There are more than 800 fragrances of fine coffee.

The aroma of coffee itself is the main reason for the overall flavor properties, which is different from the perceived taste and sweetness, saltiness, bitterness and sour taste. Aroma is the most important product attribute of special coffee, and even instant coffee aroma substances can stimulate our taste buds. The difference is that instant coffee lacks the most important aromatic volatile components, which also leads to a reduction in overall flavor.

The fragrance can be felt by two different mechanisms. It can be felt by using the nose or returning to the snort. Nasal sensation occurs when coffee is present in the mouth or has been swallowed and the fragrant restorative substance floats up to the nasal cavity.

At present, more than 800 aroma substances have been found in coffee. With the improvement of the accuracy of analytical methods, more and more aroma substances will be found. The aroma of coffee is determined not only by the concentration of aroma substances but also by their threshold. A relatively small number of ingredients have high concentrations and low thresholds, and they also constitute the aroma of coffee that we perceive.

The aroma of coffee is largely determined by the roasting degree of coffee beans, and there are four main reactions in the roasting process:

Maillard reaction, which is a reaction between nitrogenous substances (amino acids, proteins and trigonelline, and serotonin) and carbohydrates (sugars).

Degradation of individual amino acids, especially thionine, hydroxyl and proline.

The degradation of sugar leads to caramelization.

Carbolic acid degradation, especially quinic acid semi-group.

Other reactions are related to lipid degradation, and there are hundreds of interactions between intermediate decomposition products.