Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Taste Threshold”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources

Taste responses to monosodium glutamate after alcohol exposure.

AIMS: The aim of the present study was to evaluate the effects of acute and chronic exposure to alcohol on taste responses to a prototypic umami substance, monosodium glutamate (MSG). METHODS: The rated intensity and pleasantness of MSG taste (0.03-10.0%) was compared in chronic male alcoholics (n = 35) and control subjects (n = 25). In a separate experiment, the effects of acute exposure of the oral mucosa to ethanol rinse (0.5-4.0%) on MSG taste (0.3-3.0%) were studied in 10 social drinkers. RESULTS: The alcoholic and control group did not differ in terms of the rated intensity and pleasantness of MSG taste. Electrogustometric thresholds were significantly (P < 0.01) higher, i.e. worse, in the alcohol-dependent subjects. The difference remained significant after controlling for between-group differences in cigarette smoking and coffee drinking. Rinsing with ethanol did not alter either intensity or pleasantness of MSG taste in social drinkers. CONCLUSIONS: The present results suggest that: (i) neither acute nor chronic alcohol exposure modifies taste responses to MSG; (ii) alcohol dependence may be associated with deficit in threshold taste reactivity, as assessed by electrogustometry.

Adult↗

Seasonal alteration in taste detection and recognition threshold in seasonal affective disorder: the proximate source of carbohydrate craving.

Increased appetite with associated carbohydrate craving are core symptoms of seasonal affective disorder (SAD) and have been attributed to decreased central serotonergic function. The proximate mechanisms for centrally mediated selective macronutrient consumption are unknown. We questioned whether seasonal alterations in taste sensation could serve as a mediator of dietary intake, as implied by the term 'craving'. Specifically, individuals who were seasonally depressed and reported carbohydrate craving would be more sensitive to gustatory cues associated with the presence of carbohydrate than nondepressed subjects. Taste detection and recognition thresholds for the four primary gustatory sensations--sweet, sour, salty, and bitter--were obtained in a group of 25 SAD patients and 23 non-psychiatric subjects during the winter, after 2 weeks of 10 000 lux morning and evening light treatment, and during the summer. Relative to the comparison group, the SAD group was less sensitive to sweet taste during the winter. Sweet taste threshold in the SAD group normalized during the summer; however, 2 weeks of light treatment failed to alter sweet detection thresholds in the SAD group. Moreover, within the SAD group, season exerted significant effects on sweet, sour, and bitter detection, but it did not influence salt-detection thresholds. The findings represent the first demonstration of specific changes in taste perception associated with the self-report of carbohydrate craving in SAD and are discussed in terms of the development of sweet craving and the serotonin hypothesis of SAD.

Adult↗

[Food intake, depressed appetite and chemosensory threshold in patients with cancer during chemotherapy].

Energy and protein intake and eating-related complaints were studied in 52 patients with cancer of the breast, ovary or lung prior to and after 1 and 3 cycles of chemotherapy. Pretreatment intakes were somewhat lower than recommended, but did not change after therapy. Many patients had eating-related complaints, but these complaints did not increase after therapy. Eating-related complaints (except poor appetite) had no impact on intake. Electrical taste detection thresholds and chemical smell detection thresholds were measured before and after three cycles of chemotherapy. Changes in food intake had no relation to changes in chemosensory thresholds. Perceived taste and smell changes were not reflected in chemosensory thresholds.

Adult↗

Taste sensitivity is altered in patients with chronic renal failure receiving continuous ambulatory peritoneal dialysis.

Decreased taste sensitivity may be one of the many factors influencing the poor nutritional status of many patients with chronic renal failure. Several studies examining taste in chronic uremic and hemodialysis (HD) patients indicate decreased sensitivity; continuous ambulatory peritoneal dialysis (CAPD) patients, however, warrant investigation. The aim of this study was to determine if the taste detection threshold for each of the four tastes (sweet, salty, sour and bitter) differs between CAPD patients and age and sex matched controls with normal renal function. The thresholds were determined using Cornsweet's staircase technique for increasing and decreasing stimulus concentration, in which the subject's response determines the next concentration to be tested. A forced-choice design using three samples was used to help minimize bias. The taste detection threshold for the CAPD patients was significantly higher than that of the controls for sodium chloride (salty)(P = 0.001) and quinine (bitter) (P = 0.01). This information may be useful when designing dietary supplements and devising meal plans to help patients consume nutritionally adequate diets.

