Littérature scientifique sur le sujet « PROP taster status »

Repeated pairings of novel food-related odours with sweet tastes can result in enduring changes in sweetness of the odour alone, but have less consistent effects on odour liking. Variation in ability to taste propylthiouracil (PROP) might account for this, since PROP supertasters (ST) have been reported both to experience stronger sweetness intensity and to be more likely to dislike sweetness than do PROP nontasters (NT). Alternatively, individual differences in liking for sweetness may transfer to sweet-paired odours independently of PROP sensitivity. To explore this, evaluations of sucrose, saccharin, and PROP solutions were used to classify 92 volunteers as either sweet likers or dislikers and as PROP ST, NT, or medium tasters (MT). Changes in pleasantness of odours that had been paired with the taste of saccharin increased in sweet likers but decreased in dislikers. Odour sweetness increased regardless of PROP taster or sweet liker status. PROP ST rated saccharin as more bitter than did other taster groups and also showed greater increases in acquired bitterness of the saccharin-paired odour. Overall, these data suggest that individual differences in evaluation of saccharin reliably predict subsequent changes in evaluation of saccharin-paired odours, with hedonic changes corresponding with liking for sweet tastes and sensory changes reflecting differences in sensory quality between PROP taster groups.

Several studies have used taste sensitivity to 6-n-propylthiouracil (PROP) to evaluate interindividual taste variability and its impact on food preferences, nutrition, and health. We used a supervised learning (SL) approach for the automatic identification of the PROP taster categories (super taster (ST); medium taster (MT); and non-taster (NT)) of 84 subjects (aged 18–40 years). Biological features determined from subjects were included for the training system. Results showed that SL enables the automatic identification of objective PROP taster status, with high precision (97%). The biological features were classified in order of importance in facilitating learning and as prediction factors. The ratings of perceived taste intensity for PROP paper disks (50 mM) and PROP solution (3.2 mM), along with fungiform papilla density, were the most important features, and high estimated values pushed toward ST prediction, while low values leaned toward NT prediction. Furthermore, TAS2R38 genotypes were significant features (AVI/AVI, PAV/PAV, and PAV/AVI to classify NTs, STs, and MTs, respectively). These results, in showing that the SL approach enables an automatic, immediate, scalable, and high-precision classification of PROP taster status, suggest that it may represent an objective and reliable tool in taste physiology studies, with applications ranging from basic science and medicine to food sciences.

Taste buds containing receptor cells that primarily detect one taste quality provide the basis for discrimination across taste qualities. The molecular receptor multiplicity and the interactions occurring between bud cells encode information about the chemical identity, nutritional value, and potential toxicity of stimuli before transmitting signals to the hindbrain. PROP (6-n-propylthiouracil) tasting is widely considered a marker for individual variations of taste perception, dietary preferences, and health. However, controversial data have been reported. We present measures of the peripheral gustatory system activation in response to taste qualities by electrophysiological recordings from the tongue of 39 subjects classified for PROP taster status. The waveform of the potential variation evoked depended on the taste quality of the stimulus. Direct relationships between PROP sensitivity and electrophysiological responses to taste qualities were found. The largest and fastest responses were recorded in PROP super-tasters, who had the highest papilla density, whilst smaller and slower responses were found in medium tasters and non-tasters with lower papilla densities. The intensities perceived by subjects of the three taster groups correspond to their electrophysiological responses for all stimuli except NaCl. Our results show that each taste quality can generate its own electrophysiological fingerprint on the tongue and provide direct evidence of the relationship between general taste perception and PROP phenotype.

