The impact of temperature and a chemesthetic cooling agent on lingual roughness sensitivity.

Oral tactile sensitivity underpins food texture perception, but few studies have investigated mechanoreception in oral tissues. During food consumption, oral tissues are exposed to a wide range of temperatures and chemical entities. The objective of the present study was to assess the influence of thermal sensations on lingual roughness sensitivity. Just-noticeable difference thresholds (JNDs) were determined using the staircase method for surface roughness from stainless steel coupons (Ra; 0.177-0.465 µm). Thresholds were assessed when cooling or heating the metal stimuli (n = 32 subjects). Compared to the JND threshold obtained at an ambient stimulus temperature (21 °C: 0.055 ±â€…0.010 µm), a cold (8 °C) temperature significantly (P = 0.019) reduced tongue sensitivity (i.e. increased JND) to surface roughness (0.109 ±â€…0.016 µm, respectively) whereas warm and hot temperatures had no significant effect (35 °C: 0.084 ±â€…0.012 µm; 45 °C: 0.081 ±â€…0.011 µm). To assess whether the effect of cooling on roughness thresholds is TRPM8-dependent, we collected roughness thresholds in a second cohort of subjects (n = 27) following the lingual application of the cooling compound Evercool 190 (24.3 µM). Interestingly, when Evercool 190 was used to elicit the cold sensation, lingual roughness JNDs were unaffected compared to the control application of water (EC: 0.112 ±â€…0.016 µm; water: 0.102 ±â€…0.017 µm; P = 0.604). That lingual roughness sensitivity is decreased by cold temperature, but not chemicals evoking cold sensations, suggests the mechanism underpinning thermal modulation is not TRPM8 dependent.

Identification of Non-Volatile Compounds Generated during Storage That Impact Flavor Stability of Ready-to-Drink Coffee.

Coffee brew flavor is known to degrade during storage. Untargeted and targeted LC/MS flavoromics analysis was applied to identify chemical compounds generated during storage that impacted the flavor stability of ready-to-drink (RTD) coffee. MS chemical profiles for sixteen RTD coffee samples stored for 0, 1, 2, and 4 months at 30 °C were modeled against the sensory degree of difference (DOD) scores by orthogonal partial least squares (OPLS) with good fit and predictive ability. Five highly predictive untargeted chemical features positively correlated to DOD were subsequently identified as 3-caffeoylquinic acid, 4-caffeoylquinic acid, 5-caffeoylquinic acid, 3-O-feruloylquinic acid, and 5-O-feruloylquinic acid. The increase in the six acidic compounds during storage was confirmed by sensory recombination tests to significantly impact the flavor stability of RTD coffee during storage. A decrease in pH, rather than an increase in total acidity, was supported to impact the coffee flavor profile.

Identification of Non-Volatile Compounds That Impact Flavor Disliking of Whole Wheat Bread Made with Aged Flours.

Whole wheat flour has a shorter shelf life than refined wheat flour due to off-flavor development. An untargeted liquid chromatography/mass spectrometry (LC/MS) flavoromics approach was applied to identify compounds that negatively impact the flavor liking in whole wheat bread made from aged flours. The chemical profiles of thirteen breads made from aged flours were obtained using LC/MS and modeled by orthogonal partial least squares (OPLS) to predict flavor liking. Top predictive chemical features (negatively correlated) were identified as pinellic acid (9S,12S,13S-trihydroxy-10E-octadecenoic acid), 12,13-dihydroxy-9Z-octadecenoic acid, and 1-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphocholine. The sensory analysis confirmed the three compounds increased the bitterness intensity of the bread samples. The formation of the trihydroxy fatty acid bitter compound, pinellic acid (9S,12S,13S-trihydroxy-10E-octadecenoic acid), was impacted by the lipoxygenase activity of the flour; however, there was no influence on the formation of 12,13-dihydroxy-9Z-octadecenoic acid or 1-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphocholine. Additionally, the concentrations of all bitter compounds were significantly higher in bread made from aged flour versus non-aged flour.

Assessing regional sensitivity and desensitization to capsaicin among oral cavity mucosae.