Adult↗

A new whole-mouth gustatory test procedure. II. Effects of aging, gender and smoking.

Taste detection and recognition thresholds for the 4 basic tastes were measured in 670 healthy subjects using a new whole-mouth method in which test solutions of the 4 basic tastes were diluted 1:1 with distilled water successively in 13 steps. The taste thresholds were measured by spraying a 1 ml aliquot of solution into the mouth, starting with the lowest concentration, and asking the subject to swallow and note if a taste was detected and, if so, which one. The mouth was rinsed with distilled water only between different taste test solutions. Multiple comparison analysis showed a clear age-related increase in thresholds for salty, sour and bitter tastes for subjects in their eighth decade of life. From the third decade onwards, female subjects had significantly lower thresholds compared to males for sour taste in about half of the age groups and for salty and bitter tastes in some age groups. In contrast, for 18- and 19-year-old subjects, the gustatory thresholds of male subjects were lower than those of female subjects. Regarding smoking, male smokers in their third decade had significantly higher thresholds for bitter taste compared to male non-smokers in this age group.

Adolescent↗

Effects of age and removable artificial dentition on taste.

Sodium chloride and sucrose gustatory recognition thresholds, suprathreshold taste intensity function, and sucrose suprathreshold taste preference in healthy adult males with removable artificial dentition were compared with persons having natural dentition. In addition, several inorganic salivary constituents were evaluated for their possible relationship with these modalities. The 75 participants studied were divided into two age and two dentition groups: less than 65 years versus 65 years and older; and natural dentition only versus either removable partial dentures or complete artificial dentition. Recognition threshold and suprathreshold psychophysical functions were assessed using aqueous solutions of sodium chloride and sucrose. Suprathreshold hedonic judgments were also determined for sucrose. Samples of stimulated parotid saliva were analyzed for sodium, potassium, and bicarbonate. As age increased, a statistically significant decrease was noted in the exponent of the psychophysical function for sodium chloride. A similar, but nonsignificant, trend was observed for sucrose, which was complicated by an interaction between age and dentition status. For sodium chloride, recognition thresholds tended to be higher for older persons with removable partial and complete dentures. However, no statistically significant effect was observed on the sucrose threshold or hedonic response as a result of dentition status. Analysis of several parotid saliva constituents showed no statistically significant effect caused by age or dentition status and correlations noted among the psychophysical measures appeared to be fortuitous.

Adult↗

Elucidation of mammalian bitter taste.

A family of approximately 30 TAS2R bitter taste receptors has been identified in mammals. Their genes evolved through adaptive diversification and are linked to chromosomal loci known to influence bitter taste in mice and humans. The agonists for various TAS2Rs have been identified and all of them were established as bitter tastants. TAS2Rs are broadly tuned to detect multiple bitter substances, explaining, in part, how mammals can recognize numerous bitter compounds with a limited set of receptors. The TAS2Rs are expressed in a subset of taste receptor cells, which are distinct from those mediating responses to other taste qualities. However, cells devoted to the detection of sweet, umami, and bitter stimuli share common signal transduction components. Transgenic expression of a human TAS2R in sweet or bitter taste receptor-expressing cells of mice induced either strong attraction or aversion to the receptor's cognate bitter tastant. Thus, dedicated taste receptor cells appear to function as broadly tuned detectors for bitter substances and are wired to elicit aversive behavior.

Amino Acid Sequence↗

The generalizability of capsaicin sensitization and desensitization.

Studies using capsaicin-saturated filter papers have shown that the intensity of oral irritation tends to grow over successive samples, a phenomenon known as sensitization. If a hiatus of 5-15 min is then introduced, the intensity of irritation produced by a subsequent capsaicin stimulus is much reduced, and desensitization is said to have occurred. The use of other methodologies such as whole-mouth rinses, either with capsaicin or the irritants menthol or zingerone, have not consistently shown this response pattern, casting doubt on the extent to which sensitization and desensitization are general phenomena. Experiment 1 addressed this issue by comparing responses to whole-mouth rinses of 0.6 and 3 ppm capsaicin with those to 3 ppm capsaicin filter papers. Over an initial series of 10 samples, sensitization was evident but only for the 3 ppm capsaicin stimuli. Following a 10-min hiatus, desensitization was observed for all stimulus types. An examination of the data of individual subjects revealed considerable variability in response patterns over the initial 10 samples between subjects and, within subjects, between the filter paper and rinse stimuli, and between the test replications. Desensitization to the posthiatus stimuli was more consistent. A second experiment examined whether the capsaicin sensitization and desensitization shown by stimulation with filter papers or solutions also occurred in the context of the consumption of foods containing capsaicin. Two foods--soup and chili con carne--were consumed under conditions in which the rate of consumption was timed, as in Experiment 1, or was self-paced. In neither of the two conditions or foods was there strong evidence of sensitization, although, again, desensitization following a hiatus was evident. Substantial individual variability in response patterns was again apparent. There is thus no evidence for sensitization occurring during normal food consumption.

