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To investigate changes in the clinical state of taste disorders between 1990, 2003, and 2019 using the same methodology as that in previous studies.In June 2019, we mailed a questionnaire to 1100 otolaryngologists belonging to the Japan Society of Stomato-pharyngology and investigated three question categories: "Institution", "Number of patients for 3 months", and "Treatment". In addition, we analyzed some results by the class of institution.The rate of patients who complained of taste disorders in the 2019 survey (220/100,000 persons/year) was twice that of the 1990 survey (110/100,000 persons/year), and slightly higher than that of the 2003 survey (192/100,000 persons/year). The rate of female patients was higher than that of male patients in all age groups. The number of patients was correlated with age up to 70 years of age in both genders. The rates of performing taste tests to assess taste function in the 2019 survey were significantly decreased compared with a 2003 survey (electrogustometry: p0.001, filter paper disk method: p0.05 in university). The rate of examination of the serum zinc in the 2019 survey was increased compared with the 1990 survey (p0.001). Zinc oral therapy was used for the treatment of taste disorders in 239/299 (79.9%) patients/institutes for 3 months. In addition, 213 institutions (69.6%) answered that zinc oral therapy was efficacious for taste disorders.The patients who complained of taste disorder have increased. The zinc administration is an appropriate clinical treatment for taste disorders in Japan. To enhance treatment for taste disorders, simpler methods for assessing taste function need to be developed, and the pathological mechanisms of taste disorders other than zinc deficiency need to be clarified.

Background/purpose The tissue absorption laser has been clinically applied to alleviate pain in various areas. It is used for pain relief from temporomandibular disease (TMD) in dentistry. Although the facial and trigeminal nerves are distributed around the temporomandibular joint, the effects of laser irradiation and absorption on the neural functions have not been directly studied. In this study, the Nd:YAG laser was applied to an area where the facial nerve passes with photonic radiation for the treatment of TMD. Materials and methods Ten volunteers including seven males and three females were selected as subjects. Nd:YAG laser was irradiated area included several internal and external standard and associated acupuncture points. The chorda tympani nerve, a branch of facial nerve is distributed to the front two thirds of the tongue and is associated with the sense of taste. We evaluated the effect of laser irradiation and absorption on the taste function by means of an electric taste meter. Results No significant difference was identified in the values between before and after laser irradiation (Wilcoxon signed-rank test). Conclusion It was confirmed that there was no effect on taste function while applying Nd:YAG laser irradiation around the TMD joint.

Patients with odontogenic maxillary sinusitis (OMS) often complain of reduced taste sensitivity as well as nasal obstruction. The filter paper disc method (the conventional gustatory test) was applied to nine patients who underwent sinus surgery to open the inferior nasal meatus and sinus drainage, on three different days: 1day prior to surgery, 7days postoperative, and 28days postoperative. The same test was applied to nine non-clinical participants with or without clipping the nose to interfere with smooth nasal airflow on two different days. Acquired recognition thresholds for the four basic tastes of sweet, salty, sour, and bitter were assessed. In OMS patients, the recognition thresholds for all four tastes were markedly decreased at 7 and 28days postoperative, and subjective taste sensitivity and the elimination of nasal obstruction was improved. The mean recognition threshold for the four tastes correlated negatively with taste satisfaction scores. Clipping the nose in non-clinical participants induced increases in gustatory detection and recognition thresholds. Despite the small sample size and different ages and sexes of the study subjects, it was demonstrated that nasal obstruction in OMS patients and nose clipping in non-clinical subjects reduce taste reactivity, and surgical intervention to promote nasal airflow recovers impaired taste reactivity.

Objective Sensory processing sensitivity (SPS) is a recently proposed construct that refers to a genetically influenced tendency to more strongly and deeply process a variety of information. The aim of the study was to examine whether SPS is associated with an autoimmune disease such as type 1 diabetes (T1D). Research design and methods Participants were 128 adolescents (62 with T1D and 66 comparisons [without autoimmune disease]) and their parents who completed the Highly Sensitive Person Scale (HSPS) questionnaire, assessing SPS level. Results Higher levels of SPS were found in the T1D group than in the comparison group. Furthermore, the frequency of SPS trait was significantly higher in the T1D group than in the comparison group. Conclusions T1D is associated with higher levels of SPS. Hence, there is a need to develop interventions, treatments, and care focused on the needs of T1D patients with SPS temperament, aimed at better treatment adherence. Furthermore, longitudinal research is needed to evaluate whether SPS is a risk factor in the development of T1D.

Zanthoxylum Bungeanum Maxim. is an important seasoning in Chinese cooking, but its bitter taste limits its use by some consumers. In this study, metabolomic analysis based on ultra-high-performance liquid chromatograph-tandem mass spectrometry (UPLC-MS) was used to screen out a vast number of potential non-volatile bitter compounds in Z. bungeanum. Results showed that there were 37 potential bitter compounds in Z. bungeanum, and possible mechanisms underlying its bitter taste were provided. Further, instrumental analyses combined with sensory evaluation were used to identify the key bitter compounds in Gou jiao, a wild variant of Z. Bungeanum with a strong bitter taste. Totally 15 key bitter compounds were identified, most of which have a low bitterness recognition threshold. This study is the first comprehensive identification of non-volatile bitter compounds in Z. bungeanum and provides a basis for future investigations into mitigating bitterness and uncovering how the interaction between different bitter compounds affects taste.

The contribution of ethyl β-d-glucopyranoside (EG) to sensory profile of sea buckthorn (Hippophaë rhamnoides ssp. rhamnoides) was studied. The content of natural existing EG varied between 0.6 and 19.8g/L in the sea buckthorn studied. The taste threshold of pure EG was estimated in water solution as 1.1±1.3g/L, and the suprathreshold aqueous EG solution (5.0g/L) was perceived mainly as bitter. In aqueous sugar-acid mixtures, acids were the major contributors to sourness and astringency, whereas the added EG or sugars showed little impact on the overall sensory profile. EG addition increased the bitterness of sea buckthorn juice. The sensory profiles of the juices were dominated by intense sourness correlating with the malic acid content. The bitterness of the juices correlated with the EG content as well as the ratios EG/acids and EG/sugars. EG content shall be considered when selecting raw materials for industrial processing.

The sense of taste has a key role in nutrient sensing and food intake in animals. A standardized and simple method for determination of tastant-detection thresholds is required for chemosensory research in poultry. We established a 24-h, 2-alternative, forced-choice solution-consumption method and applied it to measure detection thresholds for 3 G-protein-coupled receptor-mediated taste modalities—bitter, sweet, and umami—in chicken. Four parameters were used to determine a significant response: 1) tastant-solution consumption; 2) water (tasteless) consumption; 3) total consumption (tastant and water together); 4) ratio of tastant consumption to total consumption. Our results showed that assignment of the taste solutions and a water control to 2 bottles on random sides of the pen can be reliably used for broiler chicks, even though 47% of the chicks groups demonstrated a consistently preferred side. The detection thresholds for quinine (bitter), L-monosodium glutamate (MSG) (umami), and sucrose (sweet) were determined to be 0.3 mM, 300 mM, and 1 M, respectively. The threshold results for quinine were similar to those for humans and rodents, but the chicks were found to be less sensitive to sucrose and MSG. The described method is useful for studying detection thresholds for tastants that have the potential to affect feed and water consumption in chickens.

