Sweet Finding: Researchers propose candidate sour sensor
Two teams of scientists have identified a protein on the surfaces of select tongue cells that may be the long-sought detector of sour taste.
People and some other animals, including mice, distinguish five recognized tastes: sweet, bitter, sour, salty, and umami, the flavor of monosodium glutamate. Over the past 6 years, researchers including Charles S. Zuker of the University of California, San Diego have ferreted out proteins on tongue-cell surfaces responsible for receiving sweet, bitter, and umami sensations.