Individual differences in the perception of orthonasal irritation induced by food

Regional brain morphology of the primary somatosensory cortex correlates with spicy food consumption and capsaicin sensitivity

Objective: Habitual spicy food consumption leads to altered perception of capsaicin. Little is known about the neural morphological correlates of habitual spicy food intake and related trigeminal perceptions. In this study, we used voxel-based morphometry to identify brain regions where regional gray matter volume (GMV) correlates to spicy food consumption. Methods: Fifty-two participants were surveyed for their spicy food dietary habit by a composite score of spicy diet duration, frequency of spicy food consumption, and preferred degree of spiciness. Forty-two participants were further assessed for oral sensitivity and intensity ratings of capsaicin-induced irritation, and intranasal sensitivity and intensity of trigeminal odors. Results: We found that the composite spicy score was positively correlated to GMV of the primary somatosensory area (SI), and the primary (M1), supplementary motor areas (SMA) and the putamen. It was negatively correlated to GMV of the anterior insula, orbitofrontal cortex, frontal gyrus and angular gyrus. The GMV of the SI area was negatively correlated to capsaicin sensitivity; the GMV of the right middle frontal gyrus was positively correlated to the irritative intensity for capsaicin at high concentration (70 μM). However, we observed no correlation between the intranasal trigeminal sensitivity and spicy food consumption or the regional GMV. Discussion: Collectively our findings suggest a central neuroanatomical reflection of altered capsaicin perception in relation to habitual spicy food consumption. Future longitudinal studies should elucidate the possible causal relationship of dietary habit and brain structural plasticity.

Effects of different woods in barbecuing: Consumers' sensory perception and liking of grilled chicken meat

The sensory effects of grilling wood on consumers' response are poorly understood, despite their potentiality in diversifying dishes. This study investigated both the effects of six materials (beech tree wood, Turkey oak wood, Sangiovese grapevine wood, olive wood, strawberry tree wood, charcoal briquettes) used to grill chicken breast meat on liking and sensory perception and consumers' interest in using wood for grilling. A consumer test was conducted (n = 99 subjects, 45% males, aged from 18 to 65 years), applying a Rate-All-That-Apply test, a liking test, and a questionnaire exploring the interest, the perceived value and the sustainability of wood as part of the food processing. The type of wood clearly affected the consumers' sensory perception and acceptability of meat. Strawberry tree wood was the most connoted and divisive sample. Turkey oak, olive tree and Sangiovese grapevine woods were associated to milder sensory profile. Two clusters were found (respectively with 54% participants in Cl1 and 46% in Cl2), with opposite preferences: while Cl2 preferred meat grilled with the most connotating wood (Strawberry tree wood) characterized by bitterness while Cl1 on the opposite preferred meat grilled with the milder woods. Consumers showed a high interest for grilling material, wood origin and wood botanical species, independently from the cluster. Strawberry tree wood was the material that most strongly connotated grilled meat and thus the most divisive one in terms of liking. Different varieties of wood and certified sustainable wood can valorize the grilling process in food services.

Food Neophobia, Odor and Taste Sensitivity, and Overall Flavor Perception in Food

Smell, which allows us to gather information about the hedonic value of an odor, is affected by many factors. This study aimed to assess the relationship among individual factors, odor sensitivity, and enjoyment, and to evaluate how overall flavor perception and liking in actual food samples are affected by odor sensitivity. A total of 749 subjects, from four different Italian regions, participated in the study. The olfactory capabilities test on four odors (anise, banana, mint, and pine), as well as PROP (6-n-prpyl-2-thiouracil) status and food neophobia were assessed. The subjects were clustered into three groups of odor sensitivity, based on the perceived intensity of anise. The liking and intensity of the overall flavor were evaluated for four chocolate puddings with increasing sweetness (C1, C2, C3, and C4). The individual variables significantly affected the perceived intensity and liking of the odors. Even if all of the odor sensitivity groups perceived the more intensely flavored samples as the C1 and C4 chocolate puddings, the high-sensitivity group scored the global flavor of all of the samples as more intense than the low-sensitivity group. The low-sensitive subjects evaluated the liking of the sweeter samples with higher scores than the moderate-sensitive subjects, whereas the high-sensitive subjects gave intermediate scores. In conclusion, odor sensitivity plays a pivotal role in the perception and liking of real food products; this has to be taken into account in the formulation of new products, suitable for particular categories with reduced olfactory abilities.

The Individual Differences in the Perception of Oral Chemesthesis Are Linked to Taste Sensitivity

Chemesthesis is a part of the flavor experience of foods. Chemesthetic perception is studied to understand its effect on food-related behavior and health. Thus, the objective of this research was to study individual differences in chemesthetic perception. Our study involved sensory tests of three chemesthetic modalities (astringency, pungency, and cooling). Participants (N = 196) evaluated the intensity of samples in different concentrations using a line scale under sensory laboratory conditions. Aluminum ammonium sulfate, capsaicin, and menthol were used as the prototypic chemesthetic compounds. The participants were divided into sensitivity groups in different chemesthetic modalities by hierarchical clustering based on their intensity ratings. In addition, an oral chemesthesis sensitivity score was determined to represent the generalized chemesthesis sensitivity. The results showed that people can perceive chemesthesis on different intensity levels. There were significantly positive correlations between (1) sensitivity scores for oral chemesthesis and taste as well as (2) each chemesthesis and taste modalities. Moreover, based on the multinomial logistic regression model, significant interactions between oral chemesthesis and taste sensitivity were discovered. Our findings showed that people can be classified into different oral chemesthesis sensitivity groups. The methods and results of this study can be utilized to investigate associations with food-related behavior and health.

