Pleasantness, familiarity, and identification of spice odors are interrelated and enhanced by consumption of herbs and food neophilia

Olfactory performance and odor liking are negatively associated with food neophobia in children aged between 3 and 9 years

BACKGROUND

Child food neophobia, i.e., rejection or avoidance of novel foods at a young age, is a prevalent nutrition problem that affects the quality of children's diet and impedes the development of healthy food preferences. Sensory sensitivity can relate to the degree of food neophobia, but previous studies rarely focused on the olfactory component of this problem in children.

OBJECTIVE

We aimed to thoroughly examine the relationship between various aspects of olfactory sensitivity and food neophobia in children.

METHODS

246 children aged between three and nine years took part in a food neophobia assessment as well as in a comprehensive, psychophysical olfactory testing.

RESULTS

We found that certain smell perception aspects such as lower odor liking, poorer odor identification ability as well as lower sensitivity to an unknown non-food odor all significantly predicted higher food neophobia in children. Among individual characteristics of either a child or a caregiver, only the child's age significantly and positively predicted food neophobia. The exploratory model looking into the role of family environment factors predicting self-reported food neophobia in children revealed that food neophobia was associated with lower control given to a child in this child's feeding process, as well as with a more frequent use of food as a reward in feeding.

CONCLUSIONS

We suggest that suppressed olfactory perception and performance can play a unique role in child nutritional difficulties. The study inspires further considerations of olfaction-engaging interventions to counteract food-neophobia in children.

Chemosensory analysis of emotional wines: Merging of explicit and implicit methods to measure emotions aroused by red wines

Wine is a cultural product capable of arousing emotions. Measuring emotions and figuring out how much they could influence preferences or purchase decisions of consumers is a new trend in sensory and consumer research. However, the complexity of feelings makes the measure of emotions extremely challenging. Thus, a comprehensive understanding of emotions related to sensory stimuli in wine tasting is still missing. The purpose of the study is to evaluate the emotional power of tasting red wines using a multidisciplinary approach, combining sensory analysis performed by trained panelists, implicit and explicit measurements of emotions and chemical analysis of the wines tasted. Various red wines, renowned for their high polyphenol content and expected to exhibit rich texture, mouthfeel, and aging potential, have been utilized to this extent. The results obtained showed that the emotions measured were well-correlated with quantitative and hedonic attributes obtained using classic sensory analysis. Some aromatic molecules can be identified as markers capable of eliciting positive and negative emotional reactions. While increasing literature in the topic is recently available, our study appears to be the first highlighting the presence of autonomic nervous system (ANS) differences verified by means of electrocardiogram (ECG) features, related to explicit and complete sensory patterns, in response to sensory stimuli related to emotional wine, with higher sympathetic values at extrema and vagal increase in the presence of neutral sensory compounds.

Children's odor pleasantness ratings may not differ according to pubertal status: Preliminary results from a sample of 11-14-year-old Czech children

Puberty tends to be viewed as a "turning point" in hedonic perception of body odor (BO)-related smells. The pubertal stage, a potential proxy for the underlying physiological changes, may contribute to variation in odor hedonic perception. Other potential modulators of odor hedonics are general semantic knowledge about odors (which also tends to be subsumed under the term "age") and perceived odor intensity. The present cross-sectional study examined differences in hedonic odor perception across puberty in 205 Czech children aged 11-14 (89 boys). We investigated whether children differ in the hedonic appraisal of BO-related (16-androstenes and castoreum control), but also food and non-food odors according to their pubertal (penis/breast and pubic hair) development and general semantic knowledge about odors (operationalized as odor identification), controlling for age and perceived odor intensity. As a subsidiary aim, we examined variation in odor identification. We asked the children to self-stage themselves using drawings depicting Tanner's penis/breast and pubic hair stages of pubertal development, estimated their general semantic knowledge about odors with a Sniffin' Sticks identification test, and obtained their pleasantness and intensity ratings of body odor-related, food, a non-food smells. We found that the participants' ratings of the 16-androstenes and those of the perceptually similar odor of castoreum differed according to perceived intensity and, in the latter case, in boys vs. girls as well, but there were no influences of pubertal status or odor identification on the perceived pleasantness. Similarly, hedonic appraisal of non-food (but not food) odors was only influenced by perceived intensity. Regarding odor identification, differences between boys and girls were limited to younger children and did not become more marked throughout puberty. Perceived pleasantness of odors, irrespective of whether they are associated with body smells, food, or other, does not appear to vary across puberty, and boys and girls seem to achieve similar levels of semantic odor knowledge as they grow up.

