FoundationalConceptsNeuroscience

many molecular constituents producing a combination of sweet and
bitter tastes. The sweet-tasting components have been identified as
derivatives of a molecule named steviol, with a molecule named ste-
vioside being found in highest concentration in the plant.

OH

HO OH

OH HO oO OH

oO OH

Oo oO

OH

HO OH

0

Steviol HO fe)

HO Oo O

OH

Stevioside

Stevioside is formed from steviol by the addition of three glucose mol-

ecules in particular places. It is approximately three hundred times

sweeter than sucrose.

Umami. In 1909 Japanese chemist Kikunae Ikeda (1864-1936)
published a paper describing glutamate as producing a distinct taste
perception, different from and in addition to the canonical four: salt,
sour, bitter, and sweet. He argued that glutamate contributes to the
distinctive taste of certain seaweeds, fish sauces, soy sauce, and dried
fish. And he proposed a method for concentrating the taste essence
in the form of MSG (monosodium glutamate), which could be added