Childhood obesity is an increasing problem in the Western world, and is affected by a multitude of interacting factors. Recent evidence suggests that taste perception may differ between obese and normal weight children. Evidence also suggests that perception of sweet and bitter taste is linked to differential food liking of various foods. To date, most studies have focused on single food items or food groups, rather than an overall view of dietary quality, and mainly on bitterness. Thus it is unclear whether taste perception is associated with dietary quality in children. Our objective was to examine the link between taste perception, dietary quality and body weight in Irish school children, in conjunction with other known influences of body weight. Taste perception was measured using the gLMS for bitter, salty and sweet stimuli. Detailed dietary intake data were collected from 525 children aged 7–13 via a 3-day diet history. Energy misreporters were identified and excluded from the dietary analyses, leaving n = 483 children. Dietary quality was assessed using Healthy Eating Index. Salivary DNA was collected and analyzed for variations in the bitter receptor gene TAS2R38. Sex differences were observed whereby intensity perception of sweetness was lower in the overweight/obese males, while no association was observed for sweet taste in the females. Despite the differences in weight status, taste perception was not associated with differences in overall dietary quality, measured via HEI score, in this cohort. Prospective cohort studies in children are necessary to better understand the association between taste intensity, food intake and weight over time.

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.

Objective Data on taste acuity after bariatric surgery are scarce, and taste perception after sleeve gastrectomy, to our knowledge, has never been investigated. The objective of this work was to retrospectively compare taste acuity and sweetness acceptability after Roux-en-Y gastric bypass and sleeve gastrectomy. Methods Subjects with a postoperative period ≥6 mo were recruited (between January and June 2012) for a non-randomized, observational study. Subjects completed sensory evaluation sessions consisting of measurement of detection thresholds for bitterness and sweetness ( N = 21), saltiness and sourness ( N = 19), and sweetness acceptability ( N = 19). Significance was established with Tukey's honest significant difference test and analysis of variance using the SAS GLM procedure. Results Sourness threshold was significantly higher among subjects who had undergone Roux-en-Y gastric bypass ( P = 0.0045). No other differences were obtained for the other thresholds or sweetness acceptability ( P > 0.05). Conclusions Further randomized studies are needed to clarify these differences.

Excessive consumption of fat and sugar is associated with development of diet related diseases. While there are multiple factors involved with overconsumption of sweet and fatty foods, the taste system is responsible for identifying sugars and fats in foods, and in this way inform consumption of potential foods. Published research linking sweet taste and sugar consumption is limited and conflicting with one recent dietary intervention supporting a link between sweet taste and sugar consumption. Fat taste is an emerging area of interest, and recent research illustrates a direct link with high-fat diet increasing fat taste thresholds while low-fat diets decrease fat taste thresholds.

Lettuce is an important leafy vegetable, consumed across the world, containing bitter sesquiterpenoid lactone (SL) compounds that may negatively affect consumer acceptance and consumption. We assessed liking of samples with differing absolute abundance and different ratios of bitter:sweet compounds by analysing recombinant inbred lines (RILs) from an interspecific lettuce mapping population derived from a cross between a wild (L. serriola acc. UC96US23) and domesticated lettuce (L. sativa, cv. Salinas). We found that the ratio of bitter:sweet compounds was a key determinant of bitterness perception and liking. We were able to demonstrate that SLs, such as 8-deoxylactucin-15-sulphate, contribute most strongly to bitterness perception, whilst 15-p-hydroxylphenylacetyllactucin-8-sulphate does not contribute to bitter taste. Glucose was the sugar most highly correlated with sweetness perception. There is a genetic basis to the biochemical composition of lettuce. This information will be useful in lettuce breeding programmes in order to produce leaves with more favourable taste profiles.

An analytical method based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) was developed to characterize volatile sulfur compounds (VSCs) in soy sauce aroma type Baijiu (SSAB) and soy sauce aroma type rounds Baijiu (SSARB). Using this method, 19 VSCs were identified and quantified. The aroma contribution of VSCs was evaluated by odor activity values (OAVs) and perceptive interactions. Seven VSCs had concentrations higher than their corresponding odor thresholds. In particular, the presence of methyl furfuryl disulfide (OAV: 7–11) and 2-methyl-3-(methyldisulfanyl)furan (OAV: 9–18) with relatively high OAVs in Baijiu was reported for the first time, and they could be the important aroma contributors to SSAB. Moreover, sensory analysis revealed that dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide enhanced the perception of fruity aromas in the matrices studied. Partial least-squares discriminant analysis (PLS-DA) analysis indicated that the VSCs could be used to distinguish SSARB.

Bitterness and astringency (dryness) are characteristic sensory attributes of flavanol-rich foods. The degree of polymerization (DP) of flavanols influences their bitter and astringent sensations. Smaller DP compounds can enter the papillae on the tongue, eliciting a bitter response. Larger DP compounds are sterically inhibited from entering papillae and instead interact with oral proteins, cause precipitation, and elicit astringent sensations. Previous research has indicated that bitterness preference is related to health status, density of fungiform papillae on the tongue, and sensitivity to bitter compounds such as 6-n-propyl-thiouracil (PROP). The purpose of this study was to examine trends in liking, bitterness intensity, and astringency intensity of wine-like products with flavanols of different DP using a consumer sensory panel. Participants (n = 102) were segmented by phenotypes: body fat percentage (BF%), body mass index (BMI), PROP sensitivity, and stated bitter food preference. Differences in wine liking, perceived bitterness intensity, and astringency intensity were observed between three model wine samples of varying flavanol mean degrees of polymerization (mDP, i.e. the average size (polymer length) of flavanol compounds in a mixture). Specifically, with increased mDP, overall liking and bitterness liking decreased, with concurrent increased perception of bitterness and astringency intensity. Greater differences between phenotypes were observed when participants were segmented by BF% and BMI classification, than when segmented by PROP sensitivity classification. Reduced ability to detect differences in bitterness and astringency were noted in participants of higher weight status. Overall, these data suggest that weight status in adults is a greater predictor of liking of flavanol-rich foods than bitterness sensitivity (as determined by PROP classification), and that reduced perception of bitterness and astringency associated with weight gain may impact selection and preference for these foods.

