CHANGE IN FLAVOR OF COFFEE DRINK DURING H EATING

We have investigated the changes in flavor of a coffee drink during st erilization heating. Gas chromatography-Olfactometry (GC-O) revealed t hat five potent aroma compounds (2-furfurylthiol, methional, 3-mercapt o-3-methylbutyl formate, beta-damascenone, and skatole) made significa nt contributions to the difference between heating and non-heating. Fu rthermore, the behavior of these five aroma compounds was studied in d etail using a model system. The residual ratios for these compounds af ter heating were 0.3-79.0%. Especially, the three sulfur compounds sho wed low ratios (2-furfurylthiol: 3.6%, methional:26.0%, 3-mercapto-3-m ethylbutyl formate: 0.3%). The volatile compounds obtained from 8-furf urylthiol, methional, and 3-mercapto-3-methylbutyl formate after heati ng included difurfuryl disulfide, which was accompanied by 2-furfural and 2-furfuryl alcohol, dimethyl disulfide, and 3-mercapto-3-methylbut anol, respectively. These results suggested that potent aroma compound s in a coffee drink were changed by oxidation, thermal degradation, an d/or hydrolysis during heating.