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The perception of orosensory stimuli, which includes flavor, can vary between individuals. These individual variations in oral sensations can be due to genetic factors and it would appear that they can predict food liking and consumption. The most studied source of variation is related to bitter taste perception associated with 6-n-propylthiouracil (PROP) responsiveness. In this context, humans can be classified as non-tasters (NT), medium tasters (MT) and supertasters (ST). Evidence suggests that genetic variation in bitter taste perception contributes to differences in the level of irritation caused by alcohol perception in solutions. The aim of this investigation was to study the bitter taste sensitivity among a group of mezcal consumers and its relationship with sensory perception and preference through PROP taster status. The tests were carried out in the state of Oaxaca in Mexico. A total of 83 mezcal consumers were classified by their PROP taster status and were asked to provide sensory descriptors for five mezcal samples and rate them according to the level of liking. The three-solution test was used to classify the subjects as NT, MT, and ST, while a Multiple Factor Analysis (MFA) was used to visualize the sensory descriptors provided by these three groups. The proportion of MT subjects was 16%, while the proportion of NT and ST was 34 and 51%, respectively. The MT provided higher liking ratings for at least three mezcal samples. According to MFA, the mezcal samples were organized in a similar configuration along the two dimensions. However, NT mentioned a limited number of simple terms (strong flavor, tasteless, burning in the mouth) to describe the samples, whereas ST used a more complex vocabulary (astringent, smoky, scratchy aftertaste). These data suggest that the preference for mezcal samples was similar for non-taster and supertasters, but there are indications that the sensory perception of mezcal differs between groups., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Taste perception plays a crucial role in determining food choices. It has been described in literature a relationship between diet composition and taste perception. Nowadays, with the rising concern in climate change and animal welfare, the number of people following a vegan diet is increasing to become a real trend. Research about differences in taste perception between vegan and omnivore is lacking. The aim of the study was to compare detection threshold for bitter, sour, umami and astringency stimuli (quinine monohydrochloride dihydrate, citric acid anhydrous, monosodium glutamate and tannic acid, respectively) participants following a vegan diet (n=24) and participants following an omnivore diet (n=30). Participants reported their consumption frequency for main food categories. The mean detection thresholds between the two groups narrowly missed significance with p-values of 0.07, 0.08, 0.06, for bitter, umami and astringency perception, respectively. No differences were found for sour taste (p-value=0.33). Further research is required to validate such findings and to understand the origin of the relationship between diet style and taste sensitivity., Competing Interests: Declaration of Competing Interest None, (Copyright © 2023 Elsevier Inc. All rights reserved.)

Aims: Type 2 diabetes leads to multiple sensory dysfunctions affecting notably the gustatory sensitivity. Although this sensory defect, by impacting food choices, might lead to unhealthy eating behavior, underlying mechanisms remains poorly studied. We have recently reported that the composition of microbiota in contact with circumvallate gustatory papillae might affect the orosensory perception of lipids in lean and normoglycemic obese subjects. This finding has prompted us to explore whether such a phenomenon also occurs in diabetic obese patients., Methods: The composition of microbiota surrounding the circumvallate papillae was analyzed in combination with the linoleic acid perception thresholds in male insulin-resistant patients and weight-matched healthy controls. Two complementary comparisons were performed: (1) controls vs diabetic and (2) diabetic low-lipid tasters versus diabetic high-lipid tasters., Results: Despite subtle modifications in the oral microbiota composition, comparison of orosensory lipid perception in controls and diabetic subjects did not lead to discriminating data due to the large inter-individual variability of linoleic acid perception thresholds. In contrast, specific bacterial signatures were found by comparing diabetic low- and high-lipid tasters leading to differential molecular pathways. Surprisingly, a lower fatty taste perception was mainly found in patients treated with metformin and/or statins, suggesting a possible side effect of these antidiabetic and/or hypolipidemic drugs on taste acuity., Conclusions: Collectively, these data show that the diabetic patients with defective fatty taste detection are characterized by a specific microbiota metabolism at the circumvallate papillae levels, this occurrence seeming amplified by drugs commonly used to counteract the damaging metabolic effects of T2D. Trial registration for original previous studies: ClinicalTrials.gov #NCT02028975.

