Chemosensory Receptors Engaged in Odor-Induced Sweetness Enhancement: Structural Diversity and Health Relevance

The impact of sugary foods on public health has contributed to the development of low-sugar and sugar-substituted products, and sugar reduction has become a major challenge for the food industry. There is growing empirical evidence that odor can enhance the perception of sweetness without increasing the caloric load. This current review summarizes the researches on odor-induced sweetness enhancement published in recent years and discusses the mechanisms and influencing factors of odor-sweetness interactions. In addition, by combing existing studies, this paper also summarizes the research methods and strategies to investigate odor-induced sweetness enhancement. Finally, the feasibility of synergistic enhancement of sweetness through the superposition of odor with other senses (texture, visual, etc.) is also discussed and analyzed. In conclusion, odor-induced sweetness enhancement may present an alternative or complementary approach for developing foods with less sugar.

Excessive intake of sugar has become a public concern. However, it is challenging for food industries to decrease sugar level without sacrificing safety and sensory profile. Odor-induced sweetness enhancement (OISE) is believed to be a novel and promising strategy for sugar reduction. In order to investigate the OISE effect of mango aroma and evaluate its degree of sugar reduction in low-sugar beverages, a mathematical model was constructed through sensory evaluation in this study. The results showed that the maximum liking of low-sugar model beverages was 4.28 % sucrose and 0.57 % mango flavor. The most synergistic of OISE was at the concentration level of 2.24 % sucrose + 0.25 % mango flavor, which was equivalent to 2.96 % pure sucrose solution. With 32.14 % sugar reduction, the mango aroma was suggested to generate the OISE effect. However, the same level of garlic aroma was not able to enhance sweetness perception, suggesting that the congruency of aroma and taste is a prerequisite for the OISE effect to occur. This study demonstrated that the cross-modal interaction of mango aroma on sweetness enhancement in low-sugar model beverages could provide practical guidance for developing sugar-reduced beverages without applying sweeteners.

… We found specific taste-smell interactions: sweetness enhancement induced by strawberry … of sweetness enhancement induced by imagined strawberry odor (combining enhancement …

… Odor-induced taste enhancement (OITE) is a phenomenon derived from the integrative processing of … The identification of odor molecules with potent taste enhancement effects and the …

Background In the context of increasing global health risks, including obesity, diabetes, and cardiovascular diseases, odor-induced taste enhancement (OITE) has emerged as an …

… enhancement of sweetness ratings for aspartame when the taste stimuli were presented with a vanilla odor. This odor-induced taste enhancement … the odor-induced taste enhancement …

… The study aimed to determine odor-induced taste enhancement (OITE) differences between … higher sweet taste enhancement than NW. We also tested salty taste enhancement without …

The purpose of this paper is to test for gender-specific effects on odor-induced taste enhancement and subsequent food consumption in olfactory food marketing.,Lab experiments conducted among female and male participants using vanillin as a stimulus and ratings of sweetness, taste pleasantness and eating of sugar-free food as measures.,Odor-induced taste enhancement is gender-specific. Female consumers outperform male consumers in olfactory reaction and sweetness perception. While men outperform women in food consumption.,Odor intensity was set to the concentration level of 0.00005per cent according to the findings from (Fujimaru and Lim, 2013). The authors believe that this intensity level is appropriate for both men and women. Still, there may be some gender effects on intensity levels, which are not explored here. The author’s test for the effects of one personal factor, gender and odor-induced taste enhancement of sugar-free food. The authors think that investigating the combined effects of more personal factors such as age, culture and so on adds to the accuracy of the results.,It seems that the stronger sensory capacities of women in terms of odor detection and recognition already confirmed in the literature extends to the cross-modal effects of this sensory detection and recognition on taste enhancement. It seems appropriate to tailor olfactory food advertising according to the gender of the target audience.,Odor-induced taste enhancement is still a novel subject in marketing. While most of the research has investigated the effects of smelling congruent odors on taste perception and food consumption among mixed groups of men and women, the value of this paper lies in the investigation of the potential moderating effects of gender on this relationship.

… However, because the enhancement effect disappeared … concluded that odor-induced taste enhancement might have … is whether odor enhancement is specific to the sweetness of …

Odor-induced sweetness enhancement (OISE) is an effective approach to lower sugar intake. In this study, static and dynamic sensory evaluations, combined with molecular docking, were used to explore the mechanism underlying sweetness enhancement in fructose solutions induced by watermelon juice odor compounds. Sensory evaluation results showed that the seven volatile odor compounds (VOCs) (ethyl acetate, ethyl propionate, octanal, (E,E)-2,4-hexadienal, (E)-2-octenal, methyl heptenone, and geranyl acetone) from watermelon juice could significantly increase the sweetness intensity of a 2.5% fructose solution, and the potency of OISE was significantly enhanced within 10 s. (E,E)-2,4-hexadienal, ethyl propionate, and methylheptenone showed the most significant OISE effects, which aligned with the sensory preference results. Further, molecular docking was used to explore the interactions between VOCs, fructose, and sweet receptors. The results showed that T1R2 was the main receptor for binding fructose and VOCs, and the interaction forces were primarily hydrogen bonds and hydrophobic interactions. In the presence of VOCs, the amino acid residues that formed hydrogen bonds with fructose were highly repetitive, with the main difference being the bond length, indicating the important role of flavor–sweetener receptor interactions in lowering fructose content and enhancing sweetness perception. Thus, this study provides a scientific basis for developing sugar-reduction technology based on aroma, in addition to enhancing sweetness.

