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Journal of Agricultural and Food... Sep 2021Red wine is rich in phenolic compounds, which chiefly determine its characteristic taste. One of its major phenolic acid constituents for which an astringency, yet no...
Red wine is rich in phenolic compounds, which chiefly determine its characteristic taste. One of its major phenolic acid constituents for which an astringency, yet no clear contribution to bitter taste has been reported, is gallic acid (GA). In previous studies, we have demonstrated bitter-tasting constituents to regulate cellular proton secretion (PS) as a key mechanism of gastric acid secretion via activation of bitter taste sensing receptors (TAS2Rs). Here, we hypothesized a contributing role of GA to the red wine-stimulated effect on PS in human gastric tumor cells (HGT-1 cells). Sensory analyses revealed that 10 μM GA as the lowest concentration tested more bitter than tap water, with increasing bitter ratings up to 1000 μM. In HGT-1 cells, the concentration of 10 μM GA evoked the most pronounced effect on PS secretion, either when added to cells as in-water solution or when spiked to a red wine matrix. GA-spiking of Zweigelt and Blaufränkisch red wine samples up to a concentration of 10 μM resulted in an equally stimulated PS, whereas the non-GA-spiked wine samples demonstrated contrary effects on PS, indicating a functional role of GA on PS. Involvement of TAS2R4 in the GA-induced PS was verified by means of an HGT-1 homozygote CRISPR-Cas9 TAS2R4 knockout approach. Moreover, gene expression analyses revealed GA to increase . These results demonstrate a functional role of TAS2R4 in GA-evoked PS as a key mechanism of gastric acid secretion aiding digestion. Moreover, our data provide mechanistic insights, which will help to produce stomach-friendly red wines.
Topics: Astringents; Digestion; Gallic Acid; Gastric Acid; Humans; Taste; Wine
PubMed: 34460245
DOI: 10.1021/acs.jafc.1c03061 -
Current Biology : CB Oct 2012In most cultures, people ingest a variety of astringent foods and beverages during meals, but the reasons for this practice are unclear. Many popular beliefs and...
In most cultures, people ingest a variety of astringent foods and beverages during meals, but the reasons for this practice are unclear. Many popular beliefs and heuristics, such as high tannin wines should be balanced with fatty foods, for example 'red wine with red meat', suggest that astringents such as pickles, sorbets, wines, and teas 'cleanse' the palate while eating. Oral astringents elicit 'dry, rough' sensations [1], in part, by breaking down mucinous lubricating proteins in saliva [2,3]. The introduction of oral lubricants, including fats, partially diminishes strong astringent sensations [4,5]. Thus, it appears that astringency and fattiness can oppose each other perceptually on an oral rheological spectrum. Most teas, wines, and 'palate cleansers', however, are only mildly astringent and an explanation of how they could oppose the fattiness of meals is lacking. Here, we demonstrate that weakly astringent stimuli can elicit strong sensations after repeated sampling. Astringency builds with exposures [6] to an asymptotic level determined by the structure and concentration of the compound. We also establish that multiple sips of a mild astringent solution, similar to a wine or tea, decrease oral fat sensations elicited by fatty food consumption when astringent and fatty stimuli alternate, mimicking the patterning that occurs during a real meal. Consequently, we reveal a principle underlying the international practice of 'palate cleansing'. Repeatedly alternating samples of astringent beverages with fatty foods yielded ratings of fattiness and astringency that were lower than if rinsing with water or if presented alone without alternation.
Topics: Adult; Alum Compounds; Astringents; Catechin; Drinking Water; Female; Food; Grape Seed Extract; Humans; Male; Meat Products; Nontherapeutic Human Experimentation; Taste; Taste Perception; Tea
PubMed: 23058798
DOI: 10.1016/j.cub.2012.08.017 -
Angewandte Chemie (International Ed. in... May 2016Herein, we systematically investigate the origin of astringent mouthfeel when we eat unripe fruits, drink coffee or tea, from the perspective of lubrication by...
