JournalTOCs

Chemosensory Perception
Journal Prestige (SJR): 0.581

Citation Impact (citeScore): 2
Number of Followers: 0

Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1936-5810 - ISSN (Online) 1936-5802
Published by Springer-Verlag

[2469 journals]

Differences in Brain Responses to Food or Tastants Delivered with and
Without Swallowing: a Meta-analysis on Functional Magnetic Resonance
Imaging (fMRI) Studies
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  Abstract: Introduction This study aimed to meta-analyze the functional magnetic resonance imaging (fMRI) data and compare the brain activations from gustatory studies with different stimulus delivery methods. Methods Published fMRI studies were included into the analysis if they evaluated the brain responses to liquid tastants or food among healthy subjects. Studies were coded into three groups: stimulus removed from the mouth by suction without the need to swallow, swallowing without controlling for its confounds, and swallowing with controlling for its confounds. Results Forty-five studies that comprised of a total of 1498 participants fulfilled the inclusion criteria. Suction studies activated the posterior cingulate. Swallowing studies covered multiple brain regions including the anterior and middle insula, the precentral gyrus, and the postcentral gyrus. Conclusions For the contrast analysis between swallowing studies with and without controlling for the confounds, the former group had larger brain activation mainly at the anterior and middle insula and the thalamus, whereas the latter group had larger brain activation mainly at the anterior cingulate, precentral gyrus, and postcentral gyrus. Implications Compared to studies that did not control for confounds of swallowing, studies that controlled for swallowing demonstrated heightened responses at the insula and reduced responses at the sensorimotor cortex.
  PubDate: 2022-04-28
Long-term Olfactory Functions in Patients with Subjective Cognitive
Decline and Mild Cognitive Impairment
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  Abstract: Introduction Olfactory function is known to be impaired in patients with Alzheimer’s disease (AD) as well as in subjective cognitive decline (SCD) and mild cognitive impairment (MCI), which are generally considered at-risk states for developing AD. The aim of the study at hand was to identify predictors of self-reported olfaction capability (SOC), self-reported capability of perceiving specific odors (SRP), olfaction-related quality of life (ORQ), and odor identification (OIT) in patients with SCD, naMCI, and aMCI. Methods The sample consisted of 33 patients with SCD, 88 with naMCI, and 43 with aMCI who consulted the Department of Neurology, Medical University of Vienna, due to memory complaints between January 2001 and May 2018. Olfactory function was assessed objectively by means of the Sniffin’ Sticks odor identification test (OIT) and subjectively by means of the ASOF-scores SOC, SRP, and ORQ at two to three points in time, with an average time interval of 39 months between the first and second examination, and 24 months between the second and third examination. Linear mixed models were used in order to identify clinical and demographic variables as predictors of mean SOC, SRP, ORQ, and OIT throughout the observation period. Results There was a statistically significant — albeit small — time-related decline of SOC and ORQ in the SCD group but not in other groups. Throughout the observation period, estimated ORQ was significantly higher in the SCD group than in the naMCI and estimated OIT was significantly higher in the naMCI group than in the aMCI group after adjusting for time of measurement and other covariates. Positive relationships between OIT and all three ASOF-scores, negative relationships between BDI-II and SOC and ORQ, and a positive relationship between WST-IQ and SRP were identified. Conclusion There is a statistically significant, albeit small, time-related decline of uncertain clinical relevance in subjective measures of olfactory capability and olfaction-related quality of life in patients with SCD. Implications In all subgroups, objectively measured odor-identification scores have a significant impact on subjective scores over time. The study at hand confirms previous observations regarding the negative influence of depression on subjective perception of olfactory capabilities known from cross-sectional studies.
  PubDate: 2022-04-27
Smelling Death, Loving Life: the Impact of Olfactory Chemosignals on Life
Satisfaction
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  Abstract: Introduction Previous research suggests that putrescine — the chemical compound that gives decomposing organic matter its distinctive odor — may trigger an inborn evolutionary mechanism that prompts individuals to avoid the smell of decay. The purpose of these two experiments was to investigate the effects of exposure to putrescine on human cognition. Methods Two between-subjects experiments (experiment 1 N = 109; experiment 2 N = 108) compared individuals exposed to either putrescine, ammonia, or water. Experiment 1 measures included odorant ratings (i.e., intensity, familiarity, repugnance, goodness), implicit measures (i.e., word completion task, moral judgment vignettes, and opinions on the death penalty), and explicit measures (i.e., death attitudes, self-esteem, and life satisfaction); experiment 2 measures included odorant ratings and life satisfaction. Results In experiment 1, there were no differences by odorant condition on implicit measures; however, those exposed to putrescine reported higher life satisfaction than those exposed to water. These results were replicated in experiment 2. Conclusions Exposure to putrescine may activate psychological threat management processes, which are then interpreted as higher life satisfaction. Implications Human olfactory perception is sensitive to putrescine, and putrescine may exert some subtle psychological effects on human cognition.