… Specifically, when a strawberry odor was presented with sucrose and subjects were instructed to rate fruitiness as well as sweetness, enhancement of sweetness was nil. This pivotal …

… Therefore, this study evaluated whether odor-induced sweetness enhancement (OISE) could be produced in sucrose solution and sucrose solution containing citric acid. The aim of this …

Sugar can play various roles in food production such as bulking or coloring agent, which can improve the pleasure of eating and enhance the appetite of the consumers. The increasing use of sugar in food industry results in consumers’ gradually weakened perception of sugar, as well as their unknowing over-consumption of sugar, which has negative impact on their health. While eating, people's taste perception can be affected by the odor of food to a certain extent. This study explored the possibility of odor sweetening, and the effect of odor intensity on sweetness perception and eating pleasure. Through user experiment, this study investigated reasonable combination of sweet odor concentration interval-food sweetness interval, aiming to enhance sweetness perception by controlling the odor of food, and to reduce people's sugar intake while ensuring the flavor of food and people's eating pleasure, thus providing a new strategy for sugar reduction.

The impact of olfactory perception on sweetness was explored in a model solution using odorants at subthreshold concentrations. First, the impact of 6 odorants, previously described in the literature as congruent with sweetness, was investigated at suprathreshold level in a sucrose solution. Ethyl butyrate and maltol were selected as they had the highest and the lowest sweetness-enhancing properties, respectively. Second, the impact on sweetness of the 2 odorants was investigated at subthreshold concentrations. A system delivering a continuous liquid flow at the same sucrose level, but with varying odorant concentrations, was used. At a subthreshold level, ethyl butyrate but not maltol significantly enhanced the sweetness of the sucrose solution. This study highlights that olfactory perception induced by odorants at a subthreshold level can significantly modulate taste perception. Finally, contrary to results observed with ethyl butyrate at suprathreshold levels, at subthreshold levels, the intensity of sweetness enhancement was not proportional to ethyl butyrate concentration.

Black tea contains sweet aroma compounds (SACs) with sweetening potential. However, a systematic understanding of their composition, enhancing effects, and underlying mechanisms is lacking. This study identified 14 key SACs in global sweet-aroma black teas using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Electronic tongue and sensory validation confirmed their sweetness-enhancing effects in a sugar-free black tea beverage and revealed their inherent taste properties (sweetness, astringency, pungency, and cooling). Molecular docking and dynamics simulation elucidated the stable bindings of T1R2/T1R3-benzeneacetaldehyde/β-damascenone, α-amylase-benzeneacetaldehyde, TRPV1-geraniol, and TRPM8-methyl salicylate, mediated by hydrogen bonding and hydrophobic interactions. These protein-ligand complexes were proposed to modulate sweetness, sweet aftertaste, heat-evoked sweetness, and cooling-enhanced sweetness, respectively. Consequently, this study demonstrates that SACs enhance sweetness through cross-modal interactions and inherent taste properties, providing novel mechanistic insights and actionable strategies for flavor optimization in tea beverages and other food products.

Growing demand for sugar reduction in beverage necessitates innovative approaches to maintain sweetness perception without compromising acceptability. Volatile compounds in Fu brick tea (FBT) were analyzed using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography/olfactometry-associated taste (GC/O-AT), identifying four key sweetness-associated aroma compounds. Threshold determination coupled with gradient monomer recombination experiments quantified compound-specific sweetness contributions. Sensory evaluation revealed α-ionone, linalool, and sclareolide as superior enhancers, with α-ionone demonstrating optimal potency and palatability. Molecular docking simulations showed T1R2/T1R3 binding energies of -7.0 kcal/mol (sclareolide), -6.2 kcal/mol (α-ionone), -5.8 kcal/mol (geranyl isovalerate) and - 5.0 kcal/mol (linalool). However, binding energy magnitude lacked absolute correlation with sensory enhancement. Molecular dynamics simulations further confirmed stable ligand-receptor complexes mediated primarily by hydrogen bonds and hydrophobic forces. This study elucidates cross-modal aroma-taste interactions as critical drivers of sweetness perception in FBT, offering a multidisciplinary methodology to design reduced-sugar beverages with preserved sensory appeal.

