Chemosensory Perception最新文献

Nasal symptoms can be associated with indoor mold overgrowth, even absent allergic sensitization. An alternative pathogenic mechanism—mucous membrane irritation by microbial volatile organic compounds (MVOCs)—has been proposed. We conducted a pilot human study of nasal irritation by two MVOCs, 1-octen-3-ol and 3-octanol, hypothesizing that the former would show greater irritant potency based upon the compounds’ relative irritant potencies in rodents.

Serial dilutions of the test compounds were prepared in odorless mineral oil vehicle, with headspace vapor concentrations documented by gas chromatography. Eight-step dilution series (with ascending concentration ratios ~?1.34) were prepared. A nasal lateralization protocol was utilized. Ten subjects (seven females), aged 23–69, were each tested on four separate days, with each test compound being presented twice in alternating/counterbalanced order over the four testing days. Individual lateralization thresholds for a given compound, taken as dilution step, were averaged across subjects.

Eight subjects were reliably able to lateralize stimuli for one or both test compounds. Among the 32 testing sessions completed by these eight subjects, 1-octen-3-ol was successfully lateralized in 15/16 and 3-octanol in 11/16. The mean dilution step at threshold was 3.125 for 1-octen-3-ol and 2.58 for 3-octanol.

When presented as brief (~?4?s.) stimuli, high concentrations of identified MVOCs can act as nasal mucosal irritants. Both detectability and repeatability, but not absolute (ppm) thresholds, exhibited compound-specific trends consistent with animal experimental data. Studies involving more protracted exposures with larger sample sizes may yield more realistic irritant threshold estimates.

At sufficiently high concentrations, MVOCs can produce nasal irritation in humans.

The olfactory system is associated with several brain areas that might be involved in neurodegenerative processes and neurodevelopmental disorders. For this reason, investigation of the olfactory function plays an important role in the assessment of individuals with autism spectrum disorder (ASD), a neurodevelopmental disorder characterized by an impairment in social communication and by a restricted and repetitive pattern of behaviors. The aim of this study was to examine odor detection threshold, discrimination, and identification in participants with ASD compared to typically developing (TD) controls.

Thirty Italian subjects (15 with ASD, mean age 19?±?0.5?years, and 15 TD controls, mean age 21.7?±?0.4?years) were evaluated by means of the Sniffin’ Sticks extended test through three different parameters, odor detection threshold, discrimination, and identification, and their sum the threshold, discrimination, and identification (TDI) score.

Our results indicated that the participants with ASD showed an impairment in odor detection threshold and TDI score compared to TD controls. No differences were found in odor identification and discrimination. Participants with ASD were significantly poorer in correctly identifying the following odors: leather, apple, rose, cinnamon, garlic, cloves, and anis. However, they were significantly better than TD controls in correctly identifying the odor of the following fruits: orange, banana, and lemon.

Our data provide a comprehensive evaluation of the three olfactory components in an Italian population and confirm an impaired odor detection threshold and TDI score in subjects with ASD compared to TD controls. In conclusion, these results suggest that the Sniffin’ Sticks extended test might be a valid tool in early detection and differential diagnosis of neurodevelopmental disorders.

Several studies evaluated the influence of cultural components on the Sniffin’ Sticks Identification Test in different countries. The aim of this study was to analyze the olfactory function in a large sample of healthy subjects living in Sardinia, an island known for its historic genetic isolation, in relation to different age ranges to provide new data in healthy Sardinian subjects.

Olfactory perception of 161 participants (108 females and 53 males; age range 19–78?years) was assessed through three different parameters: odor detection threshold, discrimination, and identification by means of the Sniffin’Sticks Extended test (SST).

Our results show that young adults were generally normosmic, while in subjects over 55, a statistically significant age-related decrease of all the parameters was observed. Regarding odor identification task, a few, such as leather, apples, lemons, cloves, and pineapples, were frequently incorrectly identified by participants probably due to the similarities between the odors and distractors.

Our data provide a comprehensive evaluation of the three olfactory components in the Sardinian population and confirm a decrease in the odor detection threshold, discrimination and identification as well as in the global TDI score in subjects over 55?years of age. These results may be useful in providing normative values for routine clinical use of the SSET in Sardinian subjects.

Brain processing of odorants in different stages during adolescence is not well understood. This study aimed to investigate differences in brain processing of pleasant and unpleasant odors between adolescent girls at different ages.