This study aimed to determine perceptual response differences and characterize desensitization to capsaicin over time across several oral cavity mucosae- the tongue, cheek, hard palate, and lip. For each region, subjects rated the intensity of capsaicin and a vehicle control over a 10-minute period. Following a rest period, capsaicin was reapplied on each pretreated area and subjects indicated which side felt more irritated then rated each side every 30 seconds, over 3.5 minutes. Results from the initial task indicated significantly greater irritation on the tongue than hard palate, hard palate than cheek and lip, but no significant differences between the cheek and lip. Time to max intensity was delayed on the hard palate compared to the tongue, cheek, and lip. Desensitization, as indicated by a significant proportion of subjects choosing the vehicle-pretreated side over capsaicin-pretreated side as having stronger irritation, was exhibited on the tongue and hard palate, but not the cheek and lip. Given these data, a secondary experiment that utilized a higher capsaicin concentration was conducted on the cheek and lip only. Results showed significantly higher overall irritation on the lip than the cheek. Desensitization was exhibited on both areas, although the extent was greater on the lip. Based on differences in sensitivity and the extent of desensitization among these areas, these results indicate oral cavity mucosae respond to, but are impacted differently by, capsaicin exposure.

Chemogenic Subqualities of Mouthfeel.

Mouthfeel refers to the physical or textural sensations in the mouth caused by foods and beverages that are essential to the acceptability of many edible products. The sensory subqualities contributing to mouthfeel are often chemogenic in nature and include heat, burning, cooling, tingling, and numbing. These "chemesthetic" sensations are a result of the chemical activation of receptors that are associated with nerve fibers mediating pain and mechanotransduction. Each of these chemesthetic sensations in the oral cavity are transduced in the nervous system by a combination of different molecular channels/receptors expressed on trigeminal nerve fibers that innervate the mouth and tongue. The molecular profile of these channels and receptors involved in mouthfeel include many transient receptor potential channels, proton-sensitive ion channels, and potassium channels to name a few. During the last several years, studies using molecular and physiological approaches have significantly expanded and enhanced our understanding of the neurobiological basis for these chemesthetic sensations. The purpose of the current review is to integrate older and newer studies to present a comprehensive picture of the channels and receptors involved in mouthfeel. We highlight that there still continue to be important gaps in our overall knowledge on flavor integration and perception involving chemesthetic sensations, and these gaps will continue to drive future research direction and future investigation.

Olfactory Adaptation is Dependent on Route of Delivery.

Odorants are perceived orthonasally (nostrils) or retronasally (oral cavity). Prior research indicates route of delivery impacts odorant perception, pleasantness, and directed behaviors thus suggesting differential processing of olfactory information. Adaptation is a form of neural processing resulting in decreased perceived intensity of a stimulus following prolonged and continuous exposure. The present study objective was to determine whether route of delivery differentially impacts olfactory adaptation and whether cross-adaptation occurs between orthonasal and retronasal pathways. Linalool (12%) or vanillin (25%) were delivered orthonasally [6 L/min (LPM)] and retronasally (8 LPM) in air phase through a custom-built olfactometer. Perceived odorant intensity was collected every 5 min over 10-min exposure. Immediately following the exposure period, cross-adaptation was assessed by shunting the delivery of the odorant from the nostrils to the oral cavity, or vice versa. A control study was also completed in which subjects underwent the orthonasal adaptation protocol using stimulus concentrations matched to the intensity of restronasal stimuli (e.g., 1.5% linalool and 6.25% vanillin). Following orthonasal delivery of both high and low vanillin concentrations, results showed perceived intensity decreased significantly at 5 and 10 min. High concentrations of orthonasal linalool similarly decreased significantly whereas lower concentrations decreased but did not reach statistical significance. Linalool and vanillin delivered retronasally did not adapt as perceived intensity actually increased significantly following a 10-min exposure. In addition, evidence of cross-adaptation was not obvious following extended odorant exposure from either delivery pathway. This study suggests that olfactory processing may be affected by the route of odorant delivery.

