Journal articles: 'Bitter substances'

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WU, CHUNSHENG, LIPING DU, LIHUI MAO, and PING WANG. "A NOVEL BITTER DETECTION BIOSENSOR BASED ON LIGHT ADDRESSABLE POTENTIOMETRIC SENSOR." Journal of Innovative Optical Health Sciences 05, no. 02 (April 2012): 1250008. http://dx.doi.org/10.1142/s1793545812500083.

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This paper presents a novel biosensor for bitter substance detection on the basis of light addressable potentiometric sensor (LAPS). Taste receptor cells (TRCs) were used as sensitive elements, which can respond to different bitter stimuli with extreme high sensitivity and specificity. TRCs were isolated from the taste buds of rats and cultured on the surface of LAPS chip. Due to the unique advantages such as single-cell recording, light addressable capability, and noninvasiveness, LAPS chip was used as secondary transducer to monitor the responses of TRCs by recording extracelluar potential changes. The results indicate LAPS chip can effectively record the responses of TRCs to different bitter substances used in this study in a real-time manner for a long-term. In addition, by performing principal component analysis on the LAPS recording data, different bitter substances tested can be successfully discriminated. It is suggested this TRCs–LAPS hybrid biosensor could be a valuable tool for bitter substance detection. With further improvement and novel design, it has great potentials to be applied in both basic research and practical applications related to bitter taste detection.

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Kurihara, Kenzo, Yoshihisa Katsuragi, Ichiro Matsuoka, Makoto Kashiwayanagi, Takashi Kumazawa, and Takayuki Shoji. "Receptor mechanisms of bitter substances." Physiology & Behavior 56, no. 6 (December 1994): 1125–32. http://dx.doi.org/10.1016/0031-9384(94)90356-5.

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Protsenko, L., M. Liashenko, A. Vlasenko, T. Hryniuk, and O. Dobrovolny. "Investigation of properties of biologically active substances and their content in cones of ukrainian hop varieties." Agricultural Science and Practice 5, no. 2 (July 15, 2018): 52–63. http://dx.doi.org/10.15407/agrisp5.02.052.

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Introduction. According to the data of foreign studies, prenyl fl avonoids and bitter substances of hop have signifi cant antioxidant, antiviral, antimicrobial, anti-infl ammatory and anti-carcinogenic properties. Methods. A complex of the following methods was used: a monographic method, analysis, synthesis and comparison, mathematical-statistical and modern physical-chemical methods of determining qualitative indices of hop, special and common in hop-growing industry, which allowed obtaining scientifi cally valid results. Results. The modern level of knowledge about biologically active compounds of hop and their properties was analyzed, in particular, bitter substances and xanthohumol. The quantitative and qualitative content of bitter substances, essential oil and xanthohumol in hop varieties of Ukrainian, European and American breeding was studied. Among the Ukrainian varieties, the highest amount of xanthohumol was found in Ruslan and Xanthus varie- ties – 1.16 % and 1.06 % against dry substances respectively, and its minimal amount was detected in the cones of the bitter Alta variety. Among the European varieties, the highest amount of this substance is contained in the German variety HallertauerTaurus – 0.9–1.0 %, up to 1 % in the Czech variety Agnus and the English va- riety Admiral, with the content of 0.95 %–1.09 %. There is a strong correlation between the accumulation of xanthohumol and alpha acids in the formation and ripening of the cones. The maximal amount of xanthohumol is formed in the hop cones in the phase of complete technical ripeness. The content of this substance in hop cones depends on the breeding variety and is a varietal trait, genetically fi xed for each variety. The quantitative amount of xanthohumol may be one of biochemical criteria of identifying the variety. Conclusions. By their characteristics, the Ukrainian hop varieties correspond to the world’s analogues, namely, according to their bio- chemical and technological indices, hop varieties Klon-18 and Zlato Polissia correspond to the characteristics of the hop of the Czech Saaz variety, the biochemical indices of the bitter Alta variety correspond to the Ger- man variety Magnum, and such varieties as Slovianka and Zahrava exceed the world’s analogues considerably in the composition and quality of bitter substances and essential oils and are unique.

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TANIMURA, SHUYA, and RICHARD D. MATTES. "RELATIONSHIPS BETWEEN BITTER TASTE SENSITIVITY AND CONSUMPTION OF BITTER SUBSTANCES." Journal of Sensory Studies 8, no. 1 (March 1993): 31–41. http://dx.doi.org/10.1111/j.1745-459x.1993.tb00200.x.

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Liashenko, M., L. Protsenko, R. Rudyk, and O. Svirchevska. "Bitter Substances in the Hop Lupulin." Agricultural Science and Practice 1, no. 1 (April 15, 2014): 20–25. http://dx.doi.org/10.15407/agrisp1.01.020.

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Aim. To investigate the quantity and structure of α-, β-acids and xanthohumol in lupulin grains of different hop varieties that essentially differ in these biochemical indexes, and also the presence of the substances both in staminate racemes and in the leaves. Methods. High performance liquid chromatography (HPLC), up-to- date physical-chemical methods of hop quality indicators’ defi nition, special and standard in the hop-growing branch, were applied. Results. It was stated that lupulin of aroma and bitter varieties contains various quantity of α- and β-acids. Therefore, the ratio of α- to β-acids in aroma hop varieties is above one (1), whereas in varieties of bitter type this ratio is much lower than one (1). No correlation between the quantity of lupulin and the contents of α- and β-acids was found. It was noted that the color of lupulin depends upon the quantity of xanthohumol. Conclusions. The performed tests give evidences on lupulin glands are located on anthers of staminate racemes and on the leaves as well, though in much less quantity and less educed. It was found that the quantity and structure of bitter substances in lupulin grains from selection varieties does not depend upon lupulin content in hop cones, but it is a grading factor. Lupulin from the staminate racemes received from various plants essentially differs in quantity of α- and β-acids. This fact is of key importance for pair selection. In petal glands on the leaves of a hop plant bitter substances are represented only by β-acids, mainly lupulone and adlupulone.

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Procházka, Pavel, Přemysl Štranc, Kateřina Pazderů, Jan Vostřel, and Jan Řehoř. "Use of biologically active substances in hops." Plant, Soil and Environment 64, No. 12 (November 30, 2018): 626–32. http://dx.doi.org/10.17221/655/2018-pse.

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In four-year experiments, hop was treated with 7 biologically active substances in two terms during vegetation: Lignohumate max (a mixture of humic acids and fulvic acids), Lexin (a mixture of humic acids and fulvic acids enriched with auxins), Lexenzym (a mixture of humic acids and fulvic acids enriched with auxins, phytohormones and enzymes precursors), Ascophyllum nodosum seaweed extract, synthetic auxin, humic acids and fulvic acids alone. The chlorophyll content was monitored after the application both in the vine leaves and in the branch leaves. After harvesting of the hops from the individual treatments, the yield of dry hops was determined and the cones were analysed for the content of alpha bitter acids. The results show that the most effective hop treatment was the application of Lexin and Lexenzym. The Lexenzym treatment provided a yield of dry hops of 1.86 t/ha, i.e. 0.47 t/ha higher compared with untreated control. The Lexin treatment provided yield higher by 0.41 t/ha of dry hops compared with the untreated control, while the harvested cones contained the most alpha-bitter acids (4.57%).

