Retronasal Olfaction Research Articles

Taste: Unraveling Tomato Flavor

New research integrating genetics, chemistry and psychophysics has led to a model for tomato flavor intensity comprising sugars and acids plus six volatile molecules, providing a blueprint for improving the flavor of what has become an iconic symbol of the declining quality of fresh fruits and vegetables.

INTERACTION OF GUAIACOL AND METHYL SALICYLATE IN BINARY MIXTURE SIGNIFICANTLY LOWERS PERCEPTUAL THRESHOLD IN HUMAN OBSERVERS

ABSTRACTThroughout the field of food chemistry, attempts to reconstruct the characteristic flavor of the tomato have remained a persistent challenge. Although the established method for analyzing tomato volatiles has focused on calculating odor thresholds for a single compound against a basic water background, the current study sought to demonstrate the influence of volatile interactions on perceptual threshold by comparing thresholds for a volatile alone and in the presence of another volatile. Thresholds were compared for methyl salicylate and guaiacol alone and in a 50/50 binary mixture. While the traditional method does not regard guaiacol as contributing significantly to the overall flavor of the tomato, results demonstrated an interaction effect, such that threshold concentrations for mixtures were consistently lower than thresholds reported separately for either methyl salicylate or guaiacol alone, with subjects displaying increased sensitivity (additivity) to a solution comprised of both chemicals. Further research will be needed to thoroughly investigate the underlying mechanisms responsible for such effects, but the results demonstrate that perithreshold and subthreshold volatiles can potentially have a measurable impact on odor perception.PRACTICAL APPLICATIONSGiven the persistent complaints surrounding the flavor of contemporary tomatoes, researchers within the field of food science have continued to make rigorous attempts to improve the overall taste and percept of the standard supermarket tomato. While emphasis has previously focused predominantly on storage, handling and esthetic appeal, priorities are beginning to shift, with consumers more readily requesting the sought after flavor of fresh, heirloom tomatoes. As a consequence, many scientists are undertaking the challenge of studying and manipulating the proportion of plant volatiles thought to be responsible for promoting the characteristic flavor of the tomato fruit, but to fully understand the impact of such volatiles, the issue of retronasal olfaction must be considered. The current research discusses how two such volatiles are capable of interacting at the level of the nose, thereby potentially altering the taste. Hopefully, future researchers will be able to incorporate such olfactory psychophysics techniques into testing panels, thereby providing a more thorough examination of consumer perception.

The Chemical Interactions Underlying Tomato Flavor Preferences

Although human perception of food flavors involves integration of multiple sensory inputs, the most salient sensations are taste and olfaction. Ortho- and retronasal olfaction are particularly crucial to flavor because they provide the qualitative diversity so important to identify safe versus dangerous foods. Historically, flavor research has prioritized aroma volatiles present at levels exceeding the orthonasally measured odor threshold, ignoring the variation in the rate at which odor intensities grow above threshold. Furthermore, the chemical composition of a food in itself tells us very little about whether or not that food will be liked. Clearly, alternative approaches are needed to elucidate flavor chemistry. Here we use targeted metabolomics and natural variation in flavor-associated sugars, acids, and aroma volatiles to evaluate the chemistry of tomato fruits, creating a predictive and testable model of liking. This nontraditional approach provides novel insights into flavor chemistry, the interactions between taste and retronasal olfaction, and a paradigm for enhancing liking of natural products. Some of the most abundant volatiles do not contribute to consumer liking, whereas other less abundant ones do. Aroma volatiles make contributions to perceived sweetness independent of sugar concentration, suggesting a novel way to increase perception of sweetness without adding sugar.

Retronasal perception of odors

We perceive odors orthonasally during sniffing; in contrast, we perceive odors retronasally during eating when they enter the nose through the pharynx. There are clear differences between orthonasal and retronasal olfaction in neuronal processing and perception, so that these two pathways convey two distinct sensory signals. The perception of foods is based on the interaction between ortho- and retronasal smell, taste, trigeminal activation and texture, so it is difficult to investigate one of these factors in isolation. Specific clinical aspects include effects of retronasal olfaction on satiation and swallowing.

