Taste Thresholds Research Articles

Elevated Salt Taste Threshold Is Associated with Increased Risk of Coronary Heart Disease.

High salt intake has been associated with coronary heart disease (CHD). The salt taste threshold could affect the salt intake, but its role in CHD is uncertain. We studied the association of salt taste threshold with CHD. In this study, the levels of salt detection threshold, recognition threshold, and taste preference were higher in CHD than in controls. The salt taste recognition threshold was significantly associated with CHD, and the significant association persisted after adjustment for traditional risk factors. Individuals with high level of salt taste recognition threshold were at a greater risk of CHD. Coincident occurrence of high level of salt taste recognition threshold, hypertension, and diabetes increased the risk of CHD. Thus, a high level of salt taste recognition threshold increases the risk of CHD, and the concurrence of high level of salt taste recognition threshold, hypertension, and diabetes further increases the risk of CHD.

The Association between Salt Taste Perception, Mediterranean Diet and Metabolic Syndrome: A Cross-Sectional Study.

Metabolic syndrome (MetS) is a widespread disorder and an important public health challenge. The purpose of this study was to identify the association between salt taste perception, Mediterranean diet and MetS. This cross-sectional study included 2798 subjects from the general population of Dalmatia, Croatia. MetS was determined using the Joint Interim Statement definition, and Mediterranean diet compliance was estimated using Mediterranean Diet Serving Score. Salt taste perception was assessed by threshold and suprathreshold testing (intensity and hedonic perception). Logistic regression was used in the analysis, adjusting for important confounding factors. As many as 44% of subjects had MetS, with elevated waist circumference as the most common component (77%). Higher salt taste sensitivity (lower threshold) was associated with several positive outcomes: lower odds of MetS (OR = 0.69; 95% CI 0.52–0.92), lower odds for elevated waist circumference (0.47; 0.27–0.82), elevated fasting glucose or diabetes (0.65; 0.45–0.94), and reduced HDL cholesterol (0.59; 0.42–0.84), compared to the higher threshold group. Subjects with lower salt taste threshold were more likely to consume more fruit, and less likely to adhere to olive oil and white meat guidelines, but without a difference in the overall Mediterranean diet compliance. Salt taste intensity perception was not associated with any of the investigated outcomes, while salty solution liking was associated with MetS (OR = 1.85, CI 95% 1.02–3.35). This study identified an association between salt taste perception and MetS and gave a new insight into taste perception, nutrition, and possible health outcomes.

The associations between genetics, salt taste perception and salt intake in young adults

Food liking is one of the main determinants of food intake. Salt taste perception and preference, that play a role in liking of salt, may be genetically determined, although research in humans is scarce. The aim of this study was to explore the associations between genetics, salt taste perception, preference, self-reported salt habit and intake. The participants were young (18–35 years) and healthy adults (32 males and 63 females). Salt taste thresholds were determined with British Standard ISO3972:2011 methodology and salt taste preference by ratings of saltiness and pleasantness of tomato soup with salt concentrations reflecting salt content in foods. Self-reported salt habit was determined by asking participants how salty they usually eat their food and salt intake with two 24-hour 5-step multiple pass recalls. Genotyping for variants in the SCNN1B rs239345 and TRPV1 rs8065080 was performed. Participants homozygous for the minor allele of the rs8065080 had lower ratings of saltiness (p = 0.008) and higher ratings of pleasantness of soup (p = 0.027) when compared to major allele carriers. Preference for salt in soup was associated with salt habit (p = 0.003) and participants with high salt preference had higher salt intake compared to those with low salt preference (2236 ± 261 vs. 1543 ± 107 mg/1000 kcal, p = 0.017). TRPV1 rs8065080 may play a role in salt taste perception and preference, which should be confirmed in a larger sample size study. Hedonic appeal of salty food should be considered when providing personalised advice to change this behaviour.