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Rezaie, Peyman, Vida Bitarafan, Michael Horowitz, and Christine Feinle-Bisset. "Effects of Bitter Substances on GI Function, Energy Intake and Glycaemia-Do Preclinical Findings Translate to Outcomes in Humans?" Nutrients 13, no. 4 (April 16, 2021): 1317. http://dx.doi.org/10.3390/nu13041317.

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Bitter substances are contained in many plants, are often toxic and can be present in spoiled food. Thus, the capacity to detect bitter taste has classically been viewed to have evolved primarily to signal the presence of toxins and thereby avoid their consumption. The recognition, based on preclinical studies (i.e., studies in cell cultures or experimental animals), that bitter substances may have potent effects to stimulate the secretion of gastrointestinal (GI) hormones and modulate gut motility, via activation of bitter taste receptors located in the GI tract, reduce food intake and lower postprandial blood glucose, has sparked considerable interest in their potential use in the management or prevention of obesity and/or type 2 diabetes. However, it remains to be established whether findings from preclinical studies can be translated to health outcomes, including weight loss and improved long-term glycaemic control. This review examines information relating to the effects of bitter substances on the secretion of key gut hormones, gastric motility, food intake and blood glucose in preclinical studies, as well as the evidence from clinical studies, as to whether findings from animal studies translate to humans. Finally, the evidence that bitter substances have the capacity to reduce body weight and/or improve glycaemic control in obesity and/or type 2 diabetes, and potentially represent a novel strategy for the management, or prevention, of obesity and type 2 diabetes, is explored.

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Lemon, Christian H., and David V. Smith. "Neural Representation of Bitter Taste in the Nucleus of the Solitary Tract." Journal of Neurophysiology 94, no. 6 (December 2005): 3719–29. http://dx.doi.org/10.1152/jn.00700.2005.

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Based on the molecular findings that many bitter taste receptors (T2Rs) are expressed within the same receptor cells, it has been proposed that bitter taste is encoded by the activation of discrete neural elements. Here we examined how a variety of bitter stimuli are represented by neural activity in central gustatory neurons. Taste responses (spikes/s) evoked by bathing the tongue and palate with intensity-matched concentrations (in M) of 2 sugars (0.32 sucrose and 0.5 D-fructose), ethanol (40%), 4 salts (0.01 NaCl, 0.008 NaNO3, 0.01 MgCl2, and 0.05 KCl), 2 acids (0.003 HCl and 0.005 citric acid), and 10 bitter ligands (0.007 quinine-HCl, 0.015 denatonium benzoate, 0.003 l-cysteine, 0.001 nicotine, 0.005 strychnine-HCl, 0.04 tetraethylammonium chloride, 0.03 atropine-SO4, 0.005 brucine-SO4, 0.03 papaverine-HCl, and 0.009 sparteine) were recorded from 51 neurons in the nucleus of the solitary tract of anesthetized rats. Cluster analysis was used to categorize neurons into types based on responses to sucrose, NaCl, HCl, and quinine-HCl. Three groupings emerged: type S (responded optimally to sweets), type N (sodium-optimal), and type H/Q (responded robustly to bitters, acids, and salts). Multivariate analyses revealed that across-neuron patterns of response among bitter stimuli were strongly correlated. However, neural type H/Q, which was most responsive to bitter tastants, was not differentially sensitive to bitter stimuli and Na+ salts, which rats perceive as distinct. Thus central neurons most responsive to bitter substances receive significant input from receptors that mediate other tastes, indicating that bitter stimuli are not represented by activity in specifically tuned neurons.

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Yoshimatsu, Jumpei, Kiyoshi Toko, Yusuke Tahara, Misaki Ishida, Masaaki Habara, Hidekazu Ikezaki, Honami Kojima, Saeri Ikegami, Miyako Yoshida, and Takahiro Uchida. "Development of Taste Sensor to Detect Non-Charged Bitter Substances." Sensors 20, no. 12 (June 18, 2020): 3455. http://dx.doi.org/10.3390/s20123455.

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A taste sensor with lipid/polymer membranes is one of the devices that can evaluate taste objectively. However, the conventional taste sensor cannot measure non-charged bitter substances, such as caffeine contained in coffee, because the taste sensor uses the potentiometric measurement based mainly on change in surface electric charge density of the membrane. In this study, we aimed at the detection of typical non-charged bitter substances such as caffeine, theophylline and theobromine included in beverages and pharmaceutical products. The developed sensor is designed to detect the change in the membrane potential by using a kind of allosteric mechanism of breaking an intramolecular hydrogen bond between the carboxy group and hydroxy group of aromatic carboxylic acid (i.e., hydroxy-, dihydroxy-, and trihydroxybenzoic acids) when non-charged bitter substances are bound to the hydroxy group. As a result of surface modification by immersing the sensor electrode in a modification solution in which 2,6-dihydroxybenzoic acid was dissolved, it was confirmed that the sensor response increased with the concentration of caffeine as well as allied substances. The threshold and increase tendency were consistent with those of human senses. The detection mechanism is discussed by taking into account intramolecular and intermolecular hydrogen bonds, which cause allostery. These findings suggest that it is possible to evaluate bitterness caused by non-charged bitter substances objectively by using the taste sensor with allosteric mechanism.

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Hoffmann, Krystyna, Józef Hoffmann, Marta Huculak-Mączka, and Jakub Skut. "Investigation of applying calcium oxide for the removal of bitter substances from hop wastes." Polish Journal of Chemical Technology 13, no. 1 (January 1, 2011): 35–40. http://dx.doi.org/10.2478/v10026-011-0007-8.

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Investigation of applying calcium oxide for the removal of bitter substances from hop wastes Utilization of brewery wastes is one of the solutions for the production of the fodder supplements containing biogenic nutrients. The condition of such application is to meet the requirements included in the regulations regarding animal feeding, particularly removing a bitter taste. The aim of the performed investigations was the removal of bitter acids from the post-extraction hop waste using the calcium oxide addition. For the examination hop wastes obtained as a by-product from the CO2 plant extraction in supercritical conditions, were applied. Physicochemical properties of the waste samples collected for the investigations were determined by applying the available standard analytical techniques. The analyses of the determination of bitter acids were carried out by the high performance liquid chromatography method. During the experiments very good effects of bitter acids removal from hop wastes, were obtained by using CaO suspensions in water. The investigations on the influence of the CaO concentration in suspension on the efficiency of bitter acids removal indicate the possibility of applying suspensions by 2 wt% for this purpose.

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Yokomukai, Yoshiko, Beverly J. Cowart, and Gary K. Beauchamp. "Individual differences in sensitivity to bitter-tasting substances." Chemical Senses 18, no. 6 (1993): 669–81. http://dx.doi.org/10.1093/chemse/18.6.669.

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Frijters, Jan E. R., and Hendrik N. J. Schifferstein. "Perceptual interactions in mixtures containing bitter tasting substances." Physiology & Behavior 56, no. 6 (December 1994): 1243–49. http://dx.doi.org/10.1016/0031-9384(94)90372-7.

