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 361 records · Page 20Linked to original sources
PubMed1990

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↗
PubMed1985

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↗
PubMed1996

Spatial acuity of touch: ubiquitous decline with aging revealed by repeated threshold testing.

Spatial acuity of touch, like that of vision, tends to decline eventually in nearly everybody's lifetime. This has been revealed by more thorough than customary testing of individual young and elderly subjects. Three kinds of acuity threshold were assessed repeatedly in the index finger. These measured ability to discriminate tactile (1) gaps (by a refined version of two-point threshold), (2) orientation of lines (across vs. along the finger), and (3) length of lines. These acuities relate to prominent discriminatory features of braille, and have been shown earlier to average about 1% larger per annum over the adult life span from about 20 to 80 years. Although there were reliable differences among the elderly subjects in the present experiment, all of them tested consistently worse than the least acute young adult controls. The customary single brief threshold tests heretofore applied are inadequate to capture this ubiquitous but differential individual deficit in advanced age; however, the average of six 15- to 20-min tests spread over 3 days proved more than adequate. The method of repeated threshold testing--applied earlier to olfactory and gustatory sensitivity, and now to tactile acuity--serves to dispel the notion that incidence of sensory loss with aging is highly idiosyncratic.

Adult↗
PubMedDate not supplied

Feeding habits and their physiological determinants. Relationships between consumer's preference for sweetness of drinks and certain physiological parameters.

Investigations determining the preferred saccharose concentration in drinks (CP(S)), gustatory threshold values, blood glucose level, basal metabolism rate and body weight index (im) were carried out with 83 cadets, aged 21--23 years. CP(S) was directly proportional to the gustatory threshold for sweet tastee, blood glucose level and basal metabolism and the correlation found in all three cases was statistically significant (p less than 0.01). The accuracy of CP(S) estimation by cadets was strictly related to their threshold difference for sweet tast depending also on smoking.

Adult↗
PubMed1985

[Plasma zinc content in patients with chronic renal insufficiency before and after kidney transplantation].

Zinc content in blood plasma was measured in patients with chronic renal failure (CRF) before and after kidney transplantation by atomic-absorption spectrophotometry. Plasma zinc was revealed to be lowered. However, routine intake of vitamin A by the patients led to an elevation in zinc content. Hemodialysis did not alter blood plasma zinc concentration. It was noted that during the postoperative period, the zinc level returned to normal. Patients with CRF show marked disturbances of taste sensitivity, which are manifested in the increased threshold of taste sensitivity and perversion of taste sensations.

Adult↗
PubMed2004

Behavioral comparisons of the tastes of L-alanine and monosodium glutamate in rats.

Recent research has implicated T1R1/T1R3 as the primary taste receptor in mammals for detecting L-amino acids, including L-monosodium glutamate (MSG) and L-alanine. Previous behavioral studies with rodents found only minimal evidence that these two substances share perceptual qualities, but those studies did not control for the taste of sodium associated with MSG. This study used several behavioral methods to compare the perceptual qualities of MSG and L-alanine in rats, using amiloride (a sodium channel blocker) to reduce the sodium component of MSG taste. Detection thresholds of L-alanine in rats ranged between 0.4 and 2.5 mM, with or without amiloride added, which are similar to threshold estimates for MSG. Conditioned taste aversion (CTA) found that rats showed strong cross-generalization of CTA between MSG and L-alanine when mixed with amiloride, indicating the two substances have similar perceptual qualities. Discrimination methods showed that rats easily discriminated between L-alanine and MSG unless the cue function of sodium was reduced. The discrimination became significantly more difficult at concentrations < 100 mM when amiloride was added to all stimuli and became even more difficult when NaCl was also added to L-alanine solutions to match the sodium concentrations of MSG. These results indicate that, perceptually, MSG and L-alanine have quite similar taste qualities and support the hypothesis that these two L-amino acids activate a common taste receptor. The differences in perceptual qualities also suggest separate afferent processing of one or both substances may also be involved.

Alanine↗
PubMed2000

Gustatory responsiveness to food-associated sugars and acids in pigtail macaques, Macaca nemestrina.