Insights into smell and taste sensitivity in normal weight and overweight-obese adolescents

Research examining connections between BMI and smell and taste sensitivity in adolescents has been minimal, methodologically inconsistent, and inconclusive. We sought to address this issue with an exploratory study of smell and taste sensitivity in overweight-obese (high BMI) and normal BMI male and female adolescents (ages 12–16 years), using previously validated chemosensory testing measures (Sniffin’ Sticks, Taste Strips, 6-n-propylthiouracil: PROP), and taking pubertal stage into account. Puberty was evaluated with the validated Pubertal Development Scale and participants were then classified as either “early” or “late” pubertal stage. We used the phenylethyl alcohol (PEA) version of the Sniffin’ Sticks olfactory threshold test and found that high BMI adolescents had significantly greater olfactory sensitivity than normal BMI adolescents. This observation contradicts previous results in overweight adults tested with the n-butanol version of Sniffin’ Sticks. We also found that participants in early puberty had significantly higher olfactory sensitivity than participants in late puberty. No significant findings for taste sensitivity were obtained, though there is a suggestion that puberty may affect salty taste thresholds. Our results illuminate a potentially important difference in sensitivity to pure olfactory versus olfactory-trigeminal stimuli as a function of BMI, which the PEA and n-butanol versions of the Sniffin’ Sticks respectively assess; and for the first time demonstrate variation in chemosensory acuity in relation to pubertal stage. These findings have implications for eating behavior during adolescence.

Correlation between Taste Threshold Sensitivity and MMP-9, Salivary Secretion, Blood Pressure, and Blood Glucose Levels in Smoking and Nonsmoking Women.

Cigarette smoking can cause taste receptors to increase the taste threshold value. Consequently, the consumption of sugar and salt will not be controlled, therefore causing systemic diseases such as hypertension and diabetes. Nicotine and tobacco in cigarettes can stimulate MMP-9 which plays vital physiological roles in normal tissue growth and repair processes. This study aimed to find the correlation between taste threshold sensitivity and MMP-9, salivary secretion, blood pressure, and blood glucose levels in smoking and nonsmoking women. This was a cross-sectional study consisting of young adult women aged 18–24 years. Subjects were divided into two groups: the nonsmoking and smoking groups. In the combined data of both groups, the sweet taste threshold was correlated with age (r = 0.308, p=0.008), blood glucose levels (r = 0.238, p=0.043), and MMP-9 (r = –0.297, p=0.011). The salt taste threshold was only correlated with systolic blood pressure in the smoking (r = 0.440, p=0.032) and combined data groups (r = 0.260, p=0.026). By using partial correlation, it was shown that the relationship between the salt taste threshold and systolic blood pressure was influenced by smoking habits. The sweet taste threshold in women was found to correlate with age, blood glucose levels, and MMP-9 levels. On the other hand, there was a significant relationship between the salt taste threshold in women with systolic blood pressure, which was the only correlation analyzed in sthis study that was found to be influenced by smoking. However, both sweet and salt taste thresholds were not statistically correlated with salivary secretion.

Sensory Evaluation of Brewed Black Tea (Camellia sinensis sp) and Stevia (Stevia rebaudiana Bert) Leaves. Case Study: Threshold of Phenolic Bitterness Consumer Preference Test

Currently the consumer needs for anti-diabetic products are very large and require answer from healthy food provider answers. Products that are commonly known are tea and stevia. Tea and stevia have advantages as an antioxidant and anti-diabetic. The use of commercially available products is very depended on sensory characteristics which can be accepted by consumers. How much is consumed (food intake) depends on the sensory sensitivity of the consumer. Tea and stevia products are products that contain poly phenols which give a sense of briskness or bitterness. At the time of serving alone, stevia tea and steeping have a certain value, which will be different if brewed simultaneously. The study aims to determine the sensory acceptance threshold value, to steeping a mixture of black tea and dried stevia leaves. The study was conducted using the absolute threshold test, using a proportion of the concentration of stevia black tea between 20:1 to 4:1(w/w) and maximum weight of 2 grams. The mixture was brewed using 200 mL hot water with a temperature of 900 Celsius for 5 minutes. The steeped product was then tested by 80 untrained panelists to find out the absolute threshold for sweet and bitter taste. From the research it was known that the absolute threshold value for sweetness of stevia-black tea was 0.39% (w/v) and bitterness ofstevia - black tea was 0.42% (w/v).

