How long can roasted coffee beans be stored, without reducing the typical coffee flavor which is mainly responsible for consumers' enjoyment? In Austria, most coffee packages have a best-before date between 12 and 24 months, but it is not regulated by law. Therefore, there is the need to evaluate changes in sensory qualities of coffee beverages prepared from stored coffee beans. For preparation of the coffee beverages, the paper filter method was used. In the quantitative descriptive analysis (QDA) 10 trained assessors evaluated the intensity of 30 coffee attributes after roasting at the 9th and 18th month of storage, respectively. The sensory evaluation results showed reduction in the sensory qualities of coffee beverages after 9 months storage of roasted coffee beans. The positive associated odor and flavor attributes decreased in their intensity, whereas the negative associated odor and flavor attributes increased significantly (P < 0.05). After 18 months of storage, the rancid odor and flavor which indicate oxidation processes were even considerably perceivable. Consequently, we can assume that changes in sensory quality characteristics of roasted and vacuum-packed coffee beans during storage are possible.
Keywords: Coffee; quantitative descriptive analysis; sensory changes; storage.