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In our diet, we ingest a variety of compounds that are TRPV1 modulators. It is important to understand if these compounds alter neural and behavioral responses to taste stimuli representing all taste qualities. Here, we will summarize the effects of capsaicin, resiniferatoxin, cetylpyridinium chloride, ethanol, nicotine, N -geranyl cyclopropylcarboxamide, Kokumi taste peptides, pH, and temperature on neural and behavioral responses to taste stimuli in rodent models and on human taste perception. The above TRPV1 agonists produced characteristic biphasic effects on chorda tympani taste nerve responses to NaCl in the presence of amiloride, an epithelial Na + channel blocker, at low concentrations enhancing and at high concentrations inhibiting the response. Biphasic responses were also observed with KCl, NH 4 Cl, and CaCl 2 . In the presence of multiple stimuli, the effect is additive. These responses are blocked by TRPV1 antagonists and are not observed in TRPV1 knockout mice. Some TRPV1 modulators also increase neural responses to glutamate but at concentrations much above the concentrations that enhance salt responses. These modulators also alter human salt and glutamate taste perceptions at different concentration ranges. Glutamate responses are TRPV1-independent. Sweet and bitter responses are TRPV1-independent but the off-taste of sweeteners is TRPV1-dependent. Aversive responses to acids and ethanol are absent in animals in which both the taste system and the TRPV1-trigeminal system are eliminated. Thus, TRPV1 modulators differentially alter responses to taste stimuli.

White-faced sakis (Pithecia pithecia) are commonly considered as frugivores but are unusual among primates as they do not specialize on ripe fruits but rather include a high proportion of unripe fruits into their diet, even during seasons when ripe fruits are available. Using a two-bottle preference test of short duration we therefore assessed whether this dietary specialization affects the taste responsiveness and sour-taste tolerance of four adult white-faced sakis for five food-associated acids. We found taste preference thresholds of the sakis to be 1-10 mM for citric acid, 0.5-20 mM for ascorbic acid, 2-10 mM for malic acid, 0.1-1 mM for tannic acid, and 2-20 mM for acetic acid, respectively. When given the choice between a reference solution of 50 mM sucrose and mixtures containing varying concentrations of sucrose plus citric acid, the sakis displayed a high sour-taste tolerance and required only 100 mM of sucrose (when mixed with 10 mM citric acid) or 200 mM of sucrose (when mixed with 30 or 50 mM citric acid), respectively, to prefer the sweet-sour mixture over the purely sweet 50 mM sucrose reference solution. These results demonstrate that white-faced sakis have a well-developed taste sensitivity for food-associated acids which is not inferior to that of primates specializing on ripe fruits. Compared to other platyrrhine primates, the sakis displayed a markedly higher sour-taste tolerance. These results may therefore reflect an evolutionary adaptation to the dietary specialization of the white-faced sakis to sour-tasting unripe fruits., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest regarding this work., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Theacrine, a purine alkaloid derived from Camellia assamica var. kucha, has a distinct bitter taste. Our previous study found the lower recognition threshold of theacrine at 25 °C than 45 °C. This study aims to investigate the bitterness characterizations of theacrine at aforementioned temperatures and its taste perception mechanism. Sensory analysis exhibited higher bitterness intensity for theacrine at 25 °C than 45 °C. Subsequently, flow cytometry was performed to verify the above characterization at the cellular level. It revealed that theacrine could activated the bitter receptor hTAS2R14 and the calcium signal at 25 °C was higher than 45 °C. Ultimately, the interaction mechanism was studied by molecular dynamics simulations, indicating that the conformation of theacrine-hTAS2R14 had a higher binding capacity and better stability at 25 °C. Overall, temperature affected the binding of theacrine to the bitter receptor hTAS2R14, resulting in the stronger bitterness intensity of theacrine at 25 °C than 45 °C., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose of Review: The miracle fruit contains the glycoprotein miraculin which can modify the taste perception of food and beverages at low pH conditions, altering the consumers' food preferences. This review aims to critically evaluate all available evidence on miracle fruit/ miraculin and taste modification and its potential role in improving food preferences., Recent Findings: Miracle fruit suppresses sourness and induces sweetness in acidic food/ beverages. At low pH conditions, miracle fruit enhances the sweet taste and decreases the perceived intensities of salty and bitter tastes in solutions. However, the role of miracle fruit in sweet, salty, and bitter food is not adequately studied. The above effects alter the food-liking scores in individual foods and mixed diets. Miracle fruit is a pH-dependent taste modifier with the potential to be used in food applications to improve consumer food preferences. Future research on the changes in food preferences with the optimum miraculin dose, food type, and intrapersonal variations in taste sensitivity is warranted., (© 2024. The Author(s).)