Maternal high-fat (HF) diet affects offspring's metabolic phenotype. Sweet taste is an important factor in promoting appetite. In order to determine the effects of maternal HF diet throughout gestation and lactation on taste sensitivity to sucrose in rat offspring, we measured conditioned aversion threshold for sucrose by conditioned taste aversion (CTA) associated with two-bottle choice tests, and measured mRNA expression of sweet taste receptors in taste buds. In male offspring, conditioned aversion threshold for sucrose lay between 0.007 M and 0.009 M in control group, while in those with HF dams, the threshold significantly increased to be between 0.011 M and 0.02 M. In female offspring, conditioned aversion threshold for sucrose lay between 0.003 M and 0.005 M in control group, whereas maternal HF diet increased it to be between 0.007 M and 0.009 M. Maternal HF diet increased T1R2 and T1R3 mRNA expression in taste buds of male offspring, while only increased T1R2 mRNA expression in female offspring. Both male and female offspring with HF dams had lower α-gustducin mRNA expression, whereas only male offspring with HF dams had lower OB-Rb mRNA expression in taste buds. Our data suggest that maternal HF diet decreased taste sensitivity to sucrose in both male and female offspring, which may be partly due to altered expression of sweet taste receptors and related downstream pathways in taste buds.

This study aimed to assess the correspondence between the evolution of phenolic compounds and the development of appearance and mouthfeel in Cabernet Sauvignon (Vitis vinifera L. cv.) dry red wines during 18-month aging in bottle. The wines were sealed with six types of bottle stoppers. The results showed that phenolic compounds presented four evolution patterns along with wine aging in bottle, mainly depending on their chemical nature. Most of the anthocyanins had significant differences in concentration amongst the wines sealed with the six bottle stoppers at the 18-month point. Analysis of partial least squares (PLS) revealed that wine appearance quality was positively correlated with the levels of malvidin-3-O-(6-O-acetyl)-glucoside-4-vinylguaiacol, gallocatechin and dihydrokaempferol-3-O-rhamnos, while the development of mouthfeel properties was positively associated with the evolutions of malvidin-3-O-glucoside-ethyl-(epi)catechin, peonidin-3-O-(6-O-acetyl)-glucoside, malvidin-3-O-(6-O-coumaryl)-glucoside-pyruvic acid and peonidin-3-O-glucoside-4-vinylphenol. No obvious association was observed between the development of wine sensory characteristics and the evolution of dissolved oxygen in wine.

Oxytocin (OXT) suppresses food intake and lack of OXT leads to overconsumption of sucrose. Taste bud cells were recently discovered to express OXT-receptor. In the present study we tested whether administering OXT to wild-type mice affects their licking behavior for tastants in a paradigm designed to be sensitive to taste perception. We injected C57BL/6J mice intraperitoneally (i.p.) with 10 mg/kg OXT and assayed their brief-access lick responses, motivated by water deprivation, to NaCl (300 mM), citric acid (20 mM), quinine (0.3 mM), saccharin (10 mM), and a mix of MSG and IMP (100 mM and 0.5 mM respectively). OXT had no effect on licking for NaCl, citric acid, or quinine. A possible effect of OXT on saccharin and MSG + IMP was difficult to interpret due to unexpectedly low lick rates to water (the vehicle for all taste solutions), likely caused by the use of a high OXT dose that suppressed licking and other behaviors. A subsequent experiment focused on another preferred tastant, sucrose, and employed a much lower OXT dose (0.1 mg/kg). This modification, based on our measurements of plasma OXT following i.p. injection, permitted us to elevate plasma [OXT] sufficiently to preferentially activate taste bud cells. OXT at this low dose significantly reduced licking responses to 0.3 M sucrose, and overall shifted the sucrose concentration — behavioral response curves rightward (mean EC50saline = 0.362 M vs. EC50OXT = 0.466 M). Males did not differ from females under any condition in this study. We propose that circulating oxytocin is another factor that modulates taste-based behavior.

Past research on the relationship between taste sensitivity and fruit and vegetable (FV) intake in children has focused on sensitivity to bitter taste. The effects of sensitivity to sweet taste on intake of FV have never been investigated. Furthermore, the effects of children's weight on intake of FV are inconclusive. This study measured the effects of Sucrose Detection Threshold (SDT) and weight status on intake of FV in children. The participants of this study were 99 children between 5–9 years old. Parents reported their own and their children's 24 hour intake of FV and completed a measure of children's sensory sensitivity. Children completed the triangle test with suprathreshold concentrations of sucrose ranging between 0.2% and 1.6%, in 0.2% increments. Two MANCOVAs showed that, controlling for parental intake and children's sensory sensitivity, there was a main effect of SDT on intake of fruit (p

SummaryAn organism’s behavioral decisions often depend upon the relative strength of appetitive and aversive sensory stimuli, the relative sensitivity to which can be modified by internal states like hunger. However, whether sensitivity to such opposing influences is modulated in a unidirectional or bidirectional manner is not clear. Starved flies exhibit increased sugar and decreased bitter sensitivity. It is widely believed that only sugar sensitivity changes, and that this masks bitter sensitivity. Here we use gene- and circuit-level manipulations to show that sweet and bitter sensitivity are independently and reciprocally regulated by starvation in Drosophila. We identify orthogonal neuromodulatory cascades that oppositely control peripheral taste sensitivity for each modality. Moreover, these pathways are recruited at increasing hunger levels, such that low-risk changes (higher sugar sensitivity) precede high-risk changes (lower sensitivity to potentially toxic resources). In this way, state-intensity-dependent, reciprocal regulation of appetitive and aversive peripheral gustatory sensitivity permits flexible, adaptive feeding decisions.

People differ in both their sensitivity for bitter taste and their tendency to respond to emotional stimuli with approach or avoidance. The present study investigated the relationship between these sensitivities in an affective picture paradigm with startle responding. Emotion-induced changes in arousal and attention (pupil modulation), priming of approach and avoidance behavior (startle reflex modulation), and subjective evaluations (ratings) were examined. Sensitivity for bitter taste was assessed with the 6-n-propylthiouracil (PROP)-sensitivity test, which discriminated individuals who were highly sensitive to PROP compared to NaCl (PROP-tasters) and those who were less sensitive or insensitive to the bitter taste of PROP. Neither pupil responses nor picture ratings differed between the two taster groups. The startle eye blink response, however, significantly differentiated PROP-tasters from PROP-insensitive subjects. Facilitated response priming to emotional stimuli emerged in PROP-tasters but not in PROP-insensitive subjects at shorter startle lead intervals (200-300ms between picture onset and startle stimulus onset). At longer lead intervals (3-4.5s between picture onset and startle stimulus onset) affective startle modulation did not differ between the two taster groups. This implies that in PROP-sensitive individuals action tendencies of approach or avoidance are primed immediately after emotional stimulus exposure. These results suggest a link between PROP taste perception and biologically relevant patterns of emotional responding. Direct perception-action links have been proposed to underlie motivational priming effects of the startle reflex, and the present results extend these to the sensory dimension of taste.