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Huang, Yongjian, Hang Xun, Guilin Yi, Ti Li, Xi Yao, and Feng Tang. "Integrated Metabolomic and Transcriptomic Analysis Reveals the Effect of Artificial Shading on Reducing the Bitter Taste of Bamboo Shoots." Horticulturae 8, no. 7 (July 1, 2022): 594. http://dx.doi.org/10.3390/horticulturae8070594.

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Bamboo shoot is a delicious and nutritious forest vegetable. It has been found that bamboo shoots collected from low-light environments have a less bitter taste. The molecular mechanism of light in the regulation of bitter substance accumulation in bamboo shoots is still unclear. In this study, we applied a shading treatment to Pleioblastus amarus bamboo shoots in the preharvesting period. The reduction in the bitterness intensity was confirmed by a sensory test. An integrated metabolomic and transcriptomic analysis was performed on P. amarus bamboo shoots grown under shading treatment and normal growing conditions, and 56 differentially accumulated metabolites and 178 differentially expressed genes were identified. The results showed that the contents of a series of phenolic acids related to the tyrosine metabolism pathway were downregulated under shading treatment, revealing that shading decreased the accumulation of phenolic acids and further mediated the resulting bitter taste of the bamboo shoots. This work will be helpful for understanding the regulatory mechanisms governing the bitter tasting substances in bamboo shoots grown under a shading treatment and provides a reference for the use of shading treatment in cultivation practices to improve the taste of bamboo shoots.

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Ishida, Misaki, Haruna Ide, Keishiro Arima, Zeyu Zhao, Toshiro Matsui, and Kiyoshi Toko. "Identification of the Principle of Taste Sensors to Detect Non-Charged Bitter Substances by 1H-NMR Measurement." Sensors 22, no. 7 (March 28, 2022): 2592. http://dx.doi.org/10.3390/s22072592.

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A taste sensor with lipid/polymer membranes is attracting attention as a method to evaluate taste objectively. However, due to the characteristic of detecting taste by changes in membrane potential, taste sensors cannot measure non-charged bitter substances. Many foods and medicines contain non-charged bitter substances, and it is necessary to quantify these tastes with sensors. Therefore, we have been developing taste sensors to detect bitter tastes caused by non-charged substances such as caffeine. In previous studies, a sensor for detecting bitterness caused by caffeine and theobromine, theophylline, was developed, using a membrane modified with hydroxybenzoic acid (HBA) as the sensing part. The sensor was designed to form intramolecular hydrogen bonds (H-bonds) between the hydroxy group and carboxy group of HBA and to successively cause the intermolecular H-bonds between HBA and caffeine molecules to be measured. However, whether this sensing principle is correct or not cannot be confirmed from the results of taste sensor measurements. Therefore, in this study, we explored the interaction between HBA and caffeine by 1H-nuclear magnetic resonance spectroscopy (NMR). By the 1H NMR detection, we confirmed that both the substances interact with each other. Furthermore, the nuclear Overhauser effect (NOE) of intermolecular spatial conformation in solution was measured, by which 2,6-dihydroxybenzoic acid (2,6-DHBA) preferably interacted with caffeine via the H-bonding and stacking configuration between aromatic rings. Identifying the binding form of 2,6-DHBA to caffeine was estimated to predict how the two substances interact.

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Sambu, Sammy. "The determinants of chemoreception as evidenced by gradient boosting machines in broad molecular fingerprint spaces." PeerJ Organic Chemistry 1 (December 3, 2019): e2. http://dx.doi.org/10.7717/peerj-ochem.2.

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The ability to identify and reject bitter molecules may determine evolutionary fitness. These molecules might be in potentially toxic or contaminated food. Surprisingly, the ability to identify but tolerate or even enjoy bitter foods and medicines may be beneficial. For example, the tolerance of bitterness as a spice or as a medicine may lead to better nutritional, immunological and health outcomes. More recently the ability of intensely bitter compounds to induce innate immune responses to counter infection has inspired the screening of new drugs and the repurposing of safe, known drugs to new uses. These avenues of study may also help to address long-standing questions regarding unexpected side-effects and placebo/nocebo effects. Therefore, to distinguish all these effects ranging from desire to aversion, there is a need to quantitatively determine the concentration thresholds and to position these bitter substances on a unified taste threshold spectrum. Such an understanding may help elucidate the concentration-based molecular drivers for the chemoreceptive response to bitter substances. This article reports the development of a gradient boosting machine (GBM) that enables a direct interrogation of molecular structure with no intermediary chemical properties. Using molecularly engineered simulations, it is shown that potassium acesulfame has a hidden bitterness motif that is centered on the chemoreceptive spectrum uniting bitterness and sweetness molecular motifs. The resultant shifted perception from a touchstone bitterness sensation to a bitter after-taste is attributable to this cached molecular motif.

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Gibbs, Matthew, Marcel Winnig, Irene Riva, Nicola Dunlop, Daniel Waller, Boris Klebansky, Darren W. Logan, Stephen J. Briddon, Nicholas D. Holliday, and Scott J. McGrane. "Bitter taste sensitivity in domestic dogs (Canis familiaris) and its relevance to bitter deterrents of ingestion." PLOS ONE 17, no. 11 (November 30, 2022): e0277607. http://dx.doi.org/10.1371/journal.pone.0277607.

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As the most favoured animal companion of humans, dogs occupy a unique place in society. Understanding the senses of the dog can bring benefits to both the dogs themselves and their owners. In the case of bitter taste, research may provide useful information on sensitivity to, and acceptance of, diets containing bitter tasting materials. It may also help to protect dogs from the accidental ingestion of toxic substances, as in some instances bitter tasting additives are used as deterrents to ingestion. In this study we examined the receptive range of dog bitter taste receptors (Tas2rs). We found that orthologous dog and human receptors do not always share the same receptive ranges using in vitro assays. One bitter chemical often used as a deterrent, denatonium benzoate, is only moderately active against dTas2r4, and is almost completely inactive against other dog Tas2rs, including dTas2r10, a highly sensitive receptor in humans. We substituted amino acids to create chimeric dog-human versions of the Tas2r10 receptor and found the ECL2 region partly determined denatonium sensitivity. We further confirmed the reduced sensitivity of dogs to this compound in vivo. A concentration of 100μM (44.7ppm) denatonium benzoate was effective as a deterrent to dog ingestion in a two-bottle choice test indicating higher concentrations may increase efficacy for dogs. These data can inform the choice and concentration of bitter deterrents added to toxic substances to help reduce the occurrence of accidental dog poisonings.

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Naim, M., R. Seifert, B. Nürnberg, L. Grünbaum, and G. Schultz. "Some taste substances are direct activators of G-proteins." Biochemical Journal 297, no. 3 (February 1, 1994): 451–54. http://dx.doi.org/10.1042/bj2970451.

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Amphiphilic substances may stimulate cellular events through direct activation of G-proteins. The present experiments indicate that several amphiphilic sweeteners and the bitter tastant, quinine, activate transducin and Gi/Go-proteins. Concentrations of taste substances required to activate G-proteins in vitro correlated with those used to elicit taste. These data support the hypothesis that amphiphilic taste substances may elicit taste through direct activation of G-proteins.