Taste-preference thresholds for five food-associated sugars and acids, respectively, as well as relative sweet-taste preferences were assessed in six pigtail macaques using two-bottle choice tests of brief duration (1 min). In experiment 1, the animals were found to significantly prefer concentrations as low as 10 mM maltose and sucrose, 20 mM fructose and glucose, and 30 mM lactose over tap water. In experiment 2, the monkeys were given a choice between all binary combinations of the same five saccharides presented in equimolar concentrations of 50, 100, 200, and 400 mM. Preferences for individual sugars were stable across the concentrations tested and indicate the following order of relative effectiveness: maltose>sucrose>glucose> or =fructose> or =lactose. In experiment 3, Macaca nemestrina was found to significantly discriminate concentrations as low as 5 mM malic acid, 10 mM ascorbic acid, 20 mM citric acid and acetic acid, and 0.5 mM tannic acid from the alternative stimulus. With the latter substance, the monkeys rejected all suprathreshold concentrations tested, whereas with the former four substances, the animals showed an inverted U-shaped function of preference. The results showed pigtail macaques to be the first primate species tested so far whose taste-preference threshold for maltose is as low as that for sucrose, and which - similar to rodents - prefers maltose over equimolar concentrations of sucrose and other saccharides. Further, unlike most other primates, pigtail macaques do not generally reject acidic tastants but show a substance- and concentration-dependent change in their behavioral response that may range from rejection to preference. The results support the assumption that the gustatory responsiveness of M. nemestrina to food-associated sugars and acidic tastants might reflect an evolutionary adaptation to its dietary habits.

Acetic Acid↗
PubMed2005

Structures, sensory activity, and dose/response functions of 2,5-diketopiperazines in roasted cocoa nibs (Theobroma cacao).

The taste compounds inducing the blood-like, metallic bitter taste sensation reported recently for a dichloromethane extract prepared from roasted cocoa nibs were identified as a series of 25 diketopiperazines by means of HPLC degustation, LC-MS/MS, and independent synthesis. Among these 25 compounds, 13 cis-configured diketopiperazines, namely, cyclo(L-IIe-L-Phe), cyclo(L-Val-L-Leu), cyclo(L-Pro-L-Pro), cyclo(L-IIe-L-Pro), cyclo(L-Val-L-Tyr), cyclo(L-Ala-L-Tyr), cyclo(L-Phe-L-Ser), cyclo(L-Ala-L-IIe), cyclo(L-Leu-L-Phe), cyclo(L-Pro-L-Val), cyclo(L-Pro-L-Thr), cyclo(L-Pro-L-Tyr), and cyclo(L-Val-L-Val) were identified for the first time in cocoa. In addition, the taste recognition thresholds for the metallic as well as the bitter taste of the diketopiperazines were determined, and after quantitative analysis by using two diastereomeric diketopiperazines as the internal standards, the sensory impact of the diketopiperazines was evaluated on the basis of their dose-over-threshold (DoT) factors calculated as the ratio of the concentration and the threshold concentration of a compound. These data revealed DoT factors above 1.0 exclusively for cis-cyclo(L-Pro-L-Val), cis-cyclo(L-Val-L-Leu), cis-cyclo(L-Ala-L-Ile), cis-cyclo(L-Ala-L-Leu), and cis-cyclo(L-Ile-L-Pro), whereas all of the other diketopiperazines were present below their individual bitter taste threshold concentrations and should therefore not contribute to the cocoa taste. Because the DoT factors do not consider the nonlinear relationship between the concentration and gustatory response of an individual compound, we, for the first time, report on the recording of dose/response functions describing the human bitter taste perception of diketopiperazines more precisely.

Adult↗
PubMed2004

Taste function in Sjögren's syndrome patients with special reference to clinical tests.

OBJECTIVE: We analyzed the correlation between taste functions and clinical features in patients with Sjögren's syndrome (SS). METHODS: Sixty-three patients were divided into two groups: group A consisting of patients with primary or secondary SS of the European classification, and group B consisting of non-SS complaining of dry eye and mouth. RESULTS: Eighteen percent of the group A patients and 11% of the group B patients complained of taste disorders. Electrogustometric examination detected taste disorders in 27% of the group A patients and 38% of the group B patients, while the filter paper disc method showed taste disorders in 30% of group A and 40% of group B. In group A, unstimulated and stimulated salivary flows were correlated with the ability to discriminate taste analyzed by the filter paper disc method, but not with the taste electrogustometric threshold. Serum zinc concentration was not significantly correlated with taste disorders in either group. CONCLUSION: Our findings showed that SS patients presented taste disorders less frequently than previously reported, and we speculated that taste disorder found in SS patients were due to the salivary flow deficiency that might prevent substances from reaching the taste buds.

Adult↗
PubMed1986

Sensoric and chemical limits in lowering the dose of sodium nitrite in the process of pork curing.

