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PubMed2004

Chemical and sensory characterization of DOC red wines from Marche (Italy) related to vintage and grape cultivars.

Monomeric phenols, color and copigmentation parameters, pigments with different chemical structure, tannin, glucose, fructose, glycerol, ethanol, and organic acids were determined in DOC red wines from Marche (Italy), obtained during three different vintages ranging from 1996 to 2000. The intensity of the bitter and astringent tastes of the wines was determined with panel tastings. Lacrima di Morro and Vernaccia di Serrapetrona (obtained from local cultivars) were different from Rosso Piceno, Rosso Piceno Superiore, and Rosso Conero (produced from different percentages of Sangiovese and Montepulciano). Vernaccia, a red, sweet, "spumante" wine, was an outlier. Lacrima showed a low tannin content, a high content of small pigments and phenols, and a high ratio of copigmented color, which persisted after 3 years of aging. The chemical determinations accounted for a high percentage of variability of measured panel astringency, copigmented color, and measured wine absorbance at 520 nm. It was not possible to create a predictive model for bitterness.

Fruit↗
PubMed2005

Isolation, structure determination, synthesis, and sensory activity of N-phenylpropenoyl-L-amino acids from cocoa (Theobroma cacao).

Application of chromatographic separation and taste dilution analyses recently revealed besides procyanidins a series of N-phenylpropenoyl amino acids as the key contributors to the astringent taste of nonfermented cocoa beans as well as roasted cocoa nibs. Because these amides have as yet not been reported as key taste compounds, this paper presents the isolation, structure determination, and sensory activity of these amino acid amides. Besides the previously reported (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-3-hydroxy-L-tyrosine (clovamide), (-)-N-[4'-hydroxy-(E)-cinnamoyl]-L-tyrosine (deoxyclovamide), and (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tyrosine, seven additional amides, namely, (+)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-aspartic acid, (+)-N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid, (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-glutamic acid, (-)-N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid, (-)-N-[4'-hydroxy-(E)-cinnamoyl]-3-hydroxy-L-tyrosine, (+)-N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-aspartic acid, and (+)-N-[(E)-cinnamoyl]-L-aspartic acid, were identified for the first time in cocoa products by means of LC-MS/MS, 1D/2D-NMR, UV-vis, CD spectroscopy, and polarimetry, as well as independent enantiopure synthesis. Using the recently developed half-tongue test, human recognition thresholds for the astringent and mouth-drying oral sensation were determined to be between 26 and 220 micromol/L (water) depending on the amino acid moiety. In addition, exposure to light rapidly converted these [E]-configured N-phenylpropenoyl amino acids into the corresponding [Z]-isomers, thus indicating that analysis of these compounds in food and plant materials needs to be performed very carefully in the absence of light to prevent artifact formation.

Amides↗
PubMed2000

Saliva tannin interactions.

Many plant foods contain tannins, compounds that bind proteins, such as mammalian enzymes. Although described as tasteless, tannins can be detected orally by their astringency. However, the actual mechanism of oral detection and the effect of tannins on mastication and swallowing have been little investigated. Here, we show from in vitro tests that tannic acid, a common standard in tests used to detect tannins, significantly reduces the lubricating qualities of human saliva both by decreasing its viscosity and increasing friction, both factors lending support to the notion that astringency is a tactile phenomenon. From the literature, it is clear that this effect depends on the presence of salivary proline-rich proteins (PRP). In a mammalian context, ingestion of tannin-rich foods in a species with salivary PRP will be signalled by interference with bolus formation during mastication while the increase in friction may also be detectable and lead to increased tooth wear if the signal is ignored. In a human context, cross-cultural preferences for tannin-rich beverages such as tea, coffee and red wine at the end of meals may be explained by reduction in adhesion of food particles to the oral mucosa allowing their rapid oral clearance.

Adult↗
PubMed1989

Proanthocyanidins from Krameria triandra root.

Oligomeric proanthocyanidins were isolated from rhatany root (Krameria triandra) and characterised by acid hydrolysis, thiolytic degradation, and spectroscopic methods. They consisted of 2-14 flavanol units with mainly 2,3-cis configuration and with a propelagonidin:procyanidin ratio of 65:35. The predominant interflavan linkage was [4,8]. [4,6]-Bonds were present in the higher oligomers, presumably forming branched chain units. The astringency of the drug was mainly due to proanthocyanidins with degrees of polymerization from 5-10, and these were also the astringent compounds of rhatany tea and tincture. A pharmacological screening of the extract revealed a significant antimicrobial effect.