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Rhyu, Mee-Ra, Yiseul Kim, and Takumi Misaka. "Suppression of hTAS2R16 Signaling by Umami Substances." International Journal of Molecular Sciences 21, no. 19 (September 24, 2020): 7045. http://dx.doi.org/10.3390/ijms21197045.

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Interaction between umami and bitter taste has long been observed in human sensory studies and in neural responses in animal models, however, the molecular mechanism for their action has not been delineated. Humans detect diverse bitter compounds using 25-30 members of the type 2 taste receptor (TAS2R) family of G protein-coupled receptor. In this study, we investigated the putative mechanism of antagonism by umami substances using HEK293T cells expressing hTAS2R16 and two known probenecid-insensitive mutant receptors, hTAS2R16 N96T and P44T. In wild type receptor, Glu-Glu, inosine monophosphate (IMP), and l-theanine behave as partial insurmountable antagonists, and monosodium glutamate (MSG) acts as a surmountable antagonist in comparison with probenecid as a full insurmountable antagonist. The synergism with IMP of umami substances still stands in the suppression of hTAS2R16 signaling. In mutagenesis analysis, we found that Glu-Glu, MSG, and l-theanine share at least one critical binding site on N96 and P44 with probenecid. These results provide the first evidence for a direct binding of umami substances to the hTAS2R16 through the probenecid binding pocket on the receptor, resulting in the suppression of bitterness.

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Wooding, Stephen P., Vicente A. Ramirez, and Maik Behrens. "Bitter taste receptors." Evolution, Medicine, and Public Health 9, no. 1 (January 1, 2021): 431–47. http://dx.doi.org/10.1093/emph/eoab031.

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Abstract Bitter taste perception plays vital roles in animal behavior and fitness. By signaling the presence of toxins in foods, particularly noxious defense compounds found in plants, it enables animals to avoid exposure. In vertebrates, bitter perception is initiated by TAS2Rs, a family of G protein-coupled receptors expressed on the surface of taste buds. There, oriented toward the interior of the mouth, they monitor the contents of foods, drinks and other substances as they are ingested. When bitter compounds are encountered, TAS2Rs respond by triggering neural pathways leading to sensation. The importance of this role placed TAS2Rs under selective pressures in the course of their evolution, leaving signatures in patterns of gene gain and loss, sequence polymorphism, and population structure consistent with vertebrates' diverse feeding ecologies. The protective value of bitter taste is reduced in modern humans because contemporary food supplies are safe and abundant. However, this is not always the case. Some crops, particularly in the developing world, retain surprisingly high toxicity and bitterness remains an important measure of safety. Bitter perception also shapes health through its influence on preference driven behaviors such as diet choice, alcohol intake and tobacco use. Further, allelic variation in TAS2Rs is extensive, leading to individual differences in taste sensitivity that drive these behaviors, shaping susceptibility to disease. Thus, bitter taste perception occupies a critical intersection between ancient evolutionary processes and modern human health.

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Oami, K. "Membrane potential responses of paramecium caudatum to bitter substances: existence of multiple pathways for bitter responses." Journal of Experimental Biology 201, no. 1 (January 1, 1998): 13–20. http://dx.doi.org/10.1242/jeb.201.1.13.

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The membrane potential responses of Paramecium caudatum to the external application of bitter substances were examined by employing conventional electrophysiological techniques. Mutant cells defective in voltage-gated Ca2+ channels were used to record the potential responses in the absence of contamination by Ca2+ action potentials. The cells produced a transient depolarization followed by a transient hyperpolarization in response to a rapid whole-cell application of chloroquine, strychnine nitrate or brucine. Of these chemicals, chloroquine was the most potent. Cells produced a simple depolarization in response to a localized application of test chemicals to the anterior region, whereas they produced a transient hyperpolarization in response to an application to the posterior region. Membrane potential responses to an application of chloroquine declined with repeated application. The presence of chloroquine in the external bathing solution strongly inhibited the membrane potential responses to an application of brucine or strychnine. However, the presence of chloroquine did not affect the membrane potential responses to an application of quinine. It is suggested that chloroquine, strychnine and brucine share a common component of their transduction pathways, but that the transduction pathway for quinine is different.

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OLESIŃSKA, KATARZYNA. "Sesquiterpene lactones – occurrence and biological properties. A review." Agronomy Science 73, no. 3 (November 29, 2018): 83–95. http://dx.doi.org/10.24326/asx.2018.3.7.

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Sesquiterpene lactones are secondary metabolites commonly found in higher plants as well as mosses, lichens, and fungi. Currently, over 5000 of such compounds have been identified with a majority isolated from Asteraceae plants. They are characterised by different chemical structures associated with the presence of various carbon pathways and functional groups, which exert an impact on their pharmacological activity. These colourless substances are soluble in fats, alcohols, or water. They are often bitter ingredients regarded as bitter compounds. They are accumulated mainly in leaves, flower parts and seeds; less frequently, they are present in roots. Sesquiterpene lactones exhibit multidirectional biological activity: some of them have anticancer, anti-inflammatory, antidiabetic, analgesic, antiparasitic, antifungal, and bacteriostatic effects. Therefore, high hopes are placed on the medical and pharmaceutical use of these substances. Lactone compounds are also regarded as a potential source of new active substances used in agriculture to combat plant pathogens

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Spielman, A. I., H. Nagai, G. Sunavala, M. Dasso, H. Breer, I. Boekhoff, T. Huque, G. Whitney, and J. G. Brand. "Rapid kinetics of second messenger production in bitter taste." American Journal of Physiology-Cell Physiology 270, no. 3 (March 1, 1996): C926—C931. http://dx.doi.org/10.1152/ajpcell.1996.270.3.c926.

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The tasting of bitter compounds may have evolved as a protective mechanism against ingestion of potentially harmful substances. We have identified second messengers involved in bitter taste and show here for the first time that they are rapid and transient. Using a quench-flow system, we have studied bitter taste signal transduction in a pair of mouse strains that differ in their ability to taste the bitter stimulus sucrose octaacetate (SOA); however, both strains taste the bitter agent denatonium. In both strains of mice, denatonium (10 mM) induced a transient and rapid increase in levels of the second messenger inositol 1,4,5-trisphosphate (IP3) with a maximal production near 75-100 ms after stimulation. In contrast, SOA (100 microM) brought about a similar increase in IP3 only in SOA-taster mice. The response to SOA was potentiated in the presence of GTP (1 microM). The GTP-enhanced SOA-response supports a G protein-mediated response for this bitter compound. The rapid kinetics, transient nature, and specificity of the bitter taste stimulus-induced IP3 formation are consistent with the role of IP3 as a second messenger in the chemoelectrical transduction of bitter taste.