Breaking paradigms: a new definition for halitosis in the context of pseudo-halitosis and halitophobia

It is known that almost one-third of patients who seeks treatment for bad breath do not have genuine halitosis. Halitosis can occur even in cases when the malodor is not perceived by those around the patient and can neither be confirmed by organoleptic tests, nor by sulfur portable monitor readings. In such cases, these patients have been considered as halitophobic or have pseudo-halitosis. The complaint might signal the existence of a chemosensory dysfunction. Factors associated with taste and smell perception can be potentially connected to the occurrence of oral malodor. The threshold values of volatile sulfur compounds that have been used to establish the diagnosis of genuine halitosis do not take into account that the patient may perceive low levels of these and of other volatile compounds through retronasal olfaction. The current concept of halitosis requires the presence of a signal that has been based on equipment results, from the olfactory perception of the examiners and of those who interact with the patient. Nevertheless, the concept does not encompass the symptoms of halitosis. This paper addresses some of the possible causes of chemosensory dysfunction and proposes a new definition for halitosis.

Two decades of supertasting: Where do we stand?

Oral chemosensation can vary greatly across individuals, both in terms of the lowest concentration that can be detected (threshold) and in the magnitude of perceived intensity for stimuli at higher concentrations (suprathreshold response). Individuals who experience greater taste intensity are often termed supertasters, and this phenotype has typically been measured via the suprathreshold bitterness of the tastant propylthiouracil (PROP). Notably, supertasting extends beyond bitterness and other tastants to include oral somatosensation and retronasal olfaction, and it may also include finer acuity as well. Here, we describe the evolution of the supertasting concept over the last 20years, and summarize the current state of the field. Alternative phenotyping approaches that are not dependent on PROP are reviewed, and the molecular genetics of broadly tuned heightened taste and orosensory response are discussed. We conclude by initiating a conversation on nomenclature as we look toward the next 20years of chemosensory research.

Enhancement of Retronasal Odors by Taste

Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste ("sweet," "sour," "salty," and "bitter") and odor ("other") intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste-odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of "cherry" and "vanilla" flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods.

The Candy Smell Test in Clinical Routine

The "Candy Smell Test" (CST) has been introduced as a new testing method for the evaluation of the human sense of smell. In contrast to other established orthonasal smell tests, the CST addresses the retronasal application of odors, typical for food aroma effects during mastication and swallowing. The aim of this study was to evaluate the CST in a clinical setting in patients with olfactory dysfunction and normal controls against the Sniffin' Sticks test. Furthermore, cutoff points for normal and pathological results in the CST should be determined. The olfactory performance of 96 patients presenting with olfactory disorders and 71 healthy controls was evaluated with the CST-comprised of 23 different aromatized smell candies and the extended Sniffin' Sticks test (threshold, discrimination, and identification). The control group was gender matched but included also younger persons. The tested subjects could easily understand the procedures and were motivated to participate. The CST correlated well with the Sniffin' Sticks for all tested subjects and for patients (n = 96) and controls (n = 71). The proposed cutoff value to differentiate normosmia from hyposmia in the CST was a score of <16 (i.e., 16 correctly identified odors) of 23. A score below 13 in the CST was the cutoff value for anosmia. The CST is an easy-to-handle reliable tool to investigate retronasal olfaction suited for clinical determination of normosmia, hyposmia, and ansomia. In addition, it can be used for investigation where self-application is necessary such as in large survey studies.

