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

Taste Perception with Age: Generic or Specific Losses in Supra-threshold Intensities of Five Taste Qualities?

The influence of ageing on supra-threshold intensity perception of NaCl, KCl, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine HCl, monosodium glutamate (MSG) and inosine 5'-monophosphate (IMP) dissolved in water and in `regular' product was studied in 21 young (19¿33 years) and 21 elderly (60¿75 years) persons. While the relative perception (intensity discrimination) seems to be remarkably resistant to the effect of ageing, the absolute perception (intensity rating) decreased with age for all tastants in water, but only for the salty and sweet tastants in product. When assessed while wearing a nose clip, only the perception of salty tastants was diminished with age. The slopes of the psychophysical functions were flatter in the elderly than in the young for the sweet, bitter and umami tastants in water, and for the sour tastants in product only. The age effects found were almost exclusively generic and never compound-specific within a taste. This study indicates that the relevance of determining intensities of tastants dissolved in water for the `real life' perception of taste in complex food is rather limited

Effect of concentration on taste-taste interactions with foods for elderly and young subjects

An increase in concentration of one of the tastants in a 'real food' might affect not only the perception of the taste quality of that manipulated tastant but also the other perceivable taste qualities. The influence of concentration increase of sodium or potassium chloride in tomato soup, sucrose or aspartame in iced tea, acetic or citric acid in mayonnaise, caffeine or quinine HCl in chocolate drink, monosodium glutamate (MSG) or inosine 5'-monophosphate (IMP) in broth on the other perceivable taste qualities in these foods was studied in 21 young subjects (19-33 years) and 21 older subjects (60-75 years). The results showed that for each of these tastants, except for the two acids, increasing the concentration provoked significant positive or negative interaction effects on the perception of one or more other taste qualities of the product. Especially in the young, olfaction plays a larger role in the assessment of taste intensity than has been hitherto assumed. The elderly are less able to discriminate between the taste qualities in a product, whereas the young are more able to do so