Taste receptors, first described for their gustatory functions within the oral cavity and oropharynx, are now known to be expressed in many organ systems. Even intraoral taste receptors regulate non-sensory pathways, and recent literature has connected bitter taste receptors to various states of health and disease. These extragustatory pathways involve previously unexplored, clinically relevant roles for taste signaling in areas including susceptibility to infection, antibiotic efficacy, and cancer outcomes. Among other physicians, otolaryngologists who manage head and neck diseases should be aware of this growing body of evidence and its relevance to their fields. In this review, we describe the role of extragustatory taste receptors in head and neck health and disease, highlighting recent advances, clinical implications, and directions for future investigation. Additionally, this review will discuss known TAS2R polymorphisms and the associated implications for clinical prognosis., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

The sweet taste of saccharides, such as sucrose and glucose, and other sweeteners is known to result from activation of the TAS1R2/R3 receptor expressed in taste receptor cells (TRCs) of the taste bud. Recent reports have suggested the existence of an additional sweet taste signaling pathway for metabolizable saccharides that is dependent on the activity of glucose transporters, especially SGLT1, also expressed in TRCs. We have investigated the potential contribution of SGLT1 to glucose taste signaling in humans. Concentration-response analysis of glucose mediated changes in membrane potential measured in Chinese hamster ovary (CHO) cells transiently expressing the human SGLT1 (hSGLT1) yielded an EC50 value of 452 μM. The SGLT inhibitor phlorizin inhibited the membrane potential response to 10 mM glucose with an IC50 of 3.5 μM. In contrast, EC50 values of 127 and 132 mM were obtained from concentration-response analysis of glucose taste in vehicles of water or 20 mM NaCl, respectively, by rapid throughput taste discrimination with human subjects. Lactisole, an antagonist of TAS1R2/R3, at a concentration of 1 mM completely inhibited taste responses to glucose concentrations of 250 mM and below. Phlorizin (0.2 mM) and the high potency SGLT1-selective inhibitor mizagliflozin (10 μM) failed to inhibit glucose taste detection measured at peri-threshold concentrations in the rapid throughput taste discrimination assay. A Yes/No experiment using the taste discrimination assay revealed that 0.2 mM phlorizin was discriminable from water for some subjects. Taken together the results indicate that agonist activation of TAS1R2/R3 is sufficient to account for all glucose taste without contribution by an alternative SGLT-mediated signaling pathway. Furthermore, the taste of phlorizin could be a confounding variable for studies evaluating a role for SGLTs in taste., Competing Interests: The rapid throughput taste discrimination technology used in the human taste studies also is used for commercial purposes by Opertech Bio (TāStation®). RKP is a co-founder and stockholder of Opertech Bio, which independently funded the human taste studies. RKP is named as inventor on patents for the rapid throughput taste discrimination technology. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Palmer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Assessment of taste and somatosensory perception in clinical practice lacks fast tests that are validated and reliable. Recently, a 12-item identification test for taste and oral trigeminal perception, and its shorter version, the Seven-iTT, was developed. The objectives of this study were to evaluate its test-retest reliability and establish normative data., New Method: Two-hundred participants (120 women, 80 men) with a good sense of taste performed a whole-mouth identification test using 12 filter-paper strips impregnated with low and high concentrations of sweet, sour, salty, bitter, astringency, and spiciness. Fifty of them repeated the task, with a median interval of 122 days from the first visit. Test-retest reliability was determined using Spearman correlation and the Bland-Altman plot method., Results: There was a significant correlation in identification score between the first and the second session for both versions of the test (r ≥ 0.28; p ≤ 0.048). The Bland-Altman plot reflected a good congruence between the results of the two sessions. Additionally, frequencies of correct identification were consistent between sessions, with women outperforming men (p = 0.005). Hypogeusia was established at Seven-iTT score of 3 of less., Comparison With Existing Methods: The identification test combines taste and somatosensory perception, thus creating a more detailed diagnosis tool. Scores were correlated with self-rated taste perception., Conclusion: The present results confirmed the applicability of Seven-iTT for a reliable, fast evaluation of taste and somatosensory perception in the general population, that can be extended to clinical practice., Competing Interests: Declaration of Competing Interest The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