The Interaction of Gestational and Postnatal Ethanol Experience on the Adolescent and Adult Odor‐Mediated Responses to Ethanol in Observer and Demonstrator Rats

Gestational ethanol exposure enhances the adolescent reflexive sniffing response to ethanol odor. Postnatal exposures of naïve animals as either an observer (i.e., conspecific) or demonstrator (i.e., intoxicated peer) using a social transmission of food odor preference paradigm also yields enhanced odor-mediated responses. Studies on the interaction of fetal and postnatal exposures using the social transmission paradigm have been limited to the responses of observers. When combined, the enhanced response is greater than either form of exposure alone and, in observer females, yields adult persistence. The absence of a male effect is noteworthy, given that chemosensory mechanisms are suggested to be an important antecedent factor in the progression of ethanol preference. Observers gain odor information on the breath of the demonstrator through social interaction. Demonstrators experience the pharmacologic properties of ethanol along with retronasal and hematogenic olfaction. Thus, we tested whether augmentation of the fetal ethanol-induced behavioral response with postnatal exposure as a demonstrator differed from that as an observer. We also examined whether re-exposure as a demonstrator yields persistence in both sexes. Pregnant dams were fed an ethanol containing or control liquid diet throughout gestation. Progeny received four ethanol or water exposures: one every 48 hours through either intragastric infusion or social interaction with the infused peer beginning on P29. The reflexive behavioral sniffing response to ethanol odor was tested at postnatal (P) day 37 or P90, using whole-body plethysmography. When tested in either adolescence or adulthood - fetal ethanol exposed adolescent ethanol observers and demonstrators significantly differed in their odor-mediated response to ethanol odor both between themselves and from their respective water controls. Nonetheless, adolescent ethanol re-exposure as a demonstrator, like an observer, enhanced the reflexive sniffing response to ethanol odor at both testing ages by augmenting the known effects of prior fetal ethanol experience. At each age, the magnitude of the enhanced odor response in demonstrators was similar to that of observers. Interestingly, only re-exposure as a demonstrator resulted in persistence of the behavioral response into adulthood in both sexes. The method of ethanol re-exposure plays an important role in prolonging the odor-mediated effects of fetal exposure. While ethanol odor-specific exposure through social interaction is important, additional factors such as the pairing of retronasal and hematogenic olfaction with ethanol's intoxicating properties appear necessary to achieve persistence in both sexes.

Rehabilitation of Smell after Total Laryngectomy

Rehabilitation of Smell after Total Laryngectomy

Olfactory Perception of 6 Amino Acids by Human Subjects

The olfactory properties of 6 amino acids were assessed in 20 human subjects using psychophysical tests of detectability, discriminability, and chemesthesis. Mean olfactory detection thresholds were found to be 10 microM for D-methionine, 80 microM for L-methionine, 200 microM for L-cysteine, 220 microM for D-cysteine, 75 mM for D-proline, and 100 mM for L-proline. When presented at clearly detectable and intensity-matched concentrations, the subjects readily discriminated between the odors of the L-forms of cysteine, methionine, and proline, whereas they failed to distinguish between the L- and D-forms of a given amino acid. The subjects also failed in localizing the side of monorhinal stimulation with all 6 amino acids when presented at the same concentrations as in the discrimination tasks. These results suggest that amino acids may contribute to the flavor of food not only as taste stimuli but also as olfactory stimuli perceived via ortho- or retronasal smelling. In contrast, it is unlikely that amino acids contribute to flavor perception via chemesthesis. Given that the odors of 4 of the 6 amino acids tested here were detected at concentrations lower than their corresponding taste detection thresholds, this may have important implications for the widespread use of amino acids as food additives as well as for the evaluation of off-flavors caused by amino acids.