The specific cured meat odour and taste stimulus thresholds in pork containing different quantities of sodium nitrite were determined in relation to the residual nitrite level and relative contents of nitrosylpigments in meat. It was stated, that the specific odour and taste detection thresholds were equal to 10 and below 10 mg NaNO2/kg of meat, respectively, and the specific odour and taste recognition thresholds were equal to 26 and 21 mg NaNO2/kg of meat, respectively. The detection and recognition thresholds corresponded to 2.4 and 8.5 mg of residual nitrite in meat, respectively. In all the cases the relative contents of nitrosylpigments were above 50%. Taking into account the maintening of specific cured meat odour and taste, the dose of sodium nitrite in pork curing may be lowered to 30 mg/kg.

Animals↗
PubMed2004

Depressive symptoms and taste reactivity in humans.

Animal studies suggest that induction of depression-like states may alter preference for sweet tastants. A major goal of the present study was to search for correlations between depressive symptoms measured by the Beck Depression Inventory (BDI) and taste responses to sweet and bitter substances. Thirty-three nonclinical volunteers rated intensity and pleasantness of chocolate and vanilla milk as well as of sucrose- and quinine-soaked filter paper disks. Reactivity to citric acid (sour) and sodium chloride (salty) was also tested with the paper disk methodology. Taste detection thresholds were assessed by means of electrogustometry. A weak inverse relationship was found between the BDI scores (range: 3-33) and rated intensity of paper disks soaked in 60% sucrose. No correlations were found between depressive symptoms and intensity, pleasantness or identification of the other samples. Similarly, there was no relationship between the BDI scores and responses to chocolate and vanilla milk. BDI scores were not associated with electrogustometric thresholds. These data suggest that depressive symptoms may not influence taste reactivity in nonclinical population.

Aconitic Acid↗
PubMed1996

[Evaluation of gustatory threshold changes in healthy subjects].

Changes in gustatory thresholds were examined in 30 healthy volunteers by conducting electrogustometry and the filter-paper disc method, three times with a 4 week or longer interval. Gustatory thresholds, obtained from either method, notably decreased in the second and the third examination in many subjects. In chronological observations by using the electrogustometry, changes of 6 dB or less in the chorda tympani nerve area or 8 to 10 dB less in the glossopharyngeal nerve area were considered to be not significant. In the filter-paper disc method, the threshold changes with one concentration grade of test solution were observed at high frequency, while the threshold changes with two concentration grades or more were very rare, however all changes were significant. In the filter-paper disc method, changes of the gustatory threshold in one or two kinds of tastes were relatively frequently observed. However, the gustatory thresholds of three or four kinds of tastes rarely changed simultaneously even by one concentration grade of those taste solutions. If such multiple changes of the taste thresholds occur, even when each taste threshold changed only by one concentration grade, it was as a significant change.

Adolescent↗
PubMed1994

The effect of age on the recognition thresholds of three sweeteners: sucrose, saccharin and aspartame.

It is believed that people's sensitivity to taste declines with age but the evidence is inconclusive. This study was designed to test the hypothesis that taste recognition thresholds (TRTs) for sweetness are higher in older than in younger individuals, using groups of 16 younger subjects (18-30) and 16 older subjects (60-85). Three test substances were used: sucrose, aspartame and saccharin. A questionnaire recorded variables which might have affected TRTs, but data failed to show any trend that might have biased the principle variate-age. There was a significant alteration with age of recognition thresholds, at least for sucrose and saccharin. The differences between the groups for the three sweeteners were due to the fact that all the very sensitive subjects were young. None of the older subjects had particularly poor discrimination: all but one had TRTs within the range of younger subjects. Although there are age-related taste changes, they are much less dramatic than commonly occurs with other senses, such as sight and hearing. The findings of this study have implications for institutional catering and the dietary management of older people using non-sugar sweeteners.

Adolescent↗
PubMed2002

Relationships between threshold-based PROP sensitivity and food preferences of Tunisians.