Different Olfactory Percepts Evoked by Orthonasal and Retronasal Odorant Delivery.

The Duality of Smell hypothesis suggests odorants delivered orthonasally elicit different sensations compared with those delivered retronasally despite activating the same receptors in the olfactory epithelium. Presently, we investigated this further using a matching paradigm free from odorant or semantic memory bias. Subjects were asked to evaluate an aroma delivered in one condition (orthonasal or retronasal delivery) and match the same aroma from 4 unknowns evaluated in the same or different delivery conditions. Panelists matched flavors in 4 delivery conditions: orthonasal-orthonasal, retronasal-retronasal, retronasal-orthonasal, and orthonasal-retronasal. For orthonasal presentation, panelists smelled samples using their nostrils, and for retronasal presentation, panelists swallowed aqueous flavors. In Experiment 1, panelists were instructed to match familiar flavors (banana, grape, orange, raspberry). In Experiments 2 and 3, panelists used the same experimental design with either 4 unfamiliar flavors (kinnow, longan, pawpaw, prunus) or 4 distinct subtypes of a strawberry flavor (woody, green, ripe, candy). In Experiment 1, the number of correct matches in each condition did not significantly differ suggesting stability in the perceptual construct across delivery routes. However, in Experiments 2 and 3, significantly more samples were correctly matched in the orthonasal-orthonasal and retronasal-retronasal conditions compared with the retronasal-orthonasal or orthonasal-retronasal conditions suggesting aroma perception is dependent on delivery route. Additionally, across the 4 delivery methods, the ability to correctly match flavors decreased as flavor familiarity decreased or similarity increased and may reflect the different cognitive strategies employed by subjects when matching these stimuli. Our results suggest odorant percepts are route-dependent and consistent with the Duality of Smell phenomenon.

Quantification of Oral Roughness Perception and Comparison with Mechanism of Astringency Perception.

Texture contributes to food acceptance, but oral texture perception is incompletely understood. Presently, we quantified individual sensitivities to lingual tactile roughness and assessed the impact of age, salivary flow (SF), and fungiform papillae density (FPD) on threshold and suprathreshold perception. Additionally, we tested the hypothesis that individuals highly sensitive to tactile roughness exhibit sensitivity to astringent stimuli. Detection thresholds (DTs) were determined using the staircase method for surface roughness from stainless steel coupons (Ra; 0.177-0.465 µm) and astringency elicited by epigallocatechin gallate (EGCG; 0-1.64 mM) and tannic acid (TA; 0-0.71 mM) from 30 individuals. Suprathreshold sensitivity was assessed from intensity ratings of electroforming comparator surfaces with roughnesses ranging from 0.51 to 22.8 µm and astringent stimuli ranging from 0 to 5.2 mM (EGCG) and from 0 to 1.9 mM (TA). SF, FPD, and astringent food pleasantness scores were collected. Variability in threshold roughness sensitivity enabled dividing subjects into high (RHi; n = 16) and low (RLo; n = 14) sensitivity groups; however, no significant differences in age, FPD, or SF were observed across these cohorts. Interestingly, compared with RLo, the RHi group exhibited greater sensitivity to EGCG but not TA astringency and indicated greater pleasantness from astringent foods (e.g., unripe bananas and dark chocolate). When participants were allocated into high (SalivaHi; n = 15) or low SF (SalivaLo; n = 15) groups, TA-evoked astringency thresholds were significantly lower in SalivaHi whom also indicated greater pleasantness from astringent red wines. For suprathreshold assessments of surface roughness or astringency, no significant associations were identified with age, FPD, or SF. Suprathreshold roughness sensitivity was, however, associated with suprathreshold sensitivity to EGCG but not TA astringency.

Lingual tactile sensitivity: effect of age group, sex, and fungiform papillae density.

