Aroma Stimuli Research Articles

Lavender Essential Oil Inhalation Improves Attentional Shifting and Accuracy: Evidence from Dynamic Changes of Cognitive Flexibility and Power Spectral Density of Electroencephalogram Signals.

Cognitive flexibility, a vital component of executive function, entails the utilization of extended brain networks. Olfactory stimulation has been shown to influence various brain functions, particularly cognitive performance. To investigate aroma inhalation's effects on brain activity dynamics associated with cognitive flexibility, 20 healthy adults were recruited to complete a set-shifting task during two experimental conditions: no aroma stimuli vs. lavender essential oil inhalation. Using Thomson's multitaper approach, the normalized power spectral density (NPSD) was assessed for five frequency bands. Findings confirm that aroma inhalation significantly affects behavioral indices (i.e., reaction time (RT) and response accuracy) and electroencephalogram (EEG) signatures, especially in the frontal lobe. Participants showed a tremendous increase in theta and alpha NPSD, associated with relaxation, along with beta NPSD, associated with clear and fast thinking after inhaling the aroma. NPSD of the delta band, an indicator of the unconscious mind, significantly decreased when stimulated with lavender essential oil. Further, participants exhibited shorter RT and more accurate responses following aroma inhalation. Our findings revealed significant changes in oscillatory power and behavioral performance after aroma inhalation, providing neural evidence that olfactory stimulation with lavender essential oil may facilitate cognitive flexibility.

Exploring Crossmodal Associations Between Sound and the Chemical Senses: A Systematic Review Including Interactive Visualizations.

This is the first systematic review that focuses on the influence of product-intrinsic and extrinsic sounds on the chemical senses involving both food and aroma stimuli. This review has a particular focus on all methodological details (stimuli, experimental design, dependent variables, and data analysis techniques) of 95 experiments, published in 83 publications from 2012 to 2023. 329 distinct crossmodal auditory-chemosensory associations were uncovered across this analysis. What is more, instead of relying solely on static figures and tables, we created a first-of-its-kind comprehensive Power BI dashboard (interactive data visualization tool by Microsoft) on methodologies and significant findings, incorporating various filters and visualizations allowing readers to explore statistics for specific subsets of experiments. We believe that this review can be helpful for researchers and practitioners working in the food and beverage industry and beyond these scopes (e.g., cosmetics). Theoretical and practical implications discussed in this article point to computational approaches that facilitate decision-making regarding multisensory experimental methodology design.

Study on the Psychological States of Olfactory Stimuli Using Electroencephalography and Heart Rate Variability.

In the modern information society, people are constantly exposed to stress due to complex work environments and various interpersonal relationships. Aromatherapy is attracting attention as one of the methods for relieving stress using aroma. A method to quantitatively evaluate such an effect is necessary to clarify the effect of aroma on the human psychological state. In this study, we propose a method of using two biological indexes, electroencephalogram (EEG) and heart rate variability (HRV), to evaluate human psychological states during the inhalation of aroma. The purpose is to investigate the relationship between biological indexes and the psychological effect of aromas. First, we conducted an aroma presentation experiment using seven different olfactory stimuli while collecting data from EEG and pulse sensors. Next, we extracted the EEG and HRV indexes from the experimental data and analyzed them with respect to the olfactory stimuli. Our study found that olfactory stimuli have a strong effect on psychological states during aroma stimuli and that the human response to olfactory stimuli is immediate but gradually adapts to a more neutral state. The EEG and HRV indexes showed significant differences between aromas and unpleasant odors especially for male participants in their 20-30s, while the delta wave and RMSSD indexes showed potential for generalizing the method to evaluate psychological states influenced by olfactory stimuli across genders and generations. The results suggest the possibility of using EEG and HRV indexes to evaluate psychological states toward olfactory stimuli such as aroma. In addition, we visualized the psychological states affected by the olfactory stimuli on an emotion map, suggesting an appropriate range of EEG frequency bands for evaluating psychological states applied to the olfactory stimuli. The novelty of this research lies in our proposed method to provide a more detailed picture of the psychological responses to olfactory stimuli using the integration of biological indexes and emotion map, which contributes to the areas such as marketing and product design by providing insights into the emotional responses of consumers to different olfactory products.