Is there a biological basis in the selection of medicinal plants in the human species? An initial approach based on chemosensory perception of taste

The ability to identify tastes associated with plant chemicals may have favored humans in identifying plant chemists with pharmacological activity throughout human evolutionary history. The genetic basis of taste perception influences people's varying sensitivity to perceive chemical stimuli of taste. This biological basis can play an important role in plant selection to compose local medical systems, given the argument in the ethnobiological literature that plant taste can influence their selection as a medicinal resource. Thus, we sought to investigate whether there is a biological basis in the selection of these resources. Our investigation was made through the survey of ethnobiological data on the knowledge of medicinal plants and sensitivity data on the perception of bitter taste in two local communities. We tested whether local experts and active tasters of medicinal plants are more sensitive to the perception of bitter taste than the rest of the population. Additionally, we evaluated whether people who are more sensitive to bitter taste cite more plants with taste and assign more therapeutic targets to them. We did not corroborate any of our assumptions. It is likely that the bitter taste threshold is not as relevant in the selection of medicinal plants as the processes of cultural transmission.

Sensory characteristics of low sodium dry-cured beef and their relation to odor intensity and electronic nose signals

ABSTRACT In this study, the influence of Na content in dry-cured beef by partial replacement with KCl, L-lysine, and L-histidine was investigated. Dry-cured beef aged over 57 days, compared to the control groups (100% NaCl), salt-substituted groups (SS, 39.7% of NaCl, 51.3% of KCl and a blend of 7% L-lysine and 2% L-histidine) had a significant impact on the taste thresholds, relative odor activity value (ROAV), electronic nose (E-nose), and sensory evaluation. This study revealed that the salt substitute process modified the sensory profile by intensifying the “aroma” and differentiating the control group from SS group. The results represented salt substitute analysis of dry-cured beef and may be used by food companies and other stakeholders to understand the changes in sensory characteristics of dry-cured beef due to 100% NaCl process. Salt substitute was developed successfully, presenting a good performance.

To Assess the Influence of Habitual Mouth Breathing and its Associated Taste Alterations

Background: If the sense of taste is impaired, it may often negatively affect patient’s food intake, nutritional status and consequently health condition because it provides information about the food we eat. Aim and Objective: To study the influence of habitual mouth breathing and its associated taste alterations and also investigate the cause of this influence. Method and Methodology: Total eighty subjects were taken out of which forty healthy volunteers (male-26; female14) participated in this study. The mean age of these subjects was 25.6± 1.9 (SD) years (age range, 19-36 years). Furthermore forty subjects (male-21; female-19) with a habit of mouth breathing (MB) were taken. The mean age of these subjects was 29.5± 3.4 (SD) years (age range, 19-40 years). A taste threshold is the minimum concentration at which taste sensitivity to a particular substance or food can be perceived. The subjects were told to avoid eating or drinking anything, with the exception of water for 3 hours before evaluation. In addition, a complete Ear, Nose, Throat examination was performed. We carried out the chemical method of gustatory testing by using filter paper taste strips. This is a validated gustatory test, used to measure the gustatory sensitivity of the tongue for 5 tastants; sweet, sour, salty, bitter, and umami. We measured the recognition thresholds only on one side on the tongue either left or right. There are many factors that can alter taste senstivity. Considering these factors can help us better understand and ensure accurate sensory taste perception. Although there are a variety of factors but some that influence taste perception more than others are discussed in this study. These various effects are brought about by the many organic and inorganic constituents of saliva. In response to these variations in saliva, taste sensitivity may also fluctuate widely. Conclusion: Relationships between individual salivary constituents and certain taste substances have been explored in human psychophysical and animal experiments. However, there are many organic and inorganic salivary constituents whose effects on taste acuity have not yet been fully elucidated

The associations between genetics, salt taste perception and salt intake in young adults

