Taste Thresholds Research Articles

Effect of monitoring salt concentration of home-prepared dishes and using low-sodium seasonings on sodium intake reduction.

Objective methods such as the monitoring of salt concentrations in home-prepared dishes may be effective in reducing salt intake. We investigated the effect of monitoring the salt concentration of home-prepared dishes (Monitoring) on salt reduction and change in taste threshold, and the effect of the simultaneous use of low-sodium seasonings (Seasoning) to compare the effect of Monitoring with the conventional method. We conducted a double-blind randomized controlled study using a 2 × 2 factorial design with two interventions. A total of 50 participants (40-75 years-old) were recruited among residents of Niigata Prefecture, a high sodium-consuming population in Japan, then randomly allocated to four groups. After excluding participants with incomplete urine collection, change in salt intake was evaluated using 24-hour urinary excretion as a surrogate of intake for 43 participants. Change in taste threshold was evaluated in 48 participants after excluding those with incomplete threshold measurement. The Monitoring intervention group showed a significant decrease in sodium intake (-777 mg/24 h), whereas the decrease in the Seasoning intervention group was not significant (-413 mg/24 h). Sodium intake did not statistically differ between the intervention and control groups (-1011 mg/24 h and -283 mg/24 h for Monitoring and Seasoning, respectively). The changes in taste threshold measurement were very small and did not markedly differ between groups. Monitoring the salt concentration of dishes had a potentially stronger salt-reducing effect than the use of low-sodium seasonings, a conventional method. Confirmation requires additional study with a larger sample size.

Relationship between the Influence of Others’ Opinions on Taste during Co-Eating and the Empathy of Individuals

The purpose of this study was to investigate whether the opinions of people eating together affect the taste of the foods they eat. In addition, if the opinions of others influence taste for one of the people eating with them, are the others’ opinions related to the empathy of individuals? Finally, this study was also intended to consider whether the taste threshold changes depending on the opinions of others. Twelve healthy young women (aged 18.4 ± 0.8 years; mean ± SD) participated in the present study. The participants tasted bread under three conditions: 1) quiet condition: a participant ate with three quiet persons, 2) positive condition: a participant ate with three persons who were talking favorably about taste, and 3) negative condition: a participant ate with three persons who were talking negatively about the taste. The electrical taste threshold was tested before and after tasting the bread, and a visual analog scale (VAS) was completed immediately after the tasting. Before the first trial, participants were asked to complete the Interpersonal Reactive Index (IRI). In the positive condition, the taste score increased significantly compared with the negative condition. There was no significant relationship between taste and empathic concern. To our knowledge, taste changed according to the comments of other people who were eating together. However, the change in taste due to the other’s speech was not related to the individual’s empathy. The results of the present study suggest that people experience food as delicious when others eating with them comment about the food being “delicious,” and this tendency did not depend on individuals’ empathy.

Sensibilidade gustativa em idosos: uma revisão narrativa

Objective: This study is a narrative review about the palate and the various aspects related to taste alterations in aging, as well as nutritional management. Data sources: A bibliographic search was carried out in the PubMed database from March to July 2017. For the purpose of the search, the terms "taste perception", "taste disorders", "taste threshold", "taste" bud", "elderly" with the help of Boolean operators (AND and OR). Summary: One of the earliest recipients involved in food identification and evaluation is the taste receptor. With aging, a loss of taste occurs due to changes in the membranes of taste cellsinvolving altered function of ion channels and sensory receptors in addition to reducing the number of taste pores. These disorders may be associated withseveral conditions, including polypharmacy, smoking, alcohol, inadequate oral hygiene and debilitating diseases such as kidney and liver disease, cancer,respiratory infections, AIDS and diabetes mellitus, Parkinson's disease and cognitive disorders. Simple measures such as the use of natural condiments andseasonings, increased water intake, proper chewing and proper oral hygiene can bring great benefits by avoiding or circumventing gustatory changes in the elderly, being essential the performance of the nutritionist. Conclusions: It is essential to understand the changes in gustatory function that permeate the aging process in order to detect these changes early and contribute to a better quality of life for the elderly.