  PubDate: 2022-03-16
Human Oral Sensitivity to and Taste Modulation by
3-Mercapto-2-Methylpentan-1-ol
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  Abstract: Introduction 3-Mercapto-2-methylpentan-1-ol (3 M) is a key onion flavor (aroma), but past sensory work has focused primarily on ortho-nasal presentation. A series of experiments was conducted to characterize human sensitivity to oral 3 M solutions, then determine how 3 M impacts perception of basic tastes. Methods Detection thresholds were measured for a food grade, racemic mixture using a forced-choice staircase procedure (n = 19). Recognition was measured by presenting a single stimulus per trial (3 M, vanillin, or water), with “onion,” “vanilla,” or “water” as responses (n = 18). Supra-threshold intensity (n = 20) was measured for various concentrations using the general labeled magnitude scale (gLMS). Odor-taste interactions were studied using mixtures of 3 M and exemplars of basic tastes. Participants rated the intensity of basic tastes, or both taste and aroma, using the gLMS (n ranged from 10 to 15). All stimuli were in aqueous solution. Results Participants detected oral 3 M at about 0.90 ppb and recognized 3 M as “onion” at about 5 ppb. Supra-threshold intensity increased roughly as a cumulative logistic function of concentration. 3 M enhanced the rated savory intensity of monosodium glutamate, but did not enhance the dominant qualities of exemplars of the other four basic tastes. Under a response-context more favorable to an analytic approach, savory enhancement was reduced but not eliminated. Savory enhancement was eliminated with nose-clips. Conclusions Oral sensitivity was lower than previous retronasal studies would suggest, but roughly consistent with concentrations in cooked allium varieties. Oral 3 M selectively enhanced savory intensity, an effect likely due to retronasal aroma rather than taste or mouthfeel. Implication 3 M is a promising candidate aroma to enhance or impart a savory flavor.
  PubDate: 2022-02-25
  DOI: 10.1007/s12078-022-09295-w
Virtual Reality Immersion: Taste and Texture Changes for Identical Samples
of Two Common Condiments
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  Abstract: Introduction The effect of seven virtual environments (visual and auditory) on the rating of sensory attributes of identical samples of ketchup and salad dressing was assessed. Methods Fifty-one participants were recruited and immersed in virtual scenes evoking heat, cold, height and fear, high speed and fear, sadness, pleasure, and relaxation. The participants tasted samples of both products while being subjected to virtual stimuli. Each panelist tested the seven environments, and control tests were carried out without the VR headset. Panelists rated eight descriptive attributes based on their perception, and results were analyzed by principal component analysis to obtain a general overview of the rated attributes, and by generalized procrustes to explain possible correlations between virtual environments and attribute ratings. Results Heat evoking scene caused increased intensity of hotness and moisture, and decreased bitterness; cold evoking scene increased sweetness perception. Virtual environments increased sweetness, moisture, and bitterness perception in men when compared to women. Conclusions Virtual reality contexts influenced the taste and texture perception of ketchup and salad dressing; moreover, the effect of these stimuli was different in men and women. Implications Besides applications in condiments, the obtained results can shed light on the influence of virtual stimuli on food product sensory perception in general, since virtual environments for sensory tests are gaining great interest for researchers and the food industry.