N-Succinyl amino acids (N-Suc-AAs) are increasingly recognized for their potential as taste-active compounds. However, research into the green synthesis, taste-enhancing properties, and mechanisms of N-succinyl-L-leucine (N-Suc-Leu) remains limited. This study employed an enzymatic synthesis method, catalyzed by protamex and pancreatin, to produce N-Suc-Leu, with its structure confirmed. Multiple sensory techniques demonstrated that N-Suc-Leu markedly enhanced the umami, saltiness, and kokumi intensity, and prolonged the duration of umami by 25%. Sigmoid curve analysis further revealed the synergistic enhancement of N-Suc-Leu on the perceptions of umami and saltiness. Molecular docking and dynamics simulations revealed that N-Suc-Leu could bind with T1R1, T1R3, TMC4, and CaSR, enhancing the sensations of saltiness, umami, and kokumi, and bound closely to these receptors without altering their overall conformation. These findings offered a systematic explanation of the potential and mechanism of enzymatically synthesized N-Suc-Leu in enhancing taste and provided novel insights into potential strategies for the development and innovation of taste enhancers and food flavors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Two lipid sensors, CD36 and GPR120, are crucial for the orosensory detection of fat taste and for mediating fat preference. However, the mechanism by which endogenous lipid (FAHFA) binds to CD36 to initiate intracellular signaling remains unexplained. Hence, the primary objective of this study is to investigate the binding mechanism of FAHFA to CD36 and its role in isolated mouse taste bud cells (mTBCs). The Schrodinger platform was used to assess the molecular dynamics of protein and ligand interactions, and an in vitro experiment was used to validate the findings. Based on the docking score of the ligand, the molecular mechanistic activities of the targeted complexes, CD36-5-POHSA (-8.2 kcal/mol), were investigated using the dynamic simulation. In comparison to linoleic acid (LA), POHSA rapidly increased [Ca 2+ ]i via acting on CD36, and 5-POHSA treatment in mTBCs activated src-kinase at 20 μM. CD36 siRNA transfection in TBCs downregulate the CD36 protein expression as well as [Ca 2+ ]i flux. This study suggests that 5-POHSA may help combat taste abnormalities and the adverse effects of obesity by binding to the lingual CD36 receptor and activating the tongue-brain axis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Crossmodal correspondences, the tendency for a sensory feature / attribute in one sensory modality (either physically present or merely imagined), to be associated with a sensory feature in another sensory modality, have been studied extensively, revealing consistent patterns, such as sweet tastes being associated with pink colours and round shapes across languages. The present research explores whether such correspondences are captured by ChatGPT, a large language model developed by OpenAI. Across twelve studies, this research investigates colour/shapes-taste crossmodal correspondences in ChatGPT-3.5 and -4o, focusing on associations between shapes/colours and the five basic tastes across three languages (English, Japanese, and Spanish). Studies 1A-F examined taste-shape associations, using prompts in three languages to assess ChatGPT's association of round and angular shapes with the five basic tastes. The results indicated significant, consistent, associations between shape and taste, with, for example, round shapes strongly associated with sweet/umami tastes and angular shapes with bitter/salty/sour tastes. The magnitude of shape-taste matching appears to be greater in ChatGPT-4o than in ChatGPT-3.5, and ChatGPT prompted in English and Spanish than ChatGPT prompted in Japanese. Studies 2A-F focused on colour-taste correspondences, using ChatGPT to assess associations between eleven colours and the five basic tastes. The results indicated that ChatGPT-4o, but not ChatGPT-3.5, generally replicates the patterns of colour-taste correspondences that have previously been observed in human participants. Specifically, ChatGPT-4o associates sweet tastes with pink, sour with yellow, salty with white/blue, bitter with black, and umami with red across languages. However, the magnitude/similarity of shape/colour-taste matching observed in ChatGPT-4o appears to be more pronounced (i.e., having little variance, large mean difference), which does not adequately reflect the subtle nuances typically seen in human shape/colour-taste correspondences. These findings suggest that ChatGPT captures colour/shapes-taste correspondences, with language- and GPT version-specific variations, albeit with some differences when compared to previous studies involving human participants. These findings contribute valuable knowledge to the field of crossmodal correspondences, explore the possibility of generative AI that resembles human perceptual systems and cognition across languages, and provide insight into the development and evolution of generative AI systems that capture human crossmodal correspondences., Competing Interests: Declaration of competing interest The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

N-Succinyl amino acids (N-Suc-AAs) are garnering attention for their potential as taste-active compounds. The intricate variety of N-Suc-AAs presented considerable challenges in identifying those with taste-active properties. Consequently, we employed structure-based virtual screening to pinpoint taste-active N-Suc-AAs, revealing N-succinyl-L-tryptophan (ST) as a compound with high affinity for different taste receptors. Following this discovery, ST was synthesized through an enzymatic process, achieving a yield of 40.2%, with its structure verified via NMR spectroscopy. Sensory evaluation alongside electronic tongue assessments indicated that ST at a concentration of 1 mg/L significantly enhances umami, kokumi, and saltiness intensities, while concurrently mitigating bitterness from various bitter compounds, whilst itself remaining tasteless. Additionally, time-intensity (TI) results elucidated a marked augmentation in umami duration and a notable diminution in bitterness duration for solutions imbued with 1 mg/L ST. Molecular docking study suggested ST interacted with diverse taste receptors as an agonist or antagonist, primarily through hydrogen bonds and hydrophobic interactions. This study marked the inaugural report on the enzymatic synthesis of ST and its efficacy in improving taste characteristics, underscoring the importance of ST in improving sensory qualities of food products and fostering innovation within the seasoning industry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The objective of this study is to review the association of TAS2R38 polymorphisms and taste phenotypes to bitter compounds (phenylthiocarbamide [PTC]/propylthiouracil [PROP]), and its association among persons who drink alcohol and individuals with smoking behavior. A literature search was carried out in PubMed, ScienceDirect, Cochrane, and Wiley online library databases using the keyword "(Bitter taste receptor genes OR TAS2R38) AND (PROP OR propylthiouracil) AND (PTC OR phenylthiocarbamide)," "(Bitter taste receptor genes OR TAS2R38) AND (alcohol)," "(Bitter taste receptor genes OR TAS2R38) AND (tobacco OR smoker)" to find articles evaluating the association of taste phenotypes and TAS2R38 polymorphisms, and its association among persons who drink alcohol and individuals with smoking behavior. The analysis show that TAS2R38 taster genotype (proline-alanine-valine [PAV] allele) was significantly (OR, 5.88; CI [3.87, 8.95], p < .001) associated with taster phenotype for bitter compounds (PTC/PROP), and TAS2R38 nontaster genotype (alanine-valine-isoleucine allele) was significantly (OR, 6.73; CI [4.57, 9.90], p < .001) associated with nontaster phenotype for bitter compounds. Further, TAS2R38 taster genotypes (PAV homozygotes and heterozygotes) were significantly associated with higher alcohol intake (OR, 5.15; 95% CI [2.66, 9.98]; p < .001) and among individuals with smoking behavior (OR, 1.73; 95% CI [1.24, 2.42]; p = .001). This suggests that TAS2R38 single nucleotide polymorphisms can be identified by clinically assessing taste phenotype status for bitter compounds and can be used as a potential therapeutic target in the prevention and treatment of harmful higher alcohol intake and smoking behavior. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