How well can young adults and children discriminate between odors?

It is widely believed that people can distinguish between many odors although there is limited empirical evidence. Odor discrimination tasks are employed much less often than other measures of olfaction, but, interestingly, performance is typically ~ 75% correct. This less-than-perfect performance is rarely highlighted, although it suggests that people may not be as good at discriminating odors as is commonly believed. Odor discrimination is understudied in children, and although available evidence suggests that it improves with age, children perform better when the task is simpler. In the present study, we explored odor discrimination in children and young adults with a relatively simple same-different task using common and uncommon odors. We found that children perform as well as young adults, but that overall performance was less than perfect and depended on the odors to be discriminated. We found evidence that ability to discriminate between odors improves as the difference in pleasantness of the odors increases. In a second experiment, we tested this directly by exploring whether odors that differ in pleasantness and edibility, two dimensions that appear to be important in olfactory perception, are easier to discriminate than odors that are the same on those dimensions. We found further evidence that odors that differ in pleasantness are easier to discriminate.

Odor Hedonic Profile (OHP): a self-rating tool of everyday odors

Odor hedonic estimation (pleasant/unpleasant) is considered the first and one of the most important dimensions in odor perception. Although there are several published scales that rate odor hedonicity, most of them use odorants that induce biases related to stimulus properties or test conditions and make difficult clinical or industrial applications. Thus, this study aimed to propose a model of odor hedonic profile (OHP) based on 14 items related to everyday odors without stimulus. The OHP is a self-rating tool based on the hedonic estimate representation and allows the determination of specific profiles, i.e., "conservative," "neutral," "liberal," "negative olfactory alliesthesia," and "positive olfactory alliesthesia." It can be useful in different contexts (e.g., food studies) and general pathologies (e.g., eating disorders) or pathologies with mood/emotional disturbances (e.g., depression).

Wearable Sensors to Evaluate Autonomic Response to Olfactory Stimulation: The Influence of Short, Intensive Sensory Training

In the last few decades, while the sensory evaluation of edible products has been leveraged to make strategic decisions about many domains, the traditional descriptive analysis performed by a skilled sensory panel has been seen to be too complex and time-consuming for the industry needs, making it largely unsustainable in most cases. In this context, the study of the effectiveness of different methods for sensory training on panel performances represents a new trend in research activity. With this purpose, wearable sensors are applied to study physiological signals (ECG and skin conductance) concerned with the emotions in a cohort of volunteers undergoing a short, two-day (16 h) sensory training period related to wine tasting. The results were compared with a previous study based on a conventional three-month (65 h) period of sensory training. According to what was previously reported for long panel training, it was seen that even short, intensive sensory training modulated the ANS activity toward a less sympathetically mediated response as soon as odorous compounds become familiar. A large-scale application of shorter formative courses in this domain appears possible without reducing the effectiveness of the training, thus leading to money saving for academia and scientific societies, and challenging dropout rates that might affect longer courses.

Odor perception of aromatherapy essential oils with different chemical types: Influence of gender and two cultural characteristics

