Effects of Blending and Addition of Ethanol, Milk or Sugar on Aroma of Coffee Brews

Abstract

On the blending of fresh coffee and stale one, an additional effect was observed regarding the concentration of each component and fresh coffee could not improve the aroma of stale coffee. The mutual interaction of volatile components was observed in the case of blending two varieties of fresh coffees, but there was no additional effect. The addition of ethanol, milk and sucrose reduced the total concentration of volatile components in the headspace. In the addition of ethanol and milk, peaks 2(unknown), 4(n-hexane), 7(propionaldehyde) and 9(2-methylfuran) decreased but the mechanisms of the action were different. In the case of sucrose, all volatile components decreased with different decreasing percentages. Incidentally, when 1.0ml of ethanol was added to 100ml of coffee brew, the total amount of aroma decreased by 10.0% and 5.0ml of milk, 3.2%; 10.0g of sucrose, 18.4%, respectively.