To assess the biological value of environmental stimuli, animals' sensory systems must accurately decode both the identities and the intensities of these stimuli. While much is known about the mechanism by which sensory neurons detect the identities of stimuli, less is known about the mechanism that controls how sensory neurons respond appropriately to different intensities of stimuli. The ionotropic receptor IR76b has been shown to be expressed in different Drosophila chemosensory neurons for sensing a variety of chemicals. Here, we show that IR76b plays an unexpected role in lowering the sensitivity of Drosophila sweet taste neurons. First, IR76b mutants exhibited clear behavioral responses to sucrose and acetic acid (AA) at concentrations that were too low to trigger observable behavioral responses from WT animals. Second, IR76b is expressed in many sweet neurons on the labellum, and these neurons responded to both sucrose and AA. Removing IR76b from the sweet neurons increased their neuronal responses as well as animals' behavioral responses to sucrose and AA. Conversely, overexpressing IR76b in the sweet neurons decreased their neuronal as well as animals' behavioral responses to sucrose and AA. Last, IR76b 's response-lowering ability has specificity: IR76b mutants and WT showed comparable responses to capsaicin when the mammalian capsaicin receptor VR1 was ectopically expressed in their sweet neurons. Our findings suggest that sensitivity of Drosophila sweet neurons to their endogenous ligands is actively limited by IR76b and uncover a potential molecular target by which contexts can modulate sensitivity of sweet neurons., Competing Interests: The authors declare no conflict of interest.

The role of taste perception, its relationship with oral microbiota composition, and their putative link with eating habits and food intake were the focus of the present study. A sample of 59 reportedly healthy adults (27 male, 32 female; age: 23.3 ± 2.6 years) were recruited for the study and taste thresholds for basic tastes, food intake, and oral microbiota composition were evaluated. Differences in taste perception were associated with different habitual food consumption (i.e., frequency) and actual intake. Subjects who were orally hyposensitive to salty taste reported consuming more bakery and salty baked products, saturated-fat-rich products, and soft drinks than hypersensitive subjects. Subjects hyposensitive to sweet taste reported consuming more frequently sweets and desserts than the hypersensitive group. Moreover, subjects hypersensitive to bitter taste showed higher total energy and carbohydrate intakes compared to those who perceived the solution as less bitter. Some bacterial taxa on tongue dorsum were associated with gustatory functions and with vegetable-rich (e.g., Prevotella) or protein/fat-rich diets (e.g., Clostridia). Future studies will be pivotal to confirm the hypothesis and the potential exploitation of oral microbiome as biomarker of long-term consumption of healthy or unhealthy diets.

Taste sensitivity to sugars plays an essential role in the initiation of feeding behavior. In Drosophila melanogaster , recent studies have identified several gustatory receptor ( Gr ) genes required for sensing sweet compounds. However, it is as yet undetermined how these GRs function as taste receptors tuned to a wide range of sugars. Among sugars, fructose has been suggested to be detected by a distinct receptor from other sugars. While GR43A has been reported to sense fructose in the brain, it is not expressed in labellar gustatory receptor neurons that show taste response to fructose. In contrast, the Gr64a-Gr64f gene cluster was recently shown to be associated with fructose sensitivity. Here we sought to decipher the genes required for fructose response among Gr64a-Gr64f genes. Unexpectedly, the qPCR analyses for these genes show that labellar expression levels of Gr64d and Gr64e are higher in fructose low-sensitivity flies than in high-sensitivity flies. Moreover, gustatory nerve responses to fructose in labellar sensilla are higher in Gr64d and Gr64f mutant lines than in mutant flies of the other Gr64a-Gr64f genes. These data suggest the possibility that deletion of GR64D or GR64F may indirectly induce enhanced fructose sensitivity in the labellum. Finally, we conclude that response to fructose cannot be explained by a single one of the Gr64a-Gr64f genes.

Thermal modulation of signaling pathways leads to excitation of taste receptor cells, but the underlying mechanisms remain unclear. Furthermore, it has long been known that there are contrast effects in various senses. In this study, we investigated cold-taste contrast and the relationship between taste and somatosensation. We lowered intraoral temperature using cold stimulus as a pretreatment, then returned to normal temperature in 249 healthy subjects, before administering room temperature taste-stimulating solutions to investigate changes in sensitivity to the four basic tastes (Sweet, Salt, Sour, and Bitter). Statistical comparisons of taste recognition thresholds before and after cold stimulus showed increased taste sensitivity for all four basic tastes. After categorizing different levels of pre-cold stimulus taste sensitivity into groups and comparing changes in sensitivity to the four basic tastes before and after stimulus, we found that the lower the sensitivity to the four basic tastes, the greater the increase in sensitivity induced by cold stimulus. These findings suggest that taste and low temperature send afferent signals which cause interaction in the afferent pathways between the peripheral and central nervous systems. Cold stimulus may offer one possible treatment strategy for dysgeusia.

