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PubMed2003

Oral shear stress predicts flavour perception in viscous solutions.

The perception of sweetness and flavour were studied in viscous solutions containing 50 g/l sucrose, 100 p.p.m. iso-amyl acetate and varying concentrations of three hydrocolloid thickeners (guar gum, lambda-carrageenan and hydroxypropylmethyl cellulose). Zero-shear viscosity of the samples ranged from 1 to 5000 mPas. Perception of both sweetness and aroma was suppressed at thickener concentrations above c* (coil overlap concentration, the point at which there is an abrupt increase in solution viscosity as thickener concentration is increased). Sensory data for the three hydrocolloids was only loosely correlated with their concentration relative to c* (c/c* ratio), particularly above c*. However, when perceptual data were plotted against the Kokini oral shear stress (tau), calculated from rheological measurements, data for the three hydrocolloids aligned to form a master-curve, enabling the prediction of flavour intensity in such systems. The fact that oral shear stress can be used to model sweetness and aroma perception supports the hypothesis that somatosensory tactile stimuli can interact with taste and aroma signals to modulate their perception.

Adult↗
PubMed1976

The effect of conditioned stimuli signalling food upon the autochthonous instrumental responses in dogs.

Food CSs, presented (i) concomitantly with SD controlling bar pressing for food, or (ii) on the background of non-discriminated bar pressing (FR 1/15), suppress instrumental performance but elicit undiminished conditioned salivation. This result supports Soltysik-Konorski's model of CNS mechanism controlling food-oriented behavior which postulates drive inhibition by taste-consummatory neurons.

Animals↗
PubMedDate not supplied

Hippocampal inactivation enhances taste learning.

Learning tasks are typically thought to be either hippocampal-dependent (impaired by hippocampal lesions) or hippocampal-independent (indifferent to hippocampal lesions). Here, we show that conditioned taste aversion (CTA) learning fits into neither of these categories. Rats were trained to avoid two taste stimuli, one novel and one familiar. Muscimol infused through surgically implanted intracranial cannulae temporarily inactivated the dorsal hippocampus during familiarization, subsequent CTA training, or both. As shown previously, hippocampal inactivation during familiarization enhanced the effect of that familiarization on learning (i.e., hippocampal inactivation enhanced latent inhibition of CTA); more novel and surprising, however, was the finding that hippocampal inactivation during training sessions strongly enhanced CTA learning itself. These phenomena were not caused by specific aspects of our infusion technique--muscimol infusions into the hippocampus during familiarization sessions did not cause CTAs, muscimol infusions into gustatory cortex caused the expected attenuation of CTA, and hippocampal inactivation caused the expected attenuation of spatial learning. Thus, we suggest that hippocampal memory processes interfere with the specific learning mechanisms underlying CTA, and more generally that multiple memory systems do not operate independently.

Animals↗
PubMed2005

[A study of measurements of and factors influencing threshold levels of taste perception].

The threshold levels of taste perception on the right and left side of the tip, root of tongue and soft palate in 60 healthy volunteers were measured by means of an electrogustometry test and a filter-paper disk taste test to confirm the following hypotheses: (1) the threshold on the tip of the tongue was lower than those of the root of the tongue and soft palate, (2) there was a different threshold level between sweet, salty, sour and bitter tastes on the tip of the tongue, (3) some personal properties influenced the person's threshold. Measured threshold levels were compared between these six locations with multiple comparisons. Factors influencing the threshold level on the tip of the tongue, thereafter, were investigated using multivariate logistic regression models. Those factors included sex, age, serological, psychological and behavioral factors. As a result, the thresholds levels on the tip of the tongue were significantly lower than the root of the tongue and soft palate. The thresholds for sweet and bitter taste on the tip of the tongue were also lower than those for salty and sour taste. Increase of age, male, serological increase of zinc and usual alcohol drinking were identified as factors of increase for several thresholds, and increase of anxiety was identified as a factor of decrease for two thresholds of four tastes (sweet, salty, sour and bitter) on the tip of the tongue in the logistic regression models. Increase of depression, mouth breathing, habitual tonus of the tongue and smoking did not appear to be influential factors.

Adult↗
PubMed1979

Zinc metabolism in humans: a kinetic model.