… explore effective strategies for sweetness enhancement and sugar … sweetness perception were first introduced; Then, we summarised the research progress of several sweet-enhancing …

… In sum, the goals of the present study were to (i) replicate odor-induced enhancement of sweetness in aqueous solutions, (ii) assess the effect of color on sweetness judgments and …

… the mechanisms underpinning aroma–taste interactions, as well as the neurophysiological … , and trigeminal interactions on food flavor perception. Afterward, we present interactions …

… We systematically explore this crossmodal dialogue, from initial receptor-level interactions in the … of sweet, olfactory, and bitter pathways exemplifies citral’s role as a cross‑modal flavor …

BACKGROUND Excessive sugar intake induces health issues such as excess energy, obesity and cardiovascular diseases. Reducing sugar consumption has become a global consensus; however, achieving this without compromising flavour perception remains a major challenge. Previous studies have highlighted the potential risks associated with non-nutritive sweeteners, and novel measures for sugar reduction, such as modifying sweetener ratios and enzymatic conversion, are limited in scope. In-depth studies have revealed that aroma-induced sweetness enhancement is a promising alternative for reducing sugar consumption without compromising perceived sweetness, enabling a healthy way of enjoying sweet flavours AIM OF REVIEW: By systematically sorting out current knowledge on the mechanism of action, evaluation approaches, and influencing factors of aroma-induced sweetness enhancement, and revealing the cross-modal interaction mechanism between aroma and taste, this study aims to provide a theoretical framework for advancing research on multisensory flavor perception. Furthermore, it underscores the potential of the interdisciplinary integration of neurosensory science and food science to inform the design of flavor optimization strategies for low-sugar products, thereby contributing to healthier dietary solutions for targeted populations. KEY SCIENTIFIC CONCEPTS OF REVIEW Herein, the physiological basis of taste and smell and their perceptual pathways are systematically reviewed, and the neural and psychological factors of olfactory-gustatory synergy are investigated. In addition, this review summarises the sensory evaluation methods and neuroimaging techniques to assess the sweetening effects of aroma. Moreover, it discusses various factors influencing aroma-induced sweetness enhancement, including the physical properties of food, eating environment, individual differences in consumers and oral processing. Aroma-based sweetening has great potential for sugar reduction without compromising sweetness, and future in-depth research requires interdisciplinary cooperation covering multiple dimensions such as molecular mechanisms, personalisation techniques, ingredient screening, stability optimisation, evaluation method innovation and health regulation adaptation.

… Synesthesia is the involuntary physical experience of a cross-modal association. It is … ), gustatory (eg sucrose), and combined olfactory gustatory stimuli (eg strawberry, sucrose). They …

This study employed time‐intensity and temporal dominance of sensations analyses to quantify the contribution of the retronasal pathway to sweet perception by comparing the dynamic perception of sucrose and rebaudioside A (Reb A) under conditions with and without a nose‐clip (which physically blocks the retronasal pathway). Results showed that blocking the retronasal pathway significantly reduced both the intensity and duration of sweetness for sucrose and Reb A. Analysis using the newly developed “retro‐taste partition coefficient” revealed distinct temporal patterns of retronasal dependency: Reb A exhibited a higher retronasal contribution in the early phase of perception, whereas sucrose demonstrated a significantly stronger dependency during the later stages. Compared to sucrose, Reb A still shows perceptible gaps in sweetness quality and temporal profile. Furthermore, Reb A elicited pronounced bitterness and astringency, which became more pronounced during the later stages of perception when the retronasal pathway was blocked. This study highlights the critical role of the retronasal pathway in sweet perception and provides a temporal‐dynamic analytical framework along with quantitative tools for the sensory optimization of sweetener formulations.

… of ethyl hexanoate (sweet odor) and sucrose (sweet taste) at … combination by comparing among cross-modal combinations, … Simple effect tests for interaction between condition and …

A greater congruency of audio and video expands the temporal binding window (TBW). A similar phenomenon may occur with a combination of odor and taste, which are the main components of flavor.

This study investigated the sweetness-enhancing effects of nine sweet aroma compounds from sweet orange on 5% sucrose solution. Through static sensory evaluations and electronic tongue analysis, carveol was found to enhance sweetness most significantly (28.8%), followed by γ-decalactone (23.2%), γ-nonalactone (23.0%), and δ-decalactone (20.0%). By using the time-intensity method for dynamic sensory evaluation, it was shown that the perception of sweetness increased rapidly and the duration was slightly prolonged after the addition of sweet aroma compounds. Molecular docking showed a binding free energy of −5.9 kcal/mol for the T1R2/T1R3-sucrose complex. Ternary complexes with added aromatic compounds had substantially lower energies (−8.62 to −10.5 kcal/mol), indicating enhanced receptor-ligand affinity. Molecular dynamics results showed that the addition of aromatic compounds led to the decrease in the binding energy of the T1R2/T1R3-sucrose system, the enhancement of hydrogen bonds and hydrophobic interactions, and the stabilization of dynamic changes in protein conformation.

Growing demand for sugar-reduced foods necessitates a deeper understanding of odor-induced sweetness enhancement. This study explored durian-derived volatile sulfur compounds (VSCs) as sucrose potentiators through integrated SPME-GC/MS, sensory evaluation, and computational analyses. GC/O-AT, recombination, and omission experiments identified 10 key VSCs associated with 'sweet' prioritized for investigation. Sensory evaluation identified optimal sucrose concentration (30 g/L) for sweetness amplification, particularly with S-ethyl ethanethioate and dipropyl disulfide showing significant enhancement, while dimethyl trisulfide suppressed sweetness. Molecular docking revealed stable binding of sweet-enhancing VSCs to T1R2/T1R3-sucrose complexes (-9.811 to -8.274 kcal/mol), mediated by hydrogen bonds and hydrophobic interactions in the Venus flytrap domain. Molecular dynamics confirmed that dipropyl disulfide stabilized receptor-ligand binding through multifaceted interactions. It was found that the binding energy has a certain correlation with the perceived intensity. Future research should integrate cross-modal sensory and molecular biology approaches to optimize low-sugar flavor compensation strategies.