Background: Taste perception influences food choice, and may contribute to both weight status and disordered eating. Relatively little work has attempted to disentangle contributions of weight status and Binge Eating Disorder (BED) to human taste perception. We predicted weight status and BED would interact, showing difference in taste perception from non-eating disorder matched groups., Methods: The four study groups included: normal weight BED (NW BED), normal weight healthy controls (NW HC), overweight BED (OW BED), and overweight healthy controls (OW HC) (N = 60). Groups were matched for age (±5 years), ethnicity, and weight status. Participants were assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders, the Eating Disorder Examination Version 16.0, and the NIH Toolbox Gustatory Assessment with additional taste solutions and taste stimulus delivered with edible taste strips., Results: Interactions were found between weight status and diagnosis on measures of regional taste intensity for quinine hydrochloride (CI 95% [44.61, 56.31], p = 0.018), sucrose (CI 95% [46.79, 56.45], p = 0.003), and 6-n-propylthiouracil (CI 95% [25.557, 39.269], p = 0.015). OW BED participants perceived these taste stimuli significantly less intensely than OW HC and NW BED. Whole mouth taste intensity tests at suprathreshold amounts did not reveal group differences. All four groups reported similar hedonic response to taste stimuli. Edible taste strips had medium to large significant correlations with NIH Gustatory Assessment taste stimuli., Conclusions: There were significant differences in the taste perception of OW BED relative to the other three groups. These findings may provide partial explanation as to why previous studies correlating taste and weight status have mixed results. Replication in larger samples assessed longitudinally is needed to extend this work., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Taste sensitivity plays a major role in controlling feeding behavior, and alterations in feeding habit induced by changes in taste sensitivity can drive speciation. We investigated variability in taste preferences in wild-derived inbred lines from the Drosophila melanogaster Genetic Reference Panel. Preferences for different sugars, which are essential nutrients for fruit flies, were assessed using two-choice preference tests that paired glucose with fructose, sucrose, or trehalose. The two-choice tests revealed that individual lines have differential and widely variable sugar preferences, and that sugar taste sensitivity is polygenic in the inbred population tested. We focused on 2 strains that exhibited opposing preferences for glucose and fructose, and performed proboscis extension reflex tests and electrophysiological recordings on taste sensilla upon exposure to fructose and glucose. The results indicated that taste sensitivity to fructose is dimorphic between the 2 lines. Genetic analysis showed that high sensitivity to fructose is autosomal dominant over low sensitivity, and that multiple loci on chromosomes 2 and 3 influence sensitivity. Further genetic complementation tests for fructose sensitivity on putative gustatory receptor (Gr) genes for sugars suggested that the Gr64a-Gr64f locus, not the fructose receptor gene Gr43a, might contribute to the dimorphic sensitivity to fructose between the 2 lines., (© The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Although putatively taste has been associated with obesity as one of the factors governing food intake, previous studies have failed to find a consistent link between taste perception and Body Mass Index (BMI). A comprehensive comparison of both thresholds and hedonics for four basic taste modalities (sweet, salty, sour, and bitter) has only been carried out with a very small sample size in adults. In the present exploratory study, we compared 23 obese (OB; BMI > 30), and 31 lean (LN; BMI < 25) individuals on three dimensions of taste perception - recognition thresholds, intensity, and pleasantness - using different concentrations of sucrose (sweet), sodium chloride (NaCl; salty), citric acid (sour), and quinine hydrochloride (bitter) dissolved in water. Recognition thresholds were estimated with an adaptive Bayesian staircase procedure (QUEST). Intensity and pleasantness ratings were acquired using visual analogue scales (VAS). It was found that OB had lower thresholds than LN for sucrose and NaCl, indicating a higher sensitivity to sweet and salty tastes. This effect was also reflected in ratings of intensity, which were significantly higher in the OB group for the lower concentrations of sweet, salty, and sour. Calculation of Bayes factors further corroborated the differences observed with null-hypothesis significance testing (NHST). Overall, the results suggest that OB are more sensitive to sweet and salty, and perceive sweet, salty, and sour more intensely than LN., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The sense of taste is important, as it allows for assessment of nutritional value, as well as safety and quality of foods, with several factors suggested to be associated with taste sensitivity. However, comprehensive variables regarding taste and related factors have not been utilised in previous studies for assessments of sensitivity. In the present study, we performed cross-sectional analyses of taste sensitivity and related factors in geriatric individuals who participated in the SONIC Study. We analysed 2 groups divided by age, 69-71 years (young-old, n = 687) and 79-81 years (old-old, n = 621), and performed a general health assessment, an oral examination and determination of taste sensitivity. Contributing variables were selected by univariate analysis and then subjected to multivariate logistic regression analysis. In both groups, females showed significantly better sensitivity for bitter and sour tastes. Additionally, higher cognitive scores for subjects with a fine taste for salty were commonly seen in both groups, while smoking, drinking, hypertension, number of teeth, stimulated salivary flow salt intake and years of education were also shown to be associated with taste sensitivity. We found gender and cognitive status to be major factors affecting taste sensitivity in geriatric individuals., (© 2016 John Wiley & Sons Ltd.)