Animals↗
PubMed2005

Final report of the safety assessment of Acacia catechu gum, Acacia concinna fruit extract, Acacia dealbata leaf extract, Acacia dealbata leaf wax, Acacia decurrens extract, Acacia farnesiana extract, Acacia farnesiana flower wax, Acacia farnesiana gum, Acacia senegal extract, Acacia senegal gum, and Acacia senegal gum extract.

These ingredients are derived from various species of the acacia plant. Only material derived from Acacia senegal are in current use according to industry data. The concentration at which these ingredients are reported to be used ranges from 9% in mascara to 0.0001% in tonics, dressings, and other hair-grooming aids. Gum arabic is a technical name for Acacia Senegal Gum. Gum arabic is comprised of various sugars and glucuronic acid residues in a long chain of galactosyl units with branched oligosaccharides. Gum arabic is generally recognized as safe as a direct food additive. Little information is available to characterize the extracts of other Acacia plant parts or material from other species. Acacia Concinna Fruit Extract was generally described as containing saponins, alkaloids, and malic acid with parabens and potassium sorbate added as preservatives. Cosmetic ingredient functions have been reported for Acacia Decurrens Extract (astringent; skin-conditioning agent--occlusive) and Acacia Farnesiana Extract (astringent), but not for the other Acacias included in this review. Toxicity data on gum arabic indicates little or no acute, short-term, or subchronic toxicity. Gum arabic is negative in several genotoxicity assays, is not a reproductive or developmental toxin, and is not carcinogenic when given intraperitoneally or orally. Clinical testing indicated some evidence of skin sensitization with gum arabic. The extensive safety test data on gum arabic supports the safety of Acacia Senegal Gum and Acacia Senegal Gum Extract, and it was concluded that these two ingredients are safe as used in cosmetic formulations. It was not possible, however, to relate the data on gum arabic to the crude Acacias and their extracts from species other than Acacia senegal. Therefore, the available data were considered insufficient to support the safety of Acacia Catechu Gum, Acacia Concinna Fruit Extract, Acacia Dealbata Leaf Extract, Acacia Dealbata Leaf Wax, Acacia Decurrens Extract, Acacia Farnesiana Extract, Acacia Farnesiana Flower Wax, Acacia Farnesiana Gum, and Acacia Senegal Extract in cosmetic products. The additional data needed to complete the safety assessment for these ingredients include (1) concentration of use; (2) identify the specific chemical constituents, and clarify the relationship between crude Acacias and their extracts and the Acacias and their extracts that are used as cosmetic ingredients; (3) data on contaminants, particularly relating to the presence of pesticide residues, and a determination of whether Acacia melanoxylon is used in cosmetics and whether acamelin (a quinone) and melacacidin (a flavin) are present in the Acacias that are being used; (4) skin sensitization study (i.e., dose response to be determined); (5) contact urticaria study at use concentration; and (6) ultraviolet (UV) absorption spectrum; if there is significant absorbance in the UVA or UVB range, then a photosensitization study may be needed. It was also noted that other data may be needed after clarification of the chemical constituents of the Acacia-derived ingredients.

Acacia↗
PubMed2004

Metallic taste and retronasal smell.

A series of experiments investigated the nature of metallic taste reports and whether they can be attributed to the development of a retronasal smell. Two studies showed that the metallic sensation reports following oral stimulation with solutions of FeSO4 were reduced to baseline when the nose was occluded. No such reduction was seen for CuSO4 or ZnSO4, which were more bitter and astringent, respectively, and less metallic. A discrimination test based on weak but equi-intense levels of FeSO4 and CuSO4 showed that FeSO4 could be discriminated from water with the nose open but not when occluded, but that discrimination of CuSO4 from water was not impaired by nasal occlusion. A discrimination test demonstrated that the headspace over solutions of FeSO4 was not different from water, although some subjects could discriminate FeSO4 solutions from water in the mouth when the nose was occluded, perhaps by tactile or astringent cues. These results confirm that metallic taste reports following oral stimulation with FeSO4 are likely due to development of a retronasal smell, possibly following a lipid oxidation reaction in the mouth. However, metallic taste reports may arise from different mechanisms with copper and zinc salts.