Eleven girls aged 9–10?years and 20 girls aged 15–16?years participated in an fMRI study (1.5?T, repetition time 2.5?s) where two odorants (peach and n-butanol) were delivered passively to the participants’ nostrils. Psychophysical measurements for odor intensity, pleasantness, and familiarity were recorded.

Compared to older ones, younger girls were less familiar with peach odor. Stronger brain activation of piriform cortex, amygdala, bilateral insular cortex, anterior cingulate cortex, and dorsal striatum (caudate and putamen) was observed in younger vs. older girls, whereas in older girls there was no superior activation in olfactory regions as compared to younger participants.

The findings demonstrating differences of brain activation patterns between girls of two age groups may reflect olfactory perception development during adolescence.

The US Food and Drug Administration banned most “sweet” flavorants for use in cigarettes due to the concern that sweet flavors appeal to young, beginning smokers. However, many of the same flavors, including fruity and confection-associated aromas (e.g., vanilla), are still used in e-cigarettes. Sweet flavors may have a number of effects, including enhancement of the taste of other ingredients. The current work focused on the impact of model flavorants on the taste of a mixture of propylene glycol and vegetable glycerine, solvents used in most e-cigarettes and related products.

A device delivered mixtures of propylene glycol and vegetable glycerine into the mouth in parallel with puffs of clean air (control) or odorized air. Aromas included two “fruity” esters (“pineapple” and “banana”), two confection-associated aromas (“vanilla” and “caramel/malty”), menthol (not a “sweet” aroma, but commonly used in e-cigarettes), and a “burnt” aroma not expected to enhance flavor. Twenty young adults, aged 18–25, rated the sweetness, bitterness, and pleasantness of all stimuli (within-subjects design).

Both fruity aromas significantly enhanced sweetness, both confection-associated aromas significantly enhanced pleasantness, and the caramel/malty aroma significantly reduced bitterness. Menthol and the “burnt” aroma had no measurable effects on the taste of solvent mixtures.

Some flavorants modulated the taste of solvents commonly used in e-cigarettes in ways consistent with an enhanced sensory profile.

If similar effects occur in actual products, improved flavor profiles could facilitate continued use, particularly in non-smokers experimenting with e-cigarettes and related products.

There is significant concern over the health implications of increased consumption of sugars added to foods and beverages. Understanding the increase in sugar intake, as well as consideration of potential substitutes, will require research in multiple domains. Research on hedonic ratings of sucrose suggests that individuals can be classified into two distinct liking profiles: sweet likers and sweet non-likers. However, no known studies have investigated liking for the natural, non-nutritive sweetener, stevia. The present study aimed to investigate the relationship between liking of stevia and liking of sucrose as a function of beverage background.

Forty young adults, 20 high concentration and 20 moderate concentration stevia likers, gave intensity and pleasantness ratings for stevia blend and sucrose taste solutions that varied in concentration and background.

The results revealed a significant relationship between stevia blend liking and sucrose liking. The majority of stevia high concentration likers were high concentration sucrose likers. Pleasantness ratings also significantly varied as a function of background: the discrepancy in pleasantness ratings between stevia blend high concentration likers and moderate concentration likers observed in distilled water was attenuated in a citric beverage background.

The majority of high concentration stevia likers were sucrose likers; however, pleasantness ratings also significantly varied as a function of stimulus background. Limiting sucrose in the modern diet is an important research area for diabetes and other health issues. The results suggest that perception of pleasantness and sweetness at varying sweetener concentrations is not fully generalizable from one beverage background to another.

Infant body odor is subjectively pleasant to parents and activates reward areas in the brain. Hence, body odor perception might contribute to parental bonding. However, it is unknown whether the perceived pleasantness of children’s body odor varies over the course of a child’s development.

Two hundred and thirty-five parents (M?=?36.9?years, SD?=?7.3) were asked to assess the personal odor pleasantness of their children (N?=?367; M?=?9.3?years, SD?=?6.4).

Odor pleasantness was found to decrease as a function of children’s age. Neither sex of the parent nor sex of the child contributed significantly to this effect.

We propose that the effect of age-related changes on personal odor pleasantness reflects olfactory modulation of parental-child relationships.

Our study suggests that perception of young children’s personal odor as pleasant may contribute to bonding and thereby caretaking, which is needed to a lesser degree after puberty than before.