A single-response emotion word questionnaire for measuring product-related emotional associations inspired by a circumplex model of core affect: Method characterisation with an applied focus

Product-centric emotion research can deepen understanding of consumers’ product experiences and food choices. Emotion measurement has become widespread in product research, and questionnaires where consumers respond to emotion words are popular and manifold. The present research adds to this multiplicity by presenting a parsimonious single-response questionnaire that spans the dimensions of pleasure and arousal, and their combinations. These are represented in a circular layout with 12 axes radiating from a central point. Each of the arms represents an emotion domain that is exemplified by two emotion words, and consumers’ task is to select the word pair that best represents how they feel. The questionnaire is informed by a circumplex model of human core affect, and methodological aspects relevant for use in applied product research were investigated in 23 consumer studies (n = 104–270 participants per study) spanning a very broad range of products and categories. The first of four research questions (RQ) established that the questionnaire is suitable for use with tasted stimuli (12 studies, 1 of which with aroma stimuli), written stimuli (10 studies) and image stimuli (1 study) (RQ1). Suitability of the questionnaire with New Zealand consumers was confirmed, and extended to Chinese consumers who took part in 7 of the 23 studies (RQ2). Responses obtained using the questionnaire appeared to be repeatable (RQ3a), and based on the criterion of the regression vector (RV) coefficient being equal to or greater than 0.95, stability (RQ3b) could be achieved with as few as 30 consumers despite only obtaining a single response per consumer per stimulus. Finally, it was found that the degree of differences between stimuli in a study influenced discrimination, which was larger when stimuli were more different (RQ4). This intuitively made sense and mirrored past research. By capturing the valence × arousal space, this questionnaire spans more broadly than most emotion word questionnaires for applied and product-focused research, and a notable feature of the obtained responses was that all were relevant (to a larger or smaller extent) in each of the 23 studies. The results are specific to the tested questionnaire variant and future research is needed to determine its goodness-of-fit to the underpinning circumplex model. Comparisons with existing product emotion research questionnaires are yet to be performed, as is testing of questionnaire variants.

Study of Chardonnay and Sauvignon blanc wines from D.O.Ca Rioja (Spain) aged in different French oak wood barrels: Chemical and aroma quality aspects

This study discusses chemical data corresponding to the analysis of twenty-one wood-extractable aromatic compounds in twenty-four different barrels varying in the toasting level at three sampling times: at the end of the alcoholic fermentation and after 5 and 12months of aging. Twelve barrels contained monovarietal Chardonnay wine while the other twelve barrels contained Sauvignon blanc wine. The levels of nearly all the analyzed compounds increased with the aging time, with the exception of vinylphenols and methyl vanillate, which decreased. These latter compounds had significantly higher levels in the Chardonnay wines than in the Sauvignon blanc. Furfural, guaiacol and vanillin derivatives increased with the toasting level. ANOVA study showed significant interactions between the toasting level and aging time as well as between the variety and aging time, which revealed significant differences in the levels of the compounds studied in the wines dependent on the toasting level, variety and aging time.Quality perception based exclusively on orthonasal aroma stimuli was evaluated by a panel of Spanish wine professionals in 12-month aged wines belonging to both grape varieties. Experts from D.O.Ca Rioja aroma did not share a common aroma quality concept for aged Chardonnay and Sauvignon blanc wines. Considering the cluster formed by the majority of experts (76%) for the Chardonnay and cluster 1 (56%) for Sauvignon blanc, quality scores were negatively correlated with the concentration level of 4-vinylphenol and positively with the concentration level of (E)-isoeugenol. The opposite was observed for cluster 2 (44%) identified for Sauvignon blanc wines.