Adult↗

Hedonic response to sucrose solutions and the fear of weight gain in patients with eating disorders.

Previous research has shown that patients with bulimia nervosa (B), anorexia nervosa, restricting type, or restrictive-anorectic (RA), and anorexia nervosa, binge eating, purging type, or anorectic-bulimic (AB) exhibit a reduced hedonic response to sucrose compared with control subjects. We hypothesized that this response could be linked to an excessive fear of weight gain rather than a decreased ability to experience pleasure. We therefore compared the hedonic responses to sucrose solutions in B, RA and AB women (n=20/group) in two different conditions: sucrose solution swallowed vs. sucrose solution spit. Under double-blind conditions and according to a Latin square design, patients received sucrose in solution (0, 5, 10, 20, and 40%) and rated each concentration for pleasantness on a nine-point scale. The two test conditions were randomly administered. The threshold concentration of sweet taste perception was also assessed, and the subjects filled out Chapman's Social and Physical Anhedonia Scale. The hedonic response to sucrose adjusted for the sweet taste perception threshold was significantly lower in the 'swallow' than in the 'spit' condition. There was a significant effect of sucrose concentrations as well as a significant condition by concentration interaction. When 'fear to swallow' sucrose solution responses were included as a covariate, the significant difference between the conditions of 'swallow' or 'spit' disappeared, but there was a significant concentration by condition by fear to swallow interaction and an almost significant covariate effect. When 'Drive for Thinness' on the Eating Disorder Inventory was included as a covariate, similar results were obtained. Social Anhedonia but not Physical Anhedonia correlated positively with 'Drive for Thinness' and 'fear of swallowing sucrose solutions', and correlated inversely with maximal hedonic response to the 'swallow' condition. 'We conclude that the hedonic responses to sucrose in patients with eating disorders are decreased when solutions are swallowed. This may reflect excessive fear of gaining weight rather than decreased ability to experience pleasure'.

Administration, Oral↗

Use of innate behaviors to evaluate sensory function in the dog.

The need to evaluate sensory function in the dog is discussed. A group of techniques that use innate behaviors (species-typical behaviors) and are effective in the evaluation of sensory function of domestic animals are described. Techniques to measure olfactory, gustatory, auditory, and visual function are included.

Animals↗

Olfactory ability as a function of nasal air flow volume in laryngectomees.

This study tested a number of hypotheses concerning the interrelationships between the olfactory abilities and the volume of nasal airflow in laryngectomees. Data were collected from 25 laryngectomees and 25 control subjects and comprised the following: 1) Odor threshold and identification test results. In the threshold test, an 11-step aqueous dilution series of butanol was used. In the odor identification tests, 14 common odorants were used. 2) Measurement of nasal air flow volume in liters per minute. For olfaction and airflow, the laryngectomees' measurements were made under two conditions: 1) using unassisted airflow through the nose, and 2) using a laryngeal bypass that linked the stoma to the mouth and allowed airflow through the nose. The major findings showed that among laryngectomees olfactory abilities depend on nasal airflow. It is concluded that laryngectomees have intact olfactory mechanisms that function normally when adequate airflow volume is provided.

Humans↗

Electrogustometry: strengths, weaknesses, and clinical evidence of stimulus boundaries.