Accurate measurement of chemosensory function is challenging. For assessing olfactory function, the most commonly applied test is the olfactory identification test. The ability to choose the correct descriptor for an odour among different false descriptors is central for the efficacy of these tests. Across several validation studies of the identification tests, the use of closely related descriptors was found to cause low identification rates. We hypothesised that this could be caused by a high chemical resemblance between the odorant and the listed odour descriptor options. By analysing the chemical overlap between the odorant and the odours used as descriptors, we investigated if chemical resemblance could be a possible confounder in olfactory identification tests.

We used gas chromatography-mass spectrometry to detect volatile compounds in the falsely identified odorant. The headspace analysis was repeated on three samples to ensure correct chemical compound detection. Compounds previously identified in odours of false descriptors were identified through a literature review.

This study identified a widespread chemical overlap between citrus odours commonly used as descriptors in clinical olfactory identification tests, which can complicate the distinction between normosmic and anosmic patients.

These findings emphasise the importance of thorough considerations when selecting new odorant descriptors during the modification of odour identification tests and the importance of revalidation after modifying descriptors.

The degree of chemical resemblance between the odours used as descriptors can be used to adjust the level of difficulty in identification tests; contrasted odours will increase the specificity of detecting anosmia in a clinical test, whereas odours with larger chemical resemblance may be more sensitive when evaluating subtle effects of e.g. olfactory training.

Barth syndrome is a rare X-linked genetic disorder caused by a mutation or deletion of the tafazzin gene. Approximately 50–70% of affected males have family-reported feeding issues that affect eating habits and/or restrict dietary intake. Research to date suggests that these feeding problems may be related to differences in responsivity to taste and smell stimuli. The purpose of this study was to use indices of chemosensory function to study differences in food-related sensation and anatomy in males with and without Barth syndrome.

A cross-sectional two-group comparison design was used. Participants included 34 males with Barth syndrome between 5 and 34?years of age and 34 age-matched controls. Measures included the number of fungiform papillae on the anterior dorsal surface of the tongue and scores on the Sniffin’ Sticks olfactory threshold test.

Fungiform papilla counts did not differ significantly between males with and without Barth syndrome, suggesting that altered oral anatomy does not contribute to reported taste and feeding problems in this population. Olfactory thresholds significantly differed between groups; the Barth syndrome sample had a lower threshold for odor detection, indicating greater olfactory sensitivity. These objective measures match self-report data from the Barth syndrome population indicating that they perceive themselves as having a heighted sense of smell compared to others.

This study supports previous behavioral research indicating that olfactory sensitivity is heightened in the Barth syndrome population. Although differences in oral anatomy did not occur, previous research suggests that specific oral sensory cues (e.g., bitterness, texture) may be especially salient in Barth syndrome.

Since this is the first study to identify differences in odor threshold in the Barth syndrome population, findings should be corroborated with future research. These efforts should include odor, taste, and tactile cues at both threshold and suprathreshold concentrations. Results suggest, however, that interventions to address feeding and dietary needs of the Barth syndrome population should consider how food-related stimuli can be modified in order to facilitate appetite and reduce food refusal.

The complex aromas of cocktails provide a unique and interesting model system to evaluate the effects of alcohol matrix and aroma-aroma interactions on human aroma perception and partitioning and release of aroma compounds. Here, we study the interactions that occur in an Old-Fashioned cocktail when different types of whiskeys are mixed with different styles of bitters.

The interactions are studied in two ways, namely, by sensory descriptive analysis to evaluate changes in human aroma perception, and by headspace solid-phase microextraction and gas chromatography-mass spectrometry to study the volatile profiles individually and upon mixing.

Several aroma descriptors showed significant additive and suppressing interaction effects between bitters and whiskeys, and unique sensory characteristics were introduced by both bitters and whiskeys. Volatile compounds also showed suppressing and enhancing effects upon mixing of bitters with whiskeys.

Such behaviors point towards chemical mixture effects and the enhancements in two compounds cannot be attributed to just the addition of certain bitters as the effects differ among the four whiskeys.

These interactive sensory effects suggest further questions of interest about the inherent sensory complexity of foods and beverages; if sensory qualities in even simple cocktails, such as an Old-Fashioned, only exist upon mixing and for specific combinations of bitters and whiskeys, further unique interactions could be envisioned for more complex mixtures.