It is reported by many studies that supertasters are highly sensitive towards strong taste such as bitter, and therefore had a lower preference for those foods. However, whether the findings apply to all cultures is still debated. The study on the Malaysian population regarding their PROP status is scarce. Thus, we carried out a study to determine whether 6-n- propylthiouracil (PROP) sensitivity status affects the food preference among university students in Kelantan, Malaysia. PROP taster status was determined using PROP test paper and food preference was determined using a questionnaire. The results indicated that there was no significant difference (p>0.05) in the food preference between supertasters, medium tasters, and non-tasters except for jelly, dark chocolate, and plain tea. Contrary to popular belief that PROP taster status was negatively associated with a bitter taste, the present study found a positive correlation between PROP scores and few foods from the bitter food group (bitter gourd, dark chocolate, and plain tea) and also sweet food group (chocolate cake and chocolate spread). This indicates that the genetic factor that is associated with PROP sensitivity does not play important role in determining the food preference among Malaysians. Instead, other factors such as culture and environment could be more influential in defining the way Malaysians select their foods.

The objective of this study was to determine PROP (6-n-propyltiouracil) taster status in adults and its relationship with anthropometric variables and pleasantness of sugar, salt, and fat. A total of 123 subjects rated the intensity of PROP and sodium cloride (NaCl) solutions using the labeled magnitude scale. For pleasantness evaluation, it was used concentrated orange juice (sugar) and mashed potato (salt and fat). The subjects were classified as non-tasters (n = 35), medium-tasters (n = 33) and super-tasters (n = 55). In this study, no relationship was found between PROP taster status and age, sex, weight, body mass index, and pleasantness. Although genetic markers may influence the degree of liking of certain foods, one must consider that the mechanisms influencing eating behavior in humans are complex, and that psychological, social, and economic factors play a key role in response to food.

This cross-sectional study determined whether 6-n-propylthiouracil (PROP) taster status moderates the relationship between food consumption patterns and body composition in children. Children were recruited (n = 342, 50% female, 8–10 y) from across New Zealand. Using a food frequency questionnaire, these food consumption patterns were derived: Processed Foods, Fruit and Vegetables, and Breakfast Foods. Body composition variables included: body fat (%), fat mass (kg), fat mass index (FMI, kg/m2), body mass index (kg/m2) and waist to height ratio (W:Ht). Following adjustment for confounders, Processed Foods were positively associated with %fat (p = 0.015), fat mass (p = 0.004) and FMI (p = 0.016). Taste test strips determined PROP status. For Breakfast Foods, there were small negative associations with all body composition variables (p ≤ 0.001 to 0.037). The population sample was also stratified by PROP taster status. For the non-tasters, there were small to moderate negative associations between Breakfast Foods and each body composition variable (p = 0.003–0.045) except W:Ht (p = 0.112), and these relationships were stronger for girls compared to boys. For the tasters, there were small to moderate positive associations between Processed Foods with %fat (p = 0.030), fat mass (p ≤ 0.001) and FMI (p = 0.014). In conclusion, sensitivity to bitterness may moderate the relationship between food consumption patterns and body composition in children.

The perception of fat varies among individuals and has also been associated with CD36 rs1761667 polymorphism and genetic ability to perceive oral marker 6-n-propylthiouracil (PROP). Nevertheless, data in the literature are controversial. We present direct measures for the activation of the peripheral taste system in response to oleic acid by electrophysiological recordings from the tongue of 35 volunteers classified for PROP taster status and genotyped for CD36. The waveform of biopotentials was analyzed and values of amplitude and rate of potential variation were measured. Oleic acid stimulations evoked positive monophasic potentials, which represent the summated voltage change consequent to the response of the stimulated taste cells. Bio-electrical measurements were fully consistent with the perceived intensity during stimulation, which was verbally reported by the volunteers. ANOVA revealed that the amplitude of signals was directly associated, mostly in the last part of the response, with the CD36 genotypes and PROP taster status (which was directly associated with the density of papillae). The rate of potential variation was associated only with CD36, primarily in the first part of the response. In conclusion, our results provide direct evidence of the relationship between fat perception and rs1761667 polymorphism of the CD36 gene and PROP phenotype.