In rodents, saccharin consumption is suppressed when the sweet taste stimulus is paired with moderate doses of cocaine. Several hypotheses have been used to explain the seemingly contradictory effect of decreased consumption of a normally preferred substance following a highly rewarding drug. A common theme across these hypotheses is that saccharin is interpreted as less rewarding after cocaine pairing. We considered the alternative possibility that suppression is caused not by a change in reward circuitry, but rather by a change in taste detection, for instance by altering the afferent taste response and decreasing sensitivity to sweet taste stimuli. To evaluate this possibility, we measured saccharin taste sensitivity of mice before and after a standard cocaine-pairing paradigm. We measured taste sensitivity using a brief-access lickometer equipped with multiple concentrations of saccharin solution and established concentration-response curves before and after saccharin-cocaine pairing. Our results indicate that the EC50 for saccharin was unaltered following pairing. Instead, the avidity of licking saccharin, an indicator of motivation, was depressed. Latency to first-lick, a negative indicator of motivation, was also dramatically increased. Thus, our findings are consistent with the interpretation that saccharin-cocaine pairing results in devaluing of the sweet taste reward., (Copyright © 2015 Elsevier Inc. All rights reserved.)

A relationship between orosensory detection of dietary lipids, regulation of fat intake, and body mass index was recently suggested. However, involved mechanisms are poorly understood. Moreover, whether obesity can directly modulate preference for fatty foods remains unknown. To address this question, exploration of the oral lipid sensing system was undertaken in diet-induced obese (DIO) mice. By using a combination of biochemical, physiological, and behavioral approaches, we found that i) the attraction for lipids is decreased in obese mice, ii) this behavioral change has an orosensory origin, iii) it is reversed in calorie-restricted DIO mice, revealing an inverse correlation between fat preference and adipose tissue size, iv) obesity suppresses the lipid-mediated downregulation of the lipid-sensor CD36 in circumvallate papillae, usually found during the refeeding of lean mice, and v) the CD36-dependent signaling cascade controlling the intracellular calcium levels ([Ca(2+)]i) in taste bud cells is decreased in obese mice. Therefore, obesity alters the lipid-sensing system responsible for the oral perception of dietary lipids. This phenomenon seems to take place through a CD36-mediated mechanism, leading to changes in eating behavior.

Abstract Background The aim of this review is to evaluate the relationship between weight status and taste perception and preference of sweet, salt, fat, bitter, and sour through reviewing observational and interventional studies with objective methods. Methods A comprehensive literature search was performed in 6 online databases of PubMed, Scopus, Web of Science, Cochrane, Embase, and Google Scholar up to October 2021. The following keywords were used in the search strategy: (Taste OR "Taste Perception" OR "Taste Threshold" OR "Taste preference" OR "Taste sensitivity" OR "Taste changes") AND (weight OR "Weight gain" OR "weight loss" OR "weight change"). Results Most observational studies indicate that four taste sensitivities or perceptions (especially sweet and salt taste perception) are lower in subjects with overweight and obesity. The longitudinal studies reported that sweet and fat preference is increased along with weight gain in adults. It is concluded that taste perceptions are decreased in individuals with overweight and obesity, especially in men. Also, taste perception and preference change after weight loss but not significantly. Conclusion It is suggested that the results of the interventional studies are not conclusive and need further studies with the same and standard design adjusting cofounding variables including genetic, gender, age and food condition of subjects.

Background: The aim of this review is to evaluate the relationship between weight status and taste perception and preference of sweet, salt, fat, bitter, and sour through reviewing observational and interventional studies with objective methods. Methods: A comprehensive literature search was performed in 6 online databases of PubMed, Scopus, Web of Science, Cochrane, Embase, and Google Scholar up to October 2021. The following keywords were used in the search strategy: (Taste OR "Taste Perception" OR "Taste Threshold" OR "Taste preference" OR "Taste sensitivity" OR "Taste changes") AND (weight OR "Weight gain" OR "weight loss" OR "weight change"). Results: Most observational studies indicate that four taste sensitivities or perceptions (especially sweet and salt taste perception) are lower in subjects with overweight and obesity. The longitudinal studies reported that sweet and fat preference is increased along with weight gain in adults. It is concluded that taste perceptions are decreased in individuals with overweight and obesity, especially in men. Also, taste perception and preference change after weight loss but not significantly. Conclusion: It is suggested that the results of the interventional studies are not conclusive and need further studies with the same and standard design adjusting cofounding variables including genetic, gender, age and food condition of subjects. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study was to evaluate the impact of sweet taste perception on dietary habits among students. Furthermore, the relationship between dietary habits and caries was studied. Methodology: A cross-sectional study was conducted among 200 college-going students aged 18-23 years from the Asan Memorial Institutions. The frequency of consumption of certain food items was analyzed from a Beverage and Snack Questionnaire, and the dietary record was obtained for 3 days. The sweet taste perception level was determined as sweet taste threshold and sweet taste preference. According to the sweet taste perception level, children were grouped into low, medium, and high. Decayed, missing, and filled teeth index was used for recording the incidence of caries. Results: High sweet threshold and preference groups showed an increased incidence of dental caries compared to the low and medium threshold and preference groups. Conclusion: Sweet taste perception level influenced the dietary habits and intake of sweets. The relationship between the dietary habits and the caries was found to be significant. [ABSTRACT FROM AUTHOR]

