Aromatic compounds of coffee

Aroma science is highly complex. Researchers typically analyze the fragrances evolved during coffee bean roasting by gas chromatography coupled with olfactometry, in which skilled testers sniff and define the smell of each recognizable element.

In Italy and France the aroma and taste of coffee are importance. Consumption of coffee is part of the culture and in France the name “café” stands for the drink as well as the place where it can be served. Espresso is a preferred beverage in Italy and France because of the strong aroma of the coffee.

Aroma substances are volatile compounds which are perceived by the odor receptor sites of the smell organ, i. e. the olfactory tissue of the nasal cavity. Coffee aroma is composed of a great variety of functional chemical groups, where the composition depends on factors such as species and variety, growth conditions and crop, storage, roasting degree, let alone all other process conditions.

Coffee contains several hundred different chemical compounds, but only minorities of these contribute to the aroma. A compound’s contribution to aroma is dependent on both its concentration and the threshold at which its smell can be perceived by humans.

The basic taste sensations in coffee are formed by volatile compounds present in coffee beans. They are the main factors responsible for the aroma. They belong to various chemical groups: aliphatic hydrocarbons, sulfur compounds, pyrazines, pyridines, oxazoles, pyrroles, furans, aldehydes, ketones and phenols but only a relatively small group of them (called the key components) is responsible for the aroma of coffee, such as dimethyl disulfide, which is an essential element for improving the fragrance of coffee aroma.
Aromatic compounds of coffee