  PubDate: 2022-02-09
  DOI: 10.1007/s12078-022-09296-9
Olfactory Capabilities Towards Food and Non-food Odours in Men and Women
of Various Weight Statuses
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  Abstract: Introduction Olfaction is a sense that is closely linked to food intake and food choices in humans, but its relationship with obesity remains equivocal in the scientific literature: overall olfactory capacities seem poorer in obesity compared to normal weight, but some authors observed that individuals with obesity might have a heightened sensitivity to food odours. Our objective was to evaluate olfactory capabilities for food and non-food odours. Methods The European Test for Olfactory Capabilities (ETOC) was used. This test measures suprathreshold olfactory detection and identification capabilities. One hundred twenty-four men and women were tested, of whom 41 individuals with normal-weight, 45 individuals with overweight, and 38 individuals with obesity. Results Contrary to the major current in the literature, no differences between the three weight status groups were found in either detection or identification capabilities, for food as well as for non-food odours. Age decreased detection score while being male decreased identification score. A trend for better identification of non-food odours was found for overweight and obesity vs. normal-weight. Conclusion We encourage further research to distinguish food and non-food odours in olfactory measurements related to weight status in order to replicate our findings on a larger set of odours. Implication Future research should also focus on sensitivity to food odours by estimating detection thresholds and to control for confounding variables such as hormonal status, as well as individual liking of the odours.
  PubDate: 2021-10-19
  DOI: 10.1007/s12078-021-09294-3
Multivariate Analysis and Classification of 146 Odor Character Descriptors
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  Abstract: Introduction Smells can be described by assigning the words that come to mind when sniffing an odorous material. A great number of terms can be applied, but not all of them are independent, and it is possible to establish groups of words often applied together when describing a smell. Such classification of olfactory descriptors is of scientific interest in order to better understand the dimensionality and structure of human olfactory perception space. For this purpose, compilations of olfactory profiles contain valuable information that may lead to certain consensus in odor classification. Methods One of the most comprehensive odor databases is the Dravnieks’ Atlas, which contains quantitative olfactory profiles for 160 samples. For each one, a large panel rated the applicability of 146 odor character descriptors on a numeric scale. Results By applying principal component analysis to this Atlas, 105 descriptors were reorganized in 24 classes, and 33 attributes were considered as odors intermediate of two or three categories. The similarities between classes were studied by means of a further multivariate analysis based on latent variables, which provides valuable information about the most salient dimensions of odor space. Conclusions Consistent with other reported statistical analyses of olfactory databases, the perceptual space of odor character is multidimensional with about 20–30 dimensions, and it is better described as a continuum spectrum rather than as a segmented space. Implications Attempts to classify all possible odor descriptors in a restricted number of classes appear to be inappropriate. Instead, 24 categories of related terms are proposed here, regarding the rest as intermediate smells, assuming that olfactory classes are not independent and follow certain hierarchy according to particular underlying dimensions.
  PubDate: 2021-10-01
  DOI: 10.1007/s12078-021-09288-1
Crosstalk of Pain and Thirst Perception: A Brief Review
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  Abstract: Introduction Senses such as thirst, hunger, pain, and temperature sensation show imbalances of the internal state and have important implications for survival. Independently, thirst and pain perception create motivational states that organize behavior to fulfill the goal imposed by the perception, but little is known on how competitive these perceptions are when combined and the motivational states they create when experienced in unison. Methods A review of the literature was conducted about pain, thirst, and vasopressin. Specific inclusion was given to studies observing the association of pain and thirst together and independently. Results Articles that were reviewed were original research, reviews, and large clinical studies. Results from previous research show a relationship between motivational states, such as thirst and pain perception. Conclusions Thirst and pain are competitive motivational states that arise certain behaviors for a specific goal. Further research is needed to understand how these motivational states might be changed by one another. Implications From this review, readers can conclude that increased thirst can bring about greater pain sensation for given stimuli.
  PubDate: 2021-10-01
  DOI: 10.1007/s12078-021-09286-3
Disgust Propensity and the Bitter Aftertaste Response
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  Abstract: Introduction A high level of disgust propensity (the general tendency to respond with the emotion of disgust to any given situation) is associated with an increased sensitivity to bitter taste. The present study examined the relationship between disgust propensity and the sensitivity to bitter aftertaste. Methods A total of 200 women rinsed their mouth with concentrated wormwood tea (Artemisia absinthium). The resulting aftertaste was evaluated (intensity of bitterness and disgust) every 15 s for 10 min. A multiple linear regression analysis was calculated to capture the association between aftertaste ratings and affective variables (e.g., disgust propensity, depression symptoms). Results Higher disgust propensity was associated with higher initial disgust ratings and faster reduction of disgust over time. Higher depression scores were associated with a slower disgust reduction. Conclusion We demonstrated that affective variables predict the temporal course of the wormwood aftertaste response. Having a higher disgust propensity was associated with a shortened disgust recovery. Implications A shortened disgust recovery may be adaptive because it enables faster processing of new disgust stimuli.
