Burning Taste Research Articles

Taste Masking of Dexketoprofen Trometamol Orally Disintegrating Granules by High-Shear Coating with Glyceryl Distearate.

Orally disintegrating granules (ODGs) are a pharmaceutical form commonly used for the administration of NSAIDs because of their easy assumption and fast dispersion. The development of ODGs is not easy for drugs like dexketoprofen trometamol (DXKT), which have a bitter and burning taste. In this work, high-shear coating (HSC) was used as an innovative technique for DKXT taste masking. This study focused on coating DXKT granules using the HSC technique with a low-melting lipid excipient, glyceryl distearate (GDS). The HSC technique allowed for the coating to be developed through the thermal rise resulting from the friction generated by the granules movement inside the equipment, causing the coating excipient to soften. The design of the experiment was used to find the best experimental coating conditions in order to gain effective taste masking by suitably reducing the amount of drug released in the oral cavity. The influence of the granule dimensions was also investigated. Coating effectiveness was evaluated using a simulated saliva dissolution test. It was found that low impeller speed (300 rpm) and a 20% coating excipient were effective in suitably reducing the drug dissolution rate and then in taste masking. The coated granules were characterized for their morphology and solid-state properties by SEM, BET, XRPD, DSC, and NIR analyses. A human taste panel test confirmed the masking of DXKT taste in the selected batch granules.

Effect of Three Chlorhexidine-Based Mouthwashes on Human Gingival Fibroblasts: An In Vitro Study

Mouthwashes containing chlorhexidine (CHX) are deemed to be associated with dose-dependent side effects, including burning sensation and taste alteration. To overcome these drawbacks, mouthwashes with CHX at lower concentrations with or without adjunctive agents are proposed. The aim of this in vitro study was to investigate the effects of three CHX-based mouthwashes on human gingival fibroblasts (HGFs). After 3 days of cell culture, groups were randomly treated for 30 s, 60 s or 120 s with (a) CHX 0.05% in combination with cetylpyridnium chloride (CPC) 0.05%; (b) CHX 0.1%; (c) CHX 0.2%; or (d) NaCl as control. Cell viability, cytotoxicity and apoptosis were evaluated at 2 h, 3 days and 6 days after the exposure to the different solutions. Similar cell viability values were found among the test groups at all time points. At day 0, higher cytotoxicity was measured in the group treated with CHX 0.2%, in particular after long application time (120 s), while no significant difference was found between CHX + CPC and the control group. All the investigated mouthwashes were well tolerated by HGF cells for the tested application times. The highest cytotoxic effect was observed for CHX 0.2%; therefore, clinicians should consider limiting its usage to carefully selected clinical situations.

Analysis of efficiency of production of sausage products using non-traditional vegetable raw materials

The article is devoted to the problem of balanced nutrition in modern living conditions. The lack of vitamins, micro and macro elements negatively affects human health. Currently, much attention is paid to the problem of nutrition – new enriched products appear on the shelves, and consumers are increasingly paying attention to their composition and nutritional value. The creation of meat products intended for the prevention and treatment of diseases is an actual direction in the food industry, which has extremely important practical and social significance. The purpose of this work is to increase the nutritional value of sausages by using secondary products of regional plant materials – powdered mustard cake. By steaming the cake, the allyl mustard oil is removed, which gives a specific smell and a burning taste. The resulting additive with a residual essential oil content of not more than 0.05-0.1% is considered suitable for use in the technology of enriched meat products. As a result of the studies, the addition of processed mustard cake in the amount of 6-8 kg per 100 kg of raw meat to cooked and semi-smoked sausages positively affected the functional and technological parameters of the minced systems, as well as the main quality indicators developed in the framework of the experimental prototypes. The use of the indicated plant component in the formulations made it possible to increase the yield of the finished product, as well as to increase the stability of the minced system: in cooked sausages by 6%, in semi-smoked sausages – by 1%. A study of the biological value of protein showed an increase in this indicator in the studied product samples: in cooked sausages, this indicator increased by 1.9%, and in half-cooked sausages by 5.7%. In the test samples, essential amino acids are in more balanced proportions due to the high biological value of the protein.