Ferrous Compounds↗
PubMed1996

The use of Methenamine as an antiperspirant for amputees.

The socket of a prosthesis is a tightly closed container. Sweating inside the socket is annoying and may also irritate the skin over the stump or lead to local infection such as folliculitis. The most effective method of preventing sweating is by the use of astringent agents. Formaldehyde is a very strong astringent but is not pleasant to use and may cause skin irritation and systemic reactions. Methenamine, in water or when applied to the skin, decomposes to generate formaldehyde in small quantities which do not cause side effects. Methenamine was used on the stump of sixteen amputees. The trial was conducted as a double blind study using two different solutions market as solution A and as solution B. The effectiveness of the solutions as an antiperspirant was evaluated clinically by the subjects and the physician. Solution A containing Methenamine, was found significantly effective, both by the subjects and physician when compared with the solution B the blank one. The use of Methenamine as an antiperspirant is recommended in amputation stumps.

Administration, Topical↗
PubMed1987

[Amaranth: a technological alternative in child nutrition].

The relative high protein and oil content of amaranth grain and its relative high-protein quality are desirable characteristics to use it as a weaning food. Such a product was prepared with A. caudatus grain. Batches were processed without previous treatment of the grain, washed with water or with a bicarbonate solution. Processing consisted of cooking at atmospheric pressure for 10 min before passing the partially cooked grain through a double drum-drier heated with steam at 70 psi, and at a velocity of 3 rpm. Batches were also processed with the addition of strawberry flavor. All samples were analyzed for damaged starch and fluid characteristics using a 10% concentration, viscosity (by the Brabender amylograph), water absorption and retention, particle size, stability of the suspension, and soluble sugars. The different samples were organoleptically evaluated for acceptability, consistency, astringency, sweetness flavor and aroma, with a 20-member panel. A product with water or with milk and sugar was also evaluated. The results indicated that washing the grain prior to cooking increased the consistency of the product and eliminated the astringency of the grain. Washing also increased water absorption and retention, soluble sugars and the coefficient of consistency. all samples exhibited 100% damaged starch and had a pseudoplastic behavior. The raw grain flour gave a viscosity of 500 UB, while for the processed samples this value increased to 1,420 UB. In general, its acceptability on the part of the panelists was high. It was good for the product with strawberry flavor, but it was even better for the sample without flavor which had been previously washed. These results, as well as others reported on nutritive value, confirm the hypothesis regarding the use of processed whole grain amaranth as a weaning food.

Amaranthus↗
PubMed1985

Therapeutic agents used in the treatment of calf diarrhea.

This article discusses various therapeutic agents that have been used in the treatment of calf diarrhea, such as antibiotics, modulators of intestinal motility, gastrointestinal protectants and absorbents, astringents, agents affecting secretion, steroids, antiadhesives, antitoxins, and monoclonal antibodies. The roles of nutrition and the administration of colostrum following onset of diarrhea are also discussed.

Animal Nutritional Physiological Phenomena↗
PubMed1998

[Bactericidal and anti-toxin activities of catechin on enterohemorrhagic Escherichia coli].

We examined the bactericidal activity of catechin, an astringent ingredient of tea, on enterohemorrhagic Escherichia coli (EHEC) O157:H7 and the anti-toxin activity of catechin on vero toxin (VT), the main pathogenic factor of EHEC O157:H7. To examine bactericidal activity, we added 1 X 10(4) CFU/ml bacteria to 1.25 to 20 W/V% of green tea extract or the PBS solution containing 25 to 400 micrograms/ml of (-) epigallocatechin gallate (EGCg), which is the main catechin ingredient of green tea leaf, and counted the number of live bacteria at various intervals. After 3 to 5 hours, no live bacteria were seen in 1.25 to 2.5 (regular drinking concentration) % green tea extract. In the high concentrations of 100 to 400 micrograms/ml EGCg the number of live bacteria decreased with time and after 24 hours no survivors were seen. In the low concentrations of 25 to 50 micrograms/ml EGCg, however, no change was observed in the number of live bacteria during 5 hours. After 24 hours the bacteria in 50 micrograms/ml were killed and the number of bacteria in 25 micrograms/ml decreased to one tenth of that at the start. To examine the anti-toxin activity, we mixed equal volumes of 2 ng/0.1 ml VT2 and 0.5 to 2 mg/0.1 ml catechin in vitro and incubated them at 37 degrees C for various times. Then we inoculated 0.2 ml of the mixture intraperitonealy to BALB/c mice. One mg of catechin inhibited by 100% the lethal toxicity of 2 ng of VT2 (LD 100) to mice. The inhibition of lethal toxicity of VT2 by catechin depended on the incubation time. The rate of inhibition was 0, 40 and 100% for 9, 12 and 18-24 hours incubation, respectively. These results suggest that catechin has not only bactericidal activity on EHEC O157:H7 but also anti-toxin activity on vero toxin.

