The fruity flavor of coffee beans is intoxicating, exuding a sweet and alluring aroma. This unique flavor comes from the complex and diverse combination of chemicals in coffee beans.
First, coffee beans contain a lot of sugars. During the growth of coffee, plants convert carbon dioxide and water into simple sugar molecules such as glucose through photosynthesis. These sugar molecules are accumulated when the coffee fruit matures, and penetrate into the beans as the pressure inside the fruit increases. When we roast the coffee beans, these sugars undergo a series of complex reactions to produce a variety of compounds with sweet taste.
Secondly, coffee beans are rich in acidic substances. These acidic substances include malic acid, citric acid, oolong tea essence, etc., which will also change during the roasting process and release special aromas. For example, under high temperature, malic acid will be transformed into ethyl malic acid, which has a strong fruity aroma. Citric acid will be transformed into substances such as succinic dialdehyde and ethyl succinic dialdehyde, giving coffee beans the taste of citrus fruits.
Finally, there are a series of aromatic compounds in coffee beans. These compounds mainly come from volatile oils in coffee leaves and flowers, which are released during the roasting process. The most important of these are substances such as malasterone, 2-methylpyran, and hydroxymethylbutyrolactone produced by roasting. These aromatic compounds give coffee beans a rich and complex aroma and an attractive taste.