A quantitative model is developed that describes the kinetics of the early phases of zinc metabolism in humans. The model is based on averaged data obtained over 5 days from 17 atients with smell and/or taste dysfunction who were given 69mZn in trace amounts orally and intravenously. A function describing the rate of entry of 69mZn into systemic plasma following ingestion of the isotope is derived showing that about 37% of the ingested zinc enters plasma. Gastrointestinal absorption is essentially completed by 4 h. Sixty-seven percent of the absorbed zinc in the portal circulation is extracted by the liver before being released into the systemic circulation and agrees with the calculated extraction efficiency from the systemic circulation. There are both rapid and slow exchnage phases between plasma and liver and between plasma and red cells. The calculated steady-state zinc values for plasma, red cells, and liver agree with previously reported measured values implying there are no additional zinc pools in these tissues. The tracer data, however, account for only 10% of total body zinc, the remaining 90% in tissues whose kinetics are too slow to be resolved from a 5-day study.

Adult↗
PubMedDate not supplied

Age-dependent taste preferences in rabbits for a .025% sodium saccharin solution: preliminary findings.

Classical conditioning of rhythmic jaw movements in rabbits is an accepted model of associative learning that may be useful in assessing age-related changes in learning and motivation. A saccharin solution has been thought to be rewarding to rabbits and is often used as an unconditioned stimulus (US). To determine whether age-related differences in preference for saccharin exist, we assessed (a) saccharin versus water preferences and (b) fluid intake level differences (which might account for differing drive levels) in young (4-6 months) and old (31-69 months) rabbits. Young animals demonstrated a significant preference for water, whereas old animals strongly preferred the saccharin solution. There were no differences between young and old rabbits in overall fluid intake. These results suggest that whereas saccharin may be an appetitive US for old rabbits, it may be aversive to young ones. Thus aging may affect the incentive value of rewarding stimuli, complicating the interpretation of interactions among aging, learning, and motivational processes.

Administration, Oral↗
PubMed2001

The choice of fat-free vs. regular-fat fudge: the effects of liking for the alternative and the restraint status.

Non-restrained and restrained American women (N=157) chose a portion of a fat-free or regular-fat hot fudge, to be eaten on a portion of fat-free or regular-fat (depending on the experimental condition) ice cream. The subjects had tasted and rated samples of both fudge and ice cream earlier in the same session and, prior to the choice, they were informed of their own hedonic ratings of both fudges and of the respective fat contents ("fat-free" vs. "regular-fat"). The higher the hedonic difference (fat-free minus regular-fat) between hot fudge samples and the higher the individual restraint score, the more likely was the choice of the fat-free option. Also, the less hungry the subjects were prior to testing, the more likely they were to choose the fat-free version. On average, the hedonic difference between the hot fudge samples was roughly -0.5 for those choosing the fat-free option, while the corresponding value for subjects choosing the regular-fat version was -3 (9-point scale). The type of ice cream did not affect the choice. The data demonstrate the effects of a food (its hedonic quality), person (restrained status), and context (perceived hunger) on food choice.

Adult↗
PubMed2006

Proceedings of the SMBE Tri-National Young Investigators' Workshop 2005. Lineage-specific expansions and contractions of the bitter taste receptor gene repertoire in vertebrates.

The sense of bitter taste plays a critical role in how organisms avoid generally bitter toxic and harmful substances. Previous studies revealed that there were 25 intact bitter taste receptor (T2R) genes in humans and 34 in mice. However, because the recent chicken genome project reported only three T2R genes, it appears that extensive gene expansions occurred in the lineage leading to mammals or extensive gene contractions occurred in the lineage leading to birds. Here, I examined the T2R gene repertoire in placental mammals (dogs, Canis familiaris; and cows, Bos taurus), marsupials (opossums, Monodelphis domestica), amphibians (frogs, Xenopus tropicalis), and fishes (zebrafishes, Danio rerio; and pufferfishes, Takifugu rubripes) to investigate the birth-and-death process of T2R genes throughout vertebrate evolution. I show that (1) the first extensive gene expansions occurred before the divergence of mammals from reptiles/birds but after the divergence of amniotes (reptiles/birds/mammals) from amphibians, (2) subsequent gene expansions continuously took place in the ancestral mammalian lineage and the lineage leading to amphibians, as evidenced by the presence of 15, 18, 26, and 49 intact T2R genes in the dog, cow, opossum, and frog genome, respectively, and (3) contractions of the gene repertoire happened in the lineage leading to chickens. Thus, continuous gene expansions have shaped the T2R repertoire in mammals, but the contractions subsequent to the first round of expansions have made the chicken T2R repertoire narrow. These dramatic changes in the repertoire size might reflect the daily intake of foods from an external environment as a driving force of evolution.

