Taste dimensions of monosodium glutamate (MSG) in a food system: role of glutamate in young American subjects.

Freshly cooked chicken broth was prepared with several concentrations (0.06-0.32 M) of added NaCl. In the first study, subjects were presented with pairs of samples, each having the same concentration of NaCl (salt) but one of which contained 0.01 M monosodium glutamate (MSG). The subjects preferred the sample with added MSG when the salt levels were low to moderate. The next two studies were designed to determine the relative role of the added sodium and glutamate in MSG in enhancing palatability. In the second study, NaCl was added in amounts equivalent to the sodium in 0.01 M MSG to one of the two samples. Subjects preferred the one with more salt at the low salt level indicating that the added sodium played a role in enhancing palatability. In the last study, the concentration of sodium was held constant in the soups but the glutamate was varied by adding 0.01 M MSG to one sample and 0.01 M NaCl to the other. Subjects preferred the sample with added glutamate to the one without, at the moderate salt concentrations, demonstrating a role for glutamate alone in enhancing palatability. These studies, in sum, demonstrate that MSG increases palatability of salted soups and that both the sodium and the glutamate independently contribute to this enhancement.