The extent to which taste responses--and notably the genetically determined sensitivity to 6-n-propylthiouracil (PROP)--influences food preferences and food use is still a matter of debate. We addressed the issue on the basis of a behavioural and anthropological study performed in Tunis in 1999. The working sample consists of 123 adults of both sexes (38 men, 85 women), aged 19-59, in various social categories. Taste recognition thresholds for sucrose, fructose, sodium chloride, quinine hydrochloride, citric acid, tannic acid, oak tannin and PROP were determined by presenting, in a semi-randomised order (blind-test), series of graded aqueous solutions of each product. Subjects also tasted and rated the pleasantness/unpleasantness of 4 supra-threshold solutions of NaCl and sucrose. All subjects completed a checklist of 43 food items representative of Tunisian diet, rated in terms of flavour, cost, effect on health and prestige on a labelled affective magnitude scale. According to the underlying distribution of PROP thresholds, the subjects were separated into three categories: "non-tasters", "medium-threshold tasters", and "low-threshold tasters". Results bring out the specificity of low-threshold tasters, as exhibiting a greater taste sensitivity for most tested substances. Low-threshold taster status is also linked to higher mean food preferences ratings irrespective of sex, age and socio-cultural influences. Tasters as a group (medium-threshold tasters + low-threshold tasters) do not exhibit a higher percentage of food dislikes; however PROP sensitivity is negatively correlated with hedonic responses to NaCl solutions. These results together with the evidence of a limited set of food actually used by low-threshold tasters suggest that these subjects might have difficulties at overcoming an inherent neophobia.

Adult↗
PubMed2005

Comparative study of taste disturbance by losartan and perindopril in healthy volunteers.

The aim of this study was to compare the degree of taste disturbance by losartan, an angiotensin II receptor blocker, with that of perindopril, an angiotensin-converting enzyme inhibitor. Perindopril erbumine (2 mg), losartan potassium (25 mg), or vehicle was given to Japanese volunteers (n = 7) for 14 days in a randomized, placebo-controlled, 3-way crossover design with a 14-day washout period. Gustometry by filter-paper test and electrogustometry were performed before and at the end of each trial. Plasma renin activity (PRA) and serum and salivary zinc concentrations were measured. One subject dropped out because of a perindopril-induced dry cough, but no one claimed a taste disturbance. Detection thresholds of 4 basic tastes (sweet, salty, sour, and bitter) by the paper-disc test and electrogustometry were significantly worsened, and plasma renin activity was elevated by the drugs, whereas the deteriorating effects of 2 drugs did not significantly differ. These drugs did not affect zinc concentrations in plasma and saliva. It was concluded that losartan and perindopril similarly alter taste sensitivity during repeated dosing of the drugs.

Adult↗
PubMed2000

Role of saliva in the maintenance of taste sensitivity.

Saliva is the principal fluid component of the external environment of the taste receptor cells and, as such, could play a role in taste sensitivity. Its main role includes transport of taste substances to and protection of the taste receptor. In the initial process of taste perception, saliva acts as a solvent for taste substances; salivary water dissolves taste substances, and the latter diffuse to the taste receptor sites. During this process, some salivary constituents chemically interact with taste substances. For example, salivary buffers (e.g., bicarbonate ions) decrease the concentration of free hydrogen ions (sour taste), and there are some salivary proteins which may bind with bitter taste substances. Another effect of saliva on taste transduction is that some salivary constituents can continuously stimulate the taste receptor, resulting in an alteration of taste sensitivity. For example, the taste detection threshold for NaCl is slightly above the salivary sodium concentrations with which the taste receptor is continuously stimulated. In contrast, saliva protects the taste receptor from damage brought about by dryness and bacterial infection, and from disuse atrophy via a decrease in transport of taste stimuli to the receptor sites. This is a long-term effect of saliva that may be related to taste disorders. These various effects of saliva on the taste perception differ depending on the anatomical relationship between the taste buds and oral openings of the ducts of the salivary glands. Many taste buds are localized in the trenches of the foliate and circumvallate papillae, where the lingual minor salivary glands (von Ebner's glands) secrete saliva. Taste buds situated at the surface of the anterior part of the tongue and soft palate are bathed with the mixed saliva secreted mainly by the three major salivary glands.

Animals↗
PubMed1998

[Changes in the threshold values of lingua throughout aging].

The filter-paper-disk method was employed for measuring the threshold values of four basic taste on lingua-tip with 308 healthy females aged 20-79. Taste substance were sequentially diluted with distilluted water (30 stages from 80.0 g/dl for sucrose, 30 stages from 30.0 g/dl for NaCl, 30 stages from 8.0 g/dl for sodium tartrate, 30 stages from 4.0 g/dl for HCl quinine). The result was as follows. A sensibility of gustation decreased rapidly in accordance with aging. A decrease of bitterness sensibility was most remarkably with aging, succeeded sourness, sweetness, saltyness. Also, a decrease of a gustation sensibility is beginning in early twenties, especially the sensitivity to a sweetness and sour taste decreased conspicuously from twenties to thirties.

Adult↗