AbstractHypertension is a major cause of cardiovascular disease and overall mortality. High dietary salt intake is one of the key risk factors for hypertension and in 2017, it was one of the three leading dietary risk factors for death and disability adjusted life years globally. Despite the efforts to change this behaviour, salt consumption still exceeds the recommendations. One of the main determinants of food intake, and potentially salt, is taste. Taste perception may be genetically determined, however research exploring the associations between genetics, salt taste perception and salt intake is scarce. This may be of special importance in younger adult populations where increased preference for salt is suggested. Therefore, the aim of this study was to explore the associations between genetics, salt taste perception (taste threshold and preference) and salt intake in young adults.This study was approved by the St Mary's University Ethics Sub-Committee. Forty-two participants (18–35 years, 67% female and 33% male) completed the study. Salt taste thresholds were identified using the British Standards Institution sensory analysis method (BS ISO 3972:2011) and preference for salty taste by asking participants how salty they usually prefer to eat their food using a Likert scale. Salt intake, expressed as mg sodium/1000 kcal, was measured using a five-step multiple pass 24-hour recall for one day of the week and one weekend day. Participants were genotyped for two genetic variants in the SCNN1B and TRPV1 genes, which code for ion channels expressed in taste cells. Multiple regression analysis was performed including SCNN1B and TRPV1 variants, salt taste threshold and preference as predictor variables and sodium intake (mg/1000 kcal) as the dependent variable. Statistical significance was set at p < 0.05.Participants were normal weight (Body Mass Index 23.8 ± 3.7 kg/m2), predominantly Caucasian with salt intake 7.5 ± 2.7 g per day, reflecting current intakes in the UK. Regression model including genetics, thresholds and preference for salty taste explained 54% of the variance (p = 0.028). In this model, TRPV1 variant rs8065080 [β = 422, confidence interval (50, 794), p = 0.030] and salt preference [β = 618, confidence interval (258, 978), p = 0.004] were indicated as predictors of sodium intake. These findings suggest that genetics and preference for salty taste may be drivers of salt intake in younger populations. If replicated, this information may in the future be used in designing more personalised approaches in changing this behaviour.

Single-nucleotide polymorphism rs1761667 in the CD36 gene is associated with orosensory perception of a fatty acid in obese and normal-weight Moroccan subjects

Obese subjects have shown a preference for dietary lipids. A recent collection of evidence has proposed that a variant in the CD36 gene plays a significant role in this pathway. We assessed the association between the orosensory detection of a long-chain fatty acid, i.e. oleic acid (OA), and genetic polymorphism of the lipid taste sensor CD36 in obese and normal-weight subjects. Adult participants were recruited in the fasting condition. They were invited to fat taste perception sessions, using emulsions containing OA and according to the three-alternative forced-choice (3-AFC) method. Genomic DNA was used to determine the polymorphism (SNP rs 1761667) of the CD36 gene. Obese (n 50; BMI 34⋅97 (sd 4⋅02) kg/m2) exhibited a significantly higher oral detection threshold for OA (3⋅056 (sd 3⋅53) mmol/l) than did the normal-weight (n 50; BMI 22⋅16 (sd 1⋅81) kg/m2) participants (1⋅20 (sd 3⋅23) mmol/l; P = 0⋅007). There was a positive correlation between OA detection thresholds and BMI in all subjects; evenly with body fat percentage (BF%). AA genotype was more frequent in the obese group than normal-weight group. OA detection thresholds were much higher for AA and AG genotypes in obese subjects compared with normal-weight participants. Higher oral detection thresholds for fatty acid taste are related to BMI, BF% and not always to CD36 genotype.

Characterization of Bitter-Tasting Oxylipins in Poppy Seeds (Papaver somniferum L.).