Influence of Reheating Methods and Frozen Storage on Physicochemical Characteristics and Warmed-Over Flavor of Nutmeg Extract-Enriched Precooked Beef Meatballs.

The effects of convection-oven precooking, frozen storage (−18 °C/ two months) and four different reheating methods—namely, boiling, pan-roasting, convection oven and microwave oven on pH, color, texture, antioxidant activity and warmed-over flavor of beef meatballs were investigated. In this study, four kinds of beef meatballs were prepared: with added butylated hydroxyl toluene (0.02% BHT, M1); with nutmeg extract (0.02%, M2); with nutmeg powder (0.02%, M3) and control (no antioxidant). Addition of (0.02%) nutmeg extracts in beef meatballs M2 resulted in a significant (p < 0.05) decrease in lipid and protein oxidation, hardness and gumminess values after convection oven precooking. Again, M2 reheated by microwave oven significantly (p < 0.05) reduced cooking loss, gumminess, springiness, rancid flavor, saltiness and burnt taste and increased oxidative stability, redness and adhesiveness with the chewiness intensity and overall acceptability compared to control, M1 and M3. Conclusively, the addition of nutmeg extracts (0.02%) as a natural plant antioxidant to precooked beef meatballs can result in reduced lipid and protein oxidation levels, stabilized color and texture values and improved overall acceptance after reheated by microwave oven during two months of frozen storage.

CORRELATION BETWEEN ESTRADIOL SERUM LEVELS WITH XEROSTOMIA INVENTORY SCORE ON MENOPAUSAL WOMEN

Objective: Menopause is a condition of permanent cessation of menstruation for 12 consecutive months. This occurs due to the loss of follicular ovarian activity so that estrogen levels decrease in the body. Menopause can occur at various ages, where the average age of menopause is 51-55 y. Menopause can affect oral tissues as well as other organ systems and cause xerostomia. Some of the symptoms of xerostomia include burning feelings, taste abnormalities, dysarthria, dysphagia, dysgeusia, and halitosis.&#x0D; Methods: This study uses a case series design to assess the correlation between estradiol levels and the incidence of xerostomia in menopausal women. The incidence of xerostomia using the Xerostomia Inventory (XI) Score. This research was conducted in several places, namely H. Adam Malik General Hospital Medan and the hospital network of the Department of Obstetrics and Gynecology, Faculty of Medicine, University of Sumatra Utara. The study population was all postmenopausal women at the H. Adam Malik General Hospital in Medan and the Obgyn FK USU network hospital that met the study inclusion-exclusion criteria. This research was conducted in February with a minimum sample of 38 people.&#x0D; Results: In this study, 38 samples were obtained. Based on the results of the study, it was found that the most age groups were in the range of 56-60 y, the duration of menopause in the 5-10 y group, and the highest Body Mass Index (BMI) was obesity. The mean value of estradiol in menopausal women was 23.61±8.37 pg/ml; the mean value of XI score in menopausal women was 24.29±9.44. The correlation of estradiol levels and XI scores in menopausal women is a strong negative correlation that is-0.651 (p value&lt;0.05). Correlation value of XI score and obesity in menopausal women is a low positive correlation with r = 0.342 (p value&lt;0.05) while the value of correlation XI score with menopausal women who are not obese is a strong positive correlation with r = 0.793 (p value&lt;0, 05).&#x0D; Conclusion: Changes in the oral cavity are caused by aging and hypoestrogenism. The mean age of postmenopausal women was 56.98±4.35, with a mean BMI of 28.24±4.41. Estradiol levels in menopausal women are lower than women of reproductive age in each phase of the menstrual cycle. Significant reduction in estrogen production during menopause causes a decrease in salivary flow, leading to hyposalivation and symptoms of xerostomia.

“Musical gastronomy” in Rossini’s piano miniatures (on the example of the cycle “Quatre horsd’oeuvres et quatre mendiants”).