This study aimed to prepare and screen salty peptides and elucidate the factors triggering their saltiness properties and saltiness-enhancing effects. Electronic tongue results indicated that samples treated with Alcalase (AJ) exhibited the highest saltiness intensity (5.05 ± 0.11) and greater saltiness-enhancing compared to those treated with Flavourzyme (AF), Neutrase (AZ), and Papain (AM). Peptides identified by LC-MS/MS were docked to the TMC4 receptor, resulting in 23 peptides with good docked results. The key amino acid residues (Thr431, Arg433, Phe440, Phe432, and Ser273) were discovered. The salty peptides WPGFK (633.75 Da), YFDWPGFK (1059.17 Da), and YFDWPGFKT (1160.27 Da) were selected for salt reduction and molecular characterization studies. Electronic tongue results showed that the 0.01 % WPGFK solution matched the saltiness of the 0.24 % NaCl solution and demonstrated superior saltiness-enhancing compared to YFDWPGFK and YFDWPGFKT. Primary sequence analysis of three salty peptides suggested that the WPG amino acid segment might play a crucial role in generating saltiness. Circular dichroism (CD) analysis of the secondary structure indicated that increased random coil and decreased β-turn contents resulted in higher saltiness perception and increased random coil content led to greater saltiness-enhancing ability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Taste, a pivotal sense modality, plays a fundamental role in discerning flavors and evaluating the potential harm of food, thereby contributing to human survival, physical and mental health. Patients with tongue cancer may experience a loss of taste following extensive surgical resection with flap reconstruction. Here, we designed a gustatory interface that enables the non-invasive detection of tongue electrical activities for a comprehensive operative assessment. Moreover, it decodes gustatory information from the reconstructed tongue without taste buds. Our gustatory interface facilitates the recording and analysis of electrical activities on the tongue, yielding an electrical mapping across the entire tongue surface, which delineates the safe margin for surgical management and assesses flap viability for postoperative structure monitoring and prompt intervention. Furthermore, the gustatory interface helps patients discern tastes with an accuracy of 97.8%. Our invention offers a promising approach to clinical assessment and management and holds potential for improving the quality of life for individuals with tongue cancer., (© 2024. The Author(s).)