  PubDate: 2021-10-01
  DOI: 10.1007/s12078-020-09283-y
A New Method for a Shorter and Valid Assessment of Olfactory Threshold in
Repeated Measurement Designs Based on the Sniffin’ Sticks Test
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  Abstract: Introduction The Sniffin’ Sticks threshold test is widely used to assess olfactory threshold due to its high reliability and validity. Nevertheless, this test procedure is quite long with an average duration of 10 to 20 min. In study designs that require multiple olfactory threshold tests on short intervals, this could exhaust participants. To counteract this limitation, we developed the informed-four-reversal (INFOUR) short version of the Sniffin’ Sticks threshold test for repeated measurement designs and piloted it in a sample of normosmic participants. Methods Forty-two participants performed the original Sniffin’ Sticks version before being assigned either to the control group that repeated the original version or to the test group that conducted the INFOUR short version. Results The correlation between the original version at T1 and INFOUR at T2 was r = .75 and did not differ significantly from the retest reliability of the original version. Compared to the original version, the INFOUR took 42% less time to perform. Conclusion The INFOUR leads to a significant time saving, while maintaining good validity. Implications Therefore, this approach has the potential to be a useful tool for study protocols with repeated olfactory threshold measurements. In particular, when research protocols are time intensive or testing needs to the shortened, because the interventional effects are short or subtle.
  PubDate: 2021-10-01
  DOI: 10.1007/s12078-021-09291-6
Cultural Adaptation and Validity of the Sniffin’ Sticks
Psychophysical Test for the UK Setting
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  Abstract: Introduction Olfactory testing must be culturally adapted to be relevant to the target population. This study aimed to validate the Sniffin’ Sticks test for the UK setting. Methods A cohort study was conducted at a tertiary olfactory dysfunction clinic. Phase 1—healthy volunteers underwent the original German identification test followed by a UK adapted version. Phase 2—patients with olfactory dysfunction underwent the extended smell test (TDI) including the new descriptors. Outcome measures included differences in identification test (phase 1), retest reliability and differences in scores before and after treatment. Results A total of 31 healthy volunteers and 87 patients were recruited (6 and 31 males, respectively). Phase 1—mean identification scores showed a small improvement after descriptor adaptations (13.77 and 14.57, p = 0.0029). Phase 2—41 untreated participants had a mean identification score of 7.31 at both intervals (95% CI: − 1.15 to 1.15, p > 0.999). The mean change in treated participants was 1.88 (0.70 to 3.06, p = 0.0224). TDI score difference between treated and untreated groups was 6.63 (2.48 to 10.79, p = 0.0023). The intraclass correlation coefficient for untreated patients was high for both TDI score (ICC = 0.82, 95% CI 0.57 to 0.93) and identification score (ICC = 0.80, 0.52 to 0.93); CIs suggest the reliability is moderate to excellent. Conclusions This study confirms the validity of the descriptor adaptations of the identification component of the Sniffin’ Sticks test to distinguish between health and disease. Implications The Sniffin’ Sticks test can now reliably be used for clinical assessment of British patients, modifying only the descriptors.
  PubDate: 2021-10-01
  DOI: 10.1007/s12078-021-09287-2
Is perceptual learning generalisable in the chemical senses' A
longitudinal pilot study based on a naturalistic blind wine tasting
training scenario
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  Abstract: Introduction A growing body of research has demonstrated differences in perceptual, conceptual, and language abilities between wine experts and novices. However, it is unclear to what extent these differences are innate or acquired through training. The present study assessed the olfactory and gustatory performance of a group of university blind wine tasters before and after training. Previous research has shown that this training regimen significantly improves blind tasting accuracy, but it remains unknown whether perceptual learning from blind tasting training is generalisable to standard tests of olfactory/gustatory ability. Methods Two testing sessions were carried out for the training group (N = 14) as well as for a control group (N = 12) before and after a 5-week training period. In each session, participants underwent olfactory threshold, discrimination, and identification assessments as well as a gustatory sensitivity test. Results Olfactory discrimination significantly improved in the training group over the 5-week period, and the training group outperformed controls in olfactory identification in both sessions. Conclusions Based on our limited set of data, wine training seems to have improved olfactory discrimination, even though the method of training did not involve odorants used in the discrimination test itself. Implications These results reveal that even wine training over a short period seems to make concrete changes to olfactory performance, supporting the idea that generalised perceptual learning can take place for odour discrimination.