Background: The link between sweet taste perception and carbohydrate intake in diabetics who perform regular combined exercises has not been explored. Aims and Objectives: This study aimed at determining the impact of combined exercises on taste perception for sucrose and carbohydrate intake in patients with type 2 diabetes mellitus. Materials and Methods: A clinical trial was conducted with 225 patients with T2DM, aged 35-60 years assigned randomly into three groups; aerobic, combined, and a control group. Outcomes of the aerobic group were not reported. Combined group performed brisk walking 4-5 days/week and resistance exercises 2-3 days/week for 6 months. Supra-threshold intensity ratings, preference for sucrose, and carbohydrate intake assessed at baseline, at 3 and 6 months were measured using "general Labeled Magnitude Scale," "Monell 2-series-forced choice method," and a 3-day diet diary, respectively. Results: Ratings for the highest (combined vs. control: +3.15±0.57 vs. -7.96±0.40 mol/L, P=0.022) and the second-highest sucrose concentrations (combined vs. control: +7.79±4.49 vs. -8.98±0.99 mol/L, P=0.003) in the combined group were significantly higher with significant time × group interaction (2.02M: P=0.002, 0.64M: P=0.003). Preference for sucrose was lower in the combined group (combined vs. control: -0.08±0.14 vs. +0.01±0.03 mol/L, P=0.002), and the time × group interaction was not significant. Carbohydrate intake (combined vs. control: -46.97±21.60 vs. -6.30±9.36 g, P=0.001) and HbA1c level (combined vs. control: -0.66±1.81 vs. +0.33±1.84%, P=0.008) were reduced in the combined group, and taste sensitivity significantly predicted the carbohydrate intake with combined exercises (R2=0.64, P=0.01). Conclusion: Regular combined exercises increase sweet taste sensitivity for higher concentrations of sucrose. Taste sensitivity, not the preference determines the carbohydrate intake in exercising diabetics. [ABSTRACT FROM AUTHOR]

Oral food perception together with lifestyle may affect food preferences and choices, influencing weight gain and obesity development. The present study was designed to evaluate the association of biological (taste sensitivity) and lifestyle variables with children food preferences, assessing whether all these variables contribute to explain BMI percentile. After anthropometric evaluation, 387 children were classified for bitter and sweet taste sensitivities. Socioeconomic/lifestyle aspects and hedonics for 36 foods were collected. Watching TV during meals associate with lower preference for several vegetables, as well as being sweet taste low sensitive, in the case of girls. Moreover, regression analysis showed that bitter taste sensitivity is one of the variables contributing to explain high BMI percentiles. These results present evidences that both biological and socioeconomic and the attention that is given to food (eating in the presence or absence of distractors) are aspects that should be considered in children nutrition to prevent obesity. [ABSTRACT FROM AUTHOR]

α-Glycerophosphocholine (GPC) is a natural source of choline. It reportedly prevents aging-related decline in cognitive function, but the underlying mechanism remains unclear. Although it is understood that aging influences taste sensitivity and energy regulation, whether GPC exerts antiaging effects on such phenomena requires further elucidation. Here, we used old C57BL/6J mice that were fed a GPC-containing diet, to investigate the molecular mechanisms underlying the prevention of a decline in cognitive function associated with aging and examine the beneficial effects of GPC intake on aging-related phenomena, such as taste sensitivity and energy regulation. We confirmed that GPC intake reduces the aging-related decline in the expression levels of genes related to long-term potentiation. Although we did not observe an improvement in aging-related decline in taste sensitivity, there was a notable improvement in the expression levels of β-oxidation-associated genes in old mice. Our results suggest that the prevention of aging-related decline in cognitive function by GPC intake may be associated with the improvement of gene expression levels of long-term potentiation. Furthermore, GPC intake may positively influence lipid metabolism. [ABSTRACT FROM AUTHOR]

Origin of the great inter-individual variability of the fatty taste perception found in obese subjects is challenging. The fact that recent studies suggest interrelations between taste perception and oral microbiota composition, prompt us to explore the putative impact of such a connection in the context of obesity. To check this hypothesis, the oro-sensory perception thresholds of linoleic acid and the composition of oral microbiota surrounding the gustatory circumvallate papillae (CVPs) were analyzed in obese adult men (BMI≥30 kg/m2, n = 42). A specificmicrobial signature (higher diversity, pro-inflammatory bacterial profile, lower methanogenesis activity) discriminated subjects with a degraded fatty taste sensitivity (perception threshold≥0.05% LA= Low-LA tasters, n = 22) from high-LA tasters (n = 20). Collectively, these data substantiate the association between the microbial microenvironment surrounding CVPs and the fatty taste sensitivity and provide a plausible explanation about the variability of the fatty taste sensitivity in obesity. [ABSTRACT FROM AUTHOR]