Background: Chemotherapy is the most commonly utilized therapeutic strategy among the numerous cancer treatments. These chemotherapeutic agents have a variety of adverse reactions, one of which is taste alteration (TA), which substantially influences the patient's nutritional status and quality of life (QoL)., Objective: The study aims to assess TAs, associated factors, and the nutritional status and QoL of cancer patients undergoing chemotherapy., Methods: An observational cross-sectional study was carried out for 6 months, among cancer patients diagnosed with TA. Data was collected using a chemotherapy-induced taste alteration scale (CiTAS). Demographic details of the patients, factors associated with TA, details regarding chemotherapeutic agent used, number of current chemotherapy cycles etc, were recorded using a self-designed data collection form. Nutritional status and QoL on cancer patients were collected using Mini nutritional assessment - short form (MNA-SF) and EuroQol 5 dimension 5 levels (EQ5D5L), respectively, and statistical package for the social sciences (SPSS) software version 29 was used for the analysis of data., Results: A significant association was observed between TA and QoL. There was also a significant association between TA and predisposing factors such as nausea and dry mouth, which was obtained from the Chi-square test. Male patients were found to have higher TA than female patients. TA has also affected various aspects of QoL, such as mobility, pain, and discomfort. Patients experiencing mouth dryness or xerostomia had higher TA than others. A negative association was seen between TAs and nutritional status., Conclusion: This study shows a significant relationship between gender and TA, dry mouth, nausea, and TA. Several QoL factors like mobility, pain/discomfort, and TA were also observed. Despite this study not observing any statistical association between nutritional status and TA, clinically, most of the patients with higher TA were malnourished. This study concluded that there was a relationship between TA and QoL and that nausea and dry mouth are the predisposing factors for TA., Competing Interests: Declaration of competing interest Nil., (Copyright © 2024 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Objective: With the rapid increase in the pace of life, people are facing increasing pressures of all kinds, and depression has gradually become a serious psychological disorder in human society, strongly affecting normal social and physiological activities. Depression can disrupt an individual's taste perception and potentially result in taste disorders by affecting and altering taste receptors. This disruption can consequently impact their food preferences and overall eating experiences., Design: In this study, we used the chronic unpredictable mild stress (CUMS) method to establish a depression model in male C57BL/6 J mice and explored the changes in taste receptor expression in the lingual circumvallate papillae (CP) to elucidate the effects of depression on taste. After 6 weeks of CUMS, behavioral performance evaluations, such as forced swim, open field, and elevated plus maze tests, were conducted in depression model mice. A further two-bottle choice test was subsequently performed to determine the effect of depression on bitter taste, and the expression of bitter taste receptors in the lingual CP was detected via immunofluorescence staining., Results: In this study, we found for the first time that mice with CUMS-induced depression had decreased bitter taste sensitivity through a two-bottle choice test and demonstrated that the expression of T2r5, a receptor related to bitter taste perception, and the expression of secondary taste signaling proteins in the lingual CP were significantly decreased in mice exposed to CUMS, as determined via qRTPCR and immunofluorescence staining., Conclusions: Our study highlights how CUMS influences the perception of bitterness in the peripheral taste system, potentially elucidating stress-induced changes in eating habits., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Wang Zhaoxiang reports financial support was provided by Chinese PLA General Hospital. Cao Junkai reports a relationship with Chinese PLA General Hospital that includes: employment. Medical School of Chinese PLA is an affiliated unit of Chinese PLA General Hospital If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Introduction: Alterations in taste and smell are among the most distressing symptoms experienced by haemodialysis patients. There is limited research on the relationship between these two symptoms and malnutrition in haemodialysis patients. This study aimed to investigate alterations in taste and smell in hemodialysis patients and their relationship with malnutrition., Methods: This cross-sectional study was carried out with 149 hemodialysis patients at the dialysis centers of three state hospitals. The Taste and Smell Dysfunction Questionnaire was used to assess the changes in patients' taste and smell, and the Prognostic Nutritional Index (PNI), as well as the Controlling Nutritional Status (CONUT) tool, were utilized to evaluate their nutritional status., Findings: A substantial percentage (45.6%) of patients reported an altered sense of smell, and 40.2% reported an altered sense of taste. The aspect of taste that was most abnormal was bitterness (46.7%); 53.0% of the patients were at moderate risk of malnutrition by PNI score, and 14.8% were categorized as malnourished by CONUT score. Malnutrition was related to dialysis vintage: a 1-year increase in vintage was associated with an increased risk of malnutrition (OR: 1.17, 95% CI 1.02-1.32, p < 0.001). Altered taste was associated with malnutrition: one-unit increase in the standard deviation of the taste subdimension score was associated with a relative risk of malnutrition (OR: 6.89, 95% CI 1.67-28.39, p < 0.001). A one-unit increase in the standard deviation of the smell subdimension was associated with relative risk of malnutrition (OR: 1.35, 95% CI 1.10-1.64, p < 0.001)., Discussion: Malnutrition was found in a significantpercentage of hemodialysis patients. Altered taste and smell and the durationof dialysis treatment were significantly associated with malnutrition scores It isrecommended that healthcare professionals regularly assess alterations in tasteand smell in hemodialysis patients, as these alterations may be associated withmalnutrition, and manage these alterations accordingly., (© 2024 International Society for Hemodialysis.)