Sweetness is one of the main drivers of consumer preference, and thus is given high priority in apple breeding programmes. Due to the complexity of sweetness evaluation, soluble solid content (SSC) is commonly used as an estimation of this trait. Nevertheless, it has been demonstrated that SSC and sweet taste are poorly correlated. Though individual sugar content may vary greatly between and within apple cultivars, no previous study has tried to investigate the relationship between the amount of individual sugars, or ratios of these, and apple sweetness. In this work, we quantified the major sugars (sucrose, glucose, fructose, xylose) and sorbitol and explored their influence on perceived sweetness in apple; we also related this to malic acid content, SSC and volatile compounds. Our data confirmed that the correlation between sweetness and SSC is weak. We found that sorbitol content correlates (similarly to SSC) with perceived sweetness better than any other single sugar or total sugar content. The single sugars show no differentiable importance in determining apple sweetness. Our predictive model based on partial least squares regression shows that after sorbitol and SSC, the most important contribution to apple sweetness is provided by several volatile compounds, mainly esters and farnesene.

This narrative review examines the complex relationship that exists between the presence of specific configurations of volatile organic compounds (VOCs) in food and drink products and multisensory flavour perception. Advances in gas chromatography technology and mass spectrometry data analysis mean that it is easier than ever before to identify the unique chemical profile of a particular food or beverage item. Importantly, however, there is simply no one-to-one mapping between the presence of specific VOCs and the flavours that are perceived by the consumer. While the profile of VOCs in a particular product undoubtedly does tightly constrain the space of possible flavour experiences that a taster is likely to have, the gustatory and trigeminal components (i.e., sapid elements) in foods and beverages can also play a significant role in determining the actual flavour experience. Genetic differences add further variation to the range of multisensory flavour experiences that may be elicited by a given configuration of VOCs, while an individual’s prior tasting history has been shown to determine congruency relations (between olfaction and gustation) that, in turn, modulate the degree of oral referral, and ultimately flavour pleasantness, in the case of familiar foods and beverages.

… However, while these studies identified potent volatiles, synergy among volatile compounds to produce human sensory responses and interactions between taste and retronasal …

Gas chromatography/olfactometry-associated taste (GC/O-AT) analysis combined with mass spectrometry allowed identification of odorant compounds associated with taste attributes (sweet, salty, bitter and sour) in a multi-fruit juice. Nine compounds were selected for their odor-associated sweetness enhancement in a multi-fruit juice odor context using Olfactoscan and for their odor-induced sweet taste enhancement in sucrose solution and sugar-reduced fruit juice through sensory tests. Sweetness of the fruit juice odor was significantly enhanced by methyl 2-methylbutanoate, ethyl butanoate, ethyl 2-methylbutanoate and linalool; sweet perception was significantly enhanced in 7% sucrose solution by ethyl 2-methylbutanoate, furaneol and γ-decalactone, and in 32% sugar-reduced fruit juice by ethyl 2-methylbutanoate. GC/O-AT analysis is a novel, efficient approach to select odorants associated with a given taste. The further screening of taste-associated odorants by Olfactoscan helps to identify the most efficient odorants to enhance a target taste perception and may be used to find new ways to modulate taste perception in foods and beverages.

Regarding cross-modality research, taste-aroma interaction is one of the most studied areas of research. Some studies have reported enhancement of sweetness by aroma, although it is unclear as to whether these effects actually occur: depending on the cognitive strategy employed by panelists, the effects may disappear, e.g., forcing panelists into an analytical strategy to control for dumping may not be able to reveal perceptual interactions. Previous studies have largely focused on solutions and model foods, and did not test stimuli or concentrations relevant to real food applications. This study addresses these gaps: 18 vanilla flavored sucrose milks, varying between 0–0.75% (w/w) two-fold vanilla, and 0–5% (w/w) sucrose, were rated by 108 panelists for liking and perceived sweetness, vanilla flavor, milk flavor, and thickness. Interactions between vanilla and sucrose were measured using deviations of real mixtures from additive models (via the isobole method), indicating vanilla aroma does enhance perceived sweetness. However, the sweetness enhancing effect of vanilla aroma was not as pronounced as that of sucrose on vanilla flavor. Measurable cross-modal interactions occur despite using an analytical cognitive strategy. More work is needed to investigate the influence of perceptual strategy on the degree of taste-aroma interactions in real foods.

