PubMed HealthSearch

SEARCH · PubMed Health

Results for “Taste modeling”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

Development of altered taste preferences in tumor-bearing rats.

Experimental tumors induce a decline in food intake that may derive from changes in taste or the development of taste aversions. The preferences of tumor-bearing (TB) and non-tumor-bearing (NTB) rats for five chemicals (three palatable and two aversive taste stimuli) were studied in an animal model of experimental cancer employing the methylcholanthrene (MCA) sarcoma. In protocol 1, five groups of Fischer 344 rats were given 23-h, two-bottle preference tests (taste solution vs. water) daily from day 3 after tumor implantation until spontaneous death occurred. Both NTB and TB rats avoided quinine hydrochloride and hydrochloric acid solutions throughout the experiment indicating that tumor growth produced no disruption in the animals' perception of these normally aversive tastes. In both groups, preference for sucrose (88% to 97%) and saccharin (75% to 93%) remained high until days 22 and 17 respectively, but tended to decline with advanced tumor growth. In both cases, a reduction in total calorie intake preceded the changes in sucrose or saccharin preference by several days. With or without a tumor, rats exhibited approximately 50% preference for NaCl at all times. In protocol 2, a four-bottle preference test (sucrose vs. saccharin vs. NaCl vs. water) was administered before tumor implantation and again 3 weeks later when a decline in food intake was evident. Both TB and NTB rats displayed a dominant preference for sucrose over saccharin, NaCl, and water at the pre- and posttests. However, a comparison of the difference scores (pre- minus postimplantation) of NTB and TB rats showed a small but significant suppression of TB animals' preference for sucrose. The altered preferences for sweet but not salt taste stimuli suggest that food-related taste cues may be more susceptible to the development of taste aversions during cancer. However the contribution of taste changes to the anorexia of cancer remains unclear and it is possible that the changes in taste preference may be secondary to the reduction in food intake.

Animals

Mealtime satisfaction in public nursing homes: Associations with sensory, foodservice, and dining-room environment factors.

Satisfaction with meals is commonly used to assess how meals are experienced in nursing homes (NH), although limited evidence compares breakfast, lunch, and dinner within a unified analytical framework. This study examined the sensory and contextual factors associated with satisfaction across meals in public NH. A cross-sectional observational study was conducted using structured interviews with 290 residents aged &#x2265;60 years (median 85 years; Q1-Q3: 81-88; 63.1% women) from 19 facilities in Galicia, Spain. Overall satisfaction and 12 factors related to sensory attributes of the food, foodservice characteristics, and dining-room environment were assessed using a 5-point Likert scale. Descriptive analyses used medians and quartiles, and group comparisons were performed using nonparametric tests. Three multivariable linear regression models, one per meal, were estimated including all factors simultaneously. In adjusted models, the largest standardized coefficients were observed for taste (lunch: &#x3b2;&#xa0;=&#xa0;0.366; P&#xa0;<&#xa0;0.001), food temperature at serving (dinner: &#x3b2;&#xa0;=&#xa0;0.319; P&#xa0;<&#xa0;0.001), and menu variety (breakfast: &#x3b2;&#xa0;=&#xa0;0.301; P&#xa0;<&#xa0;0.001). Taste, food temperature at serving, menu variety, and meal schedule showed statistically significant coefficients in all models. Overall satisfaction was lower at dinner (29.0%&#xa0;&#x2265;&#xa0;4) than at breakfast (34.8%) and lunch (34.5%) (P&#xa0;=&#xa0;0.003). Selected dining-room environment factors showed significant coefficients in meal-specific models. Mealtime satisfaction was mainly associated with sensory and contextual factors related to how meals are perceived. Lower satisfaction at dinner suggests this mealtime as a relevant context for understanding variations in meal perception in NH residents.

Humans

Formation of taste aversion and preference in protein synthesis inhibition in rats.

The investigation was devoted to the role of the synthesis of protein and peptide factors during the formation of chemosensory memory in rats. Two models of gustatory memorization were used: conditioned taste aversion (CTA), induced by the association of the taste of saccharine with a toxic injection of lithium chloride, and enhanced taste preference (ETP), induced by the influence of preliminary drinking of a saccharine solution on its repeat consumption. It was found that, under conditions of the inhibition of protein synthesis in the brain of 43% by cycloheximide and of 59% by 8-azaguanine, CTA does not form. ETP does not form under the influence of cycloheximide, but not [sic] of 8-azaguanine. A hypothesis was advanced regarding the participation of a varied spectrum of protein and peptide substances in the formation of taste aversion and preference. An influence of protein synthesis blockers on the process of retrieval of gustatory memory was not found.

