Taste perception with age: pleasantness and its relationships with threshold sensitivity and supra-threshold intensity of five taste qualities

The relationships between threshold sensitivity, supra-threshold intensity of NaCl, KCl, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine HCl, monosodium glutamate (MSG) and inosine 5′-monophosphate (IMP), and the pleasantness of these stimuli in products, were studied in 21 young subjects (19-33 yr) and 21 older subjects (60-75 yr). For the young, threshold sensitivity was unrelated to supra-threshold intensity for all tastants and in all experimental conditions. For the elderly, in a few cases a relationship was found between threshold sensitivity and suprathreshold intensity, but only when subjects wore a nose clip. The optimally preferred concentration did not differ between the elderly and the young when the products were tasted without a nose clip, except for both sweet tastants, where elderly men showed a higher optimally preferred concentration than did the young. The optimally preferred concentration did not depend on the pleasantness of the foods and was unrelated to threshold sensitivity, but did show a negative correlation with the supra-threshold intensity of sucrose, aspartame and citric acid for the elderly and of NaCl, sucrose and caffeine for the young. This study does not support the assumption that age-related loss of taste sensitivity will inevitably lead to a preference for taste-enhanced foods.