Activity-guided fractionation of poppy seed (Papaver somniferum L.) extracts and analysis of fatty acid oxidation model experiments, followed by liquid chromatography time-of-flight mass spectrometry, tandem mass spectrometry, and one-/two-dimensional nuclear magnetic resonance experiments, revealed the chemical structures of five bitter-tasting fatty acids (1-5), three monoglycerides (6-8), six C18-lipidoxidation products (9-14), and four lipid oxidation degradation products (15 and 17-19) as well as two previously unreported monoglyceride oxidation degradation products, namely, 9-(2',3'-dihydroxypropyloxy)-9-oxononaic acid (1-azeloyl-rac-glycerol, 16) and 1-(2',3'-dihydroxypropyl)-8-(5″-oxo-2″,5″-dihydrofruan-2″-yl)-octonoate (1-ODFO-rac-glycerol, 20). Sensory studies exhibited low bitter taste threshold concentrations between 0.08 and 0.29 mmol/L, particularly for the higher oxidated C18-fatty acids trihydroxyoctadecenoic acid (THOE, 12), 12,13-dihydroxy-9-oxo-10-octadecenoic acid (12,13-diOH-9-oxo, 13), and 9,10-dihydroxy-13-oxo-11-octadecenoic acid (9,10-diOH-13-oxo, 14) as well as for the lipidoxidation degradation products 4-hydroxy-2-noneic acid (4-HNA, 17), 4-hydroxy-2-docecendienoic acid (HDdiA, 18), and 8-(5'-oxo-2',5'-dihydrofuran-2'-yl)-octanoic acid (ODFO, 20).

The determinants of chemoreception as evidenced by gradient boosting machines in broad molecular fingerprint spaces

The ability to identify and reject bitter molecules may determine evolutionary fitness. These molecules might be in potentially toxic or contaminated food. Surprisingly, the ability to identify but tolerate or even enjoy bitter foods and medicines may be beneficial. For example, the tolerance of bitterness as a spice or as a medicine may lead to better nutritional, immunological and health outcomes. More recently the ability of intensely bitter compounds to induce innate immune responses to counter infection has inspired the screening of new drugs and the repurposing of safe, known drugs to new uses. These avenues of study may also help to address long-standing questions regarding unexpected side-effects and placebo/nocebo effects. Therefore, to distinguish all these effects ranging from desire to aversion, there is a need to quantitatively determine the concentration thresholds and to position these bitter substances on a unified taste threshold spectrum. Such an understanding may help elucidate the concentration-based molecular drivers for the chemoreceptive response to bitter substances. This article reports the development of a gradient boosting machine (GBM) that enables a direct interrogation of molecular structure with no intermediary chemical properties. Using molecularly engineered simulations, it is shown that potassium acesulfame has a hidden bitterness motif that is centered on the chemoreceptive spectrum uniting bitterness and sweetness molecular motifs. The resultant shifted perception from a touchstone bitterness sensation to a bitter after-taste is attributable to this cached molecular motif.

Investigation of Kokumi Substances and Bacteria in Thai Fermented Freshwater Fish (Pla-ra).

A 16S rRNA next-generation sequencing technique was applied to investigate the microbial diversity and liquid chromatography-tandem mass spectrometry was used to identify glutamyl peptide profiles of 10 Thai fermented freshwater fish (Pla-ra) samples. A total of 12 genera of bacteria were able to be detected, with Tetragenococcus spp., Staphylococcus spp., and Lactobacillus spp. dominating. Of the 18 glutamyl peptides analyzed, 17 were found, even though the amounts detected were lower than the taste threshold. Despite this, an increase in mouthfulness sensation, reflecting kokumi activity, was clearly identified in most of the samples, which might be because of a synergistic effect of different sub-threshold compounds present in the samples. In principle component analysis, the relationship between microorganisms and glutamyl peptide generation was observed, especially between Tetragenococcus spp. and Lentibacillus spp. and the generation of γ-Glu-Val-Gly. Correlations between microbial diversity and the generation of taste enhancers were identified in this study.

A Comparative Study of Whole-Mouth Taste Thresholds between North Korean Refugees and South Koreans