Our previous study speculated that decreased levels of catechin were associated with heightened sweetness in Camellia nanchuanica black tea (NCBT). In this study, we found that catechin has the capacity to obscure the sweet taste of phloridzin and verified the above speculation. To delve deeper into this masking effect, we examined various concentrations of catechin (cat-10cat) and phloridzin (phl-10phl), and revealed catechin (cat-10cat) significantly reduced the sweetness of 10phl. Therefore, catechin (cat-10cat) and 10phl combinations were selected to investigate the impact on sweet taste receptor cells. The results showed increasing concentrations of catechin inhibited the calcium signal of the phloridzin-catechin solution, attributing to lower stability of phloridzin and Taste 1 Receptor Member 3 (one subunit of sweet taste receptor proteins) after addition catechin. Finally, 10phl/10cat significantly activated the central and prefrontal regions generating more bitter tastes and negative emotions which also probably contributed to mask sweet tastes of phloridzin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Binary taste perception is widely studied in aqueous solutions but less investigated in non-Newtonian fluid systems. In this study, the effect of sweet tastants on the dynamic sour taste perception in thickened fluids and its underpinning oral processing factors were investigated. Subjects were tested for taste thresholds and salivary biochemical properties. By using hydroxypropyl methylcellulose (HPMC) as a thickening agent, subjects conducted sour taste evaluation, with and without maltose and/or HPMC, using descriptive sensory analyses. A simulated fluid shear elicited by fixed-frequency mastication was applied on thickened fluid sample oral processing during time-intensity sour taste evaluation. Results showed that adding maltose to fluid samples enhanced sour taste perception, and increasing fluid viscosity generally suppressed perceived maximum sour taste. Moreover, subjects with lower sour taste sensitivity and higher salivary buffering capacity reported overall lower sour taste intensity in most samples, validating the hypothesis that salivary properties importantly affect sour taste perception., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Taste disorders in patients suffering from COVID-19 were popular. Some people even after recovery report residual effects of loss of smell and taste. This study aimed to investigate the taste Perception of Iranian Medical Sciences students during the COVID-19 pandemic., Methods: The case-control study evaluated 50 Medical Sciences students with a history of COVID-19 infection, as confirmed by the Novel Coronavirus (2019-nCOV) CFX96™ Real-Time PCR Detection System. The other participants consisted of 50 volunteer students with COVID-19 negative. The taste perception was measured with 4 different concentrations of the basic tastes. The stimuli were applied to the protruded tongue. Subjects were asked to identify the researcher when they felt the taste. Data are expressed as frequency distribution and analyzed with the Chi-Square test (P < 0.05)., Results: In this survey, 54% of participants were male and 46% were female, the mean age of participants was 22.96 ± 5 years. The results showed a significant difference in the sweet and bitter taste perception score according to the history of dietary supplement use. The bitter taste perception score declared a considerable difference since COVID-19 infection. There was no significant difference between the taste perception in the two studied groups for all 4 basic tastes according to gender, COVID-19 infection status, history of taste and smell disorders, and the elapsed time since COVID-19 infection., Conclusion: Our findings could provide important insights into taste perception. The history of dietary supplementation may influence how sweetness and saltiness are perceived. There was a noticeable difference in bitter taste perception depending on the time that had elapsed since the most recent COVID-19 infection., (© 2024. The Author(s).)

In our previous study, phloridzin, sucrose, l-alanine, and dulcitol presented synergistic effects in Camellia nanchuanica black tea (NCBT). This study aims to verify the synergistic effects of the aforementioned sweet taste compounds and the mechanism involved. By conducting σ-τ plot analysis, phloridzin at the recognition threshold concentration (phl) exhibited synergistic effects with different concentrations of sucrose (Lsuc-6suc). Various concentrations of sucrose, phloridzin, and their combinations were selected to investigate the impact on sweet taste receptor cells. The results revealed that sucrose/phloridzin significantly increased the calcium signal compared to phloridzin and sucrose alone, attributed to the greater stability of the sucrose/phloridzin combination when binding to Taste 1 Receptor Member 3 (TAS1R3; one subunit of sweet taste receptor proteins). Ultimately, the sweet taste signal of sucrose/phloridzin was transmitted to the brain, triggering the activation of more brain regions associated with sweet taste perception (right insular, postcentral, and amygdala).

Human bitter perception is important for the identification of potentially harmful substances in food. For quite some years, research focused on the identification of activators for ∼25 human bitter taste receptors. The discovery of antagonists as well as increasing knowledge about agonists of different efficacies has substantially added to the intricacy of bitter taste perception. This article seeks to raise awareness for an underestimated new level of complexity when compound mixtures or even whole food items are assessed for their bitter taste.

A fundamental requirement for all animals is to sense and respond to changes in environmental O 2 availability. Low O 2 (hypoxia) typically stimulates breathing, a universal and critical response termed the hypoxic ventilatory response (HVR). In this study, we test the hypothesis that taste-signaling pathways are used for O 2 sensing and activation of the HVR. We show that Merkel-like cells (MLCs), which are part of the taste-bud complex, function as O 2 chemoreceptor cells in larval zebrafish and that transduction of the O 2 signal uses taste-signaling pathways. Specifically, MLCs responded to hypoxia in vivo with an increase in Ca 2+ activity that can drive the HVR. In addition, MLCs transmit O 2 signals to afferent cranial nerves IX and X (nIX/X), which project into the area postrema within the hindbrain and synapse with interneurons that are in contact with vagal motor neurons. Hypoxia or chemo-activation of nIX/X caused Ca 2+ activity to increase within the area postrema and elicited hyperventilation. The results provide the first demonstration of an O 2 signaling pathway that commences with the activation of taste receptors (MLCs) to yield a critical physiological reflex, the HVR., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: Bariatric surgery reduces sweet-liking, but mechanisms remain unclear. We examined related brain responses., Methods: A total of 24 nondiabetic bariatric surgery and 21 control participants with normal weight to overweight were recruited for an observational controlled cohort study. They underwent sucrose taste testing outside the scanner followed by stimulation with 0.40M and 0.10M sucrose compared with water during functional magnetic resonance imaging. A total of 21 bariatric participants repeated these procedures after surgery., Results: Perceived sweet intensity was not different among the control, presurgery, or postsurgery groups. Bariatric participants' preferred sweet concentration decreased after surgery (0.52M to 0.29M; p = 0.008). Brain reward system (ventral tegmental area, ventral striatum, and orbitofrontal cortex) region of interest analysis showed that 0.40M sucrose activation  (but not 0.10M) decreased after surgery. Sensory region (primary somatosensory and primary taste cortex) 0.40M sucrose activation was unchanged by surgery and did not differ between control and bariatric participants. Primary taste cortex activation to 0.10M sucrose solution was greater in postsurgical bariatric participants compared with control participants., Conclusions: Bariatric surgery reduces the reward system response to sweet taste in women with obesity without affecting activity in sensory regions, which is consistent with reduced drive to consume sweet foods., (© 2024 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.)