Olfactory perception, and especially affective responses of odors, is highly flexible, but some mechanisms involved in this flexibility remain to be elucidated. This study investigated the odor perceptions of several essential oils used in aromatherapy with emotion regulation functions among college students. The influences of people's characteristics including gender, hometown region, and fragrance usage habit on odor perception were further discussed. Odor perception of nine essential oils, which can be divided into the ester-alcohol type (e.g., lavender oil) and terpene type (e.g., lemon oil) were evaluated under three odor concentrations. The results indicated that chemical type, but not concentration, significantly influenced the odor perception and there was no interaction between the two factors in this study. The arousal and emotional perception scores of odors with terpene-type oil were significantly higher than odors with ester-alcohol type. In terms of people's characteristics, participants from the southern Yangtze river gave a higher familiarity rating to almost all of these odors. The habits of fragrance usage also significantly influenced some of the odors' subjective intensity and emotional perception ratings. However, there were no significant gender differences in most of the odor perceptions. In addition, familiarity and pleasantness were positively correlated, and emotional perception and subjective intensity also showed a weak correlation. These results suggested that users' cultural characteristics could be considered to be important factors that affect the essential oil's odor perception in aromatherapy.

Odor Identification by Parkinson’s Disease Patients Tested by Using Sniffin’ Sticks versus Natural Spices

Introduction

Hyposmia is a frequent symptom of Parkinson's disease (PD), which greatly impacts patients' flavor perception and their quality of life. However, PD patients recognize some odors better than others. Identifying which food odors are still recognized by PD patients may be useful for flavor enhancement. Our aim was to evaluate the olfactory identification of Sniffin' Sticks and spice odorants in PD patients and healthy controls (HC), to identify the impact of synthetic odorants compared with real-life food and the impact of odor familiarity and pleasantness on odorant identification in PD patients.

Methods

Sniffin' Sticks odorant identification was evaluated in 80 PD patients and 105 age-matched HC. In a subset, the spice odorant identification was evaluated.

Results

The mean total score was higher for the Sniffin' Sticks than for the spice odor identification test in all participants (55.4% versus 22.5%). Sniffin' Sticks orange, peppermint, rose, and fish odorants were best correctly identified by PD patients, by 62.5, 53.8, 52.9, and 57.5%, respectively. Of the spice odor identification test, garlic and “no stimulus” were best correctly identified by PD patients, by, respectively, 38.2 and 67.6%. HC identified most Sniffin' Sticks odorants and spices better than PD patients. Odorant familiarity determined real-life food odorant identification.

Conclusion

This study demonstrates that some food odorants, both the commercial Sniffin' Sticks as natural odorants, are still recognized by PD patients. Sniffin' Sticks were better recognized compared with real-life odorants, by both HC and PD patients. Odorant familiarity determined PD patients' odorant identification; therefore, familiar food odorants may have potential for a future flavor enhancement. Implications. This is the first study, to our knowledge, to evaluate real-life food odor identification in PD patients. Our results provide a first step towards patient-appropriate flavor enhancement strategies in PD.

Sex Differences in Odor Hedonic Perception: An Overview

Odor hedonic evaluation (pleasant/unpleasant) is considered as the first and one of the most prominent dimension in odor perception. While sex differences in human olfaction have been extensively explored, gender effect in hedonic perception appears to be less considered. However, a number of studies have included comparisons between men and women, using different types of measurements (psychophysical, psychophysiological,…). This overview presents experimental works with non-specific and body odors separately presented as well as experimental studies comparing healthy participants vs patients with psychiatric disorders. Contrary to sensitivity, identification or discrimination, the overall literature tends to prove that no so clear differences occur in odor hedonic judgment between men and women. On the whole, gender effect appears more marked for body than non-specific odors and is almost never reported in psychiatric diseases. These findings are discussed in relation to the processes classically implied in pleasantness rating and emotional processes.

Some insights into the development of food and brand familiarity: The case of soy sauce in the Netherlands

With the increasing globalization, new unfamiliar flavors gradually find their way into local Western cuisines. The mechanisms behind the successful integration of novel flavors into local cuisines are largely unknown. This study investigates the effects of frequency of soy sauce use, levels of food neophobia, and brand specificity on liking of a relatively unknown flavor in the Netherlands, soy sauce. A total of eighty-nine (26 men and 63 women; mean age 47.5 ± 17.7 years) high- and low-frequency users of soy sauce rated liking of five soy sauces separately presented with and without branding information. Liking of four soy sauces with the typical salty and savory flavor increased with increasing frequency of use, and with decreasing levels of food neophobia. Another soy sauce with additives resulting in a distinctive taste was liked irrespective of the frequency of use. Soy sauces, which were recognized correctly or incorrectly as the participants' own familiar brand, received 50% higher or lower liking ratings than other soy sauces, respectively. Furthermore, users of one of the brands preferred the taste of their own brand over that of other brands, whereas users of the other brands did not show such specificity, indicating clear differences in specificity of liking soy sauce among the various user groups. This study provides insights into consumer liking and preference of semi-familiar foods, revealing the contribution of consumer traits and brand familiarity that may influence the spread of unfamiliar foods.