Expiration: The moment we experience retronasal olfaction in flavor

Respiration is essential for smell perception. Previously we found that 8–12-Hz cortical rhythms were phase-locked to inspiration onset during the presentation of odor stimuli; this is referred to as inspiration phase-locked alpha band oscillation (I-α). Generators of I-α estimated with a dipole fitting model were found in the piriform, the entorhinal cortex (ENT), the amygdala (AMG), the hippocampus (HI) and the orbitofrontal cortex (OFC). Such olfactory perception is said to occur via the orthonasal olfaction route. Another route is the retronasal olfaction route. In this study, we investigated the link between respiration phase and retronasal olfactory perception. Electroencephalograph (EEG) and respiratory flows (separately measured with mouth and nose) were simultaneously recorded during stimulation of subjects’ tongues with liquids of chocolate, sucrose and water. The percentage of subjects correctly identifying the chocolate taste was higher when subjects were asked to breathe through the nose than when they were breathing through the mouth. In the averaged EEGs triggered by the onset of expiration measured from the flow through the nose, a 8–12-Hz oscillation was observed. Generators of this potential were found in the left ENT, HI, AMG and OFC in the order of milliseconds after expiration onset. Perception of retronasal olfaction is dependent on expiration, and combining retronasal olfactory information with gustatory information and somatosensation enable us to identify flavors when drinking and feeding.

Coactivation of Gustatory and Olfactory Signals in Flavor Perception

It is easier to detect mixtures of gustatory and olfactory flavorants than to detect either component alone. But does the detection of mixtures exceed the level predicted by probability summation, assuming independent detection of each component? To answer this question, we measured simple response times (RTs) to detect brief pulses of one of 3 flavorants (sucrose [gustatory], citral [olfactory], sucrose-citral mixture) or water, presented into the mouth by a computer-operated, automated flow system. Subjects were instructed to press a button as soon as they detected any of the 3 nonwater stimuli. Responses to the mixtures were faster (RTs smaller) than predicted by a model of probability summation of independently detected signals, suggesting positive coactivation (integration) of gustation and retronasal olfaction in flavor perception. Evidence for integration appeared mainly in the fastest 60% of the responses, indicating that integration arises relatively early in flavor processing. Results were similar when the 3 possible flavorants, and water, were interleaved within the same session (experimental condition), and when each flavorant was interleaved with water only (control conditions). This outcome suggests that subjects did not attend selectively to one flavor component or the other in the experimental condition and further supports the conclusion that (late) decisional or attentional strategies do not exert a large influence on the gustatory-olfactory flavor integration.

Swallowing Is Differentially Influenced by Retronasal Compared with Orthonasal Stimulation in Combination with Gustatory Stimuli

Identical stimuli are processed differently when presented ortho- or retronasally. In contrast to orthonasal olfaction, retronasal odorant perception is strongly associated with flavor and food intake, which is usually followed by swallowing. Along with other stimuli, gustatory stimuli are known to influence the swallowing reflex. It was therefore the aim of present study to examine whether retronasal olfaction, in combination with simultaneous gustatory stimuli, influences swallowing in a manner different from that of orthonasal olfaction. Fifty normosmic and normogeusic subjects took part in the study. A sweet taste (glucose, delivered via an intraoral taste dispenser) was presented simultaneously with vanillin, a food-like odor, either ortho- or retronasally at random using a computer-controlled olfactometer. Ultrasound imaging of the mouth floor was recorded on videotape to continuously monitor swallowing activity. After retronasal stimulation, swallowing occurred significantly faster (7.49 vs. 9.42 s; P < 0.001) and also took place more frequently compared with swallowing after orthonasal stimulation (1.38 times vs. 1.14 times; P < 0.001). These results show that a food-like odorant presented retronasally in combination with a congruent taste stimulus can influence swallowing. Whether these results can be assigned to other, unfamiliar, unpleasant nonfood-like odors has yet to be determined.

Influence of simultaneous gustatory stimuli on orthonasal and retronasal olfaction

Orthonasal and retronasal olfaction processes differ. The aim of this study was to examine whether congruent and incongruent simultaneous gustatory stimuli influence orthonasal and retronasal odorant perception, using olfactory event-related potentials as a measure. Thirty-two young, healthy subjects (16 men, 16 women) took part in two test sessions. Olfactory event-related potentials were recorded in response to a food-like odor, vanillin, and to an odor usually not associated with foods, the rose-like phenylethylalcohol. Each session consisted of four randomized blocks of 15 stimuli each which were applied either orthonasally or retronasally. Simultaneously, sweet or sour gustatory stimuli were applied. In response to retronasal vanillin, stimuli latencies P2 of the event-related potentials were significantly shorter in the congruent “sweet condition” than the incongruent “sour condition”. In contrast, with orthonasal stimulation, shorter P2 latencies were seen for both odorants in the incongruent condition. Intensity of both odorants was perceived as less pronounced after retronasal stimulation than after orthonasal stimulation. In conclusion, application of a sweet taste significantly enhanced the processing of a congruent olfactory stimulus when presented through the retronasal route. Incongruent simultaneous gustatory stimulation applied during orthonasal olfaction seemed to induce conflict priming, also resulting in faster processing.