Herein, we systematically investigate the origin of astringent mouthfeel when we eat unripe fruits, drink coffee or tea, from the perspective of lubrication by simulating the dynamic weak interaction on the tongue with model protein (mucoprotein, MP) and polyphenolic compounds (tannic acid, TA). Astringency was due to the protein-mediated lubrication failure when encountering polyphenolic molecules that normally exist, for example in unripe fruits, coffee, tea. The underlying molecular mechanism of oral tribology is widely present in nature and enables us to engineer a tongue-like polyacrylamide composite hydrogel that exhibits high TA sensitivity and to develop a scientific strategy for catching slippery fish using TA-containing gloves. These results provide novel and useful insights into the failure of biological boundary lubrication on soft tissue surface with the adsorbed proteins.
Topics: Animals; Astringents; Fishes; Humans; Hydrogels; Hydrogen Bonding; Hydrophobic and Hydrophilic Interactions; Microscopy, Atomic Force; Mucoproteins; Polyphenols; Tannins
PubMed: 27059282
DOI: 10.1002/anie.201601667 -
The International Journal of... 2019To investigate whether hemostatic agents have any detrimental effects on polyether impressions and plaster casts after a clinically viable cleaning protocol.
PURPOSE
To investigate whether hemostatic agents have any detrimental effects on polyether impressions and plaster casts after a clinically viable cleaning protocol.
MATERIALS AND METHODS
A total of 60 human molar teeth were manually standardized, prepared, and subdivided into five groups (G): G0 (control/no contamination); G1 (ViscoStat Clear); G2 (ViscoStat); G3 (Astringedent); and G4 (Astringedent X). Each tooth was contaminated with a hemostatic agent for 3 minutes and cleaned with a 30-second air/water spray. Before and after contamination, an impression was taken and a plaster cast was poured. The impressions and plaster casts of all teeth were scanned using a light scanner. Data were matched using a three-dimensional analysis software that displayed color-coded maps. Means of the maximum positive/negative values and of the mean deviations in each group were calculated and compared. All color-coded maps were interpreted descriptively using the program's color scale, and all impressions and plaster casts were microscopically evaluated.
RESULTS
Values of mean deviations throughout all matched scans showed maximum values ranging from -30.1 to +17.5 μm. None of the groups showed significantly different deviation values or patterns when compared to each other. Impressions showed a thin, discontinuous coating for G2, G3, and G4; no changes were found for plaster casts.
CONCLUSION
Presented deviations showed the same values and distribution patterns within all groups. A cleaning protocol of 30 seconds of air/water spray is sufficient to remove hemostatic agents, preventing effects to polyether impressions and plaster casts. However, ferric sulfate-containing hemostatic agents left discontinuous coatings on impression surfaces.
Topics: Astringents; Casts, Surgical; Dental Impression Materials; Dental Impression Technique; Humans; Models, Dental
PubMed: 31034546
DOI: 10.11607/ijp.6148 -
Journal of Agricultural and Food... May 2021Fruits of nonastringent persimmon cultivars, as compared to astringent ones, were more resistant to infection despite having lower polyphenol content. Metabolic...
Fruits of nonastringent persimmon cultivars, as compared to astringent ones, were more resistant to infection despite having lower polyphenol content. Metabolic analysis from the pulp of nonastringent "Shinshu", as compared to the astringent "Triumph", revealed a higher concentration of salicylic, coumaric, quinic, 5--feruloyl quinic, ferulic acids, β-glucogallin, gallocatechin, catechin, and procyanidins. Selected compounds like salicylic, ferulic, and ρ-coumaric acids inhibited growth, and higher activity was demonstrated for methyl ferulic and methyl ρ-coumaric acids. These compounds also reduced growth and the black spot disease in stored fruits. On the other hand, methyl gallic acid was a predominant compound in the "Triumph" pulp, as compared to the "Shinshu" pulp, and it augmented growth and . Our results might explain the high sensitivity of the cultivar "Triumph" to . It also emphasizes that specific phenolic compounds, and not the total phenol, affect susceptibility to fungal infection.