Animals↗
PubMed2006

Broad-spectrum L-amino acid sensing by class 3 G-protein-coupled receptors.

The sensing of nutrients is essential to the control of growth and metabolism. Although the sensing mechanisms responsible for the detection and coordination of metabolic responses to some nutrients, most notably glucose, are well understood, the molecular basis of amino acid sensing by cells and tissues is only now emerging. In this article, we consider evidence that some members of G-protein-coupled receptor class 3 are broad-spectrum amino acid sensors that couple changes in extracellular amino acid levels to the activation of intracellular signaling pathways. In particular, we consider both the molecular basis of specific and broad-spectrum amino acid sensing by different members of class 3 and the physiological significance of broad spectrum amino acid sensing by the extracellular calcium-sensing receptor, heterodimeric taste receptors and the recently "deorphanized" receptor GPRC6A and its goldfish homolog, the 5.24 chemoreceptor.

Amino Acids↗
PubMed2004

Convergent analysis of cDNA and short oligomer microarrays, mouse null mutants and bioinformatics resources to study complex traits.

Gene expression data sets have recently been exploited to study genetic factors that modulate complex traits. However, it has been challenging to establish a direct link between variation in patterns of gene expression and variation in higher order traits such as neuropharmacological responses and patterns of behavior. Here we illustrate an approach that combines gene expression data with new bioinformatics resources to discover genes that potentially modulate behavior. We have exploited three complementary genetic models to obtain convergent evidence that differential expression of a subset of genes and molecular pathways influences ethanol-induced conditioned taste aversion (CTA). As a first step, cDNA microarrays were used to compare gene expression profiles of two null mutant mouse lines with difference in ethanol-induced aversion. Mice lacking a functional copy of G protein-gated potassium channel subunit 2 (Girk2) show a decrease in the aversive effects of ethanol, whereas preproenkephalin (Penk) null mutant mice show the opposite response. We hypothesize that these behavioral differences are generated in part by alterations in expression downstream of the null alleles. We then exploited the WebQTL databases to examine the genetic covariance between mRNA expression levels and measurements of ethanol-induced CTA in BXD recombinant inbred (RI) strains. Finally, we identified a subset of genes and functional groups associated with ethanol-induced CTA in both null mutant lines and BXD RI strains. Collectively, these approaches highlight the phosphatidylinositol signaling pathway and identify several genes including protein kinase C beta isoform and preproenkephalin in regulation of ethanol- induced conditioned taste aversion. Our results point to the increasing potential of the convergent approach and biological databases to investigate genetic mechanisms of complex traits.

Animals↗
PubMed2002

Analysis of taste-active compounds in an enzymatic hydrolysate of deamidated wheat gluten.

Hydrolyzed plant proteins are widely used as ingredients in culinary products for their glutamate-like ("umami") taste. Three hydrolysates were prepared from wheat gluten using different enzymatic approaches. Comparison of their taste profiles revealed the enzymatic hydrolysate of an acid-deamidated wheat gluten (WGH-3) to be the least bitter of all and to elicit an intense glutamate-like taste. Its umami taste intensity was similar to that of an enzymatic hydrolysate in which glutaminase had been employed to convert free glutamine to glutamic acid and which had a 3-fold higher concentration of free glutamate. Reconstitution studies based on the results of the chemical analysis of WGH-3 and sensory comparison of the model solution and WGH-3 indicated that other components in addition to glutamate and organic acids contribute to its glutamate-like taste. WGH-3 was fractionated by gel permeation chromatography and reversed phase high-performance liquid chromatography, and two fractions with a pronounced glutamate-like taste were obtained. In one of them four pyroglutamyl peptides were tentatively identified: pGlu-Pro-Ser, pGlu-Pro, pGlu-Pro-Glu, and pGlu-Pro-Gln. Apparently, these peptides were formed by cyclization of the N-terminal glutamine residues during the preparation of the hydrolysates.

Adult↗
PubMed1998

Posttraumatic gustatory neuralgia: a clinical model of trigeminal neuropathic pain.