Effect of chargrilled flavoring on the sensory perception and consumer acceptability of bulgogi (Korean barbecued beef)

As the home-meal replacement food industry grows, there is an increasing need for smoky flavorings that can satisfy the diverse tastes of consumers. In particular, the industry requires chargrilled flavorings that complement Korean foods. In this study, chargrilled flavoring was applied to bulgogi (Korean barbecued beef) and its effects on consumer liking, sensory perception, familiarity, and flavor congruency with the bulgogi were investigated. Eight formulations (one control and seven flavorings) were tested by 78 Korean subjects. A rate-all-that-apply test was conducted to profile the sensory attributes of the food from the consumers' perspectives. The samples with weaker woody and smoky flavors were preferred; the samples with strong woody and smoky flavors were perceived as being artificial and Western-styled, as well as less familiar and incongruent with bulgogi. This study shows that flavorings that are congruent with a food system can improve consumer liking and the perception of familiarity.

Wearable Sensors for Assessing the Role of Olfactory Training on the Autonomic Response to Olfactory Stimulation

Wearable sensors are nowadays largely employed to assess physiological signals derived from the human body without representing a burden in terms of obtrusiveness. One of the most intriguing fields of application for such systems include the assessment of physiological responses to sensory stimuli. In this specific regard, it is not yet known which are the main psychophysiological drivers of olfactory-related pleasantness, as the current literature has demonstrated the relationship between odor familiarity and odor valence, but has not clarified the consequentiality between the two domains. Here, we enrolled a group of university students to whom olfactory training lasting 3 months was administered. Thanks to the analysis of electrocardiogram (ECG) and galvanic skin response (GSR) signals at the beginning and at the end of the training period, we observed different autonomic responses, with higher parasympathetically-mediated response at the end of the period with respect to the first evaluation. This possibly suggests that an increased familiarity to the proposed stimuli would lead to a higher tendency towards relaxation. Such results could suggest potential applications to other domains, including personalized treatments based on odors and foods in neuropsychiatric and eating disorders.

Subtle olfactory dysfunction after SARS-CoV-2 virus infection in children

OBJECTIVES

Anosmia/hyposomia have been described as early signs of COVID-19 infection in adults, including young asymptomatic patients who commonly refer olfactory disfunction as their only clinical manifestation. Very few studies involving paediatric age patients have been published until now. This study aims to determine the presence of olfactory dysfunction in children with COVID-19 infection through the use of a self-reported questionnaire and a new olfactory screening tool.

METHODS

Nested case-control study. All paediatric patients screened by reverse transcription polymerase chain reaction (RT-PCR) and Anti-SARS-CoV-2 antibodies for COVID-19 infection, during the study period (March-May 2020), were asked to respond to a questionnaire about symptoms of olfactory disfunction. Patients above six years old also performed an odor identification test based on seven odorants (Kradeo®). This test was designed based on our cultural context and eating habits.

RESULTS

126 patients were recruited, including 33 with COVID-19 infection. 15% of the infected children referred anosmia and/or dysgeusia on the questionnaire, all of them were older than eleven years. The results of the odor test (69 patients) revealed subtle disturbances in the infected group (mostly misrecognition of odorants). Median odorant recognition was 3 odors [Interquartile range (IQR) 2-4] in case group and 4 [IQR 3-5] in controls. Male patients showed significantly larger disturbances than girls in both groups (p = 0.03).