The present work was aimed at understanding the sensory responses induced by dry white wine modified with increasing concentrations of different sensory active molecules. The tasting panel was composed by 34 trained subjects characterized according to gender, smoking habits, 6-n-propylthiouracil (PROP) taster status, and sensitivity to tartaric acid, tannic acid and sucrose. Additional taste/mouthfeel responsiveness was evaluated in a basal white wine added of tartaric acid, tannic acid and sucrose. The addition of a fruity odorant mixture to the base white wine enabled the assessment of orthonasal aroma and taste intensities (sweetness, sourness, saltiness). The diversity of taste/mouthfeel responsiveness in water or wine enabled to group individuals as high or low sensitives. Likewise, the tasting panel showed two groups responding differently to aroma and flavor. Both high and low aroma sensitivity individuals showed equal (p>0.05) and congruent response to in-mouth sweet flavor perception. Moreover, the high smell sensitive group was less sensitive to sourness and saltiness than the low smell sensitives for the spiked wines across all flavor concentrations. Differences in PROP taster status and sensitivity to other tastants in water solutions were not correlated with the taste/mouthfeel perceptions in wine. The individuals most sensitive to sucrose in wine taste showed higher response to the fruity aroma. In conclusion, taste, mouthfeel and flavor perceptions showed a high variability among individuals evidencing the advantage of grouping tasters with different chemosensory sensitivities to understand cross-modal sensory interactions.

abstract: Given the continued increase in obesity rates in the United States, there has been growing research regarding factors related to obesity. Researchers have examined biological factors, such as set point theory, as well as various psychological factors such as motivation, self-efficacy, and eating styles. Taster-type, defined as how an individual experiences the perception of taste (particularly bitterness), is a recent area of research that has explored the potential relationship between this phenomenon and obesity. The current study examined whether taster-type impacted weight loss, along with secondary measures of BMI, waist circumference, and food neophobia, as well as taster-type’s impact on these measures over time. This study also examined the potential role of taster-type as a predictor of weight loss, independent of the psychological variables of motivation, self-efficacy, and eating styles. Ninety adult participants, consisting of 64 females and 19 males were recruited for this study. They were asked to diet for four weeks; 60 finished the full four weeks and completed psychosocial measures over two time periods. They were asked to record their food using an online food journal, attend weekly meetings for weigh-ins, and were given psychoeducational materials regarding factors affecting weight loss. The results indicated that taster-type was not a significant factor in BMI or waist circumference, but taster-type did interact with time to reveal that supertasters consistently lost weight across the four week dieting period while nontasters leveled off after Week 2. Additionally, both groups increased in food neophobia from the start of the dieting period to the end of Week 4. Consistent with previous research, motivation and self-efficacy predicted weight loss; however, taster-type did not increase the prediction of weight loss across the dieting period. This effect only occurred at Week 2. By Week 4, no psychosocial variables were significant predictors of weight loss.
Dissertation/Thesis
Doctoral Dissertation Counseling Psychology 2016