Despite its contribution to food perception, lingual tactile sensitivity has been understudied. We hypothesized that sensitivity to threshold and suprathreshold tactile stimuli varies in the population and sought to determine proximate sources of variability. Forty-eight adults were tested for lingual threshold sensitivity via a modified letter identification task and suprathreshold sensitivity via estimation of stimulus size using magnitude estimation. In addition, taste bud density on the anterior tip of each panelist's tongue was estimated by counting the number of fungiform papillae in a 0.317 cm2 circumscribed area. Lingual tactile thresholds were significantly impacted by age group as subjects 40 years or older had higher thresholds than those in their 20s. Moreover, threshold sensitivity increased with increasing fungiform papillae count. Suprathreshold estimates of size were not affected by age group, sex, or fungiform papillae count.

Characterization of the impact of chlorogenic acids on tactile perception in coffee through an inverse effect on mouthcoating sensation.

Coffee "body" is acknowledged by coffee industry professionals to be an attribute which contributes meaningfully to overall coffee quality and is defined as the collective tactile sensation imparted by the beverage. Currently, there is limited knowledge of the chemical compounds that contribute to tactile attributes in coffee. In the present work, coffee body was determined to be comprised of 4 sub-attributes including mouthcoating, astringency, chalkiness, and thickness and the specific constituents contributing to the tactile sensation of mouthcoating were further pursued using sensory-guided fractionation via preparative-scale liquid chromatography. Signal detection-based sensory methodologies were employed to characterize the sensory effects elicited by selected compounds in water and coffee matrices. Two chlorogenic acids, 3-O-caffeoylquinic acid (3-CQA) and 4-O-caffeoylquinic acid (4-CQA), were observed to impart subtle but significantly perceptible mouthcoating effects in water and/or coffee. Counterintuitively, sensory perception was inversely related to compound concentration. Complex receptor-ligand interactions or salivary lubrication dynamics are discussed as two potential mechanisms to explain this inverse relationship. Taken together, the outcomes of the present study (1) provide new targets for coffee tactile sensation optimization and modulation, (2) identify a novel dimension of sensory impact for two compounds of the chlorogenic acid family, and (3) present a need for deeper investigation into 3-CQA and 4-CQA mechanisms of sensation.

When considering whether to waste food, consumers focus attention on food label dates rather than phrases.

Date labels have been implicated as a driver of premature discard of food by consumers, which has led to recommendations to change date labels as a way to reduce food waste. However, most proposed date label reform has focused on changing the phrase that accompanies the date on the label, and not how the date is selected. To explore the relative importance of these date label elements, we track consumers' eye movements when evaluating milk container images. When making decisions about the possible discard of milk, participants fixate significantly more on the date printed on the container than on the phrase (e.g., "use by") with >50% of decisions involving no visual fixation on the phrase. This relative inattentiveness to phrases suggests regulation of food date labels should include more focus on the process of choosing label dates.

Understanding the Effects of Smart-Speaker-Based Surveys on Panelist Experience in Immersive Consumer Testing.

Utilizing immersive technologies to reintroduce the environmental context (i.e., visual, auditory, and olfactory cues) in sensory testing has been one area of research for improving panelist engagement. The current study sought to understand whether pairing smart-speaker questionnaires in immersive spaces could positively affect the panelist experience through enhanced ecological validity. To this end, subjects performed an immersive consumer test in which responses were collected using a traditional computer-based survey, a smart-speaker approach incorporating a direct translation of the computer questionnaire into a verbal survey requiring numeric responses, and an optimized smart-speaker survey with alternative question formatting requiring spoken word-based responses. After testing, participants answered the Engagement Questionnaire (EQ) to assess participant engagement during the test, and the System Usability Scale (SUS) survey to understand the ease, and potential adoption, of using the various survey technologies in the study. Results indicated that the traditional computer-based survey was the most engaging (p < 0.001) and usable (p < 0.001), with no differences found between the two smart-speaker surveys (p = 0.803 and p = 0.577, respectively). This suggests that the proposed optimizations for the smart-speaker surveys were not robust enough to influence engagement and usability, and further research is needed to enhance their conversational capabilities.

Naturally occurring hypothermia is more advantageous than fever in severe forms of lipopolysaccharide- and Escherichia coli-induced systemic inflammation.