Background and Objectives Since Korea has been divided into two countries over 60 years ago and differences has gradually developed between the two, an influx of North Korean refugees to South Korea have soared over the past 20 years. Their complaints regarding taste intensity, particularly about strong sweetness of foods, are common after entry into South Korea. Because a long-term over-exposure or restriction to some taste stimuli causes profound alterations in corresponding taste sensitivity in humans, we hypothesized that sugar restriction, which remains common in North Korea, has influenced sweet sensitivity of North Koreans. Subjects and Method To test this hypothesis, we assessed the taste stimuli recognition and detection thresholds of both young adults North refugees and South Koreans using a 1-mL whole-mouth gustatory test applied to a series of sweet, bitter, sour, and salty solutions. Results As expected, the cumulative curve of the recognition threshold for sucrose shifted to the left and the mean recognition threshold for sucrose was significantly lower (0.5357% vs. 0.7393%, p=0.044) for North refugees than for South participants. On the other hand, the recognition threshold for salt was significantly higher (0.2174% vs. 0.1212%, p=0.027) in North refugees. No differences on the recognition taste sensitivity for quinine hydrochloride and citric acid were observed. Conclusion The findings documented in the present study indicate that a prolonged food deficit seems to have changed the taste sensitivity of healthy North Korean refugees. The altered taste sensitivity was most pronounced for sweet and salty tastes, and lasted up to 3.5 years after the refugees left North Korea. Key words: Refugees ㆍ Taste perception ㆍ Taste threshold

Novel Taste-Enhancing 4-Amino-2-methyl-5-heteroalkypyrimidines Formed from Thiamine by Maillard-Type Reactions.

Increasing the thiamine concentration in a respective process flavor yields a product with a significant higher kokumi activity. S-plot analysis of the mass spectrometric data revealed beside thiamine itself, 4-methyl-5-thiazoleethanol, (S)-((4-amino-2-methylpyrimidin-5-yl)methyl)-l-cysteine, N-((4-amino-2-methylpyrimidin-5-yl)methyl)formamide, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one, and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine as marker molecules for a process flavor with higher thiamine concentration. Sensory-based targeted isolation revealed that (S)-((4-amino-2-methylpyrimidin-5-yl)methyl)-l-cysteine, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one, and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine showed an influence on the kokumi taste activity with taste threshold concentrations between 35 and 120 μmol/L. An adapted mass spectrometric-based carbon module labeling experiment as well as quantitative studies clearly demonstrated thiamine as the only precursor and an intermolecular formation pathway for the compounds (S)-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine. On the basis of the knowledge that several thiamine derivatives showed taste-modulating activity, selected thiamine-based binary model reactions and synthesis were carried out. This resulted in the isolation of further thiamine-derived taste modulators like (S)-((4-amino-2-methylpyrimidin-5-yl)methyl)-l-cysteinylglycine, (S)-3-((((4-amino-2-methylpyrimidin-5-yl)methyl)thio)methyl)piperazine-2,5-dione, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)pentan-2-one, 5-(((furan-2-ylmethyl)thio)methyl)-2-methylpyrimidin-4-amine, and (4-amino-2-methylpyrimidin-5-yl)methanethiol, 2-methyl-5-((methylthio)methyl)pyrimidin-4-amine with taste thresholds ranging from 35 to 880 μmol/L.

Gustatory dysfunction in relation to circumvallate papilla’s taste buds structure upon unilateral maxillary molar extraction in Wistar rats: an in vivo study

Background: The interaction between taste sensation and dentoalveolar innervation is still under research. teeth loss can alter taste thresholds in humans, but the underlying mechanisms are still obscure. This study investigated the effect of unilateral maxillary molars extraction on the structure of circumvallate papilla in rats. Methods: Thirty-two male Wister rats, aged 3-4 months were randomly distributed into four groups (one control and 3 experimental ) each including 8 animals. The rats were euthanized 3, 6 or 9 weeks following the procedure. The changes in trough length and the taste buds structure and number of both sides of CVP were investigated using routine histological examination followed by statistical analysis. Results: the trough toward the extraction side was obviously shorter with a noticeable decrease of taste buds’ number than the non-extraction side. Taste buds were reduced in size and most of them showed signs of degeneration which was more evident in group II followed by group III, less deformity detected in group IV in comparison to the preceding 2 experimental groups. the non-extraction side of all experimental groups showed normal trough length and generally normal histology of taste buds. Conclusions: Maxillary molars extraction has a degenerative effect on the structure of taste buds and gustatory epithelium which were more marked at the extraction side and showed improvement upon elongation of follow up period

Bariatric Surgery Leads to Short-Term Effects on Sweet Taste Sensitivity and Hedonic Evaluation of Fatty Food Stimuli.