Animals

Characteristic response to taste stimuli of the intensities of higher harmonics in an electrochemical oscillatory system.

In general, the electrochemical characteristics of solid/liquid or liquid/liquid interfaces are highly nonlinear, i.e., the capacitance changes markedly according to the applied voltage. In this paper, we propose a novel method for evaluating these nonlinear characteristics quantitatively. That is, a sinusoidal voltage source is applied to a test solution and the waveform of the output current is analyzed by Fourier transformation. It is shown theoretically that higher harmonic components in the Fourier transformation afford us useful information on nonlinear behavior. It is stressed that our technique is entirely different from the classical impedance method, i.e., nonlinear components of the impedance can be evaluated in our method, having been ignored previously in the classical impedance measurement. As an application of this method, we have studied the effect of taste compounds on the intensities of the higher harmonics, using an electrochemical cell containing an aqueous solution of sodium oleate. It has been found that the intensities of the higher harmonics exhibit characteristic changes upon the addition of taste compounds, the change being dependent upon the taste category. The characteristic response to taste compounds in the electrochemical nonlinearity is discussed in relation to the experimental trend of the dynamic isotherm for oleic acid at an air/water interface.

Animals

Transganglionic degeneration in the gustatory system consequent to chorda tympani damage.

The chorda tympani taste nerve is prone to damage in humans. Chorda tympani damage results in taste loss accompanied by altered taste sensations, e.g., phantom tastes. To understand taste alterations this study explores the central and peripheral anatomical consequences of taste nerve injury in an animal model. The chorda tympani was severed in the middle ear of hamsters and the animals were allowed to survive for 2-161 days when sections of the brain were stained for degenerating axons with the Fink-Heimer method. Degenerating axons were present in the chorda tympani termination zone in the nucleus of the solitary tract of every case. Thus, peripheral nerve damage in the taste system results in degeneration of central axonal endings as in other sensory systems (e.g., trigeminal, vestibular). To evaluate whether the central degeneration results from ganglion cell death, geniculate ganglion cells were labeled with Fast blue by tongue injections before neurotomy, and the cells were counted 13-48 days after neurotomy. Numbers of labeled cells from experimental ganglia did not differ significantly from those in control ganglia. Moreover, the experimental cells could be double-labeled by tongue injections with a second marker, diamidino yellow or nuclear yellow, after 40 days postneurotomy. We conclude that degeneration of central axons after taste nerve section represents a long-lasting transganglionic process that likely disrupts the synaptology of the central taste system. The altered synaptology could relate to taste phenomena of central origin reported for nerve-injured patients. Geniculate ganglion cells generally survive neurotomy and can regenerate axons to the tongue.

Animals

Genome-Wide Association Analyses of Bitter Food Preferences Link Genetic Loci to Sensory and Metabolic Pathways.

BACKGROUND: Genetic variation is implicated in individual preferences for bitter-tasting foods. However, previous studies have focused on candidate genes and limited varieties of bitter-tasting foods and have treated food preference scale responses as continuous data. OBJECTIVES: The present investigation aimed to identify genetic variants associated with preferences for bitter-tasting foods using ordinal multinomial regression models in genome-wide association studies (GWAS). In addition, post-GWAS functional annotation and mapping, genetic correlations, and associations with dietary intake were examined. METHODS: Food preference and genome-wide genotyping data were used from the UK Biobank (n = 125,578). Preference data from Likert scale rankings (from 1 to 9) for 12 individual foods were analyzed using ordinal multinomial regression GWAS. In addition, 1 composite continuous variable was created for preference for cruciferous vegetables as a group and analyzed using a linear mixed-model GWAS to enable the calculation of a polygenic score (PGS) for cruciferous vegetable preference. Convergent validity of GWAS results was assessed with dietary intake data for the same food items in the CARTaGENE cohort (n = 8176). Post-GWAS gene-level and pathway-level association analyses were conducted in MAGMA (Multimarker Analysis of GenoMic Annotation). RESULTS: Forty-six single-nucleotide polymorphisms (SNPs) were identified for preferences for 11 bitter-tasting foods at a genome-wide significance level (P < 7.14 &#xd7; 10-9). Gene-set analysis for enrichment identified pathways related to caffeine metabolism and bitter taste perception for preference of coffee without sugar and grapefruit, respectively. Genes with higher expression in brain tissues showed stronger genetic associations with cruciferous vegetable preference. The PGS for cruciferous vegetable preference was weakly correlated with intake (r = 0.05, P < 0.0001), but individual SNPs were not associated with intake in a consistent manner. CONCLUSIONS: Genetic variation contributes to preferences for bitter-tasting foods among adults, and some links with food intake are detectable. Nevertheless, effect sizes are small and inconsistent, reflecting the multifactorial complexity of food intake.

bitter taste

Examination of specific nutrition/health behaviors using a social cognitive model.