The gustatory responsiveness of four adult spider monkeys to the 20 proteinogenic amino acids was assessed in two-bottle preference tests of brief duration (1 min). We found that Ateles geoffroyi responded with significant preferences for seven amino acids (glycine, l-proline, l-alanine, l-serine, l-glutamic acid, l-aspartic acid, and l-lysine) when presented at a concentration of 100 mM and/or 200 mM and tested against water. At the same concentrations, the animals significantly rejected five amino acids (l-tryptophan, l-tyrosine, l-valine, l-cysteine, and l-isoleucine) and were indifferent to the remaining tastants. Further, the results show that the spider monkeys discriminated concentrations as low as 0.2 mM l-lysine, 2 mM l-glutamic acid, 10 mM l-proline, 20 mM l-valine, 40 mM glycine, l-serine, and l-aspartic acid, and 80 mM l-alanine from the alternative stimulus, with individual animals even scoring lower threshold values. A comparison between the taste qualities of the proteinogenic amino acids as described by humans and the preferences and aversions observed in the spider monkeys suggests a fairly high degree of agreement in the taste quality perception of these tastants between the two species. A comparison between the taste preference thresholds obtained with the spider monkeys and taste detection thresholds reported in human subjects suggests that the taste sensitivity of A. geoffroyi for the amino acids tested here might match that of Homo sapiens. The results support the assumption that the taste responses of spider monkeys to proteinogenic amino acids might reflect an evolutionary adaptation to their frugivorous and thus protein-poor diet.

Vision influences taste. It is known that color plays an important role in flavor perception. However, the effect of other features of visual information such as shapes and semantic familiarity of words on the taste perception, particularly on taste sensitivity, is not clear yet. Here we study whether the sweet taste sensitivity of the subjects is affected by such visual inputs. By displaying basic geometric patterns or words with different degrees of semantic familiarity as visual inputs, the subjects rate the hedonic and semantic familiar scores, and taste a series of sucrose solutions, and their sweet sensitivities are accordingly analyzed. Our results show (1) shapes with curvature like circle and ellipse, with higher hedonic scores, increase the sweet sensitivity, whereas angular shapes like square, rectangle, triangle and pentagram do not affect sweet sensitivity; (2) semantic familiar words, with higher hedonic ratings as well, increase sweet sensitivity, whereas unfamiliar words do not affect or even reduce sweet sensitivities.

A complete understanding of bitterness perception requires identification of cognate bitter substances for all human bitter taste receptors (TAS2Rs). However, so far, no agonists have been identified for five of the 25 TAS2Rs, i.e., TAS2R41, TAS2R42, TAS2R45, TAS2R48 and TAS2R60. Due to substantial genetic variability several haplotypes exist for most bitter receptor genes. For some of the deorphaned TAS2Rs, haplotypes have been identified coding for proteins with severely impaired or even lacking receptor function, proposing that the use of non-functional receptor variants in previous investigations accounted for the failure to identify cognate bitter agonists for the orphan TAS2Rs. In the present report we reasoned that at least one out of the major genetically encoded TAS2R variants is functional. Therefore, we expressed the major haplotypes of the five orphan TAS2Rs in our functional assay and challenged the cells with 106 bitter compounds. Chloramphenicol was identified as agonist for TAS2R41. Further studies revealed that TAS2R41 is a 'specialist' receptor highly selective for this antibiotic. None of the other TAS2R variants responded to any of the 106 compounds, suggesting that the use of non-functional variants does not explain the failure to identify cognate agonists for the other four TAS2Rs. Probably, these TAS2Rs are highly selective for bitter substances absent in our compound library.

The molecular mechanisms of sodium taste transduction are not completely understood, especially those responsible for the portion of NaCl's taste in rodents that is not blocked by amiloride. As a prelude to conducting genetic analyses of peripheral NaCl taste responsiveness, we performed multiunit electrophysiological recordings from the chorda tympani (CT) nerve in C57BL/6J (B6) and A/J mice. Mice were anesthetized, the CT was accessed, and taste solutions were flowed over the tongue in order to measure the integrated whole-nerve response. NaCl was delivered before and during application of 100 μM amiloride. Pre-amiloride responses were significantly larger in A/J than B6 mice for 1–8 mM NaCl. Responses to NaCl were suppressed significantly by amiloride in both strains and to similar degrees. However, the size of the amiloride-insensitive NaCl response component was significantly larger in A/J mice than in B6 mice for NaCl at 2–16 mM. These data help to explain the prior observation that the strains differ in behavioral taste thresholds for NaCl. Specifically, the results suggest that perception of sodium-specific taste by mice depends on the ratio of amiloride-sensitive and -insensitive responses in the CT, rather than on the absolute level of the whole-nerve response to NaCl or on the size of the amiloride-sensitive component alone. Because the B6 and A/J mice differed in the size of their amiloride-insensitive components, they may prove useful in future genetic work designed to characterize the underlying transduction mechanisms.

Evidence suggests a link between an individual’s salt taste sensitivity and their acceptance and consumption of salty foods. Individuals who consume a high salt diet appear to require a higher concentration of salt to obtain the same taste sensation as those less sensitive to salt. Therefore, in the present study the influence of salt taste threshold on the acceptability and subsequent purchase intent of a number of reformulated reduced salt vegetable soups was examined. Detection and recognition thresholds of salt taste in 60 consumers were measured via ingestion of a series of salt water solutions. The same 60 consumers then evaluated five vegetable soup samples, four of which had reduced salt concentrations (∼0.45%) and one which had regular commercial salt concentrations (0.93%). A nine point hedonic acceptability scale and a five point purchase intent scale were used to rate the samples. Individual detection and recognition thresholds had no significant effect ( p > 0.05) on acceptability or purchase intent scores for any of the vegetable soup samples. However, salt detection thresholds were found to differ significantly ( p n = 26) and female ( n = 34) consumers. Significant correlations were observed between vegetable soup acceptability scores and purchase intent ratings of the same samples ( r = 0.814; p = 0.000). These results highlight the importance of both taste characteristics and the inclusion of the consumer in the reformulation process of reduced salt foods. The study also shows that salt reductions of up to 48% can be achieved in commercial vegetable soup samples without affecting consumers liking for the meal.

The present study investigated taste preferences in a sample of 1705 children aged 6 to 9 years from survey centres in Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary, and Spain and aimed to identify factors correlated with taste preference. Children’s preferences for varying levels of sucrose (sweet) in apple juice and fat, sodium chloride (salt) and monosodium glutamate (umami) in crackers were assessed using paired-comparison tests. Socio-demographics (age, sex, parental education), early feeding practises (breastfeeding, introduction of fruits), parenting behaviour (TV viewing, using food as a reward) and taste threshold sensitivity for sucrose (sweet), sodium chloride (salt), caffeine (bitter) and monosodium glutamate (umami) were investigated as possible correlates of taste preferences. Parents reported on socio-demographics, early feeding and parenting behaviour. Taste thresholds were determined via a paired-comparison staircase method. Country of residence was the strongest factor related to preferences for all four tastes. Taste preferences also differed by age. Preference for sugar and salt increased between 6 and 9 years of age while preference for monosodium glutamate decreased. The age differences remained significant even after adjustment for sex, country of residence, parental education and early feeding habits. Sex, parental education, early feeding habits, TV viewing, using food as a reward and taste thresholds were not consistently related to taste preferences among the survey centres. In summary, the results highlight the importance of culture and age in taste preferences in children younger than 10 years of age.