The natural switch from fever to hypothermia observed in the most severe cases of systemic inflammation is a phenomenon that continues to puzzle clinicians and scientists. The present study was the first to evaluate in direct experiments how the development of hypothermia vs. fever during severe forms of systemic inflammation impacts the pathophysiology of this malady and mortality rates in rats. Following administration of bacterial lipopolysaccharide (LPS; 5 or 18 mg/kg) or of a clinical Escherichia coli isolate (5 × 10(9) or 1 × 10(10) CFU/kg), hypothermia developed in rats exposed to a mildly cool environment, but not in rats exposed to a warm environment; only fever was revealed in the warm environment. Development of hypothermia instead of fever suppressed endotoxemia in E. coli-infected rats, but not in LPS-injected rats. The infiltration of the lungs by neutrophils was similarly suppressed in E. coli-infected rats of the hypothermic group. These potentially beneficial effects came with costs, as hypothermia increased bacterial burden in the liver. Furthermore, the hypotensive responses to LPS or E. coli were exaggerated in rats of the hypothermic group. This exaggeration, however, occurred independently of changes in inflammatory cytokines and prostaglandins. Despite possible costs, development of hypothermia lessened abdominal organ dysfunction and reduced overall mortality rates in both the E. coli and LPS models. By demonstrating that naturally occurring hypothermia is more advantageous than fever in severe forms of aseptic (LPS-induced) or septic (E. coli-induced) systemic inflammation, this study provides new grounds for the management of this deadly condition.

Capturing high and low levels of participant engagement in sensory and consumer evaluations via a known groups design and an implicit correlate.

Recently developed to characterize consumer engagement during sensory and consumer testing, the Engagement Questionnaire (EQ) can quantify differences in participant engagement; however, the limits of the scale to detect disengagement has not been established. We conducted a known-group experimental design to verify the EQ's ability to differentiate between an engaged and disengaged participant. Participants were randomly assigned to a more engaging (positive condition) and a less engaging sensory task (negative condition). In the positive condition, participants (N = 31) completed 20 tetrad tests; however, stimuli varied in type and difficulty. For the negative condition, participants (N = 28) completed 20 tetrads of the same sucrose concentration to promote a state of helplessness and encourage disengagement with the task. Facial expressions were collected through video recordings, using automatic facial emotion recognition software (FaceReader, Noldus Technology). Accounting for sex differences across the conditions, the EQ successfully discriminated between the positive and negative conditions. When in the positive condition, participants were more actively involved in the task (F1,59 = 23.99, p < 0.001), and experienced higher levels of purposeful intent (F1,59 = 11.10, p = 0.002) and affective value (F1,59 = 26.03, p < 0.001). Participants were more emotive in general, and experienced increased happiness (F1,42 = 22.24, p < 0.001), anger (F1,42 = 12.10, p = 0.001) and disgust (F1,42 = 4.33, p = 0.04) as well as lower levels of a neutral expression (F1,42 = 24.88, p < 0.001) in the positive condition. Now validated via known-groups analysis, the EQ can confidently differentiate a greater range of engagement. Such an instrument allows for a deeper understanding of participant engagement and its potential effect on data quality.

Identification of subthreshold chlorogenic acid lactones that contribute to flavor instability of ready-to-drink coffee.

Flavor instability of ready-to-drink (RTD) coffee during storage negatively impacts product quality. Untargeted liquid chromatography/mass spectrometry (LC/MS) analysis was applied to identify chemical compounds that degraded during storage and impacted the flavor attributes of RTD coffee. LC/MS chemical profiles of non-aged and aged coffee samples were modeled against the degree of difference sensory scores by orthogonal partial least squares with good fit (R2Y = 0.966) and predictive ability (Q2 = 0.960). The top five predictive chemical features were subsequently purified by off-line multidimensional Prep-LC, revealing ten coeluting chlorogenic acid lactones (CGLs) compounds that were identified by LC/MS and nuclear magnetic resonance (NMR). The concentrations of eight CGLs significantly decreased in the coffee during the 4-month storage. Sensory recombination testing revealed the degradation of 3-O-caffeoyl-É£-quinide and 4-O-caffeoyl-É£-quinide significantly impacted the flavor stability of RTD coffee at subthreshold concentrations.