Background: The rise in nutrition-related morbidity and mortality requires public health intervention programs targeting nutritional behavior. In addition to socio-economical, socio-cultural, psychological determinants, taste is one of the main factors that influence food choices. Differences in taste perception and sensitivity may be explained by genetic variations, therefore the knowledge of the extent to which genetic factors influence the development of individual taste preferences and eating patterns is important for public policy actions addressing nutritional behaviors. Our aim was to review genetic polymorphisms accounting for variability in taste and food preferences to contribute to an improved understanding of development of taste and food preferences. Methods: The electronic databases PubMed, Scopus, and Web of Science were searched using MeSH in PubMed and free text terms for articles published between January 1, 2000 and April 13, 2018. The search strategy was conducted following the PRISMA statement. The quality of the included studies was assessed by the validated Q-Genie tool. Results: Following the PRISMA flowchart, finally 103 articles were included in the review. Among the reviewed studies, 43 were rated to have good quality, 47 were rated to have moderate quality, and 13 were rated to have low quality. The majority of the studies assessed the association of genetic variants with the bitter taste modality, followed by articles analyzing the impact of polymorphisms on sweet and fat preferences. The number of studies investigating the association between umami, salty, and sour taste qualities and genetic polymorphisms was limited. Conclusions: Our findings suggest that a significant association exists between TAS2R38 variants (rs713598, rs1726866, rs10246939) and bitter and sweet taste preference. Other confirmed results are related to rs1761667 (CD36) and fat taste responsiveness. Otherwise further research is essential to confirm results of studies related to genetic variants and individual taste sensitivity. This knowledge may enhance our understanding of the development of individual taste and related food preferences and food choices that will aid the development of tailored public health strategy to reduce nutrition-related disease and morbidity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influence of music on taste sensitivity was examined. • A "high sweetness" soundtrack led to higher sweet taste recognition at near-threshold. • No overall differences were observed in detection and recognition thresholds. • The crossmodal influence of music depends on the parameter of taste function. Previous research has shown that music can influence taste perception. While most studies to date have focused on taste intensity ratings, less is known about the influence of musical stimuli on other parameters of taste function. In this within-subjects experiment (N = 73), we tested the effects of three sound conditions (High Sweetness soundtrack – HS; Low Sweetness soundtrack – LS; and Silence – S) on sweet taste sensitivity, namely, detection and recognition. Each participant tasted nine samples of sucrose solutions (from 0 g/L to 20 g/L) under each of the three sound conditions in counterbalanced order. We assessed the lower concentrations at which participants were able to detect (detection threshold) and correctly identify (recognition threshold) a taste sensation. Additionally, the intensity and hedonic ratings of samples above the recognition threshold (7.20 g/L) were analyzed. Affective variations (valence and arousal) in response to the sound conditions were also assessed. Although music did not lead to significant differences in mean detection and recognition thresholds, a larger proportion of sweet taste recognitions was observed at a near-threshold level (2.59 g/L) in the HS condition. The intensity and hedonic ratings of supra-threshold conditions were unaffected by the music condition. Significant differences in self-reported mood in response to the sound conditions were also observed. The present study suggests that the influence of music on the sweet taste perception of basic solutions may depend on the parameter under consideration. [ABSTRACT FROM AUTHOR]

The sense of taste holds a key integrate role in assessing the flavor of food before swallowing is initiated. If the expectations for taste are not met, palatability and pleasure of the food can decrease. In patients suffering from taste disorders, this may impair appetite and nutritional state. Testing gustatory function can be important for diagnostics and assessment of treatment effects. However, the gustatory tests applied are required to be both sensitive and reliable. In this study, we investigate the re-test validity of popular Taste Strips gustatory test for gustatory screening. Furthermore, we introduce a new sensitive Taste-Drop-Test, which was found to be superior for detecting a more accurate measure of tastant sensitivity. [ABSTRACT FROM AUTHOR]