CONCLUSION

Self-referred prevalence of olfactory disfunction in our sample of infected children is lower than that described in adults, especially among the youngest ones, maybe due to immature development of angiotensin-converting enzyme 2 (ACE2) receptors expressed in nasal mucosa. Nevertheless, one month after infection, subtle disturbances (misrecognition of odors) were identified among the infected children. This screening olfactory test provides a hygienic, user-friendly tool, suitable for screening children older than six years of age.

A network model of affective odor perception

The affective appraisal of odors is known to depend on their intensity (I), familiarity (F), detection threshold (T), and on the baseline affective state of the observer. However, the exact nature of these relations is still largely unknown. We therefore performed an observer experiment in which participants (N = 52) smelled 40 different odors (varying widely in hedonic valence) and reported the intensity, familiarity and their affective appraisal (valence and arousal: V and A) for each odor. Also, we measured the baseline affective state (valence and arousal: BV and BA) and odor detection threshold of the participants. Analyzing the results for pleasant and unpleasant odors separately, we obtained two models through network analysis. Several relations that have previously been reported in the literature also emerge in both models (the relations between F and I, F and V, I and A; I and V, BV and T). However, there are also relations that do not emerge (between BA and V, BV and I, and T and I) or that appear with a different polarity (the relation between F and A for pleasant odors). Intensity (I) has the largest impact on the affective appraisal of unpleasant odors, while F significantly contributes to the appraisal of pleasant odors. T is only affected by BV and has no effect on other variables. This study is a first step towards an integral study of the affective appraisal of odors through network analysis. Future studies should also include other factors that are known to influence odor appraisal, such as age, gender, personality, and culture.

Wearable Sensors to Characterize the Autonomic Nervous System Correlates of Food-Like Odors Perception: A Pilot Study

Background: The sense of smell has been recently recognized as one of the most important sensory features in the human being, representing a reliable biomarker for a number of clinical conditions. The relationship between olfactory function and the person’s attitude towards food has frequently been investigated, often using questionnaires. The administration of minimally invasive methods for characterizing autonomic nervous system (ANS) functionality could help in objectivizing such measurements. Methods: The present study assessed ANS activation through the analysis of the electrocardiogram (ECG) and galvanic skin response (GSR) signals, in response to olfactory stimuli using non-invasive wearable devices. The ANS activation was also studied with respect to the odor familiarity, as well as with other olfactory and food dimensions (e.g., odor identification, odor pleasantness, food neophobia). Results: We demonstrated a significant activation of the ANS, in particular of its sympathetic branch, during the olfactory stimulation, with the ECG signal seen as more sensitive to detect ANS response to moderate olfactory stimuli rather than the GSR. Conclusions: When applied to a greater number of subjects, or to specific groups of patients, this methodology could represent a promising, reliable addition to diagnostic methods currently used in clinical settings.

The Impact of Herbs and Spices on Increasing the Appreciation and Intake of Low-Salt Legume-Based Meals

Flavoring using blends of herbs and spices (H&S) instead of salt may be a promising approach to increase legume consumption and reduce salt content in foods. This study examines the effects of H&S on the appreciation and intake of low-salt legume-based dishes in a real ecological eating environment. Four mezzes with standard (0.8% w/w) (S) or lower (0.4% w/w) (LS) salt level and with or without H&S (LSHS, SHS) were developed. In a randomized cross-over trial, 94 participants attended four sessions, one week apart and received the four variants as a starter during lunch. Overall liking, food intake, and appetite ratings (visual analogue scale, VAS) were assessed during lunch. A follow-up study (n = 130) was performed where the four variants were evaluated, and overall liking was measured at the same session. Overall liking and taste scores of SHS were significantly higher compared with LS (p = 0.04 and p = 0.03, respectively), but there were no significant differences between LSHS and S. However, there were no differences in energy intake or in appetite ratings among the products. Overall appreciation was similar between the low-salt with H&S and the standard-salt mezze, suggesting that the addition of H&S is a feasible strategy for achieving a 50% reduction in salt content without compromising hedonic appreciation.