Objective: Saliva serves multiple important functions crucial for maintaining a healthy oral and systemic environment. Among them, the pH buffering effect, which is primarily mediated by bicarbonate ions, helps maintain oral homeostasis by neutralizing acidity from ingested foods. Therefore, higher buffering capacity, reflecting the ability to neutralize oral acidity, may influence taste sensitivity, especially for sour taste since it involves sensing H + ions. This study aims to explore the relationship between salivary buffering capacity and taste sensitivities to the five basic tastes in healthy adult humans., Design: Eighty seven healthy adult students participated in this study. Resting saliva volume was measured using the spitting method. The liquid colorimetric test was used to assess salivary buffering capacity. The whole-mouth taste testing method was employed to determine the recognition threshold for each tastant (NaCl, sucrose, citric acid, quinine-HCl, monosodium glutamate)., Results: Taste recognition thresholds for sour taste as well as sweet, salty, and bitter tastes showed no correlation with salivary buffering capacity. Interestingly, a negative relationship was observed between recognition threshold for umami taste and salivary buffering capacity. Furthermore, a positive correlation between salivary buffering capacity and resting saliva volume was observed., Conclusions: Salivary buffering capacity primarily influences sensitivity to umami taste, but not sour and other tastes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The sense of taste arises from the detection of chemicals in food by taste buds, the peripheral cellular detectors for taste. Although numerous studies have extensively investigated taste buds, research on neural circuits from primary taste neurons innervating taste buds to the central nervous system has only recently begun owing to recent advancements in neuroscience research tools. This minireview focuses primarily on recent reports utilizing advanced neurogenetic tools across relevant brain regions., Competing Interests: Declaration of Competing Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Prevention and treatment protocols for taste changes observed during hematopoietic cell transplantation (HCT) are not well-established. The purpose of this study was to assess the efficacy of photobiomodulation (PBM) in relieving taste changes and preventing lingual papillae atrophy. HCT patients received PBM (n = 42) on the tongue dorsum using an InGaAIP laser (660 nm, 100 mW, 1.1 W/cm 2 , 8.8 J/cm 2 ). During the HCT conditioning (T0), severe neutropenia (T1), and after neutrophil engraftment (T2), taste acuity for sweet, bitter, sour, and salty solutions, and clinical appearance of lingual papillae were compared with those of a placebo group (n = 43). PBM significantly reduced hypogeusia, ageusia, and parageusia at T1 and T2, and also successfully prevented papillae atrophy during all the analyzed HCT periods. In conclusion, PBM enhanced taste acuity during HCT. The decrease in papillae atrophy indicated a potential regenerative effect of this therapy on tongue mucosa., (© 2024 Wiley‐VCH GmbH.)

This study endeavored to high-throughput identify umami peptides from pork bone. Pork bone protein extracts were hydrolyzed using proteinase K and papain, enzymes selected through computational proteolysis of pork type I collagen under the controlled conditions predicted by umami intensity-guided response surface analysis. Peptide sequences (GVNAMLRK, HWDRSNWF, PGRGCPGN, NLRDNYRF, PGWETYRK, GPGCKAGL, VAQWRKCL, GPTAANRM) in hydrolysates were virtually screened as potential umami peptides. Sensory evaluation confirmed that six of these peptides demonstrate a progressive increase in umami intensity. Molecular docking revealed that hydrophilic amino acids in umami peptides predominantly formed hydrogen bonds with T1R1/T1R3. Specifically, residues Thr, Asn, Lys, Ser and Glu of peptides mainly interacted with Ser107/148/276 of T1R1, and residues Tyr, Arg and Asp played crucial roles in binding to the Ser104/146 and His145 of T1R3. This study offers insights into the high-value utilization of pork bones and guides the development of umami peptides in various food proteins.