Electrogustometry is well established as a clinical tool for the estimation of taste detection thresholds. Nevertheless, the user is sometimes unaware of the impact of superficially minor procedural and psychophysical factors upon the reliability and comparability of threshold estimates. The inherent strengths and limitations of the procedure are outlined, and aspects of the control and specification of the stimulus that moderate threshold measures are discussed. In addition, threshold estimates from two individuals with severe unilateral taste loss are used to illustrate the level at which anodal dc current may elicit common, rather than taste, sensation. Where chorda tympani section is complete and historical (older than 7-14 days), very high stimulus levels, conservatively over 5 micro A/mm2 (100 micro A linear current with a 5-mm diameter electrode), are required to activate trigeminal responses.

Adult↗

Taste sensitivities to PROP and PTC vary independently in mice.

Mammals use common mechanisms to detect, transduce and process taste stimulus information. For example, they share families of receptors that respond to amino acids, and sweet- and bitter-tasting stimuli. Nonetheless, it also clear that different species exhibit unique taste sensitivities that may reflect specific genetic variations. In humans, sensitivities to the chemically similar, bitter-tasting compounds 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC) are heritable and strongly correlated, suggesting a common genetic basis. However, it is unknown whether PROP and PTC taste sensitivities are similarly correlated in mice. Here we report that PROP and PTC taste sensitivities vary independently between two inbred strains of mice. In brief-access taste tests C3HeB/FeJ (C3) and SWR/J (SW) mice possess similar taste sensitivity to PTC, while SW mice are significantly more sensitive to PROP than are C3 mice. In two-bottle preference tests, however, SW mice display greater aversion to both compounds. This discrepancy may be explained by the observation that SW mice consumed taste solutions at a greater rate during the intake test than did C3 mice. Therefore, PTC avoidance is correlated with the amount of PTC consumed in the intake tests rather than the concentration of PTC tested. These findings suggest that post-ingestive factors play a significant role in PTC avoidance during intake tests and highlight an important advantage of brief-access tests over intake tests in resolving the gustatory and post-ingestive contributions to taste-related behaviors. Most strikingly, these results demonstrate that in mice, unlike in humans, PTC and PROP taste sensitivities vary independently, thereby suggesting a subtle functional diversity of bitter-taste mechanisms across mammalian species.

Animal Feed↗

Independent components of the neural population response for discrimination of quality and intensity of chemical stimuli.

The responses of a population of 30 olfactory receptor cells from spiny lobsters to 8 behaviorally relevant complex types of stimuli at 0.005, 0.05 and 0.5 mM were analyzed using multidimensional scaling to evaluate their potential for coding quality and intensity. A discrimination index was derived from the resulting stimulus coordinates, which takes into account the response similarities within type/concentration and the response dissimilarities between types/concentrations. The results indicate that quality and intensity can be discriminated by separate components of the response of the population of neurons: quality by the pattern of responses produced across the neuronal population, and intensity by the absolute response magnitude.

Animals↗

Missing ingredients: aging and the discrimination of flavor.

An experiment explored how well young, middle-aged, and elderly subjects could discriminate the presence or absence of the spice marjoram in a soup prepared according to a published recipe. Whereas most young made the discrimination at a level above chance, most middle-aged and elderly failed to. A clinical test that entails odor threshold and identification revealed that olfactory ability also diminished with age among these subjects. Furthermore, the odor thresholds measured in the test correlated significantly with the subjects' ability to discriminate flavor. Subsequent testing wherein subjects sought to discriminate flavor with their noses blocked confirmed that olfactory ability largely underlay the discrimination. The results emphasize that losses in olfaction measured most commonly with environmental odors are serious enough to have an impact on discrimination of flavors in everyday foods, even among persons of middle age. Loss of such discriminative capacity may entail risks of avoiding dangerous and overlooking beneficial ingredients in foods.

Adult↗

Interindividual differences in acuity for odor and aroma.

To determine the olfactory acuity of 27 subjects a sensory test was presented which was divided into 4 subtests, 2 for nasal and 2 for oral stimulation. Each subtest contained 28 (4 substances X 7 concentrations) olfactory detection tasks (items). The substances used were lemon and rum aroma as well as ethyl butyrate and amyl acetate, the solvents tap water and sugared tap water. Analysis showed that the test provided a clear differentiation between subjects of low, medium, and high olfactory acuity. The intercorrelations among the test substances and the split-half reliabilities of the subtests proved relatively high, whereas only moderate to low intercorrelations among the subtests were found. This was considered an effect of intraindividual variations of olfactory sensitivity. Finally, some conclusions for the construction of acuity tests for odor and aroma are presented.

Adolescent↗