… organic compounds, and all of them can interact with and/or bind flavours. The release of … However, synergistic effects occurred when combinations of intense sweeteners were tried out. …

Sweet taste is a fundamental sensory modality that plays a crucial role in food intake and preference. In recent years, many studies have shown that sweet taste perception is not an isolated physiological process but interacts significantly with other sensory systems, including other tastes modalities and olfaction. This review summarizes cross-modal sensory interactions between sweet taste and other sensory systems (saltiness, sourness, bitterness, and umami) as well as olfaction and trigeminal nerve. It clarifies that the interaction between sweet taste and other basic tastes presents concentration-dependent characteristics of enhancement, inhibition or masking, and reveals the synergistic or antagonistic effects of olfactory aroma compounds on sweet taste perception, as well as the modulation of sweet taste by trigeminal nerve-mediated temperature, texture and chemical stimulation of food. This review focuses on the mechanisms underlying these interactions and their potential applications in future food science and nutrition. These findings not only deepen the understanding of the complex sensory perception of sweet taste, but also provide important theoretical support and practical guidance for solving the health problems caused by excessive sugar intake and optimizing food sensory quality.

Here we report synergistic and antagonistic mixture interactions between sucrose, vanillin, and cocoa powder as a potential added sugar reduction strategy in chocolate milk. Objectives of this project were to (i) model consumer perception of relevant sensory attributes as a function of sucrose, vanillin, and cocoa powder in chocolate milk, (ii) test for the presence of synergistic, additive, and antagonistic interactions via the isobole method, and (iii) determine consumer acceptance of these samples with both adults and children. In Study 1, adult chocolate milk consumers (n = 136) rated perceived intensities of sweetness, bitterness, chocolate flavor, and color for 22 chocolate milk formulations created according to an experimental design to systematically cover the multidimensional design space. Dose–response contour plots and regression modeling highlighted the large contributions of sucrose‐vanillin and sucrose‐cocoa interactions to ratings of sweetness, bitterness, and chocolate flavor. Indeed, three of the five tested mixture samples showed sweetness synergy and bitterness antagonism. In Study 2, overall acceptability of these five samples was evaluated by adults (n = 142) and children (n = 61) consumers of chocolate milk. Among the three chocolate milks that showed sweetness enhancement and bitterness suppression, one with moderate levels of sucrose (4.67% [w/w]) also received liking scores above neutral (>5 on a 9‐point hedonic scale), suggesting this formulation provides the greatest potential to decrease added sugar content while preserving consumer acceptability.Practical ApplicationsSucrose, vanillin, and cocoa powder act synergistically and antagonistically on perceived sweetness and bitterness in chocolate milk. Ingredient combinations could be optimized for lowering added sugar content while maintaining acceptability by adult and children consumers of chocolate milk.

The growing consumer demand for low-sugar and low-alcohol beverages has spurred increased research into flavor-enhancement strategies. This study systematically investigated the sweet taste enhancement effect of low-concentration ethanol (4%) using a combined approach of T1R2/T1R3-expressing HEK293 cellular models and computational simulations. The fluorescence change ratio (ΔF/F0) was measured to quantify cellular response to sweeteners and assess perceived sweetness intensity. The observation of a classic dose-dependent response to sucrose confirmed the functionality and reliability of the cellular assay system. Furthermore, 4% ethanol was found to significantly enhance the relative sweetness intensity of glucose (Glc) and ethyl cyclopentenolone (ECP) by 28.29% and 46.63%, respectively, compared to aqueous solutions. Molecular modeling of T1R2/T1R3 receptor in complex with Glc or ECP, conducted in both aqueous and ethanol environments, revealed that low-concentration ethanol directly activated sweet taste receptors (STRs), stabilized receptor conformations, and enhanced ligand-binding affinity through optimized interaction networks-as evidenced by reduced root mean square deviation (RMSD) values, increased hydrogen bond formation, lower radius of gyration (Rg), and improved binding energy (ΔEbind). Furthermore, ethanol functioned as a potent sweet taste enhancer with a more pronounced effect on ECP, likely attributable to its unique structural interactions with the T1R2/T1R3 receptor. These findings provided molecular-level insights into ethanol's role as a sweetness modulator in low-alcohol beverages, offering a theoretical foundation and practical parameters for developing reduced-sugar alcoholic products.

T1R2/T1R3 belongs to G protein coupled receptors, which recognizes diverse natural and synthetic sweeteners. A novel class of positive allosteric modulators (PAMs) of T1R2/T1R3 was identified through high-throughput screening campaign. Comparing the structure of the potent compound with previously known PAM, we classified the structure of known PAM into three parts, defined as "head", "linker", and "tail". We then investigated the linker-tail structure. It was suggested by molecular docking models of T1R2/T1R3 that an amine that we introduced in the tail was the key for interaction with the receptor binding pocket. We thus synthesized various molecules and found unnatural tripeptide-PAMs, which potently enhance the sweetness of sucrose in sensory evaluation tests.