  PubDate: 2021-10-01
  DOI: 10.1007/s12078-020-09284-x
The Effect of Odour Valence and Odour Detection Threshold on the
Withholding and Cancellation of Reach-to-Press Responses
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  Abstract: Introduction Withholding uninitiated actions and cancelling ongoing ones are two main components of response inhibition, a key element of the executive control. Inhibitory performance is sensitive to emotional contexts elicited by subliminal and supraliminal visual material. However, whether stimuli from other sensory modalities, such as odours, would equally modulate response inhibition remains unclear. Here, we aimed to assess the effect of task-irrelevant odours as a function of their valence and threshold on both action withholding and action cancellation of reach-to-press movements. Method Thirty-two healthy participants performed a Go/No-Go task that included the presentation of pleasant (orange) and unpleasant (trimethyloxazole) odour primes at supra- and sub-threshold levels; clean air was included as a control condition. The reach-to-press responses were composed of an initial release phase and a subsequent reaching phase. Results Only the supra-threshold pleasant (vs. control) odour impaired action withholding. Moreover, the pleasant (vs. control) odour—presented at both sub- and supra-threshold levels—elicited more accurate Go responses, whereas the sub- and supra-threshold pleasant and unpleasant (vs. control) odours triggered faster responses in the release phase. Additionally, only the supra-threshold pleasant (vs. unpleasant) odour impaired action cancellation in the reaching phase. Furthermore, reaching responses were slower following the supra-threshold unpleasant (vs. control) odour. Conclusions Our findings extend the sparse literature on the impact of odour stimuli on goal-directed behaviour, highlighting the role of both odour valence and threshold in the modulation of response inhibition. Implications Determining the mechanisms by which odour stimuli modulate response inhibition lays the foundations for research on odour-triggered disinhibition.
  PubDate: 2021-09-27
  DOI: 10.1007/s12078-021-09292-5
The Relationship Between Olfactory Function and Emotional Contagion
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  Abstract: Introduction Research has provided evidence for the transfer of single emotions including anger, anxiety and happiness through olfactory chemosignals, yet no work has examined the role of odour function in the aggregation of more complex emotional states or in the emotional contagion process. The aim of the present study was to ascertain whether an individual’s tendency to experience emotional aggregation was affected by objective measures of their olfactory function and subjective self-assessments of the importance of their own olfactory system. Methods In this study (N = 70), participant pairs were first assessed individually for olfactory threshold and odour identification, then completed the Importance of Olfaction Questionnaire. Each pair subsequently took part in two collaborative tasks. Individual emotion measures were taken before, during and after the completion of the two tasks. Results Multilevel structural equation modelling revealed that individuals’ within-dyad positive emotional agreement scores were associated with both their ‘importance of olfaction’ scores and their olfactory function. A significant association was also found between olfactory performance and the Importance of Olfaction scores. Conclusions These results provide evidence that the subjective importance an individual assigns to their sense of smell can predict their susceptibility to experience emotional aggregation during active, collaborative tasks. Implications The findings suggest that individuals’ tendency and capability to detect and respond to emotional chemosignals, a process required for olfactory-facilitated emotional contagion, may be affected by individual differences in olfactory function and subjective attitudes toward olfaction.
  PubDate: 2021-09-23
  DOI: 10.1007/s12078-021-09293-4
Flavor Enhancement in Daily Life of Patients with Olfactory Dysfunction
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  Abstract: Introduction Patients with olfactory dysfunction report deterioration of taste due to loss of flavor, leading to less food enjoyment, alterations in dietary behaviors and stress. The aim of this study was to introduce flavor enhancement to investigate its acceptance and possible effects on quality of life. Methods In this prospective, controlled, randomized, single-blinded, cross-over pilot study, we recruited 30 olfactory dysfunction patients, of which 16 were hyposmic and 14 anosmic. After single-blinded triangle flavor discrimination test, flavor drops were randomized either in high or low concentration for 14 days and vice versa for another 14 days. Records included a daily diary and the questionnaire of olfactory disorders. Results Usage rates were excellent with 82.2% of all days, while drops were mainly used for breakfast (44.6%, p < 0.05). Hyposmics used flavor enhancement on significantly more days (median = 14) compared to anosmics (median = 11, p = 0.0094). QOD improved in 12 patients to a meaningful extent. Conclusions In this pilot study, we show that flavor enhancement is feasible accompanied by high compliance and acceptance in olfactory dysfunction patients. Flavor drops were used regardless of low or high concentrations with no adverse events noted. Implications Our findings give rise to further studies illuminating the possible advantages of flavor enhancement in patients with olfactory disorders.