Introduction: Changes in sweet and bitter taste perception during pregnancy have been reported in a limited number of studies leading, however, to inconclusive results. The current study aimed to investigate possible differences in perceived intensity and liking of sweetness and bitterness between pregnant and nonpregnant women. Methods: Forty-six pregnant and 45 nonpregnant women evaluated taste intensity and liking of five samples of each of four different products: two sweet (cake and apple + berry juice) and two bitter (salad and grapefruit juice). Product samples varied in sweetness and bitterness, respectively. Pregnant women completed also a self-administered questionnaire on changes in sweet and bitter taste perception due to pregnancy. Results: Perceived intensity of sweetness and bitterness was not different between pregnant and nonpregnant women for any of the products. However, the liking of the least sweet apple + berry juice was significantly higher, and the optimal preferred sugar content was significantly lower in pregnant compared to nonpregnant women. With regards to self-report, pregnant women who reported higher sensitivity in sweet or bitter taste did not have significantly different intensity scores from those with no self-reported changes. The apple + berry juice sample highest in sugar content was liked less by pregnant women who reported higher sensitivity toward sweet taste compared to those who reported no change. Conclusion: This study provides evidence that pregnant women may prefer lower sugar content in a juice mixture compared to nonpregnant women. Future research should focus on the possible occurrence of this phenomenon in other beverages and foods, as well. [ABSTRACT FROM AUTHOR]

• Ageing affects taste sensitivity of sweetness. • Ageing does not affect chemesthetic sensation of capsaicin and Sichuan peppercorn. • Taste sensitivity/chemesthetic sensation correlates with facial emotion perception. Food is essential in our daily life and it is important to learn about changes in taste sensitivity and chemesthetic sensation of food with increasing age. The present study aimed to 1) assess young and older adults' taste sensitivity (sweetness, saltiness) and chemesthetic sensation (induced by capsaicin and Sichuan peppercorn), and 2) explore the relationship between taste sensitivity and chemesthetic sensation with emotion perception. Thirty young and twenty-four older healthy Chinese adults took part in this study, in which their taste sensitivity and chemesthetic sensation were measured and recorded. We observed a significant decrease in taste sensitivity (sweetness) but not chemesthetic sensation (capsaicin and Sichuan peppercorn) with ageing, showing that ageing affects taste sensitivity and chemesthetic sensations in different ways. Furthermore, our results have revealed significant correlations between taste sensitivity (sweetness) and chemesthetic sensation (capsaicin) with facial emotion perceptual performance, while no significant correlation was found between any taste sensitivity/chemesthetic sensation with facial identity perceptual performance. Based on the current literature, we assume that the observed associations between taste sensitivity and chemesthetic sensation with emotion perception might be due to their shared neural processing regions or their interconnection with interoception. The findings of the present study not only revealed the age-related changes in taste sensitivity and chemesthetic sensation, but also provided the first behavioural evidence showing the cross-domain associations between emotion perception with taste sensitivity/chemesthetic sensation. [ABSTRACT FROM AUTHOR]

Taste perception plays an undisputed role in food choice, preference, and intake. Recent literature suggests that individual diet and taste sensitivity may have a reciprocal relationship, with evidence highlighting that specific diets can alter taste sensitivities. Commensurate with an increase in the prevalence of plant-based diets is the importance of investigating if following a vegetarian or vegan diet is associated with altered taste sensitivities. In this study, the taste detection thresholds for six compounds (i.e., sweet—sucrose, salty—sodium chloride, sour—citric acid, umami—monosodium glutamate, MSG, bitter—caffeine, and metallic—iron II sulphate heptahydrate) were measured for a total of 80 healthy, New Zealand European females aged 18–45 years old, who were categorised as 22 vegans, 23 vegetarians, and 35 omnivores. Each participant's detection thresholds to these compounds were measured across two sessions, using an ascending Method of Limits with two-alternative-forced-choice presentations. The threshold data were analysed using both multivariate (i.e., principal component analysis) and univariate (i.e., ANCOVA) techniques to assess differences across the three types of diet. Multivariate analysis suggested that the omnivore group had distinct taste sensitivity patterns across the six compounds compared to the vegetarian or vegan group, which were characterised by relatively heightened sensitivity to metallic and lowered sensitivity to sweetness. Furthermore, the vegetarian group was shown to have a significantly lower detection threshold to bitterness (i.e., caffeine) relative to the other two groups (p < 0.001). While future study is required to investigate the cause–effect relationship between individual diet and taste sensitivities, the present study provides a systematic evaluation of taste sensitivities of individuals following distinct diets. This information may be valuable to future gustatory research as well as to food manufacturers. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated the critical role of the sonic hedgehog in the sensory perception of taste. Salivary sonic hedgehog stimulates taste bud stem cells, also acts as a taste bud growth factor, and contributes to the receptors' development and longevity in the taste buds. This study's objective was to investigate the possible relationship between taste sensitivity and sonic hedgehog expression in saliva in normal-weight and pre-obese/obese participants (totally 46 male (47.8%) and female (52.2%) aged 19–44 were recruited). Thresholds for the six tastes (sweet, salty, bitter, sour, umami and fat) were investigated using 3-Alternate Forced Choice Methodology. Saliva was collected with the draining method for sonic hedgehog expression analysis. The results indicated significantly higher thresholds for sweet, bitter and fat in pre-obese /obese adults than normal-weight adults (p <0.05). The sonic hedgehog expression was also lower in pre-obese /obese participants than normal-weight participants (p <0.05). Furthermore, sonic hedgehog expression was higher in hypersensitive participants than hyposensitive participants (p <0.05) only among normal-weight individuals, with no significant difference in sonic hedgehog expression level by taste sensitivity in pre-obese/obese individuals (p >0.05). Sonic hedgehog expression level was negatively correlated with body mass index, sweet, salty, bitter and fat taste threshold. The study results indicated that sonic hedgehog expression level acted on taste sensitivity in normal-weight participants, with greater expression in hypersensitive individuals than hyposensitive individuals. [ABSTRACT FROM AUTHOR]