Nutrition intervention programs are not always successful. In some cases, an insufficient understanding of the interrelationships among factors influencing health behaviors may be responsible for the failures. This study used social cognitive theory, a framework for studying behaviors, to structure the relationships between measurable factors important to the frequency of health-oriented food consumption. We developed a model that incorporated factors for social environment, reinforcement, commitment, behavior modeling, knowledge, and attitude relative to the frequency of consumption of four beverages (whole milk, low-fat/skin milk, regular soda, and diet soda). Four-hundred fifty-seven middle-aged adults (mean age, 47 years; 58% female) and 709 college students (mean age, 21 years; 50% female) responded to a written questionnaire designed as a self-report on frequency of consumption and measures for 10 social cognitive variables. For all four beverages, the model explained 35% or more of the variance in frequency of consumption, thus confirming its predictive power. We used the statistical approach known as path analysis to examine the relationships within the model. The analysis demonstrated that factors influencing the consumption varied between the two age groups (e.g., nutrition knowledge was related to attitude in adult soda-drinking models but not in student soda-drinking models) and between forms of the beverages (e.g., for student models, nutrition knowledge was related to taste enjoyment for low-fat/skim milk but not for whole milk).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Neurotrophic factors in the tongue: expression patterns, biological activity, relation to innervation and studies of neurotrophin knockout mice.

How taste buds develop and how they become innervated has been a matter of debate for a long time. Brain-derived neurotropic factor (BDNF) and neurotrophin-3 (NT3) mRNA expression patterns suggested a possible involvement in lingual gustatory and somatosensory innervation. Studies of null-mutated mice showed that BDNF-/- mice had few abnormal taste buds and were unable to discriminate between primary tastes. NT3-/- mice had a severe loss of lingual somatosensory innervation. These novel findings may have clinical implications in rare human conditions such as familial dysautonomia and/or in more common cases of problems with loss of taste and sensation in the mouth such as those seen after injury to the nerves, either by accident or following oral/facial surgery. Knowledge about which proteins that are required to stimulate nerve fibers to grow into mucous membranes of the oral cavity during development suggests that these same proteins might become helpful in stimulating regeneration of injured nerves in patients, perhaps helping them to regain lost taste and sensory functions. Here, the presence of glial cell-derived neurotrophic factor (GDNF) families of neurotrophic factors and receptors in the tongue is also discussed. Further, a model for the development and innervation of taste buds in mammals is proposed.

Animals

Mechanism of nonlinear responses of taste cells to mixed tastes.

Coupling between ionic flows through different kinds of channels affects essentially the responses of multisensitive taste cells to single- and mixed-taste stimuli. The mechanism of taste transduction is studied by using a realistic model of the multisensitive cells of the rat. The transduction pathways considered are amiloride-sensitive Na+ channels for NaCl and HCl and adenosine 3',5'-cyclic monophosphate-mediating K+ channels for sucrose. Contributions of paracellular pathways and taste-insensitive ionic channels are also studied. The calculated responses of various multisensitive cells induced by single stimuli of NaCl, HCl, or sucrose reproduce experimentally observed responses as well. The two main conclusions are as follows. 1) Whether the response of a cell to a binary mixture becomes synergetic or antagonistic can be estimated from the individual responses of the cell to each component of the mixture. 2) Whether the response is enhanced or suppressed by addition of a new taste to the original taste can be determined, for most receptive cells, from a viewpoint of linear superposition of the individual responses.

Animals

What's so special about special visceral?

The brainstem is classically divided into functional columns including special and general subdivisions for somatic and visceral components. The term 'special visceral motor' is applied to branchiomotor nuclei, while 'special visceral sensory' refers to nuclei devoted to incoming gustatory and olfactory senses. The use of the term 'special visceral motor' is questioned in that the branchiomotor neurons function more like general somatic than general visceral motoneurons. The designation of taste and smell as 'special visceral sensory' systems seems inconsistent on several bases. First, taste and smell are not homologous systems: (1) the receptors are grossly dissimilar in morphology and relationship to other elements of the nervous system; (2) the two systems mediate very different behaviors and respond to different types of chemical stimuli, and (3) chemosensory systems are not 'special' (i.e. limited to cranial nerves) in that solitary chemoreceptor cells, which are distributed across the body surface, can be innervated by spinal or cranial nerves. Finally, taste is considered 'special' because it involves specialized chemosensory end organs; the visceral nerves also provide innervation to other specialized chemoreceptors (e.g. carotid body) which are considered part of the general visceral sensory system. Thus the term 'special visceral sensory' appears without solid foundation when applied to gustatory systems in contradistinction to nongustatory branchial and thoracic interoceptive systems. A reformulation of the functional columns of the brainstem is suggested in which six columns can be identified: (1) somatic motor; (2) branchial motor; (3) visceral motor; (4) visceral sensory; (5) somatic sensory, and (6) hair cell (dorsolateral placode) sensory.

