Natural flavors in soft drinks come from spices, natural extracts and oils. Other flavors such as root beer and ginger ale contain flavorings made from herbs and spices. Nature does not produce enough flavours to satisfy our taste buds. Hence, the need to depend on the artificial or man made flavourings. Many people don't realize how important color is to taste perception.
Color affects our psychological impression of food.
If you don' believe it, try eating a familiar food in the dark. The colors used in foods and beverages come from both natural and synthetic sources. Caffeine has a classic bitter taste that enhances flavor and this is the reason it has been part of almost every cola and pepper-type beverage since they were first formulated more than 100 years ago. Most of the soft drinks are slightly acidic in nature due to the presence of two common food acidulants- phosphoric acid and citric acid. These add a pleasant tartness to the soft drinks and act as preservatives.