Sensibilidade gustativa em idosos: uma revisão narrativa

Objective: This study is a narrative review about the palate and the various aspects related to taste alterations in aging, as well as nutritional management. Data sources: A bibliographic search was carried out in the PubMed database from March to July 2017. For the purpose of the search, the terms "taste perception", "taste disorders", "taste threshold", "taste" bud", "elderly" with the help of Boolean operators (AND and OR). Summary: One of the earliest recipients involved in food identification and evaluation is the taste receptor. With aging, a loss of taste occurs due to changes in the membranes of taste cellsinvolving altered function of ion channels and sensory receptors in addition to reducing the number of taste pores. These disorders may be associated withseveral conditions, including polypharmacy, smoking, alcohol, inadequate oral hygiene and debilitating diseases such as kidney and liver disease, cancer,respiratory infections, AIDS and diabetes mellitus, Parkinson's disease and cognitive disorders. Simple measures such as the use of natural condiments andseasonings, increased water intake, proper chewing and proper oral hygiene can bring great benefits by avoiding or circumventing gustatory changes in the elderly, being essential the performance of the nutritionist. Conclusions: It is essential to understand the changes in gustatory function that permeate the aging process in order to detect these changes early and contribute to a better quality of life for the elderly.

Clinical implications of taste thresholds in patients with odontogenic maxillary sinusitis

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.

Development and characterization of an α-l-rhamnosidase mutant with improved thermostability and a higher efficiency for debittering orange juice

The glycoside hydrolase, α-l-rhamnosidase, could remove the bitter taste of naringin from citrus juices. However, most α-l-rhamnosidases are easily deactivated at high temperatures, limiting the practice in debittering citrus juices. The V529A mutant of the α-l-rhamnosidase r-Rha1 from Aspergillus niger JMU-TS528 was developed with improved thermostability using directed evolution technology and site-directed mutagenesis. The enzyme mutant had a half-live of thermal inactivation T(1/2) of 1.92 h, 25.00 min, and 2 min at 60, 65, and 70 °C, respectively. In addition, it had improved substrate affinity and better resistance to the inhibition of glucose. The improved substrate affinity was related to its lowered binding energy. Most significantly, the naringin content was reduced to below the bitter taste threshold by treatment with 75 U/mL of the mutant during the preheating process of orange juice production. The comprehensive results indicate that thermostability improvement could promote the practical value of α-l-rhamnosidase in citrus juice processing.

The salt-taste threshold in untreated hypertensive patients

BackgroundThe salt-taste threshold can influence the salt appetite, and is thought to be another marker of sodium intake. Many studies have mentioned the relationship between the sodium intake and blood pressure (BP). The aim of this study was to evaluate the relationship between the salt-taste threshold and urinary sodium excretion in normotensive and hypertensive groups.MethodsWe analyzed 199 patients (mean age 52 years, male 47.3%) who underwent 24-h ambulatory BP monitoring (ABPM). Hypertension was diagnosed as an average daytime systolic BP of ≥135 mmHg or diastolic BP of ≥85 mmHg by the ABPM. We assessed the salt-taste threshold using graded saline solutions. The salt-taste threshold, 24-h urinary sodium and potassium excretion, and echocardiographic data were compared between the control and hypertensive groups.ResultsThe detection and recognition threshold of the salt taste did not significantly differ between the control and hypertensive groups. The 24-h urinary sodium excretion of hypertensive patients was significantly higher than that of the control group (140.9 ± 59.8 vs. 117.9 ± 57.2 mEq/day, respectively, p = 0.011). Also, the urinary sodium-potassium ratio was significantly higher in the hypertensive patients. There was no correlation between the salt-taste threshold and 24-h urinary sodium excretion.ConclusionsThe salt-taste threshold might not be related to the BP status as well as the 24-h urinary sodium excretion.