The candy smell test: A New Test for Retronasal Olfactory Performance

To develop and validate an olfactory test kit suitable for children and adults based on retronasal smelling of aromas combined with a sweet taste. Moreover, to explore the age limit at which olfactory testing is feasible and to extend the normative database for the validated "Sniffin' Sticks" test regarding children of younger ages. Randomized three-way crossover study in healthy children and adults. : The newly developed Candy Smell Test (CST, 23 aromatized sorbitol candies) was presented using a four-alternative, forced-choice procedure. First, 353 healthy subjects (230 children and 123 adults) were investigated in three separate sessions with the CST and the validated "Sniffin' Sticks" (composed of odor threshold, discrimination, and identification tasks). Both tests were then compared in 124 patients with olfactory disorders. Test-retest reliability showed good reproducibility of the data obtained with the CST on 2 days (r(287) = 0.75, P < .001). Test results correlated significantly with the "Sniffin' Sticks" score (r(366) = 0.84, P < .001), although the CST proves to be much easier. The age limit for obtaining valid data was 7 years for both tests. The cutoff limit for the CST scores to separate normosmics from dysosmics was a score of 16 or less out of 23. Anosmia (cutoff score <or=13) was detected with a sensitivity of 94% and a specificity of 83%. The CST is an easy-to-use, reliable, and fast test of retronasal olfactory performance suitable for the screening of smell function in children above the age of 6 years and adults.

Temporal processing of olfactory stimuli during retronasal perception

Odorants can be perceived via the nose during an inhalation or sniff (orthonasal perception) and via the mouth, nasopharynx and nasal cavity during mastication or drinking (retronasal perception). Previous data suggest that orthonasal perception provides a more efficient route with greater difficulty being reported when detecting [Halpern BP. Retronasal and orthonasal smelling. Chemosense 2004;6:1–7; Voirol E, Daget N. Comparative study of nasal and retronasal olfactory perception. Lebensmittel-Wissenschaft Technol 1986;19:316–9] and identifying [Heilmann S, Hummel T. A new method for comparing orthonasal and retronasal olfaction. Behav Neurosci 2004;118:412–9; Sun BC, Halpern BP. Identification of air-phase retronasal and orthonasal odorant pairs. Chem Senses 2005;30:1–14] single odorants retronasally. Whether the poorer sensitivity obtained via the retronasal route is largely due to the greater adsorption of odorants by the nasopharyngeal mucus compared to the nasal mucus thereby reducing their peak concentration and/or slowing their passage, has not been resolved. Importantly, the question of whether solubility of odorants in mucus or water predicts the outcomes for perception of stimuli presented via the retronasal route has not been resolved. Accordingly, the present study investigates this question by determining whether the solubility of an odorant in mucus predicts which component of a binary odour mixture is perceived first during retronasal perception. The results indicate that solubility in mucus rather than solubility in water is a better predictor of which odour will be perceived first and identified more readily during the retronasal perception of a binary mixture. In addition, lower intensity levels of single odorants occurred via the retronasal route suggesting that adsorption was greater via this route. Whether this was due to nasopharyngeal mucus having a greater adsorptive area or different composition compared to the orthonasal pathway is not known.

The way an odor is experienced during aversive conditioning determines the extent of the network recruited during retrieval: A multisite electrophysiological study in rats.