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Jioe, Irvan Prawira Julius, Huey-Ling Lin, and Ching-Chang Shiesh. "The Investigation of Phenylalanine, Glucosinolate, Benzylisothiocyanate (BITC) and Cyanogenic Glucoside of Papaya Fruits (Carica papaya L. cv. ‘Tainung No. 2’) under Different Development Stages between Seasons and Their Correlation with Bitter Taste." Horticulturae 8, no. 3 (February 24, 2022): 198. http://dx.doi.org/10.3390/horticulturae8030198.

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Papaya fruit is one of economic crops in Taiwan, mostly eaten as table fruits. In some Asian countries, unripe papaya fruit is eaten as salad and this led to trends in Taiwan as well. However, unripe papaya fruit may taste bitter during cool seasons. Glucosinolate and cyanogenic glucoside are among the substances that cause bitter taste in many plants, which can also be found in papaya. However, there is still no report about the relationship between seasons and bitter taste in papaya fruits. Thus, the purpose of this study is to investigate the glucosinolate biosynthesis and its correlation between bitterness intensity during cool and warm seasons. The bitterness intensity was highest at the young fruit stage and decreased as it developed. In addition, the bitterness intensity in cool season fruits is higher than in warm season fruits. Cyanogenic glucoside and BITC content showed negative correlation with bitterness intensity (r = −0.54 ***; −0.46 ***). Phenylalanine showed positive correlation with bitterness intensity (r = 0.35 ***), but its content did not reach the bitterness threshold concentration, which suggested that phenylalanine only acts as cyanogenic glucoside and glucosinolate precusors. Glucosinolate content showed positive correlation with bitterness intensity at different developmental stages (r = 0.805 ***). However, the correlation value in different lines/cultivars decreased (0.44 ***), suggesting that glucosinolate was not the only substance that caused bitter taste in immature papaya fruits.

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Geran, Laura C., and Susan P. Travers. "Single Neurons in the Nucleus of the Solitary Tract Respond Selectively to Bitter Taste Stimuli." Journal of Neurophysiology 96, no. 5 (November 2006): 2513–27. http://dx.doi.org/10.1152/jn.00607.2006.

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Molecular data suggest that receptors for all bitter ligands are coexpressed in the same taste receptor cells (TRCs), whereas physiological results indicate that individual TRCs respond to only a subset of bitter stimuli. It is also unclear to what extent bitter-responsive neurons are stimulated by nonbitter stimuli. To explore these issues, single neuron responses were recorded from the rat nucleus of the solitary tract (NST) during whole mouth stimulation with a variety of bitter compounds: 10 μM cycloheximide, 7 mM propylthiouracil, 10 mM denatonium benzoate, and 3 mM quinine hydrochloride at intensities matched for behavioral effectiveness. Stimuli representing the remaining putative taste qualities were also tested. Particular emphasis was given to activating taste receptors in the foliate papillae innervated by the quinine-sensitive glossopharyngeal nerve. This method revealed a novel population of bitter-best (B-best) cells with foliate receptive fields and significant selectivity for bitter tastants. Across all neurons, multidimensional scaling depicted bitter stimuli as loosely clustered yet clearly distinct from nonbitter tastants. When neurons with posterior receptive fields were analyzed alone, bitter stimuli formed a tighter cluster. Nevertheless, responses to bitter stimuli were variable across B-best neurons, with cycloheximide the most, and quinine the least frequent optimal stimulus. These results indicate heterogeneity for the processing of ionic and nonionic bitter tastants, which is dependent on receptive field. Further, they suggest that neurons selective for bitter substances could contribute to taste coding.

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Katsuragi, Yoshihisa, Takeshi Yasumasu, and Kenzo Kurihara. "Lipoprotein that selectively inhibits taste nerve responses to bitter substances." Brain Research 713, no. 1-2 (March 1996): 240–45. http://dx.doi.org/10.1016/0006-8993(95)01541-8.

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Behrens, Maik, Ming Gu, Shengjie Fan, Cheng Huang, and Wolfgang Meyerhof. "Bitter substances from plants used in traditional Chinese medicine exert biased activation of human bitter taste receptors." Chemical Biology & Drug Design 91, no. 2 (September 14, 2017): 422–33. http://dx.doi.org/10.1111/cbdd.13089.

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Kinzeler, Nicole R., and Susan P. Travers. "Licking and gaping elicited by microstimulation of the nucleus of the solitary tract." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 295, no. 2 (August 2008): R436—R448. http://dx.doi.org/10.1152/ajpregu.00189.2008.

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Intraoral infusions of bitter tastants activate expression of the immediate-early gene c-Fos in neurons located in the medial third of the rostral nucleus of the solitary tract (rNST). The distribution of these neurons is distinct from that activated by sour or sweet stimuli. Bitter stimuli are also distinctive because of their potency for eliciting gaping, an oral reflex that functions to actively reject potentially toxic substances. Glossopharyngeal nerve transection profoundly reduces, whereas decerebration spares, the bitter-evoked Fos-like immunoreactivity (FLI) pattern and gaping, implicating the medial rNST as a substrate for the sensory limb of oral rejection. The present experiment tested this hypothesis using microstimulation (100 Hz, 0.2 ms, 5–40 μA) to activate the rNST in awake rats. NST microstimulation elicited licking and gaping, and gaping was evoked from a restricted rNST region. The results indicated some topographic organization in sites effective for evoking gaping, but, in direct conflict with the hypothesis, lateral sites farther from bitter-evoked FLI were more effective than medial sites centered closer to FLI-expressing neurons. The gape-effective sites resemble locations of bitter-responsive neurons recently observed in neurophysiological recordings. These results indicate that bitter-responsive rNST neurons critical for triggering gaping may not express FLI and imply an alternate function for bitter-responsive neurons that do.

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Anurova, Mariya, Elena Bakhrushina, Anna Moiseyeva, and Ivan Krasnyuk. "Principles of masking organoleptic properties of bitter tasting medicines." Farmacevticheskoe delo i tehnologija lekarstv (Pharmacy and Pharmaceutical Technology), no. 1 (February 1, 2020): 25–32. http://dx.doi.org/10.33920/med-13-2001-02.

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Patient compliance of drug therapy is the key factor in achieving the pharmaceutical effect. Taste masking is particularly important in pediatrics and geriatrics because the unpleasant taste negatively affects drug uptake. Patient compliance can be improved through balanced organoleptic properties of medicines. It is particularly important to choose optimal correction method for medicines with high concentration of the active substance. Hopantenic acid has been chosen as a model drug due to its bitter taste. Taste masking technologies for creating a new dosage form with optimal organoleptic properties are proposed in the article. The objective is to achieve an experimentally justified choice of technological approach to masking bitter taste of a substance and to create a new dosage form on its basis. Materials and methods. Alternative technologies were considered to solve this problem: granulation, creation of complexes with ion-exchange resins, introduction of a gel composition and taste-masking using sweeteners. Organoleptic properties in dry compositions (pure substance of hopantenic acid, granulate and resinate based on it), and also after preparation of liquid dosage forms and incorporation them into gel, were evaluated by A. I. Tentsova method. Choice of sweetener and its concentration to achieve an optimally balanced taste took place at the final stage. Hopantenic acid was chosen as a model substance. Hopantenic acid is a nootropic drug stimulating cognitive functions, nervous system, enhancing intellectual functioning, decreasing nervous system activity, with anticonvulsant action. The main therapeutic indications are mental retardation, dementia, epilepsy. Results and discussion. The study has shown that optimal technology for masking unpleasant taste of hopantenic acid is its introduction into a gel composition, and a promising dosage form is an oral gel. Compri-Zucker G sweetener (Südzucker АG, Germany) in concentration of 5 % has been chosen to create pleasant taste due to its highest taste rating. Conclusion. It has been determined as a result of the study that oral gel with active drug concentration of 5 % and sweetener concentration of 5 % has optimal organoleptic properties. Thus, this combination of active and additional substances can be considered the most perspective for developing a new dosage form of a medicine.