Six cases are reported in which the primary complaint was episodic, recurrent facial pain that was triggered by a taste stimulus. The pain first occurred days to weeks after head and neck surgery. Patients reported that a food stimulus placed in the mouth evoked episodic, electric shock-like pain in a preauricular location on the surgical side. The smell of food or, less reliably, emotional excitement could also trigger pain. Mandibular movement did not evoke the pain, and between lancinating attacks there was either no pain or only mild discomfort. Following an episode of pain, there was a refractory period during which the pain could not be elicited. Physical examination demonstrated a preauricular sensory loss of variable distribution. No abnormal sweating or vasomotor findings were clinically apparent. No odontogenic, muscular, salivary gland, neurologic, or psychologic pathology was found to explain the clinical symptoms. The pain was not relieved with standard doses of anticonvulsants that are commonly used to treat trigeminal neuralgia. The duration of the recurrent pain symptoms in this group was 8 to 132 months without remission. Gustatory neuralgia may be a discrete syndrome that results from abnormal interactions between salivary efferent fibers and trigeminal sensory afferent fibers in the injured auriculotemporal nerve. The unique features of the disorder make it a potentially useful clinical model for the investigation of autonomic/sensory interactions in neuropathic pain.

Adult↗
PubMed1979

Spatial firing patterns of auditory neuron network modelling by computer simulation.

This communication examines, in digital computer simulated network, input signals and response patterns established at excitatory neurons' level i.e. the membrane potential of neuron soma. It is restricted to spatial patterns of the auditory neuron networks and time factor for nervous conduction and transmission is neglected compared with long maintained membrane potentials of neuron somas. The model analyzes the change in the spatial patterns of the membrane potential in the two dimensional networks of the auditory system. In order to evaluate the contribution of the various parameters, it is started that the simplest model has only one parameter, lateral inhibition. The other parameters are then added, one at a time, to successive models. The lateral inhibition is a necessary condition in the auditory nervous system if any sharpening of the response areas in the single neurons is to occur. A necessary condition for the validity of the model is that is should be applicable to the other senses such as vision and chemical patterns, taste. The threshold feature of auditory neurons aids in producing a sharpening in the neuron of the auditory relay nuclei. It does this clipping the spatial response patterns in one dimensional arrays of excitatory neurons. Recurrent inhibition seems a necessary condition in the sensory nervous system that any kinds of input signals are to be preserved over a wide range of stimulus intensity. In other words, this network has a wide dynamic range against any kinds of input signals. A simple self-recurrent negative feedback does not contribute to the sharpening, but more complex socalled averaged type does. A neuron network is capable of responding stably to stimuli with a wide range of intensity and with any kind of spatial patterns if there is a simple negative feedback mechanism. When there is no negative feedback, input signals soon disappear or saturate in the neuron network. Therefore, recurrent inhibition is the most important mechanism. Spontaneous activity appears to aid in the sharpening by providing a kind of contrast, that is by reducting the amount of activity in neurons adjacent to the excitatory area. Moreover, the effect of spontaneous activity in the model seems to make repples around the excitatory area and suggests that an introduction of activity at any stage of the networks, from whatever source for example reticulum formation and thalamus, might appreciably alter the response patterns at subsequent neuron network. This suggests that the mechanism of the consciousness that might be controlled by the thalamus and or reticular formation. These two dimensional neuron networks may be expanded to three dimensional neuron networks. The former might simulate the auditory nervous system while the latter might simulate the visual system.

Animals↗
PubMedDate not supplied

[Failure effects and gender differences in perfectionism].

