Search Results (109)

Background/Objectives: Taste perception has emerged as a key determinant of eating behavior and metabolic regulation, but its relationship with body mass index (BMI) remains incompletely understood. We investigated the relationships among global, sweet, and lipid taste sensitivity; sweet- and lipid-taste-related polymorphisms; caloric intake; and BMI. Methods: Taste sensitivity was assessed using taste strips (overall and sweet) and detection thresholds for fatty acids (oleic, linoleic, and palmitic acids). Genotyping of polymorphism genes was conducted. Pearson correlation analyses examined bivariate associations between taste variables and BMI. Multiple regression models were performed to identify independent predictors of BMI and to evaluate the mediating role of caloric intake. Results: A strong inverse correlation was found between total and sweet taste sensitivity and BMI, particularly in super-tasters (STs) and participants with the sensitive genotype of sweet-taste-related polymorphisms. Similarly, greater sensitivity to fatty acids was associated with lower BMI, specifically in non-tasters (NTs) and participants with the insensitive genotype of CD36 polymorphisms. In multiple regression models, overall and lipid sensitivity were the most significant predictors of BMI, which were inversely associated with it. TAS1R2 and TAS1R3 also showed independent effects. Importantly, caloric intake was not retained in the final model. Conclusions: Taste sensitivity is inversely associated with BMI independently of caloric intake. These findings suggest that the gustatory system could influence body weight through mechanisms beyond energy consumption, probably involving food choice and extra-oral receptor-mediated metabolic regulation. Taste perception and related genetic factors may represent important targets for personalized nutrition and obesity prevention strategies. Full article

Excessive fructose consumption is associated with metabolic syndrome (MS). This study evaluated the effect of two coffee by-products, coffee pulp (CP) and coffee silverskin (SK), on fructose-induced intestinal changes. Sprague–Dawley rats were assigned to six groups (n = 6/group) for 10 weeks: Control, Fructose (FRU; 20% fructose in drinking water), CP, CP + FRU, SK, and SK + FRU. CP and SK were administered by oral gavage (250 mg/kg/day) using corn oil as vehicle. Intestinal morphology, gene expression (RT-qPCR), and gut microbiota composition (16S rRNA sequencing) were assessed. Fructose significantly increased jejunal expression of the glucose transporters SGLT1 and GLUT2. CP and SK reversed SGLT1 and GLUT2 overexpression and reduced GLUT5 expression relative to the FRU group. Fructose also markedly increased expression of sweet taste receptors TAS1R2 and TAS1R3 and the transcription factors SREBP-1c and ChREBP. Both CP and SK normalized TAS1R2 and TAS1R3 expression, whereas SK additionally prevented SREBP-1c and ChREBP overexpression. Both by-products restored fructose-induced reductions in microbial richness and alpha diversity. CP also modified beta diversity and increased the abundance of the genus Blautia compared with FRU. In conclusion, CP and SK reversed several fructose-induced intestinal alterations, namely in the jejunal expression of sugar-sensing and absorption-related genes. Additionally, CP showed microbiota-modulating effects, whereas SK modulated the jejunal expression of key transcription factors (SREBP-1c and ChREBP) involved in carbohydrate and lipid metabolism. Overall, these findings suggest that CP and SK may represent promising candidates for mitigating fructose-induced intestinal alterations. Full article

The liver, a by-product of livestock processing, is abundant in protein and serves as an excellent precursor for bioactive and taste-active peptides. However, comprehensive reviews on its valorization remain limited. This review summarizes recent advances in utilizing liver as a source of bioactive peptides (BPs) and taste-active peptides (TAPs). It systematically outlines the composition of liver and preparation methods of liver-derived peptides, discusses the diverse bioactivities of peptides from livestock liver and its taste characteristics, and also examines current challenges along with future perspectives. Liver-derived peptides possess various bioactivities, such as antioxidant, anti-inflammatory, antihypertensive, and metabolism-regulatory activities. Meanwhile, they can elicit the umami, sweet, and bitter taste primarily through different taste transduction receptors. The bioactive and taste properties of peptides are closely related to molecular weight, hydrophobicity, and composition of peptides. Furthermore, ultrasound treatment and the Maillard reaction are effective methods for improving the taste characteristics of liver-derived peptides. However, current research on liver-derived peptides remains limited by inefficient screening and prediction of BPs, low bioavailability, and a narrow focus on TAPs. Overall, this review provides a theoretical reference for high-value utilization of liver-derived peptides from livestock by-products. Full article