The Effect of Aroma Stimuli on the Dynamic Balance Ability of Stroke Patients

The Effect of Aroma Stimuli on the Dynamic Balance Ability of Stroke Patients

Use of an Immediate Swallow Protocol to Assess Taste and Aroma Integration in fMRI Studies

Perception of flavor is a complex process involving the integration of taste and aroma. Few functional magnetic resonance imaging (fMRI) studies have assessed the crossmodal interactions which result in flavor perception, and all previous studies have used a retro-nasal aroma delivery with a delayed swallow, which delays retro-nasal aroma release, and thus, alters taste and aroma integration. In this paper, we assess crossmodal interactions in flavor processing using an immediate swallow fMRI paradigm in 13 healthy volunteers. We compare unimodal taste (sucrose) and unimodal retro-nasal aroma stimuli, with a congruent taste and aroma combination (flavor), to assess crossmodal flavor interactions using an immediate swallow paradigm. Subtraction and conjunction analysis methods are described, and the use of a control stimulus is addressed. Subtraction analysis was found to reveal areas of anterior insula, frontal operculum, anterior cingulate, and orbitofrontal cortex, whilst the conjunction analysis revealed additional active areas in oral somatosensory areas (SI), rolandic operculum and posterior cingulate, supporting the hypothesis that taste, olfactory, and tactile sensations are integrated to produce a flavor percept.

FUNCTIONAL MAGNETIC RESONANCE IMAGING ASSESSMENT OF THE CORTICAL REPRESENTATION OF ORAL VISCOSITY

ABSTRACT Viscosity, taste and aroma are key attributes of food. Functional magnetic resonance imaging (fMRI) is increasingly used to investigate the cortical brain response to taste and aroma; however hitherto, the response to food viscosity has been the subject of only one fMRI study. This study aims to investigate the cortical response to oral viscosity in humans using wide brain coverage and multi‐echo acquisition techniques to improve sensitivity across a range of brain regions to confirm and extend previous findings. The stimulus used was an alginate gel compared to a water control. Activation was detected by group analysis in the right postcentral gyrus/somatosensory cortex, in the right rolandic operculum/parietal operculum cortex and in a more anterior part of the left insula. No activation was detected in the orbitofrontal cortex. PRACTICAL APPLICATIONSRecent neuroimaging studies have begun to unravel the cortical representation of taste and aroma stimuli, detecting brain activation in primary sensory and secondary association areas, as well as those cortical areas associated with reward and emotional behavior. Functional magnetic resonance imaging techniques, as shown here, can be easily extended to the study of the cortical response to oral viscosity, thus adding a unique tool to the field of texture studies.

Improved methods for fMRI studies of combined taste and aroma stimuli

Previous neuroimaging studies of the cortical representation of gustatory and olfactory stimuli have often delivered tastants to the mouth in very small quantities or stimulated olfaction orthonasally. In studies of retro-nasal olfaction, swallowing was generally delayed to reduce head motion artefacts. The present fMRI study aims to improve upon such methodological limitations to allow investigation of the cortical representation of flavour (taste and aroma combination) as it typically occurs during the consumption of liquid foods. For this purpose we used (1) a novel, automated, sprayed stimulus delivery system and a larger volume of liquid sample (containing sweet tastants and banana/pear aroma volatiles) to achieve more extensive stimulation of the oral cavity taste receptors, (2) a pseudo-natural delivery paradigm that included prompt swallowing after each sample delivery to obtain physiological retro-nasal olfactory stimulation, (3) fMRI acquisition with wide brain coverage and double-echo EPI to improve sensitivity. We validated our paradigm for the delivery of volatiles using atmospheric pressure chemical ionisation mass spectrometry. This showed that the main retro-nasal delivery of volatiles in the paradigm occurs immediately after the swallow. Several brain areas were found to be activated, including the insula, frontal operculum, rolandic operculum/parietal lobe, piriform, dorsolateral prefrontal cortex, anterior cingulate cortex, ventro-medial thalamus, hippocampus and medial orbitofrontal cortex.