Perfectionism is a dimension which has been studied very little as a separate entity. It is not even considered as a nosological factor. No classification of the medical sciences underlines its importance other than to speak of a personality trait, of an aspect, or of a parameter. Nevertheless, perfectionism is related to multiple disorders such as depression (18, 20, 36), suicide (8, 16, 55), nutritional problems (11, 28), anxiety (3), obsessive-compulsive personality disorder (53), social phobia (2), as well as insomnia (46). Certain authors stress the possible role of perfectionism in the development or the persistence of a substantial number of these disorders (7, 22, 38). Given these facts, it is all the easier to understand the interest shown by clinicians and researchers in the subject. Better detection and evaluation of its impact on behaviour is important in putting therapies in place (6, 53). Relationships between perfectionism and fear of failure have been approached (21, 51, 54). Correlations between perfectionism and high levels of state and trait anxiety have been demonstrated (23). The evaluation of perfectionism has been dealt with very little. Some questionnaires devote a sub-category to it, such as the Eating Disorder Inventory and the Irrational Beliefs Test. However, recently, it has been recognized that perfectionism is a multidimensional construct. Two Multidimensional Perfectionism Scales have been developed and investigated in relative isolation. Frost, Marten, Lahart and Rosenblate defined perfectionism as the setting of excessively high standards for performance associated with critical self-evaluation. Six dimensions are described: concern over making mistakes, high personal standards, parental expectations, parental criticism, doubt about quality of performance and organization. Internal consistency and validity have been established (25, 26). Hewitt and Flett (30, 31, 33, 35) have developed another approach where three dimensions of perfectionism are described: SOP (Self Oriented Perfectionism) related to high standards and self criticism, SPP (Socially Prescribed Perfectionism) related to the need of approval from others and fear of negative evaluation, OOP (Other-Oriented Perfectionism) reflecting a tendency to set high expectations for others and to evaluate them in a demanding way; this component is related, especially for males, to self-esteem, hostility and authoritarianism. Validity and internal consistency have been established too (30, 31, 35). The Frost and al's Multidimensional Perfectionism Scale and the Hewitt and Flett's scales are closely associated, except concerning the OOP. Because this component could provide new information, we have chosen the second scale, referring to the French translation and validation of Labrecque (45). EMP is the French name of MPS; it is a self-report questionnaire of 45 questions, in fact three subscales of 15 items rated on a 7-point Likert-type scale. MPS was administered to 617 first year students at the university of Liège (table II). Differences are considered according to gender and experience of failure i.e. the fact of repeating an academic year. We realized a component analysis with promax rotation. Among the different possibilities offered by the scree-test the choice of a 4 factor solution stresses the original structure: SOP (14 items), SPP (12 items), OOP (9 items) and anti OOP (10 items); the last one is additional but allows for respecting semantics and saturation of the items. The first aim of confirming validity and internal consistency is satisfactory. In other respects the multidimensional structure of the concept leads to consideration of a positive, adaptive perfectionism and a more negative perfectionism, facilitating psychopathology (59, 60, 61). So it seems interesting to compare the different components of MPS in order to find an eventual sex-failure effect. The evaluation of perfectionism is obvious, considering it as a personality trait, but it can be used also in taking into account stress and its impact, for instance that of academic performance (29, 37, 39, 58). Conferring on MPS more pertinence in gender differentiation and failure evaluation is an other goal of this research. Through the particular choice of statistical results, sex and sex-failure effects can be demonstrated: a MANOVA underlines sex effect (lambda de Wilks = 0.96, p = 0.001) and sex-failure effect (lambda de Wilks = 0.98, p = 0.05). Structure of MPS is different in four groups (FE: women with failure, FnE: women without failure, ME: men with failure, MnE: men without failure). ANOVA show differences of MPS3, MPS1 and MPS2. Far more promising is the use of LISREL method allowing for the construction of a coherent model of relationships between some dimensions of MPS and Test-Anxiety, approached here with THEE (test d'habileté aux études et à leur évaluation) French abbreviated version (49) of TASTE (Test for Ability to Study and Evaluation). In fact according to the literature of fear of failure, girls score higher on anxiety and procrastination but less on self-confidence. The structural model shows different pathways, more especially between SPP (socially prescribed perfectionism), T2 (sense of incompetence) and T1 (anxiety). SOP (self oriented perfectionism) and SPP (socially prescribed perfectionism) by girls are very much correlated; it seems that they are more subjected to society and its exigencies of studying but consequently they are more at risk of anxiety and a sense of incompetence. SOP (self oriented perfectionism) by boys functions more indiscriminately of SPP (socially prescribed perfectionism) and is negatively correlated with self-incompetence; boys are more self-confident but they usually procrastinate more probably because failure expectancies would be particularly harmful for their self-esteem; consequently, failure should be related to something else than their own capacity; this may be an explanation of the high rate of male dropouts and failure in the first year at the university of Liège; also a factor explaining the female domination at the university. In the same way the first choice of studies is moving towards shorter and less difficult orientation (46). In case of failure the model is very similar according to gender: SOP (self oriented perfectionism) and T1 (anxiety) are directly connected; SOP and SPP are in this case better correlated by boys but the path between SPP, sense of incompetence and anxiety is less significant than in girls. In conclusion, providing some modifications according to semantics, the choice of a four factor solution allows for confirmation of the original structure of MPS and for internal consistency. The different components of MPS vary according to gender: SOP and more OOP discriminate men and women; SPP allows for differentiating women with failure. A structural model enhances the role of perfectionism in the cognitive and behavioural contexts; for instance it clarifies its action on fear of failure and success rates according to gender.

Adult↗
PubMed2005

Neural representation of bitter taste in the nucleus of the solitary tract.

