Taste responses to saltiness of experimentally prepared tomato juice samples.

Responses to changes in salt and acid concentration in experimentally prepared tomato juice samples were examined in young and aging adults. Results indicated that perceived saltiness intensity and taste preference ratings were strongly affected by both salt and acid concentration. Addition of acid increased the salt intensity ratings at all salt levels, including the unsalted samples, indicating that the apparent saltiness of the tomato juice was increased by the addition of acid alone. The highest taste preference rating occurred near the 0.6% salt level, with no added acid (equivalent to commercial tomato juice); however, the taste preference rating for the 0.3% salt, 0.3% citric acid sample was not significantly different from that of the higher salt, no added acid sample. Saltiness intensity was similar for the two samples. This offers compelling evidence that a trade-off can be accomplished by substituting acid for some of the salt in tomato juice without affecting its palatability or apparent saltiness, thus providing an acceptable solution for those desiring to limit salt intake. While marked lessening of ability to make discriminations occurred only in the oldest subjects, they showed no evidence of distortion in preference but tended to accept those samples most preferred by the younger subjects.