  PubDate: 2021-07-08
  DOI: 10.1007/s12078-021-09289-0
Peri-threshold Trigeminal Stimulation with Capsaicin Increases Taste
Sensitivity in Humans
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  Abstract: Introduction Taste perception is affected by trigeminal stimuli, i.e., capsaicin. This has been studied at suprathreshold concentrations. However, little is known about taste perception at threshold level in the presence of low concentration of capsaicin. The aim of the study was to explore whether taste sensitivity for sweet, sour, salt, bitter, and umami is modulated by the presence of capsaicin in the peri-threshold range. Methods Fifty-seven adults (age range 19–85 years; 32 women) with functional gustation participated in the study. Based on their perception of phenylthiocarbamide (PTC), the group was stratified into non-tasters (n = 20) and tasters (n = 37). Threshold for sweet (sucrose), sour (citric acid), salty (sodium chloride), bitter (quinine-hydrochloride), and umami (sodium-glutamate) tastes was estimated using a single-staircase paradigm (3-alternative forced choice; volume per trial 0.1 ml) with or without 0.9-µM capsaicin added. This capsaicin concentration had been determined in pilot studies to be in the range of oral perception thresholds. Results The addition of capsaicin produced lower taste thresholds for sweet, sour, salty, and bitter but not for umami. In contrast, neither PTC taster status nor sex affected these results. Conclusion The current results indicate that a low concentration of capsaicin increases gustatory sensitivity. Implications The current findings provide evidence supporting different effects of capsaicin on taste perception at threshold level. It has implications for boosting taste sensitivity or flavor enjoyment with low concentration of capsaicin.
  PubDate: 2021-07-01
  DOI: 10.1007/s12078-021-09285-4
Sequential Effects in Odor Perception
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  Abstract: Introduction Our visual, auditory, and tactile perception is not solely determined by what we process at a given moment in time, but also determined by what we perceived recently. These sequential effects can either be negative (repulsive) or positive (assimilative). Here, we investigated whether such sequential effects also occur in odor perception. Method Participants rated a sequence of 40 different odors (varying widely in hedonic valence) on four different characteristics (intensity, familiarity, valence, and arousal). For each of these characteristics, we conducted an inter-trial analysis, based on whether the rating on the preceding trial was low or high. Results We found a positive serial dependence for both odor intensity and familiarity ratings. That is, the rating on the current trial was higher when the rating on the previous trial was high than when the rating on the previous trial was low. We observed no sequential effects for odor valence and arousal ratings. Conclusion The olfactory system integrates previous stimuli into the current perception of intensity and familiarity. Implications The current findings may be relevant for marketing applications and may guide the design and use of olfactory-enhanced virtual and augmented reality systems.
  PubDate: 2021-06-26
  DOI: 10.1007/s12078-021-09290-7
Context Effect on Temporal Resolution of Olfactory–Gustatory,
Visual–Gustatory, and Olfactory–Visual Synchrony Perception
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  Abstract: Introduction 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. Methods 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. Results The temporal resolution was significantly higher under the wide-range condition than under the narrow-range condition, supporting our hypothesis. Conclusion 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. Implication 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).
  PubDate: 2021-04-01
  DOI: 10.1007/s12078-020-09282-z
Debittering Moringa oleifera (Lam.) Leaves in Fortified South Indian
Instant Soup
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  Abstract: Introduction 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. Methods 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. Results 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. Conclusions 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. Implications 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.
  PubDate: 2021-04-01
  DOI: 10.1007/s12078-020-09280-1
Exploring the Relationship Between Psychopathy and Taste Perception
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  Abstract: Introduction 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. Methods 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. Results 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. Conclusions Higher degrees of psychopathic traits are associated with higher disgust ratings of bitter stimuli. Implications The findings suggest that the chemical senses may be another confirmatory method for differentiating those with low and high psychopathic traits.
  PubDate: 2021-04-01
  DOI: 10.1007/s12078-020-09278-9