Effect of Degree of Roast on Roast Coffee Qualities Using Spouted Bed Roaster

Abstract

The objective of this research was to study for roasting of coffee bean by spouted bed technique. The roasted coffee bean would be studied on properties and sensory quality tests. The study was conducted by Arabica coffee bean processed by wet process and moisture content at 14.29% dry basis. Coffee bean was roasted at 700 grams in each degree of roasting: city(-), city, full city and Italian and roasting temperature about 255-264 ^oC until at required coffee bean color. The result found that moisture content of roasted coffee beans are decreased to about 1.05-1.57% dry basis. At higher degree of roasting levels, the coffee beans will burst faster and brightness, red color, yellow color, true density and bulk density will be decreased, whereas, roast loss and organic roast loss will be increased. In addition, the heating time at higher degree of roasting levels will longer than at the soft degree of roasting. For sensory quality tests found that the aroma, clean cup, acidity and flavor will be decreased at higher degree of roasting levels. At degree of roasting level on city: the sweetness, mouth feel, aftertaste and balance will highest and will be decreased at degree of roasting level on full city and Italian, respectively. Moreover, the coffee taste will be the best at degree of roasting level on city.