Isolation and characterization of key contributors to the "kokumi" taste in soybean seeds.

The water extract of soybean seeds (Glycine max (L.) Merr.) is nearly tasteless, but "kokumi" taste sensation was confirmed upon addition of a basic umami solution containing glutamic acid, inosine monophosphate, and sodium chloride. To identify the key contributors to the "kokumi" taste sensation in soybean seeds, sensory-guided fractionation, taste sensory analyses, and LC-MS/MS analyses were utilized. γ-glutamyl-tyrosine and γ-glutamyl-phenylalanine were identified as contributors to "kokumi taste"; specifically, these γ-glutamyl peptides imparted the "kokumi" taste sensation at a low taste threshold in a basic umami solution. Raffinose and stachyose, which are sufficiently present in soybean seeds, exhibited a synergistic effect in regard to the enhanced "kokumi" taste sensation of γ-glutamyl peptides. This is the first report that the combined use of γ-glutamyl peptides and oligosaccharides can increase the "kokumi" intensity, which suggests that soybean extracts or soymilk can be used to enhance the "kokumi" taste sensation in food products.

Effects of sulfate and nitrate on the taste of water: a study with a trained panel

The role of sulfate and nitrate in the taste of drinking water is not entirely clear. Taste threshold concentrations (TTCs) were estimated for these two species by the 3-AFC method by a trained panel, as sodium and calcium salts. In both cases TTCs for nitrate were about 100 mg NO 3 /L, twice the usual reference value of international recommendations. TTCs for sulfate were about 160 mg SO 4 /L (sodium salt) and 80 mg SO 4 /L (calcium); 75% detection values were also estimated for both anions. An experiment with a series of duo-trio tests plus preference showed that sulfate at low concentrations tended to improve the taste of water. However, at high concentrations it was perceived negatively: salty and bitter were the main descriptors used. The reversion concentration took place between 176 and 259 mg SO 4 /L. These results indicate that nitrate has to be considered an important issue for health, but with no relevant role in the taste of water. Sulfate shows a positive influence at moderate concentrations but becomes negative at high levels. The usual aesthetic-based level of 250 mg/L established by international regulations appears to be reasonable. The findings of this study with trained panellists are preliminary. Future research with consumer panels is recommended.

Bitter taste threshold and bronchial obstruction in bronchial asthma

Aim. To compare bitter taste sensitivity to potassium chloride and parameters of bronchial patency in patients with bronchial asthma (BSA). Material and methods. The study involved 40 healthy volunteers, 82 patients with allergic asthma (ABA), 48 patients with non-allergic asthma (NABA). Spirometry was conducted. The method of Robert I.Henkin et al. (1963) was used to determine the threshold of taste sensitivity to the bitter taste (potassium chloride). Results. The bitter taste threshold was significantly higher in asthmatic patients, particularly in patients with allergic variant of the disease compared to healthy volunteers. Statistically significant inverse correlations were revealed between bitter taste threshold and those volume (VC: τ=-0,306; n=43, p<0,01) and speed parameters (FEV1: τ=-0,429; n=44, p<0,01; MEF50: τ=-0,419; n=43, p<0,01; MEF75: τ=-0,460; n=44, p<0,01) that were obtained after inhalation of β2-agonist (berotec). Moreover, negative correlation (τ=-0,221, n=56, p<0,01) was documented between bitter taste threshold and blood ionized calcium level. Non-allergic BA was characterized by significant negative correlation between bitter taste threshold and initial vital capacity. Conclusion. The above findings suggest that changes in bitter taste sensitivity and disorders of bronchial patency in allergic BA may have common pathogenetic mechanisms based in accordance with modern concepts on disturbances in signal transduction systems coupled to G-proteins.

Bounding Analysis of Drinking Water Health Risks from a Spill of Hydraulic Fracturing Flowback Water.