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KROFTA, K., A. RÍGR, F. KROUPA, and F. BERÁNEK. "Bitter substances and essential oils analyses of hop hybrid new selections." Kvasny Prumysl 42, no. 7 (July 1, 1996): 237–340. http://dx.doi.org/10.18832/kp1996016.

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Okahata, Yoshio, Hiroshi Ebato, and Kazuhiro Taguchi. "Specific adsorption of bitter substances on lipid bilayer-coated piezoelectric crystals." Journal of the Chemical Society, Chemical Communications, no. 18 (1987): 1363. http://dx.doi.org/10.1039/c39870001363.

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Naito, M., N. Sasaki, and T. Kambara. "Mechanism of the electric response of lipid bilayers to bitter substances." Biophysical Journal 65, no. 3 (September 1993): 1219–30. http://dx.doi.org/10.1016/s0006-3495(93)81159-7.

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Guinard, J. "Does consumption of beer, alcohol, and bitter substances affect bitterness perception?" Physiology & Behavior 59, no. 4-5 (May 1996): 625–31. http://dx.doi.org/10.1016/0031-9384(95)02124-8.

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Sakurai, Hidetoshi, Hidenori Koga, Gaku Ishikawa, Tatsuo Endo, Chinami Matsuyama, Tomohiro Yano, Naoko Ohta, Hitomi Kumagai, Huong Thi Thu Nguyen, and Jan Pokorny. "Formation of bitter substances in solutions containing vitamin C and aspartame." International Congress Series 1245 (November 2002): 383–85. http://dx.doi.org/10.1016/s0531-5131(02)01014-2.

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Su, Yuan, Hang Jie, Qing Zhu, Xiaoling Zhao, Yan Wang, Huadong Yin, Shailendra Kumar Mishra, and Diyan Li. "Effect of Bitter Compounds on the Expression of Bitter Taste Receptor T2R7 Downstream Signaling Effectors in cT2R7/pDisplay-Gα16/gust44/pcDNA3.1 (+) Cells." BioMed Research International 2019 (October 31, 2019): 1–12. http://dx.doi.org/10.1155/2019/6301915.

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Bitterness is an important taste sensation for chickens, which provides useful sensory information for acquisition and selection of diet, and warns them against ingestion of potentially harmful and noxious substances in nature. Bitter taste receptors (T2Rs) mediate the recognition of bitter compounds belonging to a family of proteins known as G-protein coupled receptors. The aim of this study was to identify and evaluate the expression of T2R7 in chicken tongue tissue and construct cT2R7-1 and cT2R7-2-expressing HEK-293T cells to access the expression of PLCβ2 and ITPR3 after exposure with different concentrations of the bitter compounds. Using real-time PCR, we show that the relative expression level of T2R7 mRNA in 5, 1, 0.1, and 10−3 mM of camphor and erythromycin solutions and 5 mM of chlorpheniramine maleate solutions was significantly higher than that in 50 mM KCL solutions. We confirmed that the bitter taste receptor T2R7 and downstream signaling effectors are sensitive to different concentrations of bitter compounds. Moreover, T2R7-1 (corresponding to the unique haplotype of the Tibetan chicken) had higher sensitivity to bitter compounds compared with that of T2R7-2 (corresponding to the unique haplotype of the Jiuyuan black-chicken). These results provide great significance of taste response on dietary intake to improve chicken feeding efficiency in poultry production and have certain reference value for future taste research in other bird species.

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Gulbransen, Brian D., Tod R. Clapp, Thomas E. Finger, and Sue C. Kinnamon. "Nasal Solitary Chemoreceptor Cell Responses to Bitter and Trigeminal Stimulants In Vitro." Journal of Neurophysiology 99, no. 6 (June 2008): 2929–37. http://dx.doi.org/10.1152/jn.00066.2008.

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Nasal trigeminal chemosensitivity in mice and rats is mediated in part by epithelial solitary chemoreceptor (chemosensory) cells (SCCs), but the exact role of these cells in chemoreception is unclear. Histological evidence suggests that SCCs express elements of the bitter taste transduction pathway including T2R (bitter taste) receptors, the G protein α-gustducin, PLCβ2, and TRPM5, leading to speculation that SCCs are the receptor cells that mediate trigeminal nerve responses to bitter taste receptor ligands. To test this hypothesis, we used calcium imaging to determine whether SCCs respond to classic bitter-tasting or trigeminal stimulants. SCCs from the anterior nasal cavity were isolated from transgenic mice in which green fluorescent protein (GFP) expression was driven by either TRPM5 or gustducin. Isolated cells were exposed to a variety of test stimuli to determine which substances caused an increase in intracellular Ca2+ ([Ca2+]i). GFP-positive cells respond with increased [Ca2+]i to the bitter receptor ligand denatonium and this response is blocked by the PLC inhibitor U73122. In addition, GFP+ cells respond to the neuromodulators adenosine 5′-triphosphate and acetylcholine but only very rarely to other bitter-tasting or trigeminal stimuli. Our results demonstrate that TRPM5- and gustducin-expressing nasal SCCs respond to the T2R agonist denatonium via a PLC-coupled transduction cascade typical of T2Rs in the taste system.

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Sincar, Cerasela Dorina, Camelia Ana Grigore, Silvia Martu, Liliana Lacramioara Pavel, Alina Calin, Alina Plesea Condratovici, and Bianca Ioana Chesaru. "Chemical Senses Taste Sensation and Chemical Composition." Materiale Plastice 54, no. 1 (March 30, 2017): 172–74. http://dx.doi.org/10.37358/mp.17.1.4810.

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Taste and smell are chemical senses, which means that the receptors (chemoreceptors) of these senses respond to chemical stimuli. In order for a substance to produce a taste sensation, it should be ingested in a solution or subsequently dissolved in saliva; a solid substance put in the mouth perfectly dry is tasteless. Therefore, taste receptors or taste buds occur only on wet surfaces, more precisely in the oral cavity in land vertebrates; however, in aquatic animals, these receptors are scattered all over the body. There are functionally different types of receptors for each of the primary tastes and the distribution of each type is not even on the surface of the tongue mucosa. The sweet and sour sensitive buds are located mainly on the tip of the tongue, those sensitive to acids are located on the sides of the tongue and those stimulated by the bitter taste are located towards the back of the tongue and in the epiglottis area. Taste may be generated by substances which touch the taste buds through the blood; thus, histamine injected intravenously causes a metallic taste, glucin a sweet taste, whereas jaundice may trigger a bitter taste due to the big concentration of gallbladder constituents in the blood.