Based on the molecular findings that many bitter taste receptors (T2Rs) are expressed within the same receptor cells, it has been proposed that bitter taste is encoded by the activation of discrete neural elements. Here we examined how a variety of bitter stimuli are represented by neural activity in central gustatory neurons. Taste responses (spikes/s) evoked by bathing the tongue and palate with intensity-matched concentrations (in M) of 2 sugars (0.32 sucrose and 0.5 D-fructose), ethanol (40%), 4 salts (0.01 NaCl, 0.008 NaNO(3), 0.01 MgCl(2), and 0.05 KCl), 2 acids (0.003 HCl and 0.005 citric acid), and 10 bitter ligands (0.007 quinine-HCl, 0.015 denatonium benzoate, 0.003 l-cysteine, 0.001 nicotine, 0.005 strychnine-HCl, 0.04 tetraethylammonium chloride, 0.03 atropine-SO(4), 0.005 brucine-SO(4), 0.03 papaverine-HCl, and 0.009 sparteine) were recorded from 51 neurons in the nucleus of the solitary tract of anesthetized rats. Cluster analysis was used to categorize neurons into types based on responses to sucrose, NaCl, HCl, and quinine-HCl. Three groupings emerged: type S (responded optimally to sweets), type N (sodium-optimal), and type H/Q (responded robustly to bitters, acids, and salts). Multivariate analyses revealed that across-neuron patterns of response among bitter stimuli were strongly correlated. However, neural type H/Q, which was most responsive to bitter tastants, was not differentially sensitive to bitter stimuli and Na(+) salts, which rats perceive as distinct. Thus central neurons most responsive to bitter substances receive significant input from receptors that mediate other tastes, indicating that bitter stimuli are not represented by activity in specifically tuned neurons.

Action Potentials↗
PubMed2005

Screening of bitterness-suppressing agents for quinine: the use of molecularly imprinted polymers.

The purpose of the present study was to examine the possibility of using molecularly imprinted polymers (MIPs) to screen for bitterness-suppressing agents. Quinine was selected as the bitter substance standard. L-arginine (L-Arg), L-ornithine (L-Orn), L-lysine (L-Lys), and L-citrulline (L-Ctr) were tested as bitterness suppressant candidates. In a high-performance liquid chromatography study using a uniformly sized MIP for cinchonidine, which has a very similar structure to quinine, the retention factor (k) of quinine was significantly shortened by the addition of L-Arg or L-Orn to the mobile phase, whereas slight or no decrease was observed when L-Ctr and L-Lys were added. The abilities of these amino acids to decrease the k of quinine were ranked in the following order: L-Arg = (L-Orn >(L-Ctr >>(L-Lys. A linear relationship between the reciprocal of k and the concentration of the amino acids indicated a single competitive model at a single site. The magnitude of the association constants obtained seemed to be directly related to the inhibitory effect of the test substances on the affinity of quinine for the receptor site. Nuclear magnetic resonance and molecular modeling studies suggested a one-to-two hydrogen-bonding-based complex formation of one quinine molecule with two methacrylic acid molecules (Q-2MAA) in chloroform. In the molecular modeling studies, the N--N distance of the quinine molecule in the assumed Q-2MAA complex was calculated to be 5.12 angstroms, similar to the N - N distances of the two amino acid complexes (L-Arg-2MAA, L-Orn-2MAA), which were 4.84 and 5.30 angstroms, respectively. This suggests that L-Arg and L-Orn may compete with the quinine molecule in the cinchonidine-imprinted space. Finally, the results of human gustatory sensation tests correlated well with the MIP data. The proposed method using MIPs seems to have a potential for screening bitterness-suppressing agents for quinine.

Arginine↗
PubMed1995

Psychosocial determinants of fruit and vegetable consumption.

Psychosocial correlates of fruit and vegetable consumption were studied in an adult Dutch population (n = 367) based on the ASE model of attitudes, social influence and self-efficacy. Attitudes were a summation of beliefs about taste, different health consequences, and costs in time and money. Social influences were measured through the social stimulation respondents expected to get from important others to consume adequate amounts of fruit and vegetables and by asking the subjects about the behaviour of important others. Self-efficacy reflected the respondents' ability to consume adequate amounts of fruit and vegetables in various situations. Self-efficacy and attitudes were consistently and significantly associated with consumption of boiled or otherwise heated vegetables, of salads, and of fruit. Furthermore, respondents reporting low consumption of these food groups had lower self-efficacy expectations and less positive attitudes than subjects with relatively high consumption of fruit and vegetables. It is concluded that nutrition education aimed at stimulating fruit and vegetable consumption should focus especially on changing attitudes and self efficacy expectations.

Adult↗