Elucidation of a lingual detection mechanism for high-viscosity solutions in humans.

While perception of high-viscosity solutions (η > 1000 cP) is speculated to be linked to filiform papillae deformation, this has not been demonstrated psychophysically. Presently, just-noticeable-viscosity-difference thresholds were determined using the forced-choice staircase method and high-viscosity solutions (η = 4798-12260 cP) with the hypotheses that the tongue would be chiefly responsible for viscosity perception in the oral cavity, and that individuals with more, longer, narrower filiform papillae would show a greater acuity for viscosity perception. Subjects (n = 59) evaluated solutions in a normal, "unblocked" condition as well as in a "palate blocked" condition which isolated the tongue so that only perceptual mechanisms on the lingual tissue were engaged. Optical profiling was used to characterize papillary length, diameter, and density in tongue biopsies of a subset (n = 45) of participants. Finally, psychophysical and anatomical data were used to generate a novel model of the tongue surface as porous media to predict papillary deformation as a strain-detector for viscosity perception. Results suggest that viscosity thresholds are governed by filiform papillae features. Indeed, anatomical characterization of filiform papillae suggests sensitivity to high-viscosity solutions is associated with filiform papillae length and density (r = 0.68, p < 0.00001), but not with diameter. Modelling indicated this is likely due to a reciprocal interaction between papillae diameter and fluid shear stress. Papillae with larger diameters would result in higher viscous shear stress due to a narrower gap and stronger fluid-structure interaction, but a larger-diameter papilla would also deform less easily.

A tingling sanshool derivative excites primary sensory neurons and elicits nocifensive behavior in rats.

Szechuan peppers contain hydroxy-α-sanshool that imparts desirable tingling, cooling, and numbing sensations. Hydroxy-α-sanshool activates a subset of sensory dorsal root ganglion (DRG) neurons by inhibiting two-pore potassium channels. We presently investigated if a tingle-evoking sanshool analog, isobutylalkenyl amide (IBA), excites rat DRG neurons and, if so, if these neurons are also activated by agonists of TRPM8, TRPA1, and/or TRPV1. Thirty-four percent of DRG neurons tested responded to IBA, with 29% of them also responding to menthol, 29% to cinnamic aldehyde, 66% to capsaicin, and subsets responding to two or more transient receptor potential (TRP) agonists. IBA-responsive cells had similar size distributions regardless of whether they responded to capsaicin or not; cells only responsive to IBA were larger. Responses to repeated application of IBA at a 5-min interstimulus interval exhibited self-desensitization (tachyphylaxis). Capsaicin did not cross-desensitize responses to IBA to any greater extent than the tachyphylaxis observed with repeated IBA applications. These findings are consistent with psychophysical observations that IBA elicits tingle sensation accompanied by pungency and cooling, with self-desensitization but little cross-desensitization by capsaicin. Intraplantar injection of IBA elicited nocifensive responses (paw licking, shaking-flinching, and guarding) in a dose-related manner similar to the effects of intraplantar capsaicin and serotonin. IBA had no effect on thermal sensitivity but enhanced mechanical sensitivity at the highest dose tested. These observations suggest that IBA elicits an unfamiliar aversive sensation that is expressed behaviorally by the limited response repertoire available to the animal.

Novel menthol-derived cooling compounds activate primary and second-order trigeminal sensory neurons and modulate lingual thermosensitivity.