Topics: Alternaria; Astringents; Diospyros; Fruit; Polyphenols
PubMed: 33983017
DOI: 10.1021/acs.jafc.1c01312 -
Journal of the Irish Dental Association Dec 2015
Topics: Astringents; Gingiva; Gingival Retraction Techniques; Hemostatics; Humans; Time Factors; Tooth Preparation; Vasoconstrictor Agents
PubMed: 26902073
DOI: No ID Found -
Journal of Dentistry Aug 2017This electron microscopic study aimed at investigating effects of oral astringent stimuli on the enamel pellicle's morphology.
OBJECTIVES
This electron microscopic study aimed at investigating effects of oral astringent stimuli on the enamel pellicle's morphology.
METHODS
Pellicles were formed in situ within 30min on bovine enamel slabs, fixed to individuals' upper jaw splints. The pellicle-coated specimens were immersed in vitro in seven diverse astringent solutions and subsequently analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, as well as transmission electron microscopy (TEM). Four biocompatible astringents, namely the polyphenol epigallocatechin gallate, the metal salt iron(III) sulfate, the basic protein lysozyme, and the aminopolysaccharide chitosan, were additionally applied in situ. After rinsing the oral cavity with these compounds, the pellicle's ultrastructure was imaged by SEM and TEM, respectively. Untreated pellicle samples served as controls.
RESULTS
Exposure to polyphenols and lysozyme induced particularly thicker and electron-denser pellicles in comparison to the control pellicle with similar characteristics in vitro and in situ. In contrast, acidic chitosan and metal salt solutions, respectively, revealed minor pellicle alterations. The incorporation of Fe and Al into the pellicles treated with the corresponding inorganic salts was verified by EDX analysis.
CONCLUSIONS
Astringent-induced pellicle modifications were for the first time visualized by TEM. The ultrastructural alterations of the dental pellicle may partly explain the tooth-roughening effect caused by oral astringent stimuli.
CLINICAL SIGNIFICANCE
Astringents might modify the pellicle's protective properties against dental erosion, attrition, as well as bacterial adhesion, and by this means may influence tooth health. The findings may thus be particularly relevant for preventive dentistry.
Topics: Adult; Aluminum Chloride; Aluminum Compounds; Animals; Astringents; Bacterial Adhesion; Catechin; Cattle; Chitosan; Chlorides; Dental Enamel; Dental Pellicle; Ferric Compounds; Humans; Materials Testing; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Mouth; Muramidase; Polyphenols; Preventive Dentistry; Salivary Proteins and Peptides; Spectrometry, X-Ray Emission; Surface Properties; Time Factors; Tooth Attrition; Tooth Erosion
PubMed: 28619693
DOI: 10.1016/j.jdent.2017.05.011 -
Food Chemistry Jan 2022Hydroxycinnamoyl quinic acids are important phenolic acids in tea, particularly fermented teas. However, there have been fewer studies that have confirmed their taste...
Identification of 4-O-p-coumaroylquinic acid as astringent compound of Keemun black tea by efficient integrated approaches of mass spectrometry, turbidity analysis and sensory evaluation.
Hydroxycinnamoyl quinic acids are important phenolic acids in tea, particularly fermented teas. However, there have been fewer studies that have confirmed their taste properties. The aim of this study was to investigate the astringent compounds in Keemun congou black tea (KBT) using a combination of mass spectrometry, turbidity analysis, and sensory evaluation. Turbidity analysis determined that p-coumaroylquinic acids were the astringent contributing compounds in KBT. Moreover, the separated compound D16 was identified as trans-4-O-p-coumaroylquinic acid (trans-4-O-pCoQA) by nuclear magnetic resonance spectroscopy and first confirmed to be the astringent contributing compound in KBT by sensory evaluation. Its astringent threshold concentration was tested to be 38 µM. The trans-4-O-pCoQA content in eight KBT samples of various grades ranged from 40.20 ± 0.15 ~ 65.53 ± 0.22 µM. Turbidity analysis combined with sensory evaluation could be a powerful tool for identifying critical compounds responsible for the astringent taste.