Objective A manipulation of chorda tympani nerve (CTN) is frequently necessary during the surgical therapy of stapedial ankylosis. The aim of this study was to re-assess the taste function before and after stapes surgery in patients with unilateral stapes ankylosis. Methods Eighteen patients (14 female and 4 male) with unilateral stapedial ankylosis were included. Taste and olfactory function were measured preoperatively, 3 days and 3 months after surgery by questionnaire, chemical taste test, electrogustometry, and Sniffin'Sticks. The patients who reported deterioration in taste and revealed pathological taste test results were re-investigated 8–12 months after surgery. Postoperatively 11 patients were treated intravenously for 3 days for inner ear protection with 1 g of cortisone. The gustatory and olfactory results were compared with age and sex specific normative data. Results A significant transient decrease of gustatory measurement values was found on the ipsilateral two thirds of the anterior tongue. 12 out of 17 patients whose CTN was slightly manipulated during stapes surgery reported tongue sensations, such as numbness or gustatory blindness of the ipsilateral tongue side. The measures of chemical taste test significantly decrease in lateralized taste test on the ipsilateral side and in whole mouth testing. There was no significant increase of the EGM measures at the ipslateral tongue. In 11 of 12 patients with symptoms, complaints recovered within one year after surgery completely. The factor “cortisone” did not have a significant effect on the taste test results after surgery. Conclusion In conclusion, even after minor CTN manipulation the rate of postoperative taste disorders or tongue symptoms after stapes surgery is high. The symptoms appear to be transient. Therefore CTN should be preserved in stapes surgery after mild trauma of the CTN. Transient taste alteration should be mentioned prior to stapes surgery.

The objective of this study was to determine whether humans could detect long-chain fatty acids when these lipid molecules are delivered to the oral cavity by edible taste strips. For suprathreshold studies, up to 1.7 umoles of stearic acid or linoleic acid were incorporated into 0.03 mm thick, one-inch square taste strips. Normalized taste intensity values for stearic acid were in the barely detectable range, with values equal to, or slightly above control strips. One-third of test subjects described the taste quality as oily/fatty/waxy. Approximately 75% of test subjects could detect the presence of linoleic acid when this fatty acid was incorporated into dissolvable strips. Normalized taste intensity values for linoleic acid were in the weak to moderate range. The most commonly reported taste quality responses for linoleic acid were fatty/oily/waxy, or bitter. When nasal airflow was obstructed, the perceived taste intensity of linoleic acid decreased by approximately 40 percent. Taste intensity values and taste quality responses for linoleic acid were then compared among tasters and non-tasters of 6-n-propylthiouracil (PROP). Individuals who could detect the bitter taste of PROP reported higher taste intensity values for linoleic acid compared with PROP non-tasters. However, taste quality responses for linoleic acid were similar among both PROP tasters and PROP non-tasters. These results indicate that humans can detect long-chain fatty acids by both olfactory and non-olfactory pathways when these hydrophobic molecules are delivered to the oral cavity by means of edible taste strips. These studies further show that genetic variation in taste sensitivity to PROP affects chemosensory responses to the cis-unsaturated fatty acid linoleic acid in the oral cavity.

Bitterness in wine, especially in white wine, is a complex and sensitive topic as it is a persistent sensation with negative connotation by consumers. However, the molecular base for bitter taste in white wines is still widely unknown yet. At the same time studies dealing with bitterness have to cope with the temporal dynamics of bitter perception. The most common method to describe bitter taste is the static measurement amongst other attributes during a descriptive analysis. A less frequently applied method, the time-intensity analysis, evaluates the temporal gustatory changes focusing on bitterness alone. The most recently developed multidimensional approach of the temporal dominance of sensations method reveals the temporal dominance of bitter taste in relation to other attributes. In order to compare the results comprised with these different sensory methodologies, 13 commercial white wines were evaluated by the same panel. To facilitate a statistical comparison, parameters were extracted from bitterness curves obtained from time-intensity and temporal dominance of sensations analysis and were compared to bitter intensity as well as bitter persistency based on descriptive analysis. Analysis of variance differentiated significantly the wines regarding all measured bitterness parameters obtained from the three sensory techniques. Comparing the information of all sensory parameters by multiple factor analysis and correlation, each technique provided additional valuable information regarding the complex bitter perception in white wine.

There are no credible data to support the notion that individual taste qualities have dedicated pathways leading from the tongue to the end of the pathway in the brain. Moreover, the insular cortex is activated not only by taste but also by non-taste information from oral stimuli. These responses are invariably excitatory, and it is difficult to determine whether they are sensory, motor, or proprioceptive in origin. Furthermore, umami is a more unfamiliar and complex taste than other basic tastes. Considering these issues, it may be effective to minimize somatosensory stimuli, oral movement, and psychological effects in a neuroimaging study to elicit cerebral activity by pure umami on the human tongue. For this purpose, we developed an original taste delivery system for functional magnetic resonance imaging (fMRI) studies for umami. Then, we compared the results produced by two authorized models, namely, the block design model and event-related design model, to decide the appropriate model for detecting activation by umami. Activation by the umami taste was well localized in the insular cortex using our new system and block design model analysis. The peaks of the activated areas in the middle insular cortex by umami were very close to another prototypical taste quality (salty). Although we have to carefully interpret the perceiving intensities and brain activations by taste from different sessions, this study design might be effective for detecting the accession area in the cortex of pure umami taste on the tongue.

These studies examined the differences in sweet taste perception and implicit attitude toward sweet between normal-weight and overweight/obese adults; and tested the effects of soft drink consumption on sweet taste, explicit preference and implicit attitude toward sweet in normal-weight subjects. In study 1, normal-weight (n = 22) and overweight/obese (n = 11) adults were assessed for sweet taste intensity and pleasantness. Implicit attitude toward sweet was assessed by implicit association test (IAT). In study 2, normal-weight, lightly active adults (n = 12) underwent one month soft drink supplementation (≈760 ml/day). This increased their daily carbohydrate intake by 2.1 ± 0.2g/kg body weight. Sweet taste perception, explicit preference and implicit attitudes to sweet were assessed. In both studies salty taste was also assessed as a contrasting perception. Overweight/obese subjects perceived sweet and salty tastes as less intense (-23% and -19%, respectively) and reported higher IAT scores for sweet than normal-weight controls (2.1-fold). The supplementation changed sweet intensity/pleasantness ratings and it increased explicit preference (2.3-fold) for sweet in a subgroup of initial sucrose-dislikers. In conclusion, overweight/obese individuals are more implicitly attracted to sweet. One month of soft drink supplementation changed sweet taste perception of normal-weight subjects.