The instinctive rejection of bitter taste has been crucial to the survival of our species and continues to influence food choices. In fact, the bitter taste receptors have evolved to protect the body from the ingestion of foods potentially harmful to health. However, some foods are widely consumed despite their high intensity of bitterness, for example coffee, one of the world’s most popular beverages. Coffee is drunk for its pleasant flavour and aroma as well as for the stimulatory properties arising from its caffeine content. Such properties, as well as the addition of sugar and/or milk, are most likely responsible for our learned preferences for coffee. The aim of this work was to study the relationship between the preference patterns for coffee and the perception of its bitterness. For this purpose, factors relating to both the product – degree of roasting - and the individual - bitterness perception and caffeine metabolism rate - were studied. First, the effect of the roasting temperature on coffee sensory profile and preference was investigated, initially by describing the sensory properties of coffee brews prepared with both under-roasted (140-165°C) and standard roasted (220°C) beans. In addition, seventy-five coffee consumers rated their liking for unsweetened and freely sweetened under-roasted coffee samples. Increasing the bean processing temperature positively affected both the perceived intensity of some sensory attributes specific to coffee and also consumers’ liking. In particular, coffee processed at temperature higher than 150°C were described by the terms “coffee”, “roasted”, “burnt”. Furthermore, no significant differences in the intensity of these attributes were found between samples processed at temperatures higher than 155°C and samples roasted at the standard temperature. In general, samples processed at temperatures higher than 150°C were preferred. However, a subgroup of subjects who liked the samples roasted at lower temperatures was found. These subjects were on average less neophobic than the others, that is, more inclined to consume unfamiliar/unconventional foods. Later, the effects of bitterness sensitivity and caffeine metabolism rate on perception of, and liking for coffee were examined. One hundred and thirty-five regular coffee consumers participated in the study. Subjects were characterised in terms of bitterness sensitivity (fungiform papillae – FP - number and sensitivity to the bitter compound 6-n-propylthiouracil –PROP-); caffeine metabolism rate (slow and fast metabolizers); attitudes and food behaviour (frequency – number of coffees per day- and modality - black, with sugar, with milk- of coffee consumption; preference for and familiarity with bitter foods; self perceived effect of caffeine intake). Caffeine metabolism was investigated by competitive immuno-enzymatic assay. Subjects provided saliva samples after 12 hours of caffeine abstinence (T0) and at 30 and 90 minutes after ingestion of caffeine (100 mg). The individual caffeine metabolism rate in 90 minutes was expressed as a caffeine metabolism index (CmI), computed as the ratio between the amount of residual caffeine in saliva 60 minutes after the adsorption peak and the amount of caffeine at the adsorption peak corrected with the baseline. Subjects rated their liking for six unsweetened and freely sweetened coffee samples selected on the base of their roasting degree, caffeine content and bitterness. The immersive test technique was applied to evaluate the effect of the context on coffee liking. In particular, just before starting the test, subjects were asked to describe the most preferred situation for consuming coffee (time of the day, place, company, etc.) and to imagine that they were doing coffee tasting in that particular situation. In a separate session, subjects evaluated the sourness, bitterness and astringency in the coffee samples. Psychophysical curves were constructed for caffeine and quinine-HCl over 6 concentrations. No significant relationships were found between the FP number, the PROP taster status and the caffeine metabolism rate. Subgroups of subjects were identified based on these indices and differences in preference and sensory responses were explored independently in the subgroups. Both FP density and PROP taster status affected taste sensitivity for bitter compounds in general (caffeine; quinine-HCl) and the use of sugar in coffee. In particular, subjects with a higher FP number rated the bitterness of caffeine and quinine-HCl solutions and sourness of coffees stronger than subjects with a lower FP number. They also added more sugar to, and gave higher liking ratings for, the coffee samples. While coffee liking was unrelated to PROP taster status, PROP non-tasters added more sugar to the coffee samples than did PROP super-tasters. However, super-tasters rated sourness, bitterness and astringency as stronger than non-tasters, both in coffee samples and in standard solutions. Caffeine metabolism was related to bitterness perception both in coffee samples and in standard solutions of caffeine, but not of quinine-HCl. In particular, subjects with a lower caffeine metabolism index rated the bitterness of coffees and of caffeine solutions as stronger than subjects with a higher caffeine metabolism index. Moreover, they added more sugar in coffees and consumed less coffees daily. In general, the results demonstrate that even in high coffee consuming cultures such as Italy, there are clear sensory variations in the coffees that are consumed. Coffee consumption and preference, in terms of frequency and modality, are influenced both by the sensory properties of coffee and the psychological, physiological and metabolic characteristics of consumers. In the coffee production process, the roasting degree is a crucial step towards the development of the sensory properties affecting consumer preference. Furthermore, both the physiological indices – FP number and PROP taster status – and the caffeine metabolism rate play a significant role in taste sensitivity for bitter compounds in general and also in the preference for coffee with or without sugar.