“Musical gastronomy” in Rossini’s piano miniatures (on the example of the cycle “Quatre horsd’oeuvres et quatre mendiants”).

Divan Şiirinin Estetik Dünyasında Şem'-i Kâfur (Kâfurdan Mum)

The name of camphor tree is camphora in Latin, Kampfer in German, camphre in French and camphor in English. Camphora (camphor) is formed in the oil cells in the leaves, bark and wooden parts of the tree, and crystallizes inside the clefts on the trunk. Later, it is extracted from branches and stems by steam distillation. It is a compound separated from volatile oil through crystallization. An evergreen species, these trees have created thousand years of forests. The tree is native to Japan and South China. However, it is also cultivated in areas with suitable climate conditions. It has a sharp smell and bitter and burning taste accompanied by a cooling effect afterwards. It has been known that as camphor has a wide range of application areas, it is also used in candle making. Referring to candles made from camphor, classical Ottoman poetry used expressions such as “kâfuri sem´a”, “kâfuri sem´”, “sem´a-i kâfur” and “sem´-i kâfur”, creating a wide imagination. In divans (collections of poems), candles made from camphor is the most frequently used expression in the couplets on camphor. This study discussed imagery of sem´-i kâfur in 2 categories: “Imagery Related to Sem´-i Kâfur” and “Various Aspects”. Little imagery that is not included in this classification was analyzed under the title “Various Imagery on Sem´-i Kâfur”. Thus, an element in the aesthetic world of the divan poetry has been tried to be put forward in detail.

The influence of roasting conditions on volatile flavour compounds in raw and roasted cashew kernels (Anacadium ocidentale) grown in Nigeria

The use of inappropriate temperature-time combinations during the roasting of nuts could lead to quality defects, such as burnt taste, short shelf-life, rancidity, and poor flavour. In this study, cashew kernels were roasted in a forced airflow-drying oven for 20, 40,and 60 min at 100, 120, 140, and 160°C. The productswere evaluated for volatile flavour compounds and the sensory evaluation of the roasted cashew kernelsat different roasting conditions. The volatile fraction was isolated using the combined steam distillation–extraction procedure and identified by gas chromatography–flame-ionization detection (GC-FID). The consumer acceptability test was carried out by 100 panellists using nine point hedonic scales to assess preferences for like or dislike, colour, taste, texture, flavour,and overall acceptability. It was found that there were significant differences in flavour compounds between the different conditions of roasting. Twenty-nine volatile compounds were identified in both fresh and roasted cashew kernelscomprising five main classes,which consist of 12 hydrocarbons, eight aldehydes, four ketones, three alcohols,and one acid. The volatile compounds(mg/100g) ranged from 5.03x10-2to 1.20 (2-butanone), 7.46x10-6to 1.85 (hexanal), 8.91x10-6to 1.94 (acetone), 6.74x10-1to 2.24 (benzaldehyde). The amount of generated volatile compounds increased astheroasting temperature and time increased. The consumer acceptability test revealed that samples roasted for 40 or 60 min at 140°C produced the most acceptable product in terms of all the measured attributes. The study showed that the roasting conditions produced acceptable cashew kernelsof desirable colour and superior flavour quality that enhance direct and commercial utilization.

Optimizing the Effect of Temperature-Time Combinations on the Quality Attributes of Roasted Cashew (Anacardium occidentale) Kernel

