The Rio defect is a coffee off-flavor associated to unpleasant medicinal, phenolic, and iodine-like notes. 2,4,6-Trichloroanisole (TCA) is the main marker of this alteration. A new approach for TCA detection in green coffee beans was evaluated using chemical ionization time-of-flight mass spectrometry and employing a Vocus ion source and ion-molecule reactor (IMR). The sample set consisted of 22 green Coffea arabica from different geographical origins, four of which presented the Rio defect according to an expert cup-tasting panel. Vocus CI-MS was able to perform TCA detection in 3 s, with a sensitivity comparable to that of a sensory panel and showed remarkably good correlation (R2 ≥ 0.9997) with SPME-GC-MS measurements carried out on coffee headspace and hydro-alcoholic extracts. The results demonstrate how the introduction of new quick and sensitive analytical tools could help provide a more comprehensive picture of the Rio coffee off-flavor.
Keywords: 2,4,6-trichloroanisole (TCA); Rio defect; Vocus CI-MS; coffee.