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Techawinyutham, Laongdaw, and Rapeephun Dangtungee. "Anti-Rodent Polymer Composites." Key Engineering Materials 818 (August 2019): 1–6. http://dx.doi.org/10.4028/www.scientific.net/kem.818.1.

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This study is to examine substances which can protect the polymer composites against gnawing from rodent. Polyvinyl chloride (PVC) compound acted as polymer matrix was mixed with anti-rodent substances in internal mixer. Several substances were added in PVC namely: denatonium benzoate (DB), capsaicum oleroresin (CO), deltamethrin (DM), caffeine, pepper, salt, wasabi and essential oil. There were 6 sets of anti-rodent samples. The percentage of weight loss of each sample was recorded and compared. The result showed the best repellent substances were DB and CO giving bitter taste and burning sensation to the rodent, respectively. The best anti-rodent composites are samples in set 6 consisting of DB at concentration of 1.961 wt% and SiCO at concentration of 12.162 to 23.529 wt%.

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Khamidov, Arifjon Zhakhongirovich, Hakim Rakhmanovich Tukhtaev, Sabirjan Nigmatovich Aminov, and Bakhtigul Zhavli Kizi Azimova. "PROCESSING OF BITTER ALMOND KERNELS AND OBTAINING EXTRACTS BASED ON THEM." chemistry of plant raw material, no. 2 (June 10, 2021): 301–7. http://dx.doi.org/10.14258/jcprm.2021027775.

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Mountain almond kernels (seed) processing products are of practical interest as fungicidal, antimicrobial and antiviral substances, and also find application in medicine and cosmetics for various purposes. The composition and some technological properties of seeds of mountain almond seed (Amygdalus communis L. varietas amara DC.). Cultivated in the mountain zones (Bostanlyq) of Uzbekistan were studied. To obtain seeds from cold pressing, fatty oil was separated. The cake was degreased with organic solvents, the residues were dried and ground. Using gas-liquid chromatography, the presence of 3.24% amygdalin in the composition of crushed powder of bitter almonds was established. Spectral analysis of bitter almond powder showed the presence of Mg, P, Ca, K, Si, Sr, Fe, Mn, B, Cu and other elements. The nitrogen content of the powder determined by the Dume method was 5.72 (±0.2)%. Aqueous and ethanol extracts were obtained from bitter almond powder with a yield of 10.5 and 13.2%. Chromatographic analysis of the composition of the extracts showed the presence of 0.0029% amygdalin in aqueous and 27.2% in ethanol extracts. Protein with a yield of 35.25±0.2% was isolated from the studied powder of bitter almonds. The protein is purified by dialysis, centrifugation and identified by IR spectroscopy. The amino acid analysis of the composition of the hydrolyzate protein of bitter almonds showed the presence of glycine, aspartic acid, arginine, glutamine, alanine and other amino acids. Bitter almond seed powder, extracts and protein isolated from it are of practical interest for cosmetology practice.

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KUBÍČEK, J. "Higher yields of bitter substances from hop using kieselguhr during hop boiling." Kvasny Prumysl 33, no. 8 (August 1, 1987): 254–59. http://dx.doi.org/10.18832/kp1987051.

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ŠROGL, J., J. ČEPIČKA, and P. PRŮCHA. "The changes of bitter substances contents during fermentation in cylindro-conical vessels." Kvasny Prumysl 40, no. 10 (October 1, 1994): 296–300. http://dx.doi.org/10.18832/kp1994019.

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IIYAMA, Satoru, Kiyoshi TOKO, and Kaoru YAMAFUJI. "Effect of bitter substances on a model membrane system of taste reception." Agricultural and Biological Chemistry 50, no. 11 (1986): 2709–14. http://dx.doi.org/10.1271/bbb1961.50.2709.

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Vereshchagin, A. L., E. V. Anikina, A. I. Syrchina, M. F. Lapin, L. A. Azin, and A. A. Semenov. "Chemical investigation of the bitter substances of the fruit of Lonicera caerulea." Chemistry of Natural Compounds 25, no. 3 (1989): 289–92. http://dx.doi.org/10.1007/bf00597704.

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Iiyama, Satoru, Kiyoshi Toko, and Kaoru Yamafuji. "Effect of Bitter Substances on a Model Membrane System of Taste Reception." Agricultural and Biological Chemistry 50, no. 11 (November 1986): 2709–14. http://dx.doi.org/10.1080/00021369.1986.10867831.

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Margolskee, Robert F. "Molecular mechanisms of taste transduction." Pure and Applied Chemistry 74, no. 7 (January 1, 2002): 1125–33. http://dx.doi.org/10.1351/pac200274071125.

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Taste transduction is a specialized form of signal transduction by which taste receptor cells (TRCs) encode at the cellular level information about chemical substances encountered in the oral environment (so-called tastants). Bitter and sweet taste transduction pathways convert chemical information into a cellular second messenger code utilizing cyclic nucleotides, inositol trisphosphate, and/or diacyl glycerol. These messengers are components of signaling cascades that lead to TRC depolarization and Ca++ release. Bitter and sweet taste transduction pathways typically utilize taste-specific or taste-selective seven transmembrane-helix receptors, G proteins, effector enzymes, second messengers, and ion channels. The structural and chemical diversity of tastants has led to the need for multiple transduction mechanisms. Through molecular cloning and data mining, many of the receptors, G proteins, and effector enzymes involved in transducing responses to bitter and sweet compounds are now known. New insights into taste transduction and taste coding underlying sweet and bitter taste qualities have been gained from molecular cloning of the transduction elements, biochemical elucidation of the transduction pathways, electrophysiological analysis of the function of taste cell ion channels, and behavioral analysis of transgenic and knockout models.

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Dhar, Pintu, Himangshu Sarma, and Hemanta Kumar Sharma. "Fixed Dose Oral Dispersible Tablet of Bitter Drug Using Okra Mucilage: Formulation and Evaluation." Journal of Drug Delivery and Therapeutics 10, no. 5 (September 15, 2020): 149–58. http://dx.doi.org/10.22270/jddt.v10i5.4393.

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Background: The solid oral dosage forms containing bitter drugs need improved palatability for administration. Formulation scientists have given attention to the improvement of taste masking technologies and utilised various strategies. Objective: The present work aimed to mask the bitter taste of Promethazine Hydrochloride by formulating Oral Dispersible Tablets using Okra mucilage as a taste-masking agent. Methods: The Okra mucilage was extracted from Okra by the aqueous extraction process. An emulsion solvent diffusion technique was used for masking the bitter taste of Promethazine Hydrochloride by using Okra mucilage. The Oral Dispersible Tablet was prepared by the wet granulation method. The mucilage and the formulation were characterized and evaluated by standard methods and protocols. Results: Taste masking of the bitter drug was successfully achieved by Okra mucilage. The DSC and FTIR study revealed that the drug molecule was compatible with okra mucilage and drug entrapment efficacy was found to be 94.76%. The palatability test asserted that masking of the bitter taste of the drug. The In vitro drug release study showed that the F7 tablet batch has a better drug release rate and followed non- fickian mechanism of drug release. Conclusion: Thus, taste masking with Okra mucilage was successful and this opens opportunities for application of common edible substances in formulation development. Keywords: Fast disintegrating tablet; Natural polymer; Mouth dissolving tablet; Promethazine Hydrochloride; Taste masking

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Zheng, Xiao, Fei Wu, Yanlong Hong, Lan Shen, Xiao Lin, and Yi Feng. "Developments in Taste-Masking Techniques for Traditional Chinese Medicines." Pharmaceutics 10, no. 3 (September 12, 2018): 157. http://dx.doi.org/10.3390/pharmaceutics10030157.