A bounding risk assessment is presented that evaluates possible human health risk from a hypothetical scenario involving a 10,000-gallon release of flowback water from horizontal fracturing of Marcellus Shale. The water is assumed to be spilled on the ground, infiltrates into groundwater that is a source of drinking water, and an adult and child located downgradient drink the groundwater. Key uncertainties in estimating risk are given explicit quantitative treatment using Monte Carlo analysis. Chemicals that contribute significantly to estimated health risks are identified, as are key uncertainties and variables to which risk estimates are sensitive. The results show that hypothetical exposure via drinking water impacted by chemicals in Marcellus Shale flowback water, assumed to be spilled onto the ground surface, results in predicted bounds between 10-10 and 10-6 (for both adult and child receptors) for excess lifetime cancer risk. Cumulative hazard indices (HICUMULATIVE ) resulting from these hypothetical exposures have predicted bounds (5th to 95th percentile) between 0.02 and 35 for assumed adult receptors and 0.1 and 146 for assumed child receptors. Predicted health risks are dominated by noncancer endpoints related to ingestion of barium and lithium in impacted groundwater. Hazard indices above unity are largely related to exposure to lithium. Salinity taste thresholds are likely to be exceeded before drinking water exposures result in adverse health effects. The findings provide focus for policy discussions concerning flowback water risk management. They also indicate ways to improve the ability to estimate health risks from drinking water impacted by a flowback water spill (i.e., reducing uncertainty).

Correlation between Dysgeusia and Spleen qi Deficiency Patterns in Patients with Burning Mouth Syndrome

Objectives This study evaluated the correlation between taste function and spleen qi deficiency in patients with burning mouth syndrome (BMS) and compared subgroups of BMS (i.e., dysgeusia and non-dysgeusia subgroups). Methods This study included 60 participants categorized into two groups: a BMS group and healthy control (HC) group. Taste threshold was measured within six levels using solutions of four basic taste qualities. Subjects’ Oral Health Impact Profiles (OHIPs-14) and Spleen qi Deficiency Questionnaire (SQDQ) scores were analyzed. Results Taste thresholds for sweet (sucrose) and salty (NaCl) tastes were significantly lower in the BMS group than in the HC group, but sour (citric acid) and bitter (quinine HCl) tastes showed no significant differences between groups. In the dysgeusia and non-dysgeusia subgroups, no significant differences in the four basic taste thresholds were found. SQDQ scores were significantly higher in the BMS group compared to the HC and in the dysgeusia group compared to the non-dysgeusia group. OHIPs-14 and SQDQ scores for the BMS group were significantly and positively correlated. Conclusions Spleen qi deficiency is related to taste function and can be used to treat BMS patients with taste dysfunction. Keywords: burning mouth syndrome, dysgeusia, taste disorder, taste threshold, spleen qi deficiency

Influence of cancer and acute inflammatory disease on taste perception: a clinical pilot study

PurposeCancer patients are at high risk of malnutrition and tumor cachexia further increasing morbidity and mortality. Reasons for cachexia are not clear yet, but inflammatory processes as well as the occurrence of taste disorders reducing nutrient uptake are discussed to play key roles. The purpose of this study was to gain insight into causative factors of taste disturbance in cancer patients. Does the cancer itself, inflammatory processes or cancer therapy influence taste disorders?MethodsTo capture an underlying taste disorder patients with cancer (n = 42), acutely hospitalized inflammatory disease patients (n = 57) and healthy controls (n = 39) were examined. To assess the influence of chemotherapy, patients with and without chemotherapy were compared. Taste tests were performed according to DIN ISO 3972:2011. Inflammation was recorded using laboratory parameters. Statistical evaluation was conducted using the Software R.ResultsCancer patients showed significantly increased taste thresholds for sweet, salty, and umami compared to healthy controls. There were no significant differences in taste detection and recognition between patients with former, current, or without chemotherapeutical treatment. Patients with an acute inflammatory disease showed an increased taste threshold for umami compared to healthy controls.ConclusionsIt could be shown that cancer patients suffer from taste disorders irrespective of an existing chemotherapeutical treatment. Cancer-related inflammation appears to have a greater impact on taste perception than an acute inflammatory process. Therefore, an adapted dietary adjustment should be carried out at an early stage for cancer patients in order to avoid nutritional disorders caused by a taste disorder.

