Sour tasteAversive taste qualities, such as bitterness and sourness, are often associated with noxious compounds. In the case of sourness, our ability to perceive this taste helps us to avoid unripe or spoiled foods, and maintain acid-base homeostasis.
Sour flavours tend to create a “mouth-watering sensation”, because when a sour-tasting food enters the mouth, saliva is excreted to help dilute the acidity.
The results of twin studies estimate that genes are responsible for 53% of the variation in sour taste preference.
As with salty taste, the stimuli for sourness are also ions. Hydrogen ions that are released by acids (as sour substances) directly enter the taste cells on the tongue and trigger electrical signals to the brain. The pH of a substance, or the concentration of weak acids, plays an important role in how sour foods, drinks or ingredients taste.
According to the current literature, our ability to taste sourness is associated with specific TAS1R1 gene variants, which we also test for.