The use of inappropriate temperature-time combinations during roasting of nuts could lead to quality defects, such as burnt taste, dark colour, short shelf-life, rancidity, and poor flavour. The objective of this study was to determine the effect roasting temperature (100-160°C) and time (20-60 min) on colour parameters (L*, a*, and b*- values), Browning Index (BI), Hardness, consumer acceptability and moisture content of both whole cashew-kernel and cashew nut paste using Response Surface Methodology. The experimental runs were established using central composite rotatable design. Second-order polynomial models were developed for predicting the determined product properties. The results showed that CIELAB L*-value of the colour decreased from 54.41 to 41.23 while a*- and b*- values increased from 6.08 to 15.84 and 13.77 to 25.92, respectively, p<0.05 as the temperature and time increased. The moisture content and hardness decreased from 6.35 to 1.02% and 34.24 to 19.94 N, respectively, while BI increased from 47.47 to 97.94 as the temperature and time increased. The results showed that colour parameters (L*, a*, b*-values, BI) of whole cashew-kernel and a*-values of cashew nut paste could be used to monitor the roasting quality of cashew nut. The regression models significantly described the changes in moisture, hardness and colour parameters at p<0.05 (R2=0.96). The recommended range of roasting temperature and time of wholekernel for cashew paste was 145°C and 40 min with desirability of 0.85 which is measure of goodness of fit of RSM model. The study showed that the optimized processing conditions produced acceptable cashew kernel and paste of desirable colour and superior flavour quality with short processing time that will enhance direct and commercial utilization.

Influence of gamma radiation on the physical and sensory properties of two Brazilian rice cultivars.

Little has been reported about the effects of gamma radiation on the physical and sensory characteristics of rice. Samples were irradiated with 60 Co in doses 0, 1, 2 and 5 kGy, on a rate of 0.4 kGy h-1 . The evaluation of instrumental color showed that increasing doses promoted the yellowing (higher b* value) of the rice grains. Hardness was decreased and stickiness was increased in cooked rice with increasing doses. Sensory evaluation using quantitative descriptive analysis showed that increasing doses promoted higher occurrence of yellowish appearance, emergence of burnt aroma, and an increase of bitter and burnt taste. The sensory acceptance test by 9-point hedonic scale showed alteration of the samples irradiated with 5 kGy in all evaluated attributes (appearance, color, aroma, taste and texture). The lowest dose (1 kGy), however, had good acceptability by the panelists. Rice may be subjected to 1 kGy dose of gamma radiation without changes or with small changes in physical properties and with good overall acceptability. © 2016 Society of Chemical Industry.

Influence of low pH on the metabolic activity of Lactobacillus buchneri and Lactobacillus parabuchneri strains in Tilsit-type model cheese

Round-shaped and uniformly distributed eyes are important quality features for several Swiss semi-hard cheese varieties such as Tilsit. Recently, the growth of histamine-producing strains of Lactobacillus parabuchneri has been associated with cheese defects, such as crack formation and burning taste. In this paper, the influence of pH on the metabolic activity of added strains of Lactobacillus buchneri and L. parabuchneri, which possess various CO2-producing activities, was studied in Tilsit-type model cheeses. Two different pH values were obtained by modifying the cheese-making process (curd washing and type of ripening). Lactate, free amino acids, free short-chain fatty acids and 1,2-propanediol were determined in the ripened cheeses. In the acidic cheeses (average pH = 5.40), significantly more 1,2-propanediol was produced, presumably from lactate. Lactobacillus parabuchneri FAM 21731, a histamine-producing strain, produced small amounts of 1,2-propanediol (0.2 mmol.kg−1) and high amounts of histamine (3.3 mmol.kg−1). Ornithine was produced by all the studied strains, with the highest amount of 9.0 mmol.kg−1 produced by L. parabuchneri FAM 21835 in the acidic cheeses. Standard cheese making representing the high pH group (curd washed and smear ripened, average pH = 5.70), and the addition of a glutamate decarboxylase-positive L. buchneri, resulted in higher amounts of γ-aminobutyric acid (GABA) (8.1 compared to 3.3 mmol.kg−1 in the control standard cheeses). Irrespective of the strain, the GABA level was much higher in all the acidic cheeses than in the standard cheeses (14.7 compared to 4.6 mmol.kg−1, respectively). The study clearly demonstrates the importance of the cheese pH in the metabolic activity of the added strains during cheese ripening.

