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Biomedical subjects

T B Clark

Publications and source records attributed to T B Clark.

At least 37 records · Page 2Linked to original sources
PubMed1981

Molecular mechanism of sweet taste: relationship of hydrogen bonding to taste sensitivity for both young and elderly.

Taste detection thresholds for 11 sweeteners varying widely in chemical structure were determined for young and elderly subjects. The rank orders of the thresholds for young and elderly were highly correlated (Spearman's rho=0.976) although the thresholds were 2.72 times higher on the average for the elderly when compared with the young. This decreased sensitivity was statistically highly significant, p=0.000266. Sweeteners with the lowest detection thresholds tended to have the greatest number of units (AH-B systems) capable of intermolecular hydrogen bonding. In addition, use of the method of magnitude estimation with 10 sweeteners revealed that the elderly perceived less growth in intensity with increasing concentration than young subjects. The slopes of the psychophysical functions relating concentration and perceived intensity were flatter in all cases for elderly subjects; the mean ratio, slope(young)/slope(elderly), was 2.06. The largest relative decline in slope was found for those stimuli with the greatest number of possible AH-B types, suggesting that the possibilities for concerted intermolecular hydrogen bonding may decline with age. If the elderly compensate for their diminished taste acuity with increased consumption, they may constitute a population with higher than average risk of any adverse dose-related biological effects of artificial sweeteners.

Adult↗
PubMed1980

Magnitude estimates of amino acids for young and elderly subjects.

Serial dilutions of twenty-three amino acids were presented to young and elderly subjects who rated the relative intensities of the dilutions using the magnitude estimation procedure. In each case the slope of the psychophysical function relating concentration and perceived intensity was flatter for the elderly subjects: the mean ratio (slope (young)/slope (elderly)) was 2.55. This result could be due to an age-related decline in gustatory apparatus or associated central areas as well as memory loss and decline in performance often found in the elderly. No conclusive relationships between the slopes of the psychophysical functions were found with chemical structure, taste quality, or solubility.

Adolescent↗
PubMed1979

Qualitative differences among sweeteners.

Seventeen sweeteners varying widely in chemical structure were arranged in a three-dimensional space by two multidimensional scaling procedures, INDSCAL and ALSCAL. Fructose, glucose, sorbose, xylitol and xylose tended to fall near one another. Two sweeteners with a syrupy component, maltose and sorbitol, fell further away. Ca cyclamate and the dipeptide aspartame were the two artificial sweeteners which fell closest to and thus tasted most like the sugars. The proteins monellin and thaumatin, as well as the chalcone glycoside, neohesperidin dihydrochalcone, all have long aftertastes and thus tended to fall proximate to one another. Stimuli with the highest metallic and bitter ratings (acetosulfan, sodium saccharin, rebaudioside and stevioside) tended to fall near one another with the amino acid d-tryptophan located a little farther away. Adjective scales were related to the spatial arrangement. Wide variability in the patterns of intensity ratings over subjects suggests that the sweet taste may be mediated by several peripheral receptor mechanisms.

Adolescent↗