Animals

[Psychophysics of sweet taste. II. Statistical theory of the stimulus-response behavior of sweet taste receptors].

Considering various conditions of adaptation, the authors determined the Weber discrimination thresholds for the sweet taste of saccharose. When the adaptation to the basic stimulus is maintained and use is made of the differential coefficient behaviour, the discrimination threshold is an exponential function of the concentration. The discrimination threshold is by definition that amount of stimulant per unit of volume which will produce an effect of the magnitude of 1. Consequently, the numbers of moles being substituted, its reciprocal, the probability of obtaining a stimulus response, is greater than 1. A differential equation, namely (formula: see text), can be formulated as the basis of the stimulus-response behaviour of saccharose, the integration of which yields a discrimination characteristic expressed as (formula: see text). S = concentration of the solution as the stimulus intensity; R = stimulus response expressed in steps. The parameter b is the maximum probability of the stimulus response and can be termed substance-specific concentration coefficient. Rm is the maximum step number when the stimulus intensity tends to infinity; it is also substance-specific. As this characteristic involves both the proportional factors and the differential coefficients, it is called P-D characteristic. From this invariant relationship, the static P characteristic for a very slow increase in stimulus intensity can be derived. When the adaptation to the basic stimulus is abolished by mouth rinsing between tests in paired comparisons, the dependence of the discrimination threshold on the concentration is more than exponential. The stimulus-response characteristics obtained with different time-courses of stimulation are approximated by both the Weber-Fechner and the Stevens law.

Animals

Dynamic contrast: a sensory contribution to palatability.

By focusing on a sensory model for palatability, the "ice-cream effect", we speculate on some principles underlying palatability. We propose that the most highly palatable foods are likely to have higher levels of "dynamic contrast" (moment-to-moment sensory contrast from the everchanging properties of foods manipulated in the mouth). The sensory feature contributing most to dynamic contrast seems to be somatosensation. Texture, for example, over the course of masticating a crunchy food, changes markedly such that each alteration contributes differently and dynamically to sensory contrast. Our purpose herein is to propose that dynamic contrast contributes significantly to palatability of foods and beverages.

Animals

Profitability and acceptability of fat- and sodium-modified hot entrees in a worksite cafeteria.

OBJECTIVES: To compare the acceptability of fat- and sodium-modified entrees before and after implementation of a marketing program and to determine the effect offering and marketing these healthful entrees had on total cafeteria and entree sales in a worksite cafeteria. DESIGN: The research was conducted in five phases, including sales data collection, acceptance testing of unmodified hot entrees, acceptance testing of modified entrees, and implementation of a marketing campaign for promoting low-fat, sodium-controlled food selections. SETTING: The Kansas Farm Bureau and Affiliated Services (KFB) employee cafeteria. SUBJECTS: KFB employees who ate lunch in the employee cafeteria and were willing to participate in the study. MAIN OUTCOME MEASURES: Sales data (percent of customers purchasing a modified entree and sales of modified entree as a percent of total sales); nutrient analysis data (energy, grams of total fat, percent of energy from fat, milligrams of cholesterol, and milligrams of sodium); and acceptability data (11 characteristics were measured using a seven-point hedonic scale). STATISTICAL ANALYSIS PERFORMED: General linear model analysis of variance was used to compare sales data from phases 1 to 5 and to compare acceptability data from phases 2 to 4. RESULTS: No significant differences in sales data were observed during the 7-month study. No significant changes in overall acceptability were found for any entree. However, customers tended to rate overall acceptability higher when entrees were marketed as lower in fat and sodium. APPLICATIONS/CONCLUSIONS: Customers in worksite cafeterias may be more willing to tolerate changes in flavor attributes when modified entrees are marketed as "healthful" and nutrition information is available.

Diet, Fat-Restricted

Time course of burn to repeated applications of capsaicin.

Human subjects rated the burn of 100 ppm capsaicin applied to the tongue via filter paper and replaced every minute. Capsaicin was presented at a constant concentration for 10 min, followed by 10 min of blank stimuli; this sequence was then repeated once. Both sensitization and desensitization were seen. A dynamic model composed of a level detector and change detector predicted the results and also previous data. Thus, the model provides a parsimonious description of responses to constant and intermittent capsaicin stimulation.

Adult