We presently investigated 2 novel menthol derivatives GIV1 and GIV2, which exhibit strong cooling effects. In previous human psychophysical studies, GIV1 delivered in a toothpaste medium elicited a cooling sensation that was longer lasting compared with GIV2 and menthol carboxamide (WS-3). In the current study, we investigated the molecular and cellular effects of these cooling agents. In calcium flux studies of TRPM8 expressed in HEK cells, both GIV1 and GIV2 were approximately 40- to 200-fold more potent than menthol and WS-3. GIV1 and GIV2 also activated TRPA1 but at levels that were 400 times greater than those required for TRPM8 activation. In calcium imaging studies, subpopulations of cultured rat trigeminal ganglion and dorsal root ganglion cells responded to GIV1 and/or GIV2; the majority of these were also activated by menthol and some were additionally activated by the TRPA1 agonist cinnamaldehyde and/or the TRPV1 agonist capsaicin. We also made in vivo single-unit recordings from cold-sensitive neurons in rat trigeminal subnucleus caudalis (Vc). GIV 1 and GIV2 directly excited some Vc neurons, GIV1 significantly enhanced their responses to cooling, and both GIV1 and GIV2 reduced responses to noxious heat. These novel cooling compounds provide additional molecular tools to investigate the neural processes of cold sensation.

Non-food odors and the duality of smell: Impact of odorant delivery pathway and labeling convention on olfactory perception.

The olfactory system encompasses two perceptual pathways (orthonasal and retronasal) that activate the same receptors in the olfactory epithelium yet are thought to elicit different perceptions. Presently, a novel matching paradigm was employed using a non-food flavor set with low retronasal familiarity (honeysuckle, lavender, rose, and jasmine) to evaluate the effect of odor type on the Duality of Smell. Additionally, the influence of cognitive strategies used by subjects was assessed by manipulating the naming convention seen by the subjects: familiar (Honeysuckle, Lavender, Rose, Jasmine), unfamiliar (Inodora, Pedunculata, Beggeriana, Didymum), and generic (A, B, C, D). Subjects were presented with a reference, either in a vial (orthonasal delivery, ON) or a 2 oz. cup (retronasal delivery, RN) and instructed to match the same aroma from four unknowns, evaluated either by the same delivery route (congruent, e.g., ON-ON, RN-RN) or different route (incongruent, e.g., ON-RN, RN-ON) than the reference evaluation. All possible combinations of orthonasal and retronasal delivery for the reference and unknowns (e.g. ON-ON, RN-RN, ON-RN, RN-ON) were assessed by all subjects. Matching performance and signal detection measures indicated that, on average, subjects performed significantly better in the congruent conditions than in the incongruent conditions. These results suggest perceptual quality of aromas is route dependent and extend the Duality of Smell hypothesis to samples with low retronasal familiarity such as non-food odors. Labeling convention also had an impact on performance but, surprisingly, not in the direction anticipated. Indeed, as the information contained in the label decreased from familiar to generic reference names, performance increased. Moreover, depending on the labeling convention used, certain aromas were easier to match than others. The present research suggests odorant matching is a function of stimulus quality, cognitive strategy, and labeling convention.

Application of the Engagement Questionnaire (EQ) to compare methodological differences in sensory and consumer testing.

Understanding the panelist experience in sensory and consumer testing is a critical step in methodological development that improves data reliability. Therefore, the Engagement Questionnaire (EQ) was recently developed to characterize consumer engagement during sensory and consumer testing and to provide a novel and translatable metric for researchers to compare methodologies. Presently, we assessed whether relatively minor methodological manipulations to common consumer testing paradigms impact panelist engagement. Specifically, panelist engagement was measured in three scenarios: over the course of a two-day consumer hedonic evaluation (Experiment 1), with differing Just-About-Right (JAR) questionnaire formats in an evaluation (Experiment 2), and with a time pressure element imposed during a consumer acceptability test (Experiment 3). In Experiment 1, subjects remained actively involved in the evaluation across both days of testing, however, they found more purpose and affective value in the task after the second day. In Experiment 2, changing the structure of JAR questions did not impact subject's level of active involvement with the task, yet certain JAR question structures did elicit higher purposeful intent and affective value in subjects. Surprisingly, in Experiment 3, subjects were less actively involved in the time-pressure condition; purposeful intent and affective value were consistent across both conditions. Overall, the EQ was able to resolve differences in panelists' perceived level of engagement across all the experimental manipulations, aiding in discussion regarding the effect even minor manipulations might have on consumer panelists. The EQ is a valuable asset to methodological development and enables comparisons of differing sensory and consumer methodologies.