1. Introduction
Coffee bean is an important commodity throughout theworld and its trade is getting larger year by year. World coffee exports has been reported to have amounted to 9.42 million bags in December 2012, comparedwith 9.14 million in December 2011. Exports in the first quarter of coffee year 2012/13 (Oct/12 to Dec/12) have increased by 15% in the
same period in the last coffee year (International Coffee Organization,www.ico.org). As a beverage, coffee is widely consumed all over the world. Roasting process is the critical step in the manufacturing of the coffee beverage since the final flavor of the product is heavily dependent on roasting. Roasting is generally performed at temperatures higher
than 200 °C. Depending upon the degree of roasting, the product gets different flavors changing from green baggy aroma to freshly roasted and to even burden aroma. Maillard reaction, Strecker degradation and yrolysis reactions are responsible together for the formation of aroma of the roasted coffee (Bagdonaite, Derler, & Murkovic, 2008).