Transient Receptor Potential Vanilloid Subtype 1: Potential Role in Infection, Susceptibility, Symptoms and Treatment of COVID-19

The battle against the new coronavirus that continues to kill millions of people will be still long. Novel strategies are demanded to control infection, mitigate symptoms and treatment of COVID-19. This is even more imperative given the long sequels that the disease has on the health of the infected. The discovery that S protein includes two ankyrin binding motifs (S-ARBMs) and that the transient receptor potential vanilloid subtype 1 (TRPV-1) cation channels contain these ankyrin repeat domains (TRPs-ARDs) suggest that TRPV-1, the most studied member of the TRPV channel family, can play a role in binding SARS-CoV-2. This hypothesis is strengthened by studies showing that other respiratory viruses bind the TRPV-1 on sensory nerves and epithelial cells in the airways. Furthermore, the pathophysiology in COVID-19 patients is similar to the effects generated by TRPV-1 stimulation. Lastly, treatment with agonists that down-regulate or inactivate TRPV-1 can have a beneficial action on impaired lung functions and clearance of infection. In this review, we explore the role of the TRPV-1 channel in the infection, susceptibility, pathogenesis, and treatment of COVID-19, with the aim of looking at novel strategies to control infection and mitigate symptoms, and trying to translate this knowledge into new preventive and therapeutic interventions.

Comparing a new rapid combined method (RapCoTT) with traditional approaches for phenotyping thermal taste

Thermal taste is the phenomenon whereby taste is induced in some individuals through the application of a changing temperature stimulus to the tongue. Research into thermal taste is currently limited by inefficient phenotyping methods, which result in large numbers of unclassified individuals. This study evaluated the performance of a new, rapid combined phenotyping approach (RapCoTT) compared to two classification approaches using traditional phenotyping methods. RapCoTT was found to be more efficient at classifying participants, whilst showing consistency in classification with existing approaches. However, learning effects impacted the efficiency of all methods, which are a likely consequence of the unusual nature of thermal taste. It was concluded that three training steps be included for the phenotyping, namely taste exposure, TCATA training and a practice run. RapCoTT was found to evoke similar patterns of perceived tastes to other methods, with some exceptions. RapCoTT provides a more efficient tool for categorising participants for comparing sensory perception and food choice behaviours within the Thermal taste phenotype and provides a robust approach for future research into the phenomenon of thermal taste.

Potential Interplay between Nrf2, TRPA1, and TRPV1 in Nutrients for the Control of COVID-19

In this article, we propose that differences in COVID-19 morbidity may be associated with transient receptor potential ankyrin 1 (TRPA1) and/or transient receptor potential vanilloid 1 (TRPV1) activation as well as desensitization. TRPA1 and TRPV1 induce inflammation and play a key role in the physiology of almost all organs. They may augment sensory or vagal nerve discharges to evoke pain and several symptoms of COVID-19, including cough, nasal obstruction, vomiting, diarrhea, and, at least partly, sudden and severe loss of smell and taste. TRPA1 can be activated by reactive oxygen species and may therefore be up-regulated in COVID-19. TRPA1 and TRPV1 channels can be activated by pungent compounds including many nuclear factor (erythroid-derived 2) (Nrf2)-interacting foods leading to channel desensitization. Interactions between Nrf2-associated nutrients and TRPA1/TRPV1 may be partly responsible for the severity of some of the COVID-19 symptoms. The regulation by Nrf2 of TRPA1/TRPV1 is still unclear, but suggested from very limited clinical evidence. In COVID-19, it is proposed that rapid desensitization of TRAP1/TRPV1 by some ingredients in foods could reduce symptom severity and provide new therapeutic strategies.

Linking producers' and consumers' perceptions in the valorisation of non-timber forest products: An analysis of Ogiek forest honey

This work aims to present a multidisciplinary approach that combines methodologies from economic anthropology and sensory science to valorise non-timber forest products; this is performed by using Kenyan forest honey as a case study to foster a positive alignment between producers and consumers living in the target market. Firstly, ethnographic research was carried out in Kenya to analyse the core competences of the forest honey producers (n = 20) and to select honey samples for the sensory evaluation. Secondly, a consumer test was performed in Italy to investigate the perception of the sensory properties by using a rate-all-that-apply test and its hedonic responses for six forest honeys by subjects living in Italy (n = 50). Based on the producers' perceptions of the definition of the harvesting area and the floral origin of the honeys, an indigenous classification was outlined. The key core competences of the producers centred around the traditional method of production. The harvesting area was determinant in the preference of the interviewees, being forest honeys produced from the nectar of indigenous melliferous species, from which originate the most appreciated products. Similarly, results from the consumer test showed that harvesting area and the floral origin influenced the hedonic response. Moreover, the drivers of liking (e.g. intense colour, clear appearance, smoked flavour) and disliking (e.g., granularity, opaque appearance) were identified. The paper suggests a development trajectory that promotes the commercial potential of local production but preserves the heritage thereof. The approach is potentially applicable to all marginalised food products and facilitates a promising prospective for sustainable development.