… and low-sugar pastry can be effective in reducing sugar intake … the sweet taste pastry eating procures; reducing pastry sugar … and pleasantness in odorinduced taste enhancement . Acta …

… to reduce the discomfort caused by wearing nose clips. … an explanation of odor-induced taste enhancement on the basis … to the degree of odor-induced taste enhancement. Possibly, the …

Through repeated pairings with a tastant such as sucrose, odors are able to take on the tastant's qualities, e.g. by becoming more sweet smelling. When such odors are subsequently experienced with a sweet tastant in solution, the mixture is often given a higher sweetness rating than the tastant alone. Odor-induced taste enhancement appears to be sensitive to whether an odor-taste combination is viewed analytically as a set of discrete qualities, or synthetically as a flavor. The present research attempted to determine if adoption of these different perceptual approaches during co-exposure with sucrose would influence the extent to which an odor would become sweet smelling and subsequently enhance sweetness intensity. In Experiment 1, subjects received multiple exposures to mixtures of sucrose with low sweetness, low familiarity odors or, as a control, the odors and sucrose solutions separately. Two groups that received mixtures made intensity ratings that promoted either synthesis or analysis of the individual elements in the mixtures. The odors became sweeter smelling irrespective of group. Only adopting a synthetic strategy produced odors that enhanced sweetness in solution. However, these effects were also shown with a 'non-exposed' control odor. This could be accounted for if the single co-exposure with sucrose that all odors received in the pre-test was able to produce sweeter odors. A second experiment confirmed this prediction. Thus, while even a single co-exposure with sucrose is sufficient to produce a sweeter odor, the adoption of a synthetic perceptual strategy during the co-exposure is necessary to produce an odor that will enhance sweetness. These data are consistent with associative leaning accounts of how odors take on taste qualities and also support the interpretation that these effects reflect the central integration of odors and tastes into flavors.

Rising living standards heighten the demand for healthier sugar-reduced foods. This study used Headspace Solid-Phase Microextraction (HS-SPME) and Gas Chromatography-Olfactometry-Mass Spectrometry (GC/O-AT) to analyze volatile components in sweet orange juice, identifying 12 key sweet aroma compounds. Sensory and electronic tongue evaluations indicated that seven sweetness-related odor substances- (E)-citral, (E)-β-farnesene, β-myrcene, tallo-ocimene, nonanal, citronellyl formate, and tallo-ocimene-significantly enhanced the sweetness of a 5 % sucrose solution. In contrast, while nonanol was found to have no sugar-reducing sweetness-enhancing effect. Furthermore, molecular docking analysis was employed to examine the regions, binding energies, and interaction forces between eight sweet and fragrant aroma compounds from sweet orange and the T1R2-T1R3 sweet taste receptor-sucrose ternary system. The average binding energies with the receptor were -3.2 kcal/mol, -1.2 kcal/mol, -3.0 kcal/mol, -1.6 kcal/mol, -5.9 kcal/mol, -5.8 kcal/mol, -3.6 kcal/mol, and -6.0 kcal/mol, respectively. However, it should be noted that binding energy alone is not the sole criterion for judging the sweetening effect. Molecular dynamics (MD) results further demonstrated that the stability of the binding between sucrose and the sweet taste receptor was improved under the influence of (E)-citral, with the interaction between the two relying on hydrogen bonds, water bridges, and hydrophobic forces. This provides a theoretical basis for validating the sweetness-enhancing effects of aroma substances and insights into novel sweetener development.

Abstract Fermentation is a critical technological process for flavor development in fermented foods. The combination of odor and taste, known as flavor, is crucial in enhancing people’s perception and psychology toward fermented foods, thereby increasing their acceptance among consumers. This review summarized the determination and key flavor compound screening methods in fermented foods and analyzed the flavor perception, perceptual interactions, and evaluation methods. The flavor compounds in fermented foods could be separated, purified, and identified by instrument techniques, and a molecular sensory science approach could identify the key flavor compounds. How flavor compounds bind to their respective receptors determines flavor perception, which is influenced by their perceptual interactions, including odor-odor, taste-taste, and odor-taste. Evaluation methods of flavor perception mainly include human sensory evaluation, electronic sensors and biosensors, and neuroimaging techniques. Among them, the biosensor-based evaluation methods could facilitate the investigation of the flavor transduction mechanism and the neuroimaging technique could explain the brain’s signals that relate to the perception of flavor and how they compare to signals from other senses. This review aims to elucidate the flavor profile of fermented foods and highlight the significance of comprehending the interactions between various flavor compounds, thus improving the healthiness and sensory attributes.

… sweet taste and is therefore commonly perceived as … congruence of odor–taste pairs is perceived gradually rather than dichotomously and that congruence interacts with the perception …

Our hedonic response to a food is determined by its flavor, an inherently multisensory experience that extends beyond the mere addition of its odor and taste. While congruency is known to be important for multisensory processes in general, little is known about its specific role in flavor processing. The aim of the present study was to delineate the effects of odor-taste congruency on two central aspects of flavor: odor referral (or mislocalization) to the mouth, and pleasantness. We further aimed to test whether an eventual effect on pleasantness was mediated by odor referral. Aqueous solutions containing odors and tastes were prepared to create food-like stimuli with varying degrees of congruency, ranging from maximally incongruent to maximally congruent in nine steps. Thirty participants reported where they perceived the odors, and how much they liked the solutions. Congruency had a positive linear effect both on odor referral to the oral cavity and on pleasantness. However, the effect of congruency on pleasantness was not mediated by odor referral. These results indicate that as an odor-taste mixture approximates a mental representation of a familiar food, its components are increasingly merged into one perceptual object sensed in the mouth. In parallel, the mixture is evaluated as increasingly pleasant, which promotes consumption of familiar foods that have been determined through experience to be non-toxic. While the modulatory role of congruency on pleasantness and odor referral was confirmed, our results also indicate that these effects arise through distinct perceptual mechanisms.