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A variety of pharmacologically active substances, including chemotherapeutic drugs and the substances from traditional Chinese medicine (TCM), always exhibit potent bioactivities after oral administration. However, their unpleasant taste (such as bitterness) and/or odor always decrease patient compliance and thus compromise their curative efficacies in clinical application. Therefore, the developments of taste-masking techniques are of great significance in improving their organoleptic properties. However, though a variety of taste-masking techniques have been successfully used to mask the unpalatable taste of chemotherapeutic drugs, their suitability for TCM substances is relatively limited. This is mainly due to the fact that the bitter ingredients existing in multicomponent TCM systems (i.e., effective fractions, single Chinese herbs, and compound preparations) are always unclear, and thus, there is lack of tailor-made taste-masking techniques to be utilized to conceal their unpleasant taste. The relevant studies are also relatively limited. As a whole, three types of taste-masking techniques are generally applied to TCM, including (i) functional masking via sweeteners, bitter blockers, and taste modifiers; (ii) physical masking via polymer film-coating or lipid barrier systems; and (iii) biochemical masking via intermolecular interaction, β-cyclodextrin inclusion, or ion-exchange resins. This review fully summarizes the results reported in this field with the purpose of providing an informative reference for relevant readers.

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Mahwish, Farhan Saeed, M. Tauseef Sultan, Ayesha Riaz, Sagheer Ahmed, Nicusor Bigiu, Ryszard Amarowicz, and Rosana Manea. "Bitter Melon (Momordica charantia L.) Fruit Bioactives Charantin and Vicine Potential for Diabetes Prophylaxis and Treatment." Plants 10, no. 4 (April 8, 2021): 730. http://dx.doi.org/10.3390/plants10040730.

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Natural products are gaining clinical significance in modern day health care systems to prevent diseases. Bitter melon, a health promoting vegetable, is traditionally used for medical nutrition therapy to cure diabetes but to reap maximum health claims, vigilant control of its substances in diet is crucial as part of curative action for effective diabetes management. In the present research, first phase focused on detection of key bioactive components, i.e., charantin and vicine in different parts of its fruit. In the second phase, normal and hyperglycemic Sprague Dawley rats were fed on skin, flesh and whole fruit of bitter melon at 150 and 300 mg/kg body weight and assessed for diabetes prophylaxis and treatment. The highest amount of charantin (0.16 ± 0.02 mg/g) was recorded in flesh while vicine was present in abundance in whole fruit (0.21 ± 0.01 μg/100 g). In normal rats, bitter melon supplementation was helpful in managing the onset of diabetes. Hyperglycemic rats showed diabetic complications including polydipsia, polyuria, glycosuria, renal hypertrophy and increased glomerular filtration rate. However, bitter melon consumption showed significant improvements in these parameters. The most potent dose was 300 mg/kg whole fruit that resulted in 31.64% lowering of blood glucose level and 27.35% increase in insulin level in hyperglycemic rats.

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Jioe, Irvan Prawira Julius, Ching-Chang Shiesh, and Huey-Ling Lin. "Bitterness of Papaya Milk Is Related to Protein and Free Amino Acid Contents, with Phenylalanine and Tyrosine/Tryptophan Levels Being the Most Important." HortScience 58, no. 3 (March 2023): 261–67. http://dx.doi.org/10.21273/hortsci16941-22.

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Papaya milk, a mixture of papaya pulp and dairy milk, is one of the most popular beverages in Taiwan. However, the enzymes present in papaya can cause accumulation of hydrophobic amino acids, resulting in a bitter taste of papaya milk. Thus, it is important to select papaya cultivars without the potential to form the bitter taste, but it is difficult to select these papaya cultivars using a sensory test. The purpose of this research was to investigate the relationship between the intensity of the bitterness with the contents of proteins and free amino acids. The results indicated that neither milk nor papaya alone tastes bitter. Heating the milk or the papaya before mixing and mixing only papaya latex with milk confirmed that an enzyme in papaya causes the bitter taste in papaya milk. The intensity of bitterness positively correlated with the contents of total soluble protein, free amino acids and the phenylalanine and tyrosine/tryptophan contents. Analyses using different papaya accessions in different seasons showed that tyrosine/tryptophan (r = 0.613***) and phenylalanine (r = 0.612***) correlate more strongly with bitterness intensity than the total soluble protein (r = 0.258*) or free amino acids (r = 0.38**). In this drink, milk provides the substrates to form the bitter substances, but the enzymes in the papaya are needed for the reaction to occur. The levels of the amino acids phenylalanine and tyrosine/tryptophan showed the highest correlation with the intensity of bitterness.

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Stachowiak, Witold, Marcin Wysocki, and Michał Niemczak. "“Bitter” Results: Toward Sustainable Synthesis of the Most Bitter Substances, Denatonium Saccharinate and Denatonium Benzoate, Starting from a Popular Anesthetic, Lidocaine." Journal of Chemical Education 99, no. 4 (March 30, 2022): 1604–11. http://dx.doi.org/10.1021/acs.jchemed.1c00995.

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Jeon, Tae-Il, Young-Kyo Seo, and Timothy F. Osborne. "Gut bitter taste receptor signalling induces ABCB1 through a mechanism involving CCK." Biochemical Journal 438, no. 1 (July 27, 2011): 33–37. http://dx.doi.org/10.1042/bj20110009.

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T2Rs (bitter taste-sensing type 2 receptors) are expressed in the oral cavity to prevent ingestion of dietary toxins through taste avoidance. They are also expressed in other cell types, including gut enteroendocrine cells, where their physiological role is enigmatic. Previously, we proposed that T2R-dependent CCK (cholecystokinin) secretion from enteroendocrine cells limits absorption of dietary toxins, but an active mechanism was lacking. In the present study we show that T2R signalling activates ABCB1 (ATP-binding cassette B1) in intestinal cells through a CCK signalling mechanism. PTC (phenylthiocarbamide), an agonist for the T2R38 bitter receptor, increased ABCB1 expression in both intestinal cells and mouse intestine. PTC induction of ABCB1 was decreased by either T2R38 siRNA (small interfering RNA) or treatment with YM022, a gastrin receptor antagonist. Thus gut ABCB1 is regulated through signalling by CCK/gastrin released in response to PTC stimulation of T2R38 on enteroendocrine cells. We also show that PTC increases the efflux activity of ABCB1, suggesting that T2R signalling limits the absorption of bitter tasting/toxic substances through modulation of gut efflux membrane transporters.

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Journal articles on the topic 'Bitter substances'

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