At first sight, a statue that appears in a film is a prop among others. It can serve to situate the action, it can be an attribute of a character, indicating the person’s taste and social status, and it can become a world-making detail, as in historical epics set in antiquity, where statues serve as the kind of ornament used to describe the world of the film and lend it credibility. But as it appears in a film, it raises questions about film as an art of the gesture, and about the power of film to endow inanimate objects with agency.

Aesthetic education is carried out at all stages of the age development of the individual, but the most sensitive period for its development is the period of preschool childhood. One of the most important categories in 10.25205/978-5-4437-1383-0-234-242 235 the structure of aesthetic education is artistic and aesthetic taste, which is an integrative education that combines artistic and aesthetic. The importance of developing artistic and aesthetic taste in preschoolers implies their ability in the future not only to give aesthetic assessments of works of art, but also to deeply perceive, reproduce them, and create independent works.

Historically, the aversive response of humans and other mammals to bitter-taste substances has been useful for survival, since many toxic constituents taste bitter. Today, the range of foods available is more diverse. Many bitter foods are not only safe for consumption but contain bitter constituents that provide nutritional benefits. Despite this, these foods are often eliminated from our current diets because of their unacceptable bitterness. Extensive technology has been developed to remove or mask bitterness in foods, but a lack of understanding of the mechanisms of bitterness perception at the taste receptor level has prevented the development of inhibitors or efficient methods for reducing bitterness. In our original application we proposed to: (a) investigate the time course and effect of selected bitter tastants relevant to agricultural products on the formation of intracellular signal molecules (cAMP, IP3, Ca2+) in intact taste cells, in model cells and in membranes derived therefrom; (b) study the effect of specific bitter taste inhibitors on messenger formation and identify G-proteins that may be involved in tastant-induced bitter sensation; (c) investigate interactions and self-aggregation of bitter tastants within membranes; (d) study human sensory responses over time to these bitter-taste stimuli and inhibitors in order to validate the biochemical data. Quench-flow module (QFM) and fast pipetting system (FPS) allowed us to monitor fast release of the aforementioned signal molecules (cGMP, as a putative initial signal was substituted for Ca2+ ions) - using taste membranes and intact taste cells in a time range below 500 ms (real time of taste sensation) - in response to bitter-taste stimulation. Limonin (citrus) and catechin (wine) were found to reduce cellular cAMP and increase IP3 contents. Naringin (citrus) stimulated an IP3 increase whereas the cheese-derived bitter peptide cyclo(leu-Trp) reduced IP3 but significantly increased cAMP levels. Thus, specific transduction pathways were identified, the results support the notion of multiple transduction pathways for bitter taste and cross-talk between a few of those transduction pathways. Furthermore, amphipathic tastants permeate rapidly (within seconds) into liposomes and taste cells suggesting their availability for direct activation of signal transduction components by means of receptor-independent mechanisms within the time course of taste sensation. The activation of pigment movement and transduction pathways in frog melanophores by these tastants supports such mechanisms. Some bitter tastants, due to their amphipathic properties, permeated (or interacted with) into a bitter tastant inhibitor (specific phospholipid mixture) which apparently forms micelles. Thus, a mechanism via which this bitter taste inhibitor acts is proposed. Human sensory evaluation experiments humans performed according to their 6-n-propyl thiouracil (PROP) status (non-tasters, tasters, super-tasters), indicated differential perception of bitterness threshold and intensity of these bitter compounds by different individuals independent of PROP status. This suggests that natural products containing bitter compounds (e.g., naringin and limonin in citrus), are perceived very differently, and are in line with multiple transduction pathways suggested in the biochemical experiments. This project provides the first comprehensive effort to explore the molecular basis of bitter taste at the taste-cell level induced by economically important and agriculturally relevant food products. The findings, proposing a mechanism for bitter-taste inhibition by a bitter taste inhibitor (made up of food components) pave the way for the development of new, and perhaps more potent bitter-taste inhibitors which may eventually become economically relevant.