Event Abstract Back to Event The way an odor is experienced during aversive conditioning determines the extent of the network recruited during retrieval: A multisite electrophysiological study in rats. Nadine Ravel1*, Samuel Garcia1, Belkacem Messaoudi1, Marc Thevenet1, Guillaume Ferreira2, Remi Gervais1 and Julie Chapuis1 1 UMR CNRS-Lyon1 5020, France 2 Tours University, UMR INRA 85 - CNRS 6175, France Recent findings have revealed the importance of orthonasal and retronasal olfaction in food memory, especially in conditioned odor aversion (COA); however, little is known about the dynamics of the cerebral circuit involved in the recognition of an odor as a toxic food signal and whether the activated network depends on the way (orthonasal versus retronasal) the odor was first experienced. In this study, we mapped the modulations of odor-induced oscillatory activities through COA learning using multisite recordings of local field potentials in behaving rats. During conditioning, orthonasal odor alone or associated with ingested odor was paired with immediate illness. For all animals, COA retrieval was assessed by orthonasal smelling only. Both types of conditioning induced similarly strong COA. Results pointed out (i) a predictive correlation between the emergence of powerful beta (15-40 Hz) activity and the behavioral expression of COA and (ii) a differential network distribution of this beta activity according to the way the animals were exposed to the odor during conditioning. Indeed, for both types of conditioning, the aversive behavior was predicted by the emergence of a strong beta oscillatory activity in response to odor in the olfactory bulb, anterior and posterior piriform cortex, orbitofrontal cortex, and basolateral amygdala. This network was selectively extended to the infralimbic and insular cortices when the odor was ingested during COA learning. These differential networks could participate in different food odor memory; these results are discussed in line with recent behavioral results that indicate that COA can be formed over long odor-illness delays only if the odor is ingested. This work was supported by the CNRS, by the Minist Conference: 41st European Brain and Behaviour Society Meeting, Rhodes Island, Greece, 13 Sep - 18 Sep, 2009. Presentation Type: Poster Presentation Topic: Poster presentations Citation: Ravel N, Garcia S, Messaoudi B, Thevenet M, Ferreira G, Gervais R and Chapuis J (2009). The way an odor is experienced during aversive conditioning determines the extent of the network recruited during retrieval: A multisite electrophysiological study in rats.. Conference Abstract: 41st European Brain and Behaviour Society Meeting. doi: 10.3389/conf.neuro.08.2009.09.241 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 12 Jun 2009; Published Online: 12 Jun 2009. * Correspondence: Nadine Ravel, UMR CNRS-Lyon1 5020, Lyon, France, nadine.ravel@cnrs.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nadine Ravel Samuel Garcia Belkacem Messaoudi Marc Thevenet Guillaume Ferreira Remi Gervais Julie Chapuis Google Nadine Ravel Samuel Garcia Belkacem Messaoudi Marc Thevenet Guillaume Ferreira Remi Gervais Julie Chapuis Google Scholar Nadine Ravel Samuel Garcia Belkacem Messaoudi Marc Thevenet Guillaume Ferreira Remi Gervais Julie Chapuis PubMed Nadine Ravel Samuel Garcia Belkacem Messaoudi Marc Thevenet Guillaume Ferreira Remi Gervais Julie Chapuis Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A European study for the validation of a retronasal test of olfaction.

