Abstract
We investigated the adsorption characteristics of volatile organic compounds (VOCs) on the surface of coffee beans after extraction (coffee grounds). Temperature-controllable adsorption equipment of VOC vapor was manufactured, and nitrogen gas containing about 100 ppm of VOC vapor was introduced into a coffee extraction residue. The air in the downstream was analyzed with a gas chromatograph equipped with a flame ionization detector over a period of time. A breakthrough curve was obtained from the analysis of values and time, and the adsorbed amount of each volatile organic compound on the coffee grounds was calculated from a graphical integration of the breakthrough curve. Fourteen VOCs were tested, and the adsorbed amount tended to increase with increases in the boiling point of the VOCs. It was also found that the adsorbed amount of methanol and toluene was affected by the water content in the coffee grounds used in the experiment.
