Impact of drying process on chemical composition and key aroma components of Arabica coffee.

Influence of heat pump drying (HP at 40, 45 and 50 °C), tray drying (TD) and sun drying (SD) on the quality of Arabica coffee was evaluated. Drying process did not affect the caffeine content, but influenced levels of some amino acids. Sucrose content was higher in HP and TD than in SD green coffees. The perceived aroma of brewed coffee from SD was similar to HP, but differed from TD. Concentrations of 30 important odorants were compared for SD, HP (50 °C) and TD brewed coffees. 2-Furfurylthiol, a key odorant of coffee, was at the same level in SD and HP coffees and lowest in TD samples. Principal component analysis (PCA) separated SD from HP and TD, based on the concentrations of 23 odorants. Combined results of sensory and chemical analyses showed that in comparison to SD, HP was superior to TD for preserving overall flavor quality.