosides were analyzed using dimensional NMR, and two different substances, methyl-α/β-L-arabinofuranose and methyl-α/β-L-arabinopyranose, were identified. These findings can assist in verifying the authenticity of green coffee.