Physicochemical Properties and Chemical Constituents of Oil from Joan Seed (Trachyspermum ammi L)

The paper deals with the investigation of the fatty oil of carom seed (Trachyspermum ammi) for its physicochemical characteristics and fatty acid composition. Oil from carom seed collected from local market was extracted with n-hexane in a glass Soxhlet apparatus. Extracted oil was dark green, burning taste, spicy in odour and soluble in n-hexane, chloroform, pet. ether and benzene. Its chemical characteristic such as acid value (6.69), Iodine value (79.39), Peroxide value (457.11), Saponification value (184.32), Unsaponified matter (9.11), Free fatty acid value as petroselinic acid (48.1) were determined by conventional method. The composition of fatty oil was determined by Gas Liquid Chromatography (GLC). From GLC analysis the main constituents of fatty oil such as Petroselinic acid (89.35%), Oleic acid (5.86%), Linoleic acid (4.79%) were determined. For the better evaluation of these spices, it is necessary to know their complete chemical composition.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14571 J. Environ. Sci. &amp; Natural Resources, 5(2): 15-21 2012

Benzopyrene Serum Concentration After Endovenous Laser Ablation of the Great Saphenous Vein

During endovenous laser ablation (EVLA) of the great saphenous vein, patients often involuntarily mention an uncomfortable "burnt" smell and taste. When applying intense heat to proteins and carbohydrates, it is inevitable that polycyclic aromatic hydrocarbons (PAHs) are formed. This group of PAH includes the human carcinogen benzo[a]pyrene (B[a]P). This study determined the serum concentration of B[a]P just before and after EVLA. A total of 20 patients were included. The B[a]P serum concentration was determined just before and directly after EVLA. In 18 patients, B[a]P was determined before and after EVLA. In 2 patients, EVLA was not possible. In this study, no elevated serum concentration of B[a]P was found before and after EVLA. It remains to be established which heat products cause the burnt smell and taste sensation in patients during EVLA. Further research is needed to determine whether EVLA can be considered as a safe procedure.

Effect of high-dose irradiation and autoclave treatment on microbial safety and quality of ready-to-eat Bulgogi sauce

In Korea, commercialized sauce for ready-to-eat (RTE) Bulgogi is usually manufactured using heat treatment to ensure that it has a long shelf-life. However, heat treatment may adversely affect the taste and flavor of the sauce, thus, the development of suitable sterilizing methods for RTE sauces is necessary to preserve the quality of the sauce during long storage periods. In this study, total bacterial growth, the viscosity, and the sensory properties of Bulgogi sauce were compared between sterilization with gamma irradiation (0–40kGy) and autoclave treatment during storage at 35°C for 90 days. No bacterial growth was observed following irradiation at more than 10kGy or after autoclave treatment. However, the viscosity and sensory properties of samples gamma-irradiated at above 10kGy or autoclave-treated were significantly changed, even though autoclave treatment induced a burnt taste and flavor. Therefore, a gamma irradiation of 10kGy was effective to prepare ready-to-eat Bulgogi sauce with microbial safety and original sensory qualities.