Climate Change and Consumer's Attitude toward Insect Food

Given the influence of rising environmental awareness, food systems and security are receiving increasing international attention. Previous studies have discussed the acceptance of insect foods but have been primarily conducted in a European context. Hence, their results cannot be applied to Taiwanese consumers. Regarding this, our study is centered on the theory of planned behavior and considers environmental concern and food neophobia to discuss the effects of consumer attitudes, subjective norms, and perceived behavioral control on the purchase intention toward insect food. We used purposive sampling to survey questionnaire answers face-to-face in Taichung city, Taiwan. We distributed 408 surveys of which 77.45% were used in this study. The results revealed that consumer attitudes, perceived behavioral control, and food neophobia significantly influence purchase intention, whereas subjective norms and environmental concern did not demonstrate significant relationships with purchase intention. According to these results, we suggest that businesses emphasize consumers’ product experience or reduce levels of food neophobia to increase consumer interest in insect foods and improve the acceptability of such foods, thereby increasing purchase intention.

CROCUFID: A Cross-Cultural Food Image Database for Research on Food Elicited Affective Responses

We present CROCUFID: a CROss-CUltural Food Image Database that currently contains 840 images, including 479 food images with detailed metadata and 165 images of non-food items. The database includes images of sweet, savory, natural, and processed food from Western and Asian cuisines. To create sufficient variability in valence and arousal we included images of food with different degrees of appetitiveness (fresh, unfamiliar, molded or rotten, spoiled, and partly consumed). We used a standardized photographing protocol, resulting in high resolution images depicting all food items on a standard background (a white plate), seen from a fixed viewing (45°) angle. CROCUFID is freely available under the CC-By Attribution 4.0 International license and hosted on the OSF repository. The advantages of the CROCUFID database over other databases are its (1) free availability, (2) full coverage of the valence - arousal space, (3) use of standardized recording methods, (4) inclusion of multiple cuisines and unfamiliar foods, (5) availability of normative and demographic data, (6) high image quality and (7) capability to support future (e.g., virtual and augmented reality) applications. Individuals from the United Kingdom (N = 266), North-America (N = 275), and Japan (N = 264) provided normative ratings of valence, arousal, perceived healthiness, and desire-to-eat using visual analog scales (VAS). In addition, for each image we computed 17 characteristics that are known to influence affective observer responses (e.g., texture, regularity, complexity, and colorfulness). Significant differences between groups and significant correlations between image characteristics and normative ratings were in accordance with previous research, indicating the validity of CROCUFID. We expect that CROCUFID will facilitate comparability across studies and advance experimental research on the determinants of food-elicited emotions. We plan to extend CROCUFID in the future with images of food from a wide range of different cuisines and with non-food images (for applications in for instance neuro-physiological studies). We invite researchers from all parts of the world to contribute to this effort by creating similar image sets that can be linked to this collection, so that CROCUFID will grow into a truly multicultural food database.

Effects of Two Doses of Curry Prepared with Mixed Spices on Postprandial Ghrelin and Subjective Appetite Responses-A Randomized Controlled Crossover Trial

Spices are known to provide orosensory stimulation that can potentially influence palatability, appetite, and energy balance. Previous studies with individual spices have shown divergent effects on appetite and energy intake measures. In a real-life context, however, several spices are consumed in combinations, as in various forms of curries. Therefore, we investigated changes in postprandial appetite and plasma ghrelin in response to the intake of two doses of curry prepared with mixed spices. The study was undertaken in healthy Chinese men, between 21 and 40 years of age and body mass index ≤27.5 kg/m². Appetite was measured using visual analogue scales (VAS) and plasma ghrelin was measured using multiplex assay. Compared with the control meal (Dose 0 Control (D0C), 0 g mixed spices), we found significantly greater suppression in 'hunger' (both p < 0.05, after Bonferroni adjustments) as well in 'desire to eat' (both p < 0.01) during the Dose 1 Curry (D1C, 6 g mixed spices) and Dose 2 Curry (D2C, 12 g mixed spices) intake. There were no differences, however, in plasma ghrelin or in other appetite measures such as in 'fullness' or in 'prospective eating' scores. Overall, the results of our study indicate greater inter-meal satiety due to mixed spices consumption, independent of any changes in plasma ghrelin response.