Furfuryl acetate

Fructose (99%) and tannic acid (95%) were purchased from J.T. Baker (Avantor; Radnor, PA, USA). Tartaric acid (99.7%) was provided by Chem-Lab (Eernegem, West-Vlaanderen, Belgium), and caffeine (99.2%) by ACEF (Piacenza, Italy). 2-Phenylethanol (≥99%), citral (95%), linalool (97%), 1-octen-3-one (96%), cis-3-hexen-1-ol (≥98%), ethyl butyrate (≥99%), damascenone (1.1–1.4 wt.%), benzaldehyde (≥99.5%), isoamyl acetate (≥95%), gamma-dodecalactone (≥97%), sotolone (≥97%), 4-ethylguaiacol (≥98%), 4-ethylphenol (99%), eucalyptol (99%), furaneol (≥98%), ethyl caproate (≥99%), eugenol (≥98%), citronellol (95%), phenylacetaldehyde (≥95%), furfuryl acetate (≥98%), 2,4,6-trichloroanisole (99%), 2-methyl-1-propanol (99.5%), methanethiol (≥98%) were all provided by Sigma-Aldrich (St. Louis, MO, USA). Ethanol (food grade, 70%) was supplied by ITW Reagents (Milano, Italy). Tanin VR colour, Tanin VR grape, Tanin plus, Tanin galalcool were all purchased from Laffort (Bordeaux, France).

Green coffee beans (Coffea arabica, from Brazil) were bought from a commercial market in Seoul, Korea. The origin of green coffee beans was verified by the importers and experts. 2-Methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, 2-ethyl-3-methylpyrazine, 2-ethyl-5-methylpyrazine, 3-ethyl-2,5-dimethylpyrazine, furfural, furfuryl acetate, furfuryl propionate, furfuryl alcohol, 1-furfurylpyrrole, 4-ethylguaiacol, 2-methoxy-4-vinylphenol, 5-methylfurfural, quinoxaline, and C7–C30 alkane standard were obtained from Sigma–Aldrich Chemical Co. (St. Louis, MO, USA). 2-Ethylpyrazine, 2,3-dimethylpyrazine, 1-methylpyrrole, guaiacol, and 2-acetylfuran were bought from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). Divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS, 50-μm film thickness) solid-phase microextraction (SPME) fiber was purchased from Supelco, Inc. (Bellefonte, PA, USA).