Study on Roasting Kinetics and Colour Change of Coffee Bean under Pre-roasting, Roasting, and Over-roasting Conditions
Coffee is known as one of the most popular beverages in the world thanks to its unique flavour and aroma. The flavour and aroma of coffee beverages are developed through roasting. In fact, most roasting practices are based only on experiences. A common knowledge is a good cup of coffee needs an excellent touch of the hand of a coffee barista. Not many of coffee drinkers really understand how the beans are processed and why the processing is important. With enough knowledge of what is happening inside coffee beans during processing or coffee making, obviously one can improve how the coffee should be prepared and get the best coffee with desired flavour and aroma. Roasting can be divided into three stages, which are pre-roasting stage (including drying) at less than 150-160 ºC, roasting at more than 150-160 ºC, and over-roasting. So far studies on coffee roasting never cover those stages. In conducting a study on roasting a broader range of roasting condition is preferable not only for the elucidation of the process but also for supporting the whole learning process. A comprehensive investigation that can clearly help understand the effects of roasting time and temperature variations is therefore expected. As a first step, roasting kinetics and colour change under various roasting temperatures are being investigated in current research.