Chickens have been reported to have a low taste bud count and thus low taste acuity. However, more recent studies indicate that the earlier reported count of chicken taste buds may have been significantly underestimated. To answer the question of whether the taste sensing system in broiler chickens evolved during the breeding selection over the past decades, we compared the taste sensitivity to bitter and taste buds between a meat-type control strain – the 1955 Athens Canadian Random Bred (ACRB), and a modern high-yielding broiler strain – the 2012 Cobb 500. The behavioral tests showed that the ACRB did not avoid bitter taste solutions of quinine hydrochloride (QHCl) at the examined concentrations (0.5, 1, 2, and 4 mM) (P > 0.05), while the Cobb 500 significantly avoided both the 2 mM and 4 mM QHCl solutions (P < 0.01). The labeling of chicken taste buds using the molecular marker Vimentin revealed that Cobb 500 chickens had a slightly higher number (P < 0.1), but lower density of taste bud clusters in the palate (P < 0.01) and the base of the oral cavity (P < 0.05) compared to the ACRB. We also found that a single amino acid change occurred in the bitter taste receptor T2R7. However, the functional analyses using HEK293T cells transiently expressing T2R7 revealed that the functions of T2R7 were comparable between the two strains. Taken together, our results demonstrated that taste sensitivities could be affected by the selection of the broiler chickens. The modern high-yielding broilers, which have massive feed intake and appetite, had a higher sensitivity to bitter taste stimuli than the meat-type chicken strain which was established decades ago. This evolvement of taste sensitivities may be associated with the alterations of an upper level of taste system, rather than the peripheral taste system, including distribution of taste buds and functions of taste receptors. [ABSTRACT FROM AUTHOR]

The temperature range for consuming hot drinks includes temperatures that can damage cells on the tongue. We hypothesized that the consumption of very hot drinks can lead to a decrease in the ability to perceive low concentrations of tastants. We evaluated the ability to perceive low concentrations of five prototypical sapid compounds in 42 women and 40 men aged 18–65. A questionnaire made it possible to collect the usual frequencies (number of unit/day) and consumption temperature levels (medium hot/very hot) for four very common hot drinks (coffee, tea, herbal infusions, and hot chocolate). Our results showed that subjects who consumed very hot drinks (versus medium hot) were less sensitive to sweet (p = 0.020) and salty (p = 0.046) tastes. An aggravating effect of high consumption frequencies was only shown for sweet taste (p = 0.036). Moreover, our data also showed that women were more sensitive than men to sour, bitter, and umami tastes (p values < 0.05), as well as that taste sensitivity decreases with age, especially after 50 years old (all tastes; p values < 0.05). These findings strengthen our knowledge about the influence of sex and age on taste sensitivity, and they provide knowledge on the influence of consumption habits related to hot drinks on taste sensitivity. [ABSTRACT FROM AUTHOR]

As taste perception varies between individuals, it might be important in explaining food consumption behavior. Previous studies have focused on sensitivity to the bitter tastant PROP (6-n-propylthiouracil) concerning eating with little attention paid to other tastants. For the first time, connections between food consumption behavior, pleasantness, and taste sensitivity are studied with five taste modalities. Sensitivity to bitterness, sourness, umami, saltiness, and sweetness as well as an overall taste sensitivity score was determined with intensity evaluation for 199 Finnish adults. Recalled pleasantness and food consumption behavior were enquired with online questionnaires. Consumption concerned intake of vegetables, fruits, and berries; use-frequency of specific foods; and tendency to mask or modify tastes of foods. All modality-specific taste sensitivities were related to some consumption behavior but none to recalled pleasantness. A higher taste sensitivity score indicated avoidance of coffee, lower consumption of pungent foods, and a more frequent habit of adding ketchup to a meal. In conclusion, it may be more informative to study the influence of taste sensitivity on food consumption behavior with taste modalities separately rather than with a general indicator of taste sensitivity. Additionally, these results highlight the importance of studying actual behavior toward food and not just liking. [ABSTRACT FROM AUTHOR]