Final Safety Assessment of Coal Tar as Used in Cosmetics

Coal Tar is a semisolid by-product obtained in the destructive distillation of bituminous coal, which functions in cosmetic products as a cosmetic biocide and denaturant--antidandruff agent is also listed as a function, but this is considered an over-the-counter (OTC) drug use. Coal Tar is a nearly black, viscous liquid, heavier than water, with a naphthalene-like odor and a sharp burning taste, produced in cooking ovens as a by-product in the manufacture of coke. Crude Coal Tar is composed of 48% hydrocarbons, 42% carbon, and 10% water. In 2002, Coal Tar was reported to the Food and Drug Administration (FDA) to be used in four formulations, all of which appear to be OTC drug products. Coal Tar is monographed by the FDA as Category I (safe and effective) OTC drug ingredient for use in the treatment of dandruff, seborrhoea, and psoriasis. Coal Tar is absorbed through the skin of animals and humans and is systemically distributed. In short-term studies, mice fed a diet containing Coal Tar found it unpalatable, but no adverse effects were reported other than weight loss; rats injected with Coal Tar experienced malaise in one study and decreased water intake and increased liver weights in another; rabbits injected with Coal Tar residue experienced eating avoidance, respiratory difficulty, sneezing, and weight loss. In a subchronic neurotoxicity study using mice, a mixture of phenols, cresols, and xylenols at concentrations approximately equal to those expected in Coal Tar extracts produced regionally selective effects, with a rank order of corpus striatum > cerebellum > cerebral cortex. Coal Tar applied to the backs of guinea pigs increases epidermal thickness. Painting female rabbits with tar decreases the absolute and relative weights of the ovaries and decreased the number of interstitial cells in the ovary. Four therapeutic Coal Tar preparations used in the treatment of psoriasis were mutagenic in the Ames assay. Urine and blood from patients treated with Coal Tar were genotoxic in bacterial assays. Coal Tar was genotoxic in a mammalian genotoxicity assay and induced DNA adducts in various tissue types. Chronic exposure of mice to Coal Tar significantly decreased survival and liver neoplasms were seen in a significant dose-related trend; in other studies using mice lung tumors and perianal skin cancers were found. Coal Tar was comedogenic in three small clinical studies. Folliculitis is associated with the prolonged use of some tars. Several published reports describe cases of contact sensitivity to Coal Tar. Polycyclic aromatic hydrocarbons, which make up Coal Tar, are photosensitizers and cause phototoxicity by an oxygen-dependent mechanism. A retrospective study of the reproductive toxicity of Coal Tar in humans compared exposed women to controls and found little difference in spontaneous abortion and congenital disorders. Cancer epidemiology studies of patients who have received Coal Tar therapy of one form or other have failed to link treatment with an increase in the risk of cancer. Although the Cosmetic Ingredient Review (CIR) Expert Panel believes that Coal Tar use as an antidandruff ingredient in OTC drug preparations is adequately addressed by the FDA regulations, the Panel also believes that the appropriate concentration of use of Coal Tar in cosmetic formulations should be that level that does not have a biological effect in the user. Additional data needed to make a safety assessment include product types in which Coal Tar is used (other than as an OTC drug ingredient), use concentrations, and the maximum concentration that does not induce a biological effect in users.

Effect of roasting time and storage time on sensory attributes and consumer acceptability of peanut butters in southern Africa

AbstractThis study explored how sensory attributes and consumer acceptability of peanut butters varied with differing roasting times (40 to 55 min) and storage times (up to 48 weeks) for shelf‐life testing. Quantitative descriptive analysis generated sensory terms that were appropriate to the local situation. Increased roasting time was associated with the sensory attributes brown colour, roasted taste and burnt taste. Consumer acceptance varied among consumers with two preferred roasting times of either 40 min (67% of consumers) or 50 min (23% of consumers). This was related to distinct peanut flavour profiles. During the storage study of five selected butters consumer acceptability did not alter with storage period. Sensory testing, however, was more sensitive to product changes: sensory attributes that varied with storage were sticky texture, stale odour and sweetness. Copyright © 2008 John Wiley &amp; Sons, Ltd

