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New approaches to monitor semi-volatile organic compounds released during coffee roasting using flow-through/active sampling and comprehensive two-dimensional gas chromatography
- Novaes, Fábio Junior Moreira, Silva Junior, Ademário Iris da, Kulsing, Chadin, Nolvachai, Yada, Bizzo, Humberto Ribeiro, Aquino Neto, Francisco Radler de, Rezende, Claudia Moraes, Marriott, Philip John
- Food research international 2019 v.119 pp. 349-358
- charcoal, cluster analysis, coconuts, coffee beans, comprehensive two-dimensional gas chromatography, gas chromatography, ionization, molecular weight, roasting, sorbents, volatile organic compounds
- A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during coffee roasting aimed at analysing components present in the roasting plume, and to monitor their evolution during the process. Two sorbents – coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) – were evaluated while collecting substances in four sequential time intervals (0–3, 3–6, 6–9 and 9–12 min). Extracted VOCs (<200 Da) and SVOCs were analysed by gas chromatography (GC), and comprehensive two-dimensional gas chromatography (GC × GC) with flame ionisation (FID) and time-of-flight mass spectrometry (TOFMS) detection. Results showed CSC extraction presented poor recovery of VOCs and SVOCs released during roasting. However, XAD-2 was able to collect both groups, including SVOCs of >400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0–3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3–6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.