Glycyrrhizic acid (GA), a high-potency natural sweetener derived from licorice, has long been limited in alcoholic beverages due to its characteristic lingering sweetness in both aqueous and ethanol matrices. From an industrial perspective, licorice extract offers superior economic viability and processing efficiency compared to high-purity monomers. To clarify the sensory behaviour of licorice extract in formulated spirits, this study characterized the sensory attributes of licorice extract (containing 23.75% GA) in 42% and 52% vol base spirits. Quantitative results showed that the detection thresholds, recognition thresholds, and upper limits of comfort were 2.23, 15.45, and 75.13 mg/L in the 42% vol base spirit, and 5.28, 25.64, and 72.98 mg/L in the 52% vol base spirit, respectively. Suitable addition levels were identified as 30 mg/L for 42% vol and 40 mg/L for 52% vol base spirits. The relative sweetness of GA was determined to be 175.83 times that of sucrose. Sucrose showed a sweetness duration of 10 to 12 s, whereas licorice extract exceeded 16 s. Puerarin showed the strongest effect in mitigating lingering sweetness, reducing the sweetness duration to values comparable to those of sucrose at 50 mg/L in the water system and 30 mg/L in the 10% vol edible alcohol system. Molecular docking suggested that puerarin may interact more favourably with the sweet taste receptor than GA, with a binding energy of −52.72 kJ/mol, and may weaken the predicted GA–receptor interaction, as reflected by the shift in GA binding energy from −41.00 to −21.30 kJ/mol. Overall, this study provides sensory parameters specific to different ethanol matrices for applying licorice extract in formulated spirits and offers a plausible receptor-level explanation, supported by molecular docking, for the ability of puerarin to mitigate GA-induced lingering sweetness, thereby supporting the development of formulated spirits with reduced sugar content. Full article

Buds are continuously renewed sensory organs in which development, adult maintenance, and repair share overlapping molecular circuitry. During embryogenesis, WNT/β-catenin signaling promotes taste placode formation and placodal Shh expression, while SHH refines papilla spacing and restricts neighboring papilla formation. SOX2 functions as a taste-competence and progenitor maintenance factor. In adults, LGR5/LGR6–RSPO–WNT signaling sustains progenitor activity, and gustatory neurons are an important source of RSPO2; available genetic evidence is consistent with a neuron-derived contribution to the LGR5/LGR6 niche, and AAV-Cre-mediated neuron-specific ablation of Rspo2 in the petrosal ganglion led to near-complete loss of circumvallate taste buds. HH signaling from epithelial and neuronal sources further supports SOX2-dependent progenitor homeostasis. Lineage allocation is governed by transcriptional programs that include POU2F3/SKN-1a for sweet, umami, and bitter type II taste receptor cells, and ASCL1 with posterior-field NKX2-2 for type III presynaptic/sour cells. After denervation or irradiation, regeneration depends primarily on LGR5⁺/KRT14⁺ progenitors and may be supplemented, in specific injury contexts, by plasticity of a subset of K8-lineage taste receptor cells that acquire KRT14/SOX2/PCNA progenitor-like features. Key unresolved questions include the direct chromatin targets of taste lineage regulators (which remain to be defined by ChIP-seq in native taste progenitors), the identity of the type I cell selector, the contribution of dedifferentiation across injury models, and the degree to which mouse-derived networks are conserved in human taste biology. Full article

Background: Instant Cascara (IC) beverages, derived from dried coffee cherry pulp, represent an upcycled plant-based ingredient rich in phenolic compounds and methylxanthines. Although spray-drying enables the production of soluble cascara powders without carriers, previous sensory evaluation highlighted limitations in palatability, supporting the need for formulation strategies. Objective: To evaluate how the incorporation of inulin-type carriers with different degrees of polymerization modulates production yield, the apparent recovery of bioactive compounds, and formulation-dependent in vitro biological and receptor-level responses of Instant Cascara beverages. Methods: Formulations without carrier (IC 0.0) and with long-chain inulin (IC 1.0) or oligofructose-enriched inulin (IC 2.0) were prepared and characterized. Production yield, phytochemical composition, and in vitro antioxidant, anti-inflammatory, antiproliferative, and receptor-mediated responses were assessed using analytical tools, cell-based assays, and receptor-based platforms. Results: Carrier incorporation improved production yield, particularly for IC 1.0. Although differences in apparent recovery of bioactive compounds were observed, all formulations preserved relevant in vitro biological activities. IC 2.0 showed stronger nitric oxide inhibition and apoptosis induction in colorectal cancer cell models. Receptor-based assays revealed formulation-dependent differences, including reduced activation of bitter taste receptors (TAS2Rs), absence of sweet receptor (TAS1R2/TAS1R3) activation, and modulation of muscarinic (M3) and dopaminergic (D3/D4) receptor responses. These effects are consistent with variations in the composition and effective concentration of bioactive compounds between formulations, particularly caffeine. Conclusions: The incorporation of inulin-type carriers influences production yield and modulates in vitro biological responses and receptor-level responses of Instant Cascara beverages. IC 2.0 represents a formulation with a favorable balance between technological performance and functional responses, associated with a distinct receptor-level profile. This balance may be related to a reduced contribution of bitterness-associated compounds, such as caffeine, together with the preservation of other bioactive components contributing to the observed biological responses. These findings provide a mechanistic in vitro basis for future sensory and in vivo studies evaluating how formulation-dependent differences in bioactive composition may influence physiological responses and consumer perception. Full article