Awareness of use of artificial colourants in sweets preparation and their harmful effects

Background: Colour is the first notable feature of a food and often directly influences the choice of food by increasing the taste threshold, appeal and acceptability.There are natural and few traditional colours but many of the shop keepers, restaurant and processed food manufacturers prefer artificial colours. The sweet manufactures do not realize adverse health effects of colourants. The present study was undertaken to assess the awareness of use of colorants in sweets and its harmful effects among consumers and shopkeepers.Methods: A cross sectional study was conducted. A sample of 96 consumers and 20 shopkeepers across the Kolar town were randomly selected and interviewed to collect information on awareness regarding artificial colourants, permissible limits and their harmful effects by using pre-tested semi structured proforma. Data analyzed by using SPSS statistical software version 22.Results: 16.8% of the consumers did not have the knowledge regarding the artificial colorants. 42.6% of the consumers were aware of the toxic metals in colourants and 46.5% knew the harmful effects. Among shopkeepers only 15% and 10% of them had the awareness regarding the toxic metal present and their harmful effects respectively. Majority (75%) of the shopkeepers knew the permissible limits for usage of colourants. Consumers and shop keepers knew that artificial colorants can cause damage to bladder, Kidney, thyroid, brain, immune system, nerve cell development, hyper activity and genotoxicity.Conclusions: The consumers were aware of artificial colorants, various toxic metals present and their harmful effects. There is a need to increase awareness among shopkeepers regarding presence of toxic metals and their harmful effects.

Investigation of the Learning of Color-Sweetness Association on Sweet Taste Threshold

Investigation of the Learning of Color-Sweetness Association on Sweet Taste Threshold

Impact of Bitter Taste Threshold on Caries Experience in Relation to ABO Blood Types among Dental Students at Al Kufa University

Background: Blood group system and the ability to taste phenylthiocarbamide (PTC) are the most studied traits in human genetics which have been extensively used in describing genetic variations among human populations around the world that may had an effect on dental caries. The aims of present study were to investigate the caries experience among students with different bitter taste threshold in relation to blood type. Materials and Methods: The sample of present study includes dental students female aged19-21 years. The diagnosis of dental caries was done according to the criteria of Manjia et al, 1989 recording decayed lesion by severity (D1-4) MFS. Furthermore, bitter taste sensitivity was measured according to PTC (phenylthiocarbamide) test while concerning blood types, depending on the identity student’s. Statistical analysis that used in this study can be classified into two categories: Descriptive Analysis and second Inferential analysis (Levene test, One-way Analysis of Variance). Results: The data of present study demonstrated that the differences in caries experience among different bitter taste threshold were found statistically not significant although the higher mean value for the higher grades of caries severity (D2-3) were among medium taster students while the non-taster group had the higher mean value of D1. Concerning difference in caries experiences among students with different bitter taste threshold for blood types were not significant in spite of grade D1 was found higher among non –taster A, AB blood type students while for O blood type students were found within super taster. While grade D4 severity was found higher with medium taster among students with A, AB blood types while found higher with super taster among students with O type as grades D4 were absent among students with B blood type. Conclusion: Bitter taste perception which identified according to ptc test has some effect on dental caries experience and were found different for different blood type

Trigemino-gustatory interactions: a randomized controlled clinical trial assessing the effects of selective anesthesia of dental afferents on taste thresholds.

