Roasting processing of dry coffee cherry: influence of grain shape and temperature on physical, chemical and sensorial grain properties

Abstract

Roasting is responsible for physical, chemical and sensorial changes in coffee, like color change, weight loss, swelling and compounds generation that are responsible for the flavor and the taste of the beverage. Roasting of dry coffee cherry in two shapes process was studied in this work with flat and peaberry beans. The influences of temperature development and grain shape were evaluated with respect to bulk density, moisture reduction, swelling rate, changes in grain dimensions, pH, soluble solids, acidity, weight loss, reducing and non-reducing sugars, color and sensorial attributes. Three types of temperature development were compared: high temperature all the time (T1); temperature increasing with time (T2) and low temperature all the time (T3) for flat and peaberry. Roasting T1 and T3 were developed on shorter periods for peaberry beans. The same was observed with T2 for flat beans. Differences on bulk density, final moisture content, pH, swelling and soluble solids were also observed. The best results of sensorial analysis were obtained with T2 conditions for both types of coffees.