Excessive sugar intake remains a major health challenge, motivating the development of safe and effective alternatives. Thaumatin, a natural high-intensity sweet protein, elicits sweetness through activation of the sweet taste receptor (T1R2/T1R3), yet its molecular recognition mechanism remains understudied. An integrated computational strategy combining comparative modeling, protein–protein docking, and 500 ns molecular dynamics simulations (triplicates) was employed to elucidate the thaumatin–receptor binding. Structural modeling identified the closed conformation of the Venus flytrap domain (VFT) as optimal for ligand engagement. Modeling revealed a stable binding interface characterized by electrostatic complementarity and van der Waals interactions, characterized by interfacial contacts of receptors and hydrogen bonding networks. Residue-level energy decomposition highlighted key residues (W418 and E422 of T1R2; S59 of T1R3) and thaumatin residues (K67, R82, and K137) that contribute substantially to complex stabilization, consistent with experimentally reported sweetness determinants. These findings provide molecular-level insight into sweet protein recognition and establish a structural framework for rational engineering of protein-based sweeteners with enhanced potency and selectivity. Full article

Background/Objectives: Individual differences in sweet taste sensitivity, influenced by genetic factors such as variants of the taste receptor type 1 member 2 (TAS1R2), are associated with food preferences and nutrient intake. However, the relationship between TAS1R2 polymorphisms and diet quality in Koreans remains unexplored. This study investigated the association between the TAS1R2 rs35874116 (T>C, Ile191Val) variant and diet quality, assessed using the Korean Healthy Eating Index (KHEI). Methods: Analyzing data from the Korean Genome and Epidemiology Study, we evaluated the dietary quality of 41,669 Koreans based on KHEI scores and TAS1R2 rs35874116 genotypes (TT versus CT+CC). Results: The findings indicate that genetic variation in the sweet taste receptor is linked to specific components of dietary quality. Although total KHEI scores did not differ between genotypes, TT genotype carriers had significantly higher vegetable intake scores compared to C allele carriers (3.42 ± 1.35 vs. 3.37 ± 1.36, p_adjusted = 0.002). Additionally, TT carriers exhibited higher sodium intake (6.85 ± 3.53 vs. 6.95 ± 3.51, p_adjusted = 0.002) and lower scores in the moderation domain (18.82 ± 5.15 vs. 18.98 ± 5.07, p_adjusted = 0.002). Conclusions: The TAS1R2 rs35874116 variant is associated with specific aspects of diet quality in Koreans, particularly vegetable and sodium intake. These findings suggest that genetic variations in sweet taste perception influence dietary behaviors among Koreans. Full article

Background/Objectives: Sweeteners and sweetness enhancers (S&SEs) have been proposed to potentially impair appetite regulation by stimulating sweet taste receptors beyond the perception of sweetness, similar to caloric sweeteners. The evidence is, however, not clear. Methods: This sub-study investigated the acute effects of a mixture of acesulfame potassium and cyclamate (Ace-K/Cyc) versus water on postprandial appetite sensations and energy intake at baseline, after a two-month weight loss period, and after a four-month weight loss maintenance period, including (S&SE group) or excluding S&SEs (Sugar group) in the diet. A total of 26 participants (18–65 years; BMI ≥ 25.0 kg/m²) were recruited from the one-year randomized controlled SWEET trial. Subjective appetite sensations were measured using visual analogue scales while fasting and nine times during a 250-min postprandial period. During this period, a standardized breakfast (0–10 min) was served and, 2 h later, a test drink containing either Ace-K/Cyc or water (120–130 min) was given. After 265 min, an ad libitum test meal was served. Results: Of 26 participants enrolled, 22 completed test day 2 and 16 completed test day 3. The S&SEs group rated lower prospective consumption and desire to eat something sweet after the test drink with Ace-K/Cyc compared to the sugar group consuming water (p < 0.05), with effects persisting after adjusting for taste. Initial differences in hunger were explained by taste palatability. This was true for all three test days. Ad libitum energy intake did not differ (p > 0.05). Conclusions: Ace-K/Cyc compared to water reduced feelings of prospective consumption and desire to eat something sweet acutely, after two months of weight loss, and after four months of weight loss maintenance. Due to the low sample size and power, larger studies are warranted to confirm these results. Full article

