Humans can discern about 20,000 different odors and 10 intensities of each. True taste occurs on the tongue. We are born with 10,000 taste buds located on the back, sides, and tip of the tongue, on the palate, and in the throat. Our first flavor experiences are sweet ones, said Gary Beauchamp, Ph.D., director of the Monell Chemical Senses Center in Philadelphia, part of the University of Pennsylvania. Unborn infants appear to detect sweetness and newborns clearly sense and enjoy sweet tastes.
Infants seem to experience the other primary tastes to varying degrees.
The ability to detect bitter, salty, and umami tastes continues to develop throughout the first few months of life. The sour taste is at least somewhat developed at birth, but it's not clear whether further changes occur as infants get older. Breast-fed infants receive early exposure to a variety of flavors because breast milk carries the flavor of foods and spices eaten by the mother. Whether these and other early taste experiences affect food preferences later in life is the subject of ongoing research at the Monell Center. At about age 60, even healthy people begin to experience a modest decline in taste and more dramatic declines in smell.