… perceived locations of the odors after inhaling 3 odorants (citral, “sweet” and “bitter” coffee odors) … The data showed that a highly congruent taste or taste mixture significantly increased …

… In the graphs the response to the congruent taste/odor mixture=turquoise; incongruent taste/… combinations such as vanilla odor and saltiness, or chicken odor and sweetness, whereas if …

Food pairing is a relevant tool for the food industry and for culinary professionals to develop successful flavor combinations and memorable experiences, but it could also be useful for encouraging consumers to adhere to a healthier diet. The general purpose of this study was to further investigate the perception of teas and butter cookies with and without aromatic congruence, deepening in sweetness perception. The experimental included: 1) a projective mapping test (30 semi-trained panelists) to group tea samples and choose representatives of each aromatic group; 2) the determination of the main volatile organic compounds using Solid Phase Micro Extraction-Gas Chromatography Mass Spectrometry (SPME-GC-MS) to prove the aromatic congruence of the designed tea-cookie pairings; 3) a consumer study (n = 89) to assess liking, sweetness perception, of the single samples and pairings, and the pairing principles of the congruent and non-congruent parings. Results of the projective mapping showed that the tea samples could be grouped into 3 main categories by their herbal, fruity-sweet, and brown-sweet notes, results also supported by the GCMS data. Harmony was positively correlated to liking, and Balance and Similarity seemed to be related to aromatic “congruence”, although all pairings were similarly liked. Sugar content was similar in all the cookie samples and pairings, but sweetness perception was significantly influenced by the aroma of the samples, being the samples and pairings made with spearmint the least sweet ones. Pairing a tea with sweet aromas with the spearmint cookie, independently of the kind of sweet aromatics (e.g.: coconut, almond, vanilla, fruity, tropical), seemed to slightly increase sweetness perception, although significant differences were not detected with other spearmint cookie pairings. Findings of the present research sum knowledge to the food pairing area, but further research is needed in recommending appropriate methodologies for pairing assessment, as well as the potential uses of driven pairings in specific food cultures.

Little is known about the influence of visual characteristics other than colour on flavor perception, and the complex interactions between more than two sensory modalities. This study focused on the effects of recognizability of visual (texture) information on flavor perception of odorized sweet beverages. Participants rated the perceived sweetness of odorized sucrose solutions in the presence or absence of either a congruent or incongruent visual context. Odors were qualitatively reminiscent of sweet foods (strawberry and caramel) or not (savoury). Visual context was either an image of the same sweet foods (figurative context) or a visual texture derived from this product (non-figurative context). Textures were created using a texture synthesis method that preserved perceived food qualities while removing object information. Odor-taste combinations were rated sweeter within a figurative than a non-figurative context. This behaviour was exhibited for all odor-taste combinations, even in trials without images, indicating sustained priming by figurative visual context. A non-figurative context showed a transient sweetening effect. Sweetness was generally enhanced most by the strawberry odor. We conclude that the degree of recognizability of visual information (figurative versus non-figurative), influences flavor perception differently. Our results suggest that this visual context priming is mediated by separate sustained and transient processes that are differently evoked by figurative and non-figurative visual contexts. These components operate independent of the congruency of the image-odor-taste combinations.

Taste perception is significantly affected by other sensory modalities such as vision, smell, and somatosensation. Such taste sensation elicited by integrating gustatory and other sensory information is referred to as flavor. Although experimental studies have demonstrated the characteristics of flavor perception influenced by other sensory modalities and the involved brain areas, it remains unknown how flavor emerges from the brain circuits. Of the involved brain areas, orbitofrontal cortex (OFC), as well as gustatory cortex (GC), plays a dominant role in flavor perception. We develop here a neural model of gustatory system which consists of GC and OFC networks and examine the neural mechanism of odor-induced taste perception. Using the model, we show that flavor perception is shaped by experience-dependent learning of foods with congruent taste-odor pairs, providing a unique representation of flavor through the interaction between OFC and GC neurons. Our model also shows that feedback signals from OFC to GC modulate the dynamic stability of taste attractors in GC, leading to the enhancement or suppression of taste responses by smells. Furthermore, modeling shows that spatial variability in GC activity evoked by tastants determines to what extent odor enhances congruent taste responses. The results suggest that flavor perception is deeply associated with dynamic stability of GC attractors through the interaction between GC and OFC.

