Chemosensory Perception最新文献

If odor and taste are presented in a context with high temporal proximity, they are more likely to be perceived as a flavor object. However, if odor and taste are presented in a context with low temporal proximity as well as a context with high temporal proximity, they may be less likely to be perceived as a flavor object. Based on these expectations, we hypothesized that sensitivity to temporal difference between two sensations (i.e., temporal resolution of synchrony perception) is higher when odor and taste are presented under a condition including a context with low temporal proximity than under a condition excluding it.

To test this hypothesis, we required participants to determine whether olfactory and gustatory stimuli were presented simultaneously under a condition including a context with low temporal proximity (wide-range condition) and under a condition excluding it. In addition, we also tested visual–gustatory and olfactory–visual combinations.

The temporal resolution was significantly higher under the wide-range condition than under the narrow-range condition, supporting our hypothesis.

For odor and taste to be perceived as flavor, people not only must experience high temporal proximity of the two sensations but also must not experience low temporal proximity of the two sensations.

The findings of this study suggest that the higher the sensitivity to a temporal difference between odor and taste, the lower the robustness of a flavor object (i.e., the strength of the odor–taste connection).

The trigeminal system is a chemosensory system, next to smell and taste, allowing intranasal sensations such as freshness, spiciness, etc. The lateralization task is used to measure trigeminal sensitivity and consists in identifying the nostril stimulated by an odorous substance in a two-alternative forced-choice procedure. However, when performed in the standard method, this task takes almost 25 to 30?min to administer and only gives access to few information.

The aim of this pilot study was to compare two alternative methods of administering the lateralization task with the standard method in a group of 53 participants (41.6?years; 32 women). Specifically, we compared (1) the standard method of 40 constant stimuli with a duration of 500?ms, (2) a short version of 20 variable stimuli ranging from 200 to 600?ms (different duration method—DD), and (3) an automatic adaptive staircase method where the test adjusts the duration of stimulation according to the participant’s responses (adaptive duration method—AD).

Based on the number of correct answers and the thresholds obtained with the automatic staircase method, the average scores for the two alternative methods correlate with the score at the standard method. In addition, both alternative methods are able to discriminate between participants with a high sensitivity and those with a lower sensitivity. Finally, the DD method is significantly shorter in terms of administration time than the other two methods.

This pilot study presents two novel methods to evaluate trigeminal sensitivity which each have a specific superiority over the established technique.

The DD method cuts testing time in half whereas the AD method provides threshold estimates for individual nostrils.

Moringa oleifera (Lam.) is a nutritious plant species that has the potential to alleviate food insecurity in low- and middle-income regions. However, the bitter taste associated with M. oleifera leaves is a key barrier to its acceptance as food. It was hypothesized that reducing the bitterness in M. oleifera-fortified instant soups would increase their acceptance.

Acid soaking and the addition of a sweetener (aspartame) were examined for their effectiveness in the removal of bitter taste in M. oleifera leaves. Fifty assessors rated the acceptance and perceived bitterness in a randomized complete block sensory evaluation. South Indian instant soup samples with 0%, 50% and 100% replacement of vegetable powder with M. oleifera leaf powder were evaluated.

Acceptance for M. oleifera-fortified instant soups was higher for samples with lower perceived bitterness. Addition of sweetener was found to be effective in increasing the acceptability and reducing the perceived bitterness at the 50% replacement level, but not at the 100% replacement level. Perceived bitterness did not decrease in formulations with acid-soaked M. oleifera leaves.

Undesirable organoleptic properties need to be masked or removed for the acceptance of M. oleifera leaves as a regular food. We recommend that foods fortified with M. oleifera to include a sweet excipient to reduce the bitter tastes.

Fortified instant soup samples with reduced perceived bitterness had increased acceptability. Debittered M. oleifera-fortified foods would appeal to consumers, which would increase their consumption and could lead to reduced prevalence of micronutrient deficiencies.

A card-type odor identification test called the “Open Essence (OE),” consisting of 12 types of everyday odors familiar to Japanese people, was recently developed. In this study, we calculated the cut-off value of the OE score for screening for age-related olfactory decline.

Participants aged 23 to 91 performed the OE test. After we confirmed that the OE score differed significantly between young/middle-aged adults (under 65?years old) and elderly adults (over 65?years old), we assumed that the young/middle-aged group had normal olfactory ability, whereas the elderly group had experienced a decline in odor identification ability. We then performed receiver operating characteristic (ROC) analysis using the OE score.

The cut-off value of the OE score for screening for age-related olfactory decline, calculated on the basis of the ROC curve, was 8.

Individuals with the OE scores of 7 or less may have age-related olfactory decline. Our finding suggests that this cut-off value could be used to screen Japanese people with age-related olfactory decline.

The OE test is self-administered and has a cut-off value of the OE score for screening for age-related olfactory decline. Therefore, it is expected to be useful in mass screening for elderly adults.

Higher psychopathic traits have been consistently associated with poorer olfactory abilities; however, only one study as reported by Sagioglou and Greitemeyer (Appetite 96:299-308, 2016) has explored whether psychopathy is linked to taste?perception. Using self-report measures, Sagioglou and Greitemeyer (2016) found higher psychopathic traits were associated with higher liking ratings for bitter stimuli. The aim of the current study was to determine whether direct assessment of taste perception was linked with psychopathic traits.

Seventy-eight participants (41 females) rated four tastants (i.e. bitter, sweet, salty and sour), at four concentrations. For each of the 16 stimuli, participants rated how much they liked, how disgusting and how intense they perceived each tastant.

Contrary to previous findings, higher psychopathic traits were not associated with higher liking ratings for bitter stimuli, but instead associated with higher disgust ratings of bitter stimuli. Moreover, higher psychopathic traits were associated with higher taste intensity ratings, suggesting psychopathy may be associated with increased taste sensitivity.

Higher degrees of psychopathic traits are associated with higher disgust ratings of bitter stimuli.

The findings suggest that the chemical senses may be another confirmatory method for differentiating those with low and high psychopathic traits.

Previous studies have described a number of protein tyrosine kinases (epidermal growth factor receptor, ErbB2, ErbB3, and c-kit) to be expressed in taste bud cells, their innervating nerves, and in developing taste papillae.

Immunohistochemical staining of mouse taste buds was performed to characterize the expression patterns of the c-kit receptor in taste.

Here we demonstrate that c-kit positive cells are exclusively co-localized with T1R3 (which forms one half of the receptors for sweet and umami taste) in adult taste cells.

This implies that c-kit+ cells are primarily taste cells that respond to sweet and umami, but not to bitter, sour, or salty. These data indicate that the control of c-kit activation may be important for proper taste bud formation and may aid in the maintenance of this specific mature taste cell subpopulation.

Further characterization of the functional role of c-kit in taste may lead to superior taste cell cultures or organoids, and elucidate mechanisms of taste cell regulation.