Type 2 diabetes (T2D) is a major global healthcare challenge and burden on the quality of life in affected individuals. While lifestyle management is the mainstay treatment for T2D, the advent of gut-incretin-based therapies with powerful effects on metabolic health, appetite and weight regulation has focussed attention on the role of the gut in the risk, progression and management of T2D. Beyond the tongue, intestinal sweet taste receptors (STRs) are increasingly being identified and functionally characterised. Growing evidence now supports a role for nutrient-activated (e.g., sugars) intestinal STRs in the release of gut hormones from enteroendocrine cells (EECs) and the control of blood glucose and body weight. However, the specific STR pathway and mechanisms linking STRs to these homeostatic controls are poorly understood, with a notable gap existing between evidence from preclinical studies and clinical validation. This review explores intestinal STR-EEC functions and the evidence on how these functions regulate glucose metabolism and energy homeostasis. We further discuss the impact of environmental and dietary factors on these signalling pathways. Full knowledge of the signalling and regulation of intestinal STR-EEC and integrated neural pathways will bridge the current knowledge gap, with a high potential to develop new novel strategies targeting STRs or EECs that preserve hedonic taste rewards and reduce cravings, as well as improve the management of individuals with metabolic diseases. Full article

Primary ciliary dyskinesia (PCD) is a congenital motile ciliopathy causing impaired mucociliary clearance and characterized by recurrent respiratory infections affecting both the upper and lower airways. Several genes involved in taste perception pathways are expressed in extraoral tissues and have recently emerged as regulators of airway immune responses. This study aimed to (1) analyze potential correlations between PCD clinical manifestations and (2) investigate whether genetic variants within sweet signaling genes (SweetG) could be associated with PCD features. A total of 17 SNPs in nine SweetG were tested for differences in allele frequency between patients and the gnomAD European reference population using a binomial test. Regression models were used to evaluate associations between SweetG-SNPs and clinical features of patients. A cohort of 34 patients (10–69 years, 44.1% male) was included in the study. Regarding (1), a moderate/high correlation was identified among the clinical manifestations of the pathologies. Regarding (2), the minor alleles of rs5415 (SLC2A4 gene) and rs838133 (FGF21 gene) were less frequent in patients than in the reference population (p < 0.05). In addition, rs5415 and rs838133 were associated with the presence of chronic rhinosinusitis and situs inversus, respectively (p < 0.05). This study reveals associations between SweetG-SNPs and PCD as well as its specific clinical features, suggesting a potential link between sweet signaling pathways and PCD clinical variability. Although larger multicenter studies are warranted to validate these findings, they represent a promising area of research that can enhance our understanding of PCD and elucidate the genetic basis of clinical manifestations associated with the disease. Full article

Sweet taste receptors (STRs) are class C G protein-coupled receptors (GPCRs) that function as heterodimers of TAS1R2 and TAS1R3. These receptors possess multiple binding sites and can be activated by a wide range of sweet-tasting compounds. Interestingly, TAS1R2 alone or even its extracellular domain-truncated form (TAS1R2-TMD), can act as a functional receptor. Previous studies demonstrated that the sweetener S819 and the sweet inhibitor amiloride act through the transmembrane domain (TMD) of TAS1R2; however, the molecular mechanisms underlying these ligand-specific effects remain unclear, largely due to the historical lack of experimentally determined full-length STR structures. Recent breakthroughs in cryo-EM structural determination of the full-length TAS1R2/TAS1R3 complex now offer an unprecedented opportunity to elucidate receptor activation mechanisms at atomic resolution. In this study, we investigated ligand-induced conformational dynamics of hTAS1R2-TMD using microsecond-scale molecular dynamics (MD) simulations on three systems: hTAS1R2-TMD/S819 (agonist-bound), hTAS1R2-TMD/amiloride (antagonist-bound), and hTAS1R2-TMD (apo). Comparative analyses revealed that agonist and antagonist binding distinctly modulate key structural switches, including the conserved ionic lock (E6.35-R3.50), which stabilizes the inactive state and disrupts upon activation. Notably, we identified a novel salt bridge (D7.32-R3.32) that forms preferentially in the active state, potentially serving as a unique molecular switch for TAS1R2. Additional analyses uncovered ligand-specific rearrangements in hydrogen-bonding and hydrophobic interaction networks. These results provide atomistic insights into how agonists and antagonists differentially modulate TAS1R2 activation and lay a structural foundation for designing novel sweeteners and taste modulators. Full article