Objective/hypothesis A relationship between acute otitis media and elevated body mass index has recently been reported. Intriguingly, it was postulated that this relationship may result from altered chorda tympani nerve function impacting taste sensation and eating habits. We sought to test this directly by measuring chorda tympani nerve function in children with and without a previous history of acute otitis media and to determine the relationship to body mass index. Study design Retrospective cohort study. Methods Institutional research ethics board approval was obtained. Study participants included 142 children (5–18 years of age) who were recruited from an otolaryngology outpatient clinic at a tertiary academic pediatric hospital between May and August 2009. Children were excluded if they were not able to communicate effectively, younger than age 5, or had developmental disabilities. Body mass index was calculated and the history of previous otologic disease carefully elicited from the caregivers. Electrogustometric threshold, a validated measure of chorda tympani function, was obtained bilaterally in each child. Children were divided into cohorts based on the number of acute otitis media episodes, and electrogustometry thresholds were compared between cohorts. Results Electrogustometric thresholds were successfully obtained in all children. There was no significant relationship between chorda tympani nerve function and history of acute otitis media. Similarly, there was no significant association between the history of otitis media and body mass index. Conclusion This study did not demonstrate any effect of previous acute otitis media history on chorda tympani nerve function. Furthermore, it did not demonstrate a relationship between acute otitis media and elevated body mass index. This is counter-evidence to the previous hypothesis that increasing acute otitis media is responsible for increasing childhood obesity through alteration in chorda tympani nerve function.

Most of what is known about taste interactions has come from studies of binary mixtures. The primary goal of this study was to determine whether asymmetries in suppression between stimuli in binary mixtures predict the perception of tastes in more complex mixtures (e.g., ternary and quaternary mixtures). Also of interest was the longstanding question of whether overall taste intensity derives from the sum of the tastes perceived within a mixture (perceptual additivity) or from the sum of the perceived intensities of the individual stimuli (stimulus additivity). Using the general labeled magnitude scale together with a sip-and-spit procedure, we asked subjects to rate overall taste intensity and the sweetness, sourness, saltiness and bitterness of approximately equi-intense sucrose, NaCl, citric acid and QSO(4) stimuli presented alone and in all possible binary, ternary and quaternary mixtures. The results showed a consistent pattern of mixture suppression in which sucrose sweetness tended to be both the least suppressed quality and the strongest suppressor of other tastes. The overall intensity of mixtures was found to be predicted best by perceptual additivity. A second experiment that was designed to rule out potentially confounding effects of the order of taste ratings and the temperature of taste solutions replicated the main findings of the first experiment. Overall, the results imply that mixture suppression favors perception of sweet carbohydrates in foods at the expense of other potentially harmful ingredients, such as high levels of sodium (saltiness) and potential poisons or spoilage (bitterness and sourness).

Children with uncomplicated malaria are generally treated with oral medication, except those unable to take oral drugs. Even though quinine has shown to be effective in treatment of African children with uncomplicated malaria its high bitterness limited the paediatric use. This study aimed to develop taste-masked quinine tablets suitable for children and offering dosing flexibility to adjust the quinine dose in function of body weight. Methods Insoluble quinine pamoate was used to formulate fast-disintegrating tablets, using a specific tablet design (rectangular tablet which can be divided into 8 subunits) to allow dosing flexibility. The physical properties of tablets were evaluated in vitro, as well as the quinine bioavailability in healthy adults ( n = 18) and the efficacy for treatment of children with uncomplicated Plasmodium falciparum malaria ( n = 56) using a 7-day regimen of 8 mg quinine/kg. Results Quinine pamoate tablets complied with the pharmacopoeial requirements for mass uniformity, friability, content uniformity, breakability, disintegration and dissolution. The quinine pharmacokinetic parameters after single administration of a quinine pamoate tablet were similar to a commercially available quinine sulfate tablet. The fast decline in parasitemia (28.6%/24 h), the reduction rate of fever (all children were apyretic after 72 h) and the steady state quinine plasma concentration (5.7–15.8 μg/ml) proved the efficacy of the quinine pamoate tablets against P. falciparum . Conclusion Fast-dispersible and taste-masked quinine pamoate tablets improved dosing accuracy, allowed easy administration and resulted in a high efficacy during the treatment of children with uncomplicated malaria.

When aqueous NaCl solutions are tasted at continuously alternating concentrations, overall saltiness ratings exceed those observed for solutions with the same averaged, but non-alternating concentrations. In the present study, this effect is replicated for alternating aqueous sucrose solutions. We tested the hypothesis that enhancement depends on the conscious perception of intensity contrasts. High sucrose pulses were continuously alternated with low sucrose intervals at pulsation periods between 1.5s and 20s. Tastant pulsation enhanced sweetness intensity and this enhancement varied between 8 and 14%, peaking for periods from 4.5s to 6s (Study 1). This range coincided with the average pulsation period at which perceived taste pulses blended into a continuous stimulus, i.e. the taste fusion period (TFP). When comparing intensity ratings of sucrose solutions at individualized pulse periods of 0.5, 1.0 and 2.0 times TFP to ratings for continuous sucrose solutions of the same net concentration, pulsatile stimuli were perceived as significantly sweeter (p0.01; Study 2). However, sweetness intensity enhancement was the same for all pulsation periods. It was shown that sweet taste enhancement peaks at pulsation periods ranging from 0.5 to 2.0 TFP and that the level of conscious pulsation perception does not affect taste enhancement. The results suggest the introduction of enhancement effects at pre-conscious stages of gustatory processing. Further mechanisms that may account for such pre-conscious effects are discussed.

Objective The aim of the present study was to evaluate the effects of zinc supplementation on hypogeusia, serum zinc concentration and the ratio of apo/holo-activities of angiotensin converting enzyme (ACE ratio) in patients with taste impairment. ACE ratio was used as an index of zinc nutritional status. Methods Forty patients complaining of taste impairment were divided into two groups: zinc deficiency taste impairment ( n = 12) and idiopathic taste impairment ( n = 28). Patients with zincemia values of less than 63 μg/dl with no history of other disorder or medication known to cause dysgeusia were diagnosed as zinc deficiency group, while those with the same condition and values more than 64 μg/dl were considered to belong to the idiopathic group. Patients orally received 150 mg of polaprezinc containing 33 mg of zinc every day. Subjective symptom was scored according to visual analogue scale (VAS). Results Zinc supplementation improved hypogeusia in both idiopathic and zinc deficiency groups. The mean improvements of VAS were 3.02 ± 3.03 in the idiopathic group and 3.13 ± 2.53 in the zinc deficiency group. Thus, there were no significant differences in idiopathic and zinc deficiency groups. Significant correlations were found between the improvement of VAS score and the ACE ratio after zinc supplementation in both idiopathic and zinc deficiency groups. On the contrary, significant correlations were not found between the improvement of VAS score and the zinc concentration in the serum after zinc supplementation in both groups. Conclusion The results of the present study indicated that zinc deficiency is a predominant factor underlying taste impairment and ACE ratio may be a predictor of the prognosis for taste impairment after zinc supplementation, in addition to a more sensitive indicator of zinc nutrition than zinc concentration in the serum.