Event Abstract Back to Event A European study for the validation of a retronasal test of olfaction. Christos Merkonidis1*, Carl Philpott1, Mahmoud Salam1 and Thomas Hummel2 1 The Ipswich Hospital NHS Trust, United Kingdom 2 Dresden University Hospital, Smell and Taste Clinic, Germany There are various olfactory tests available for testing a patient’s sense of smell but these are essentially designed to test orthonasal olfaction. When eating food, however, it is retronasal olfaction that gives a person a sense of flavour. We present a study about the sense of smell via the retronasal route on both healthy and pathological subjects. This prospective study took place at The Ipswich Hospital and was part of a multicentre, pan-European study, which is conducted in order to validate this format of testing in a more ‘universal’ fashion. We included 28 patients (15 with no nasal disease and considered to have a normal sense of smell and 13 with active nasal pathology). All individuals were tested with 40 different odours in the form of powder, placed at the back of the tongue. In addition, all individuals had a validated orthonasal test in the form of the Sniffin Stick’s test. Olfactory disorders were due to inflammatory, infectious, idiopathic and congenital causes. There were significant differences between the healthy and pathological subjects (p<0.005) for both the orthonasal and retronasal tests. There was good correlation between the two tests in the group with nasal pathology (p<0.02). The powders most commonly incorrectly identified in both groups were cocoa, fish and almond. Retronasal testing in patients with olfactory disorders is proven to be an effective method in testing flavour perception. Conference: Summer School on Human Olfaction, Dresden, Germany, 19 Jul - 25 Jul, 2009. Presentation Type: Poster Presentation Topic: Abstracts Citation: Merkonidis C, Philpott C, Salam M and Hummel T (2009). A European study for the validation of a retronasal test of olfaction.. Conference Abstract: Summer School on Human Olfaction. doi: 10.3389/conf.neuro.09.2009.12.024 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Jul 2009; Published Online: 23 Jul 2009. * Correspondence: Christos Merkonidis, The Ipswich Hospital NHS Trust, Suffolk, United Kingdom, merkonidis@hotmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Christos Merkonidis Carl Philpott Mahmoud Salam Thomas Hummel Google Christos Merkonidis Carl Philpott Mahmoud Salam Thomas Hummel Google Scholar Christos Merkonidis Carl Philpott Mahmoud Salam Thomas Hummel PubMed Christos Merkonidis Carl Philpott Mahmoud Salam Thomas Hummel Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

EVALUATION OF THE FLAVOR QUALITY OF PEPPER (PIPER NIGRUM L.) CULTIVARS BY GC–MS, ELECTRONIC NOSE AND SENSORY ANALYSIS TECHNIQUES

ABSTRACT Pepper (Piper nigrum L.) is an extensively used spice, which has a characteristic flavor and pungency. The properties of spices such as flavor, color, pungency, etc., vary among cultivars and varieties. It is in this context that pepper cultivars namely, Panniyur 1, Balankotta, Panniyur 5 and one commercial sample were examined for flavor and odor profile using sensory, gas chromatography–mass spectrometry (GC–MS) and electronic nose (E‐nose) analyses. The flavor profile of pepper powder dispersed in cornstarch gruel clearly differentiated Balankotta samples from the other three samples; green mango‐like, turmeric‐like and earthy notes were higher in Balankotta samples, while the other samples had higher scores for pepper‐like, pungent, spicy and lingering herbaceous. The flavor profile of the essential oils of pepper samples showed a higher intensity of pepper‐like note in Panniyur 1, Panniyur 5 and commercial sample, and turmeric‐like and green mango‐like characterized Balankotta. The odor profile of the essential oils further supported the flavor profile data. Orthonasal olfaction (odor profile) provided more descriptive odor characteristics for pepper powder than pepper essential oil. The orthonasal and retronasal olfaction (flavor profile) showed an opposite trend when the flavor profile of pepper essential oil samples was carried out in a starch‐based carrier; retronasal olfaction was more effective than the orthonasal. GC, GC–MS analysis and E‐nose aroma pattern complemented the sensory flavor profiling results. The GC–MS of Balankotta pepper samples was different from Panniyur 1, Panniyur 5 and the commercial sample, showing higher content of p‐cymene. The E‐nose pattern matching further supported the sensory and instrumental data.PRACTICAL APPLICATIONSThe results of this study provided a protocol for the quality evaluation of spices, in terms of sensory quality and aroma pattern as determined by gas chromatography–mass spectrometry. Introducing the electronic nose technique for the rapid evaluation of spice aroma, as well as characterization of spices, was an added information. The results of this study gave the odor description of major compounds present in pepper essential oil and the regional variations in odor profiles, which can help in designing spice blends with specific flavor profiles.