… , congruence arises between sweet and citrus flavors because most people have experienced citrus flavorants together with sweet … how congruent or harmonious they perceived the …

… perception of olfactory stimuli. We hypothesized that congruent costimulation enhances the perception of … a stimulus (eg sweet) congruent when presented with one odor (eg strawberry), …

… an odor mixed with a sweet taste later results in that odor’s coming to be judged as more sweet smelling than a control odor … The procedures for the taste sweetness and odor sweetness …

… action was studied by molecular simulation. Molecular docking results indicated that the binding … compounds, indicating that sucrose was more tightly docked to the sweet taste receptor. …

At present, there are relatively few studies on the influence of green aroma and aldehyde aroma compounds on the sweetness perception of sucrose. This study examined the effects of 11 aroma compounds from sweet orange, characterized by green and aldehyde flavors, on the sweetness of a 5 % sucrose solution. Using artificial sensory analysis and electronic tongue technology, it was found that most aromatic compounds can inhibit sweetness perception, and the inhibitory effect of trans-2-decenoaldehyde is the most significant. The mechanism of inhibition was explored through molecular simulation, revealing that the binding free energy of molecular docking was greater than −5.9 kcal/mol. Further molecular dynamics analysis showed that compared with the T1R2/T1R3 sucrose binary system, the addition of aroma substances reduced the number of hotspot residues involved in protein ligand binding, and did not enhance the binding ability of ligand proteins, indicating an inhibitory effect.

… of odorants enhancing the sweet-smelling enhancing odorants by vanillin (V)/ethyl vanillin (EV)-specific receptors and … sensory evaluation and molecular docking (MD) analysis. Twelve …

The characteristic aroma compounds of five-fold sweet orange oil were analyzed using gas chromatography-mass spectrometry combined with the odor aroma value (OAV) method. The results indicated that limonene, linalool, dodecanol, (E,E)-2,4-decadienal, (E)-citral, linalool, (E)-2-decenal, and geraniol are important contributors. The sweetening effects of key compounds on sucrose solutions were experimentally investigated. The results showed that the sweetness effects of five compounds (limonene, citronellal, geraniol, β-sinensal and β-caryophyllene) were better than those of (E)-citral, linalool and octanal. Molecular dynamics implied that the hydrogen bonding residues of the T1R2/T1R3-sucrose system were converted from LYS65, GLU302, ASP278, and SER144 to ASP278, SER144, ASP142, and ASP213 after the addition of limonene. Meanwhile, the hydrophobic interaction forces of the system are significantly enhanced. The total energy of the T1R2/T1R3-sucrose system decreased from -32.08 kcal/mol to -63.57 kcal/mol. The synergistic sweetening mechanism of characteristic aroma compounds of sweet orange oil on sucrose was revealed.

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This study explores the synergy between eight floral aroma compounds and erythritol (p < 0.05), enhancing its sweetness. While α- and β-ionone increase sweetness, they reduce overall acceptability. At optimal concentrations, these compounds improve both sweetness and flavor, but the effect diminishes beyond certain thresholds. Electronic tongue results correlate with sensory data but cannot fully replicate human taste. Molecular docking reveals ternary complexes (T1R2/T1R3-aroma-erythritol) show better binding energies than binary systems, with α-ionone having the lowest binding energy (-10.54 kcal/mol). 100-ns simulations identify ASN70, GLY381, and SER380 as key residues. Binding free energies for neryl acetate range from - 45.21 to -57.38 kcal/mol, clarifying the mechanisms of sweetness enhancement. These findings support the reduction of erythritol in juices and the development of low-sugar beverages through aroma-induced sweetness.

Responding to global trends favoring low-sugar diets, this study explored the potential of menthol, a cooling agent, to enhance sweet taste perception through integrated sensory evaluations and molecular modeling. The results of static sensory evaluation (recognition threshold determination, paired comparison test and 15 cm-linear scale) and dynamic sensory analysis indicated that menthol lowered sweetness threshold of HFCS (from 5.98 g/L to 5.02 g/L), while intensifying maximum sweetness intensity and prolonging the duration of sweetness. Sensory analysis identified optimal sweet enhancement at 0.004–0.030 g/L menthol concentrations, while 0.060 g/L caused sweetness suppression through intensified cooling/bitter sensations. Molecular modeling comparing T1R2/T1R3-Glu/Fru system and T1R2/T1R3-Glu/Fru/Men system elucidated that the addition of menthol increased the number of hotspot residues in protein-sugars binding and stabilized interactions by occupying sites near sugar active sites, maintaining the Venus Flytrap Domain in its closed, activated configuration. These findings demonstrated the underlying contribution menthol made to sweet enhancement and sugar reduction.

… into the cross-talk between taste and smell, sweetness and temperature, sweetness and … in terms of the expression of chemosensory receptors. The expression analysis can be …

G protein-coupled receptors (GPCRs) belong to the largest class of drug targets. Approximately half of the members of the human GPCR superfamily are chemosensory receptors, including odorant receptors (ORs), trace amine-associated receptors (TAARs), bitter taste receptors (TAS2Rs), sweet and umami taste receptors (TAS1Rs). Interestingly, these chemosensory GPCRs (csGPCRs) are expressed in several tissues of the body where they are supposed to play a role in biological functions other than chemosensation. Despite their abundance and physiological/pathological relevance, the druggability of csGPCRs has been suggested but not fully characterized. Here, we aim to explore the potential of targeting csGPCRs to treat diseases by reviewing the current knowledge of csGPCRs expressed throughout the body and by analysing the chemical space and the drug-likeness of flavour molecules.