The aim of the study was to investigate the influence of water quality on taste sensitivity for basic tastes and metallic sensation. To familiarize subjects with sensory analysis, they were asked to recognize tastes, distinguish between different concentrations of basic tastes, and realize their own taste sensitivity. The International Standard ISO 3972 describes a set of tests to measure taste sensitivity. A “neutral, tasteless, still and odourless water, preferably of known hardness” is recommended for preparing the dilutions and for rinsing the mouth. The standard also recommends a series of dilutions for acid (citric acid), bitter (caffeine), salty (sodium chloride), sweet (sucrose), umami (monosodium glutamate) and metallic (iron(II)sulfate). The question arises if water quality affects taste sensitivity. Methods Twenty-three female subjects (mean age: 22), who were recruited at the University of Applied Sciences Hamburg, Faculty of Life Sciences, were tested. Deionized water, spring water and tap water were used for taste dilutions. In each experiment, subjects were initially familiarized with the basic tastes. Results In comparison to taste thresholds in spring water, the recognition thresholds are higher using tap water, and lower using deionized water. When using deionized water, sour was detected by all subjects at the lowest concentrations. Iron(II)sulfate could best be matched to metallic sensation in deionized water. Results indicate that taste sensitivity is influenced by water quality.

International audience; Unpleasant taste and especially chlorine flavor is one of the most common reasons advocated for choosing tap water alternatives as drinking water. As a consequence, the putative link between sensitivity to chlorine flavor and tap water consumption is an issue in drinking water habits studies. In the present study, we set out to examine such a link following a strategy in which we measured chlorine flavor perception at threshold and supra-threshold level for two groups of participants selected on their drinking water consumption habits. The first group included exclusive tap water consumers and the second group included exclusive bottled water consumers. In a first experiment, we used the constant stimuli procedure to evaluate the chlorine flavor detection threshold of a group of 20 tap water consumers and a group of 20 non-consumers. In a second experiment, a group of 18 tap water consumers and a group of 17 non-consumers evaluated supra-threshold flavor intensity, liking and acceptability for eight chlorinated solutions (0–10 mg/L Cl2). The results revealed no significant difference in chlorine flavor detection threshold and supra-threshold sensitivity between tap water consumers and non-consumers. Nevertheless, tap water consumers showed a higher liking score for chlorinated solutions and were found to be more inclined to accept these solutions as drinking water. Taken together these findings suggested that consumers may disparage chlorine flavor in drinking water on the basis of their tap water cognitive representation.

Efforts to reduce plate-waste (PW) are limited to those by a dietitian who serves the entire school rather than a better characterization of individuals who are served. We tested the hypothesis that children reporting habitual PW would have different physical or dietary characteristics compared with children without PW. Participants were 407 children aged 6 to 9 years in elementary schools in Kyeonggi, Korea. Information on eating behavior and food preference was collected using a questionnaire administered by parents. Among them, 91 students participated further in anthropometry, step counting, taste acuity tests, and nutrition intake from school lunches. Participants were divided into tertiles according to total frequency of leaving PW from each meal on a typical day: no PW, moderate PW, and habitual PW. Children with habitual PW showed several undesirable characteristics: consuming less of various vegetables, eating only what they like, poor table manners, and frequent consumption of street foods and cookies/beverages/fast foods. Whereas height, weight, and obesity index as well as taste acuity and daily steps in the habitual PW group were not significantly different, intakes of potassium, niacin, and folate were significantly lower compared with the other groups. Therefore, habitual PW did not seem to result from having a lower energy requirement or different taste acuity, or result in observed slowed growth, but it could place children at a risk for insufficient nutritional intake, consequently impairing growth and general health. The results emphasize the parental role in shaping children's diet and provide information for developing strategies to reduce PW of individual children.

Background: The TAS1R1 and TAS1R3 G protein–coupled receptors are believed to function in combination as a heteromeric glutamate taste receptor in humans. Objective: We hypothesized that variations in the umami perception of glutamate would correlate with variations in the sequence of these 2 genes, if they contribute directly to umami taste. Design: In this study, we first characterized the general sensitivity to glutamate in a sample population of 242 subjects. We performed these experiments by sequencing the coding regions of the genomic TAS1R1 and TAS1R3 genes in a separate set of 87 individuals who were tested repeatedly with monopotassium glutamate (MPG) solutions. Last, we tested the role of the candidate umami taste receptor hTAS1R1-hTAS1R3 in a functional expression assay. Results: A subset of subjects displays extremes of sensitivity, and a battery of different psychophysical tests validated this observation. Statistical analysis showed that the rare T allele of single nucleotide polymorphism (SNP) R757C in TAS1R3 led to a doubling of umami ratings of 25 mmol MPG/L. Other suggestive SNPs of TAS1R3 include the A allele of A5T and the A allele of R247H, which both resulted in an approximate doubling of umami ratings of 200 mmol MPG/L. We confirmed the potential role of the human TAS1R1-TAS1R3 heteromer receptor in umami taste by recording responses, specifically to l-glutamate and inosine 5′-monophosphate (IMP) mixtures in a heterologous expression assay in HEK (human embryonic kidney) T cells. Conclusions: There is a reliable and valid variation in human umami taste of l-glutamate. Variations in perception of umami taste correlated with variations in the human TAS1R3 gene. The putative human taste receptor TAS1R1-TAS1R3 responds specifically to l-glutamate mixed with the ribonucleotide IMP. Thus, this receptor likely contributes to human umami taste perception.

Investigations of the relations between taste perception and obesity have concentrated largely on sweet and bitter tastes, with little work on the "savory" tastes-salt and glutamate-and very little work on sour taste. This article briefly reviews current understanding of the relations between the ability to taste different tastes (ie, taste threshold for sweet, bitter, sour, salt, and umami) and body mass. Obese children and adolescents show a disturbance in some tastes, with reported reductions in sweet and salt thresholds. Observations on relations between sweet taste threshold and obesity are contradictory; literature discrepancies may depend on the techniques used to evaluate taste. Obese women, however, report higher intensities of monosodium glutamate perception. Taste thresholds have been reported to be raised (bitter and sour), lowered (salt), or unchanged (sweet) in obese adults. Taste perceptual changes (threshold, intensity) in obesity are complex and may be different in obese men and women and in adults and children. Very little is currently known about the relations between savory tastes-salt and umami-and body weight, and these areas merit further study.

Although the crucial distinction between unipolar depressive disorder and bipolar disorder is the presence of mania (or hypomania) in the course of the latter, significant differences between unipolar and bipolar depression have also been found in clinical studies. The primary aim of the present investigation was to assess pleasantness/unpleasantness ratings of chemosensory stimuli in depressed patients, including subjects with unipolar and bipolar depression. Sensory aspects (thresholds and identification abilities) of gustatory and olfactory function were also assessed. There were no major differences between a depression group, as a whole, and healthy controls in terms of gustatory and olfactory thresholds and identification abilities. Similarly, pleasantness ratings of various gustatory and olfactory stimuli did not differ between the control and depression group. Gustatory and olfactory thresholds and identification abilities did not differ between individuals with unipolar and bipolar depression. Bipolar patients tended to rate less gustatory stimuli as unpleasant and more olfactory stimuli as pleasant compared to unipolar patients. The present results suggest that: i) depression is not associated with any major deficit in sensory aspects of gustatory and olfactory function or altered hedonic ratings of chemosensory stimuli; ii) hedonic responses to chemosensory stimuli tend to be increased in bipolar as compared to unipolar depressed patients.