Cross-Modality of Texture and Aroma Perception Is Independent of Orthonasal or Retronasal Stimulation

To assess the influence of orthonasal and retronasal stimulation on cross-modal interactions between texture and flavor perception of food, a series of experiments have been conducted. Healthy human subjects were exposed to strawberry aroma pulses delivered by a computer-controlled stimulator based on air dilution olfactometry. Just prior to exposure to the aroma, the human subjects consumed water, custard, or protein gels with different textures without any added aroma. The aroma was delivered as a sequence of aroma pulses, in either an orthonasal or a retronasal fashion. The retronasal presentation of aroma with concomitant presentation of texture is thought to more closely mimick the in vivo flavor release of semisolid food products as compared to orthonasal stimulation. The time between oral consumption of the food, including swallowing, and the exposure to the aroma varied between 0.5 and 6.5 s. The subjects rated the intensity of the strawberry aroma. It was observed that the intensity of aroma decreased with increasing firmness of the food that was consumed. Aroma pulses delivered 6.5 s after swallowing were perceived as being more intense as compared to aroma pulses delivered immediately after swallowing. In conjunction with late delivery, the effect cross-modal interactions apparently decreased. Significantly higher odor intensities were reported for the aroma stimuli supplied orthonasally in comparison to retronasal administration. The observed cross-modal effect of texture on aroma intensity was not significantly altered by the mode of aroma delivery, i.e., orthonasal or retronasal stimulus administration.

Taste-aroma interactions in a ternary system: A model of fruitiness perception in sucrose/acid solutions

Cross-modal interactions between aroma, sweetness, and acidity were studied. A series of samples was presented to trained panelists who assessed strawberry flavor intensity using magnitude estimation with a reference modulus. The delivery of aroma stimuli from the different solutions was measured by monitoring exhaled breath using atmospheric pressure chemical ionization-mass spectrometry to determine whether there were any physicochemical effects on volatile release; no significant differences were noted. Three-dimensional predictive models were built to describe perceived strawberry flavor intensity as a function of concentrations of sucrose, acid, and volatiles. Analysis of the data identified two groups of panelists with different responses: For Group 1, increasing sucrose and/or acid levels also increased the perceived flavor intensity. For Group 2, changing sucrose concentrations had little effect, but increasing acid and/or volatile levels did. The results show different effects of organic and inorganic acids on perception, as well as clear interactions between the modalities of taste (sugar and acid) and aroma. The clustering of panelists' responses suggests that this phenomenon may depend on prior associations between the fruity flavor and the tastants.

Capsicum--production, technology, chemistry, and quality. Part III. Chemistry of the color, aroma, and pungency stimuli.

The spice capsicum, the fruits of the genus Capsicum (Family Solanaceae), is a very popular food additive in many parts of the world, valued for the important sensory attributes of color, pungency, and aroma. A large number of varieties are widely cultivated and traded. The characteristic carotenoids of the bright red paprika and cayenne-type chillies, the high character impact aroma stimuli, the methoxy pyrazine of green bell capsicum, the esters of ripe tabasco and the highly potent pungency stimuli, and the capsaicinoids of African and other Asian varieties of chillies, have been of great interest to chemists and biochemists. Research workers in other disciplines such as genetics and breeding, agriculture, and technology have been interested in this spice to develop new varieties with combinations of different optimal levels of the stimuli for the sensory attributes and to maximize production of storable products for specific end uses. Physiologists have been intensely studying the action of the highly potent pungency stimuli and social psychologists the curious aspect of growing acceptance and preference for the initially unacceptable pungency sensation. In the sequential review of all these aspects of the fruit spice Capsicum, the earlier two parts covered history, botany, cultivation and primary processing, and processed products, standards, world production, and trade. In Part III, the chemistry, the compositional variations, synthesis and biosynthesis of the functional components, the carotenoids, the volatiles, and the capsaicinoids are comprehensively reviewed.