This study aimed at analyzing the effect of the temporary removal of trigeminal dental afferents on electrogustometric thresholds (EGMt). EGMt were measured in 300 healthy subjects randomized in three groups, in nine loci on the right and left side (RS, LS) of the tongue surface before and after anesthesia. Group IAN (n=56 RS, n=44 LS) received intraosseous local anesthesia of the inferior alveolar nerve (IAN). Group MdN received mandibular nerve (MdN) block targeting IAN before its entrance into the mandibular foramen (n=60, RS, and n=40, LS); group MxN receiving maxillary nerve (MxN) anesthesia (n=56 RS and n=44 LS) was the control group. Differences between mean EGMt were analyzed with the Wilcoxon test; correlation between type of anesthesia and EGMt was performed with Spearman's rho, all with a level of significance set at p≤0.05. Significant EGMt (μA) differences before and after anesthesia were found in all loci with MdN and IAN on the ipsilateral side (p<0.05), but not with MxN. Anesthesia of the MdN was positively correlated with the increase in EGMt (p<0.001). Selective anesthesia of IAN was positively correlated only with the increase in EGMt measured at posterior and dorsal loci of the tongue surface (p<0.01). The increase in EGMt following IAN anesthesia suggests a participation of dental afferents in taste perception. Extraction of teeth may impair food intake not only due to impaired masticatory ability but also to alteration of neurological trigemino-gustatory interactions. PACTR201602001452260.

ANALYZING TASTE THRESHOLDS OF A PATIENT WITH DYSGEUSIA

ANALYZING TASTE THRESHOLDS OF A PATIENT WITH DYSGEUSIA

Fat Sensation: Fatty Acid Taste and Olfaction Sensitivity and the Link with Disinhibited Eating Behaviour.

Perception of fat taste, aroma, and texture are proposed to influence food preferences, thus shaping dietary intake and eating behaviour and consequently long-term health. In this study, we investigated associations between fatty acid taste, olfaction, mouthfeel of fat, dietary intake, eating behaviour, and body mass index (BMI). Fifty women attended three sessions to assess oleic acid taste and olfaction thresholds, the olfactory threshold for n-butanol and subjective mouthfeel ratings of custard samples. Dietary intake and eating behaviour were evaluated using a Food Frequency and Three-Factor Eating Questionnaire, respectively. Binomial regression analysis was used to model fat taste and olfaction data. Taste and olfactory detection for oleic acid were positively correlated (r = 0.325; p < 0.02). Oleic acid taste hypersensitive women had significantly increased n-butanol olfactory sensitivity (p < 0.03). The eating behaviour disinhibition and BMI were higher in women who were hyposensitive to oleic acid taste (p < 0.05). Dietary intake of nuts, nut spreads, and seeds were significantly correlated with high olfactory sensitivity to oleic acid (p < 0.01). These findings demonstrate a clear link between fatty acid taste sensitivity and olfaction and suggest that fat taste perception is associated with specific characteristics of eating behaviour and body composition.

Salty taste thresholds and preference in patients with chronic kidney disease according to disease stage: A cross-sectional study.

The present study was performed to evaluate the differences in salty taste thresholds among normal controls and non-dialysis chronic kidney disease (CKD) patients according to disease stage and to evaluate the relationship between salty taste thresholds or preferences and mean spot urine sodium concentrations. This cross-sectional study enrolled 436 patients with non-dialysis CKD and 74 normal controls. We evaluated detection and recognition thresholds, salty taste preferences and salt usage behaviours (through a questionnaire) in CKD patients and normal controls. We averaged the three most recent spot urine sodium concentrations and used this 'mean spot urine sodium' value to estimate sodium intake in CKD patients. Detection thresholds of stages 3 and 5 and recognition thresholds of stage 3 CKD patients were higher than those of normal controls. Salty taste preferences of stage 5 and salt usage behaviour scores of stages 4 and 5 CKD patients were lower than those of normal controls. Univariate analysis showed that estimated glomerular filtration rate (eGFR), salt usage behaviour score, salty taste preference, smoking, gender and zinc level were significantly associated with mean spot urine sodium in CKD patients. Multiple regression analysis showed that the eGFR and salty taste preference were independently correlated with mean spot urine sodium. Education to change salty taste preferences and regular follow up are necessary to decrease salt intake in CKD patients.