The present study deals with the evaluation of the electronic tongue multisensor system as an analytical tool for the rapid assessment of taste and flavour of beer. Fifty samples of Belgian and Dutch beers of different types (lager beers, ales, wheat beers, etc.), which were characterized with respect to the sensory properties, were measured using the electronic tongue (ET) based on potentiometric chemical sensors developed in Laboratory of Chemical Sensors of St. Petersburg University. The analysis of the sensory data and the calculation of the compromise average scores was made using STATIS. The beer samples were discriminated using both sensory panel and ET data based on PCA, and both data sets were compared using Canonical Correlation Analysis. The ET data were related to the sensory beer attributes using Partial Least Square regression for each attribute separately. Validation was done based on a test set comprising one-third of all samples. The ET was capable of predicting with good precision 20 sensory attributes of beer including such as bitter, sweet, sour, fruity, caramel, artificial, burnt, intensity and body.

Salt taste sensitivity is the capacity to identify the flavour of salt. It is possible that salt taste sensitivity threshold (STST) can influence salt appetite, and sodium ingestion is associated with hypertension. The present study evaluates the relationship between salt taste sensitivity threshold (STST) and blood pressure (BP) response to exercise during a treadmill stress test. Two hundred and three normotensive individuals undergoing evaluation before starting an exercise training program were tested for STST, using concentrated saline solutions from 0.22 to 58.4g/L. Patients were divided into two groups according to the STST: normal (n-STST) and increased (i-STST); and into two groups according to their BP response to exercise: exercise-induced hypertension (EIH) or physiological blood pressure response (n-EIH). EIH was detected in 49 (24.1%) individuals. Initial systolic and diastolic BP and their areas under the curves during the test were higher in the EIH group. Initial systolic and diastolic BP areas under the curves were significantly higher in i-STST than n-STST. There was an association between STST of at least 1.8g/L (increased STST) and EIH (OR=6.71, 95% CI 1.5-29.99) independent of gender, body mass index and age. Occurrence of EIH was associated to i-STST, suggesting that a relationship between high STST and increased BP response to exercise is possible.

Sensory-specific satiety (SSS) refers to the decline in evaluated pleasantness of a food when consumed as compared with other unconsumed foods. In two experiments it was investigated whether SSS is sensitive to manipulations of flavour intensity. In the first experiment, 40 participants (36 women) repeatedly consumed 20 ml of either high- (group Strong; n=20) or low-intensity (group Weak) strawberry lemonade. If flavour intensity affects SSS these two groups should differ, but both groups displayed an equal degree of SSS concerning the evaluation of taste, smell, mouth feel, appearance and prospective consumption (largest F=1.34). In Experiment 2, 60 participants (54 women) were randomly assigned to one of three groups of equal size and repeatedly exposed to 20 ml lemonade that increased (group Increase) or decreased (group Decrease) in flavour intensity, or retained a given intensity with each exposure (group Same). It was investigated whether online changes in flavour intensity interfere with the development of SSS, but again these groups displayed a similar degree of SSS to the lemonade (largest F=1.40). It is concluded that manipulation of flavour intensity does not likely affect SSS.

Sweet and bitter are taste qualities linked to food acceptance and rejection in humans. It was long thought that these taste sensations were closely related, but the discovery and characterization of taste receptors revealed that mammals express a single sweet receptor and many unrelated bitter receptors. Bitter-tasting chiral isomers of sweet compounds can bind to the umami receptor, rather than bitter receptors, and elicit the bitter sensation through crosstalk between labelled cells. In support of crosstalk between labelled cells, recent findings suggest that, although most receptor taste cells respond to only one taste, most presynaptic taste cells accept signals from labelled cells that respond to two or more different taste qualities.

Previous studies, which have mostly focused on concentrated NaCl solution intake, have suggested sodium depletion may be accompanied with salt taste sensory changes. To further investigate whether the function of the salt taste system changes in different patterns for highly concentrated and diluted NaCl taste stimuli, the effects of sodium depletion on NaCl taste detection threshold in rats were examined. After a conditioned taste aversion (CTA) to a suprathreshold concentration of NaCl (0.1 M) was established, rats were given a series of two-bottle choice tests between distilled water and different concentrations of NaCl. Conditioned rats will generalize the aversion to diluted solutions when they are detected. The taste detection threshold for NaCl is defined as the lowest concentration at which there is a reliable difference in the preference scores between conditioned and control subjects. The results showed that detection threshold for NaCl lay between 0.003 M and 0.005 M in sodium-replete rats, whereas in sodium-depleted rats that have an amplified action of angiotensin II in the brain, the threshold significantly decreased to be between 0.0001 M and 0.0003 M. However, in rats with a blocked action of angiotensin II in the brain the decreased NaCl detection threshold was between 0.001 M and 0.003 M. These findings suggest that sodium-depleted rats could decrease the NaCl taste detection threshold to increase the ability to find sodium ions. And the regulation of the salt taste sensitivity may be related to the action of angiotensin II in brain.

The human ability to localize odorants has been examined in a number of studies, but the findings are contradictory. In the present study we investigated the human sensitivity and ability to localize hydrogen sulphide (H 2 S), which in low concentrations stimulates the olfactory system selectively, the olfactory-trigeminal substance isoamyl acetate (IAA), and the trigeminal substance carbon dioxide (CO 2 ). A general requirement for testing of localization was the conscious perception of the applied stimuli by the participants. Using Signal Detection Theory, we determined the human sensitivity in response to stimulation with these substances. Then the subjects' ability to localize the three different substances was tested. We found that humans can detect H 2 S in low concentration (2 ppm) with moderate sensitivity, and possess a high sensitivity in response to stimulation with 8 ppm H 2 S, 17.5% IAA, 50% v/v CO 2 . In the localization experiment, subjects could localize neither the low nor the high concentration of H 2 S. In contrast, subjects possessed the ability to localize IAA and CO 2 stimuli. These results clearly demonstrate that humans, in spite of the aware perception, are not able to localize substances which only activate the olfactory system independent of their concentration, but they possess an ability to localize odorants that additionally excite the trigeminal system.

Sweet preference is higher in childhood than adulthood but the mechanism for this developmental shift is not known. The objective of this study was to assess perceptual, physiological and eating habit differences between children preferring solutions high in sugar (high preference) and children preferring solutions low in sugar (low preference). We tested 143 children (11- to 15-years old) using sip and spit methodology to assess their hedonic profile, detection threshold, and perceived intensity of sucrose. Their plasma concentration of several hormones, a biomarker of bone-growth, body size, puberty stage, and dietary habits were measured. Eighty-eight children were classified as high preference and 53 were classified as low preference based on their hedonic ratings to a series of sucrose solutions. A marker of bone growth measured in urine and plasma leptin adjusted for body weight were significantly lower in the low preference group. Children with high and low preference patterns did not differ in sensory aspects of sucrose perception, nor did they differ in age, body mass index percentile, or dietary restraint. The change in sugar preference from high to low during adolescence appears to be associated with the cessation of growth.