Understanding neural pathways and cognitive processes involved in the transformation of dietary fats into sensory experiences has profound implications for nutritional well-being. This study presents an efficient approach to comprehending the neural perception of fat taste using electroencephalogram (EEG). Through the examination of neural responses to different types of fatty acids (FAs) in 45 participants, we discerned distinct neural activation patterns associated with saturated versus unsaturated fatty acids. The spectrum analysis of averaged EEG signals revealed notable variations in δ and α-frequency bands across FA types. The topographical distribution and source localization results suggested that the brain encodes fat taste with specific activation timings in primary and secondary gustatory cortices. Saturated FAs elicited higher activation in cortical associated with emotion and reward processing. This electrophysiological evidence enhances our understanding of fundamental mechanisms behind fat perception, which is helpful for guiding strategies to manage hedonic eating and promote balanced fat consumption., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Prior studies have extensively examined modality-general representation of affect across various sensory modalities, particularly focusing on auditory and visual stimuli. However, little research has explored the modality-general representation of affect between gustatory and other sensory modalities. This study aimed to investigate whether the affective responses induced by tastes and musical pieces could be predicted within and across modalities. For each modality, eight stimuli were chosen based on four basic taste conditions (sweet, bitter, sour, and salty). Participants rated their responses to each stimulus using both taste and emotion scales. The multivariate analyses including multidimensional scaling and classification analysis were performed. The findings revealed that auditory and gustatory stimuli in the sweet category were associated with positive valence, whereas those from the other taste categories were linked to negative valence. Additionally, auditory and gustatory stimuli in sour taste category were linked to high arousal, whereas stimuli in bitter taste category were associated with low arousal. This study revealed the potential mapping of gustatory and auditory stimuli onto core affect space in everyday experiences. Moreover, it demonstrated that emotions evoked by taste and music could be predicted across modalities, supporting modality-general representation of affect., (Copyright © 2023. Published by Elsevier B.V.)

Chaya (Cnidoscolus chayamansa) leaves are known for their strong umami taste and widespread use as a dried seasoning. This study aimed to assess the impact of different drying methods [freeze drying (FD), vacuum drying, oven drying at 50 °C and 120 °C (OD120) and pan roasting (PR)] on the metabolome using mass spectrometry, umami intensity, and antioxidant properties of chaya leaves. The predominant volatile compound among all samples, 3-methylbutanal, exhibited the highest relative odor activity value (rOAV), imparting a malt-like odor, while hexanal (green grass-like odor) and 2-methylbutanal (coffee-like odor) are the second highest rOAV in the FD and PR samples, respectively. OD120 and PR samples possessed the highest levels of umami-tasting amino acids and 5'-ribonucleotides as well as the most intense umami taste, whereas FD samples exhibited the highest antioxidant capacity. These findings enhance our understanding of the aroma characteristics, umami taste, and antioxidant potential of processed chaya leaves., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aims: Taste modifies eating behaviour, impacting body weight and potentially obesity development. The Obese Taste Bud (OTB) Study is a prospective cohort study launched in 2020 at the University of Leipzig Obesity Centre in cooperation with the HI-MAG Institute. OTB will test the hypothesis that taste cell homeostasis and taste perception are linked to obesity. Here, we provide the study design, data collection process and baseline characteristics., Materials and Methods: Participants presenting overweight, obesity or normal weight undergo taste and smell tests, anthropometric, and taste bud density (TBD) assessment on Day 1. Information on physical and mental health, eating behaviour, physical activity, and dental hygiene are obtained, while biomaterial (saliva, tongue swap, blood) is collected in the fasted state. Further blood samples are taken during a glucose tolerance test. A stool sample is collected at home prior to Day 2, on which a taste bud biopsy follows dental examination. A subsample undergoes functional magnetic resonance imaging while exposed to eating-related cognitive tasks. Follow-up investigations after conventional weight loss interventions and bariatric surgery will be included., Results: Initial results show that glycated haemoglobin levels and age are negatively associated with TBD, while an unfavourable metabolic profile, current dieting, and vegan diet are related to taste perception. Olfactory function negatively correlates with age and high-density lipoprotein cholesterol., Conclusion: Initial findings suggest that metabolic alterations are relevant for taste and smell function and TBD. By combining omics data from collected biomaterial with physiological, metabolic and psychological data related to taste perception and eating behaviour, the OTB study aims to strengthen our understanding of taste perception in obesity., (© 2024 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)

Background: Bitter taste receptors (Tas2rs) are generally considered to sense various bitter compounds to escape the intake of toxic substances. Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo., Methods: To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues, multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique. A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes. Then, T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds. Perception to taste substance was also studied using two-bottle preference tests., Results: We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique. Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice. But qRT-PCR results revealed the changed expression profile of mTas2rs gene in taste buds of these mutant mice. With two-bottle preference tests, these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105. In addition, these mutant mice showed a loss of taste perception to quinine dihydrochloride, denatonium benzoate, and cucurbitacin B (CuB). Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception., Conclusions: These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues., (© 2023 The Author(s). Animal Models and Experimental Medicine published by John Wiley & Sons Australia, Ltd on behalf of The Chinese Association for Laboratory Animal Sciences.)