Topics: Astringents; Camellia sinensis; Mass Spectrometry; Taste; Tea
PubMed: 34403995
DOI: 10.1016/j.foodchem.2021.130803 -
Brain Research Nov 1992Astringent tastes are generally considered those that induce long-lasting puckering and drying sensations on the tongue and membranes of the oral cavity....
Astringent tastes are generally considered those that induce long-lasting puckering and drying sensations on the tongue and membranes of the oral cavity. Electrophysiological recordings were made here from the whole chorda tympani nerve in gerbil to understand the interactive effect of astringent-tasting molecules with a broad spectrum of tastants including mono- and divalent salts, bitter compounds, acids, and sweeteners. The astringent tasting compounds were tannic acid (24 mM at pH's 2.9 and 5.5), aluminum ammonium sulfate (30 mM), aluminum potassium sulfate (10 mM) and gallic acid (30 mM). Hydrochloric acid (1 mM, pH 2.9) was also tested to control for acidity, since aqueous solutions of astringent-tasting compounds are acidic. Adaptation of the tongue to tannic acid (24 mM) at both pH 2.9 and 5.5 markedly inhibited responses elicited by salts, acids, sweeteners, and bitter-tasting compounds. The degree of the inhibition at these two pH values is about the same which suggests that tannic acid itself (as opposed to acidity) may produce this inhibition. Chorda tympani responses to sweeteners were completely suppressed by tannic acid; responses to KCl, NH4Cl, and urea were the least suppressed. The aluminum salts also inhibited the chorda tympani responses to all stimuli tested. Gallic acid, which is weakly astringent, had minimal effects on the chorda tympani responses to the test compounds. These data suggest that both tannic acid and the aluminum salts inhibit a variety of transport pathways and receptors in taste cells for a broad spectrum of tastants. The inhibition of some of these pathways may contribute to the astringent taste sensation.
Topics: Aluminum; Animals; Astringents; Chorda Tympani Nerve; Electrophysiology; Female; Gallic Acid; Gerbillinae; Hydrolyzable Tannins; Taste
PubMed: 1467944
DOI: 10.1016/0006-8993(92)91445-k -
Indian Journal of Dental Research :... 2019Conventional complete dentures still remain a viable method of treatment for many patients in this era of fixed prosthesis like dental implants. All patients undergoing...
CONTEXT
Conventional complete dentures still remain a viable method of treatment for many patients in this era of fixed prosthesis like dental implants. All patients undergoing complete denture treatment need nonsurgical preprosthetic treatment for the preparation of healthy denture bearing mucosa as well-keratinized healthy mucosa is desirable for a complete denture.
AIMS
To evaluate and compare the keratinization before and after denture insertion at intervals of 1 week and 1 month.
SETTINGS AND DESIGN
The present study was conducted on 24 completely edentulous male subjects divided into control and study groups. Each patient in study group was asked to massage with astringent on the denture bearing mucosa over a 4-week period.
SUBJECTS AND METHODS
Exfoliative cytology was used to collect the surface cells from the palatal mucosa and buccal mucosa. The first smear was taken before the denture insertion. The second and third smears were taken after the stimulation treatment with astringent gel for each patient after 1 week and after 4 weeks. Each smear was stained with the Papanicolaou's technique. The number of basal cells, intermediate cells, and superficial cells were recorded to calculate the degree of keratinization.
STATISTICAL ANALYSIS USED
Descriptive statistics, paired samples t-test, independent t-test, and repeated-measures analysis of variance.
RESULTS
The result showed statistically significant increase in the keratinization of palatal mucosa after 4 weeks of astringent therapy and no effect was noted in the keratinization of buccal mucosa.
CONCLUSIONS
Astringent has shown to increase keratinization of palatal mucosa, and so it can be used to increase the quality of the denture bearing mucosa; moreover, the astringent stimulation has no effect on the keratinization of buccal mucosa.
Topics: Astringents; Denture, Complete; Humans; Keratins; Male; Mouth Mucosa; Palate
PubMed: 31397406
DOI: 10.4103/ijdr.IJDR_620_17