초고압 및 냉동 처리한 대추술의 품질특성

대추술의 가열살균으로 인한 품질저하를 개선하고자 초고압(500 ㎫, 5분) 및 냉동처리(-20℃에서 3일간 냉동 후 20℃에서 4시간 동안 해동)를 이용하여 대추술을 살균한 다음 가열처리구(63℃, 10분) 및 시판대추술과 비교하면서 품질특성을 조사하였다. 미생물은 초고압 및 시판대추술에서는 검출되지 않았고, 가열처리구에서는 세균류만이 10 CFU/㎖ 이하로 검출되었으며, 냉동처리구에서는 10²～10³ CFU/㎖ 수준으로 검출되어 30～60%의 살균효과를 보였다. 초고압, 냉동 및 가열처리는 대추술의 pH, 산도, 아미노산도, 환원당 및 에탄올함량 등의 성분에 유의적인 영향을 미치지 않았으나, 색도에는 유의적으로 영향을 미쳤으며 변화폭은 초고압 처리가 가장 작았고 다음으로 가열 및 시판, 냉동처리 순으로 크게 나타났다. 관능검사 결과에서는 가열처리 시 신맛 및 화한 맛이 감소하면서 전체적인 품질이 낮아진 데 비하여, 초고압 및 냉동처리 시에는 신맛과 화한맛이 변하지 않으면서 품질이 유지되었다. 한편 시판 대추술에서는 탄내, 단내 및 단맛이 뚜렷이 증가하고 신내 및 신맛이 감소하면서 가장 낮은 품질을 보였다. 이상으로부터 초고압처리는 살균효과가 우수하고 제품의 성분 및 색도에 큰 영향을 미치지 않으면서 본래 대추술의 관능적인 특성을 최대 유지할 수 있는 효과적인 비열살균법임을 알 수 있었고, 냉동처리 역시 관능적으로 받아들일 수 있는 수준으로 품질이 유지되었으나 불완전한 살균으로 인한 저장성 연구가 추가되어야 할 것이다.

The Salty and Burning Taste of Capsaicin

The tongue is a kind of funny organ. From a physiological point of view, you can place solutions on the tongue that will be toxic to most any cell, and the tongue will give information, in a hopefully reversible manner, about the solution's chemical composition and whether it should be ingested.

Medium Chain Triglycerides as Vehicle for Palatable Oral Liquids

Aqueous liquid formulations of efavirenz, a nonnucleoside inhibitor of reverse transcriptase, have prolonged burning (peppery) taste. Medium-chain triglycerides (MCT) was used as the vehicle to mask the taste and obtain palatable oral liquid formulations containing 20 mg/mL efavirenz. The use of MCT for enhancement of palatability and stability is recommended for drugs that show high solubility and partitioning in this vehicle.

The effect of metronidazole on the human taste threshold to alcohol.

SummaryA method is described for measuring the taste threshold to alcohol in a sample of 163 subjects whose average age was 27 years. The subjects taste ascending concentrations of alcohol in water from 0.25% up to 64% absolute alcohol. Five mls of each concentration is tasted for 20 seconds, spat out, and then the subject washes out his mouth with the diluent water. Alcohol is detected as a sweet taste at a concentration of 4.2±S.E. 0.24% alcohol. The sweet taste changes to a burning taste at a mean concentration of 21.2±S.E. 1.22% alcohol. The frequency distributions for the sweet and burning tastes of alcohol depart significantly from the unimodal normal shape. During the 20 seconds while alcohol is maintained in the mouth for appreciation of its taste, the concentration of the 4% solution falls to 2%, and the concentration of the 20% solution falls to 16%. The taste threshold for metronidazole was tested in the same subjects and found to be 149±S.E. 17 mg/litre; the frequency distribution curve is unimodal in shape but negatively skewed. The taste threshold for PTC in the same subjects was bimodal with modes at 20 and 1300 mg/litre.Oral administration of 600 mg of metronidazole as 200 mg tablets over a period of 14 hours, caused no change in the taste threshold to alcohol during the following 6 days. Administration of 800 mg metronidazole over a period of 20 hours, caused a significant elevation of both sweet and burning taste thresholds to alcohol which reached its maximum on the second day after the last tablet had been taken. The taste threshold returned to its pre‐metronidazole level on the fourth day. The alcohol taste threshold was raised at concentrations of metronidazole equivalent to those excreted in the saliva.The taste threshold to alcohol is a measurable human physiological characteristic. In humans, and by implication in rats, taste threshold to alcohol is appreciated through pereipheral receptors and specific afferent taste discharges, and the taste mechanism is the primary regulator of alcohol intake. The finding of a taste threshold distribution curve with more than one mode provides evidence that there may be a genetic basis to variations in alcohol taste threshold. The action of metronidazole on the alcohol taste threshold suggests that this drug may exert psychotherapeutic effects on alcohol consumption in man not only through peripheral taste receptiors but also through central taste pathways.