Thermal processing is widely applied in food manufacturing to enhance flavor, but the mechanisms underlying taste transformation remain insufficiently understood. Rehmannia Radix, traditionally processed by steaming, undergoes a distinctive shift from bitterness to sweetness, serving as a representative model for flavor modulation during processing. In this study, sensory evaluation (n = 12), electronic tongue analysis, HPLC-based sugar and marker profiling across 17 batches, and molecular docking with representative human taste receptors were combined to investigate the mechanisms of taste transformation. The results showed that steaming markedly increased sweetness while reducing bitterness (p < 0.05). Chemical profiling revealed the hydrolysis of oligosaccharides into higher-sweetness monosaccharides (e.g., fructose (Fru) +15.99%, glucose (Glu) +8.90%) and substantial degradation of bitter iridoid glycosides (e.g., catalpol (Cat) −88%). In addition, the formation of 5-hydroxymethylfurfural (5-HMF) was identified as a processing marker. Molecular docking suggested that bitter glycosides in raw samples may interfere with sweet receptor activation and stimulate bitter receptors, whereas monosaccharide enrichment and Maillard products favored sweet receptor interactions, which may explain the observed sensory changes. Overall, these results clarify the chemical basis and receptor-level mechanisms of the bitterness-to-sweetness transition during steaming and identify markers useful for monitoring flavor changes in Rehmannia Radix. Full article

The rise in diabetes and obesity worldwide has created an urgent demand for low-sugar, nutrient-dense foods with appealing flavors. This study established an endogenous and “rapid validation–stable production” platform to enhance the flavor of edible tomato fruits by integrating two key technologies in the MicroTom cherry tomato: (1) TRV viral vector-mediated transient expression and (2) Agrobacterium-mediated stable genetic transformation. We employed the human sweet taste receptor TAS1R2 for in vitro functional validation and objectively demonstrated that tomato-derived recombinant thaumatin II exhibits receptor-binding activity equivalent to that of the native protein, overcoming the limitations of traditional sensory evaluation. Non-targeted metabolomic analysis (covering 1236 metabolites) confirmed that thaumatin II expression did not significantly alter the profiles of sugars, organic acids, or key flavor compounds in tomato fruits. This provides safety data supporting the development of “ready-to-eat sugar-substitute fruits.” Our strategy offers a solution and theoretical technical support for the development of low-sugar, high-nutrient foods. Full article

Background: Sweet taste adaptation, the decline in perceived sweetness with repeated exposure, may influence dietary behavior and differs across sweeteners. Low-calorie sweeteners (LCSs) such as sucralose strongly activate the T1R2+T1R3 receptor and are generally associated with greater adaptation than sugars, although this effect can be reduced with sweetener blends. Aim: We investigated whether habitual LCS consumption affects sweet taste perception and whether blending sucralose with small amounts of sugars attenuates adaptation using sensory tests in humans and in vivo calcium imaging in a rodent model. Methods: In study 1, habitual (HC; n = 39) and non-habitual (NHC; n = 42) LCS consumers rate sweetness of sucralose (0.6 mM), glucose (800 mM), fructose (475 mM), and blends with low glucose (111 mM) or fructose (45 mM) across repeated trials (1–10) using a generalized labeled magnitude scale. In study 2, a microfluidic-based intravital tongue imaging system was used to assess in vivo responses to sweet adaptation in genetically modified C57BL/6 mice (n = 8) expressing a calcium indicator in type II/III cells of taste buds. Results: Habitual LCS use was not associated with differences in sweetness perception or adaptation (all p-values > 0.6). Sucralose alone produced stronger adaptation than when blended with sugars in both humans (p-values < 0.002) and mice (p < 0.001). Glucose and fructose alone showed adaptation (relative decrease reached on final trial compared to the first trial: −27% ± 4% for glucose, −38% ± 5% for fructose, both p-values < 0.002) but to a lower degree compared with sucralose (−66% ± 5%). Conclusions: Sweetener composition, rather than habitual LCS use, drives sweet taste adaptation. Blending sucralose with small amounts of sugars reduces adaptation at both perceptual and cellular levels, providing mechanistic insights relevant to the formulation of LCS products. Full article