Gas Chromatography - Mass Spectrometry Studies of Chemical and Compositional Changes in Brewed Coffee and Evaluation of the Factors that affect the Extraction Processes

Variations in the brewed coffee as a function of various factors that affect the extraction processes were evaluated. The holding and brewing temperatures as well as the holding time were evaluated. Based on these variations in the composition of brewed coffee, the optimum brewing temperature was in the range between 80-85°C. With a holding temperature in this range, 90% of the maximum amount of the flavored materials was achieved in less than five minutes. However, holding the brew with a lower temperature could increase the holding time. In addition, compositional changes in the brew can be related to the length of time a coffee brew has been exposed to the air. Based on these variations in the composition of the brewed coffee with aging at room temperature, the proper length of time the brew should be allowed to be exposed to air is less than 30 minutes to retain its best flavor. Holding time and temperature have an apparent effect on the composition of brewed coffee and the brewing temperatures had a significant effect on the extraction and decomposition of the components of the coffee. A correlation between the particle size distribution and the strength of the beverage was established.