A further tool to monitor the coffee roasting process: aroma composition and chemical indices.
Coffee quality is strictly related to its flavor and aroma developed during the roasting process, that, in their turn, depend on variety and origin, harvest and postharvest practices, and the time, temperature, and degree of roasting. This study investigates the possibility of combining chemical (aroma components) and physical (color) parameters through chemometric approaches to monitor the roasting process, degree of roasting, and aroma formation by analyzing a suitable number of coffee samples from different varieties and blends. In particular, a correlation between the aroma composition of roasted coffee obtained by HS-SPME-GC-MS and degree of roasting, defined by the color, has been researched. The results showed that aroma components are linearly correlated to coffee color with a correlation factor of 0.9387. The study continued looking for chemical indices: 11 indices were found to be linearly correlated to the color resulting from the roasting process, the most effective of them being the 5-methylfurfural/2-acetylfuran ratio (index).
Dipartimento di Scienza e Tecnologia del Farmaco,  Università degli Studi di Torino , Via P. Giuria 9, I-10125 Torino, Italy.
Manuela R
MR
Ruosi
Chiara
C
Cordero
Cecilia
C
Cagliero
Patrizia
P
Rubiolo
Carlo
C
Bicchi
Barbara
B
Sgorbini
Erica
E
Liberto
D040503:Coffea / Q000737:chemistry*; D003296:Cooking; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006358:Hot Temperature; D009812:Odorants / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry; D052616:Solid Phase Extraction; D055549:Volatile Organic Compounds / Q000737:chemistry* / Q000302:isolation & purification
D010936:Plant Extracts; D055549:Volatile Organic Compounds