Change in flavor of coffee drink during heating

Abstract

We have investigated the changes in flavor of a coffee drink during sterilization heating. Gas chromatography-Olfactometry (GC-O) revealed that five potent aroma compounds (2-furfurylthiol, methional, 3-mercapto-3-methylbutyl formate, β-damascenone, and skatole) made significant contributions to the difference between heating and non-heating. Furthermore, the behavior of these five aroma compounds was studied in detail using a model system. The residual ratios for these compounds after heating were 0.3-79.0%. Especially, the three sulfur compounds showed low ratios (2-furfurylthiol : 3.6%, methional : 26.0%, 3-mercapto-3-methylbutyl formate : 0.3%). The volatile compounds obtained from 2-furfurylthiol, methional, and 3-mercapto-3-methylbutyl formate after heating included difurfuryl disulfide, which was accompanied by 2-furfural and 2-furfuryl alcohol, dimethyl disulfide, and 3-mercapto-3-methylbutanol, respectively. These results suggested that potent aroma compounds in a coffee drink were changed by oxidation, thermal degradation, and/or hydrolysis during heating.