The aim of this study was to investigate the effect of bariatric surgery on sweet taste sensitivity and the hedonic evaluation of sweet, savory, and fatty food stimuli as well as associations with weight loss and food preferences assessed at a buffet meal test. The detection and recognition threshold for sweet taste and the hedonic rating of sweet, savory, and fatty food stimuli were assessed before and after a preoperative diet-induced weight loss and 6 weeks, 6 months, and 18 months after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) (n = 29). The detection threshold for sweet taste decreased after the diet-induced weight loss and 6 weeks after RYGB (both P ≤ 0.03). The hedonic rating of high-fat food stimuli decreased 6 weeks after RYGB and SG (all P ≤ 0.02). Changes in the hedonic rating of high-fat food stimuli were associated with increased preferences for high-fat foods at the buffet meal (P = 0.03) and tended to be associated with weight loss (P = 0.05). No changes were detected for sweet and savory food stimuli. RYGB increased sweet taste sensitivity; however, this effect was already seen after the diet-induced weight-loss. RYGB and SG decreased the hedonic evaluation of high-fat food stimuli, but this effect did not translate into decreased preferences for high-fat food.

Gustatory dysfunction in relation to circumvallate papilla's taste buds structure upon unilateral maxillary molar extraction in Wistar rats: an in vivo study.

Background: The interaction between taste sensation and dentoalveolar innervation is still under research. teeth loss can alter taste thresholds in humans, but the underlying mechanisms are still obscure. This study investigated the effect of unilateral maxillary molars extraction on the structure of circumvallate papilla in rats. Methods: Thirty-two male Wister rats, aged 3-4 months were randomly distributed into four groups (one control and 3 experimental ) each including 8 animals. The rats were euthanized 3, 6 or 9 weeks following the procedure. The changes in trough length and the taste buds structure and number of both sides of CVP were investigated using routine histological examination followed by statistical analysis. Results: the trough toward the extraction side was obviously shorter with a noticeable decrease of taste buds' number than the non-extraction side. Taste buds were reduced in size and most of them showed signs of degeneration which was more evident in group II followed by group III, less deformity detected in group IV in comparison to the preceding 2 experimental groups. the non-extraction side of all experimental groups showed normal trough length and generally normal histology of taste buds. Conclusions: Maxillary molars extraction has a degenerative effect on the structure of taste buds and gustatory epithelium which were more marked at the extraction side and showed improvement upon elongation of follow up period.

Effect of rootstock on yield, grape composition and wine sensory attributes of Shiraz grown in a moderately saline environment

Background and Aims The study compared the viticultural performance and wine sensory attributes of Shiraz grafted on eight rootstocks with a range in vine vigour and grown under drip-irrigation with moderately saline water. Methods and Results The rootstocks were 140 Ruggeri, 1103 Paulsen, 110 Richter, Ramsey, 101-14, M5489, M5512 and M6262. Ramsey and 140 Ruggeri had the highest leaf area index and M6262 the lowest. Ramsey had highest yield, followed by 140 Ruggeri > M5489 = 110 Richter > M5512 > 1103 Paulsen = 101-14 > M6262. Rootstock M6262 had highest wine chloride concentration of 482 and 384 mg/L in 2012 and 2013, respectively, but salty taste and a thickness mouthfeel (viscosity) were significant only in 2012. Wines from the other seven rootstocks had a chloride and sodium concentration under 175 and 40 mg/L, respectively. Colour density was highest in wine from 101-14 in 2012 and from 101-14, 1103 Paulsen and M5489 in 2013. A salt tolerance index (STI) for the eight rootstocks was calculated based on yield, leaf area index, grape juice chloride and sodium concentration and wine colour density. Conclusions Rootstock M6262 had lowest STI in both years. M5489 had highest STI in 2013 followed by 110 Richter = M5512 = 101-14 = 140 Ruggeri. The recognition threshold for salty taste may lie between a chloride concentration in wine of between 384 and 482 mg/L. Significance of the Study The STI, based on five wine grape performance parameters, provides a promising measure of rootstock salt tolerance compared with the traditional parameters of yield and/or capacity for salt exclusion.