Animals↗
PubMed1992

The general practice 'management of otitis externa'.

Clinical confusion, treatment failure and recurrence commonly plague the Management of Otitis Externa. The aim of this study was to investigate the clinical attitudes and habits of army general practitioners and to review the recent literature. The results of a questionnaire survey showed that although all the respondents agreed that aural toilet was important, only 50% felt confident in performing aural toilet and packing. There also appeared to be much greater scope for the use of astringents and effective preventative measures in addition to aural toilet. The discussion emphasises and need for careful selection of the most appropriate topical agent, whilst highlighting the roles of practical procedures, bacteriology and prevention. A practical guide to diagnosis and management is offered with the aid of illustrations and an algorithm.

Administration, Topical↗
PubMedDate not supplied

Gingival inflammatory response induced by chemical retraction agents in beagle dogs.

PURPOSE: The aim of this in vivo study on dogs was to investigate and compare the inflammatory potential of four different retraction agents on the gingival connective tissue. MATERIALS AND METHODS: All procedures on eight beagle dogs were performed under general anesthesia: taking oral hygiene measures, placing retraction cords medicated with four chemical agents into the gingival sulci, and taking tissue biopsies. The specimens were evaluated after a 10-minute exposure to chemical agents. The inflammatory response of the connective tissue underlying the sulcular and junctional epithelium triggered by retraction agents was assessed quantitatively. Microscopic images of tissue specimens were morphometrically analyzed using a computer-assisted morphometric method. RESULTS: The most intense inflammatory response in the connective tissue underlying the sulcular epithelium was triggered by astringent retraction agents--Racestyptine in specimens taken after 1 day and 1 week and Rastringent after 1 day (P < .05). Tetrahydrozoline-sympathomimetic vasoconstrictor (Visine) was found to have the lowest inflammatory potential. Retraction chemicals produced no significant effects on the connective tissue subjacent to the junctional epithelium. The ratio of the connective tissue area to that of the inflammatory infiltrate showed that 25% aluminum chloride (Racestyptine) was the most aggressive and tetrahydrozoline the least aggressive retraction agent used. CONCLUSION: All the retraction chemicals tested increased the infiltration with inflammatory cells in gingival connective tissue.

Aluminum Chloride↗
PubMed1975

Aluminum chloride in the treatment of symptomatic athelete's foot.

Various aluminum salts were evaluated for in vitro and in vivo antimicrobial activity and ability to bind with serum proteins (astrigency) with the object of finding a colorless substance to substitute for carbol-fuchsin solution (Castellani paint) in the treatment of symptomatic interdigital athlete's foot. Aluminum chlorohydrate was more powerful in killing bacteria and fungi than aluminum acetate and aluminum chloride. However, aluminum chloride showed pronounced astringency and was the only compound to bring about rapid resolution of the signs and symptoms of athlete's foot in open-ended clinical trials. This salt promptly controls odor, pruritus, and maceration. The beneficial effect depends largely on drying the surface, not killing organisms. A solution of 30% aluminum chloride was found to be equlvalent to carbol-fuchsin solution in effectively treating symptomatic athlete's foot.

Aluminum↗
PubMed1993

Clinical studies on marginal gingiva around abutment tooth (Part 3). Effect of tannin-fluoride preparation on gingival health.

It was examined whether the tannin-fluoride preparation (HY preparation), which might have a caries-reductive, plaque inhibiting and astringent action, could reduce the incidence of gingival inflammation around abutment teeth. Zinc oxide eugenol cement mixed with the HY preparation was packed in the cavity prepared in the resin base facing the abutment tooth. Gingival crevicular fluid (Periotron units:GCF), gingival index (GI), plaque index (PlI) and probing depth around the abutment teeth were measured over a 3 month period. The following results were obtained: 1. GCF decreased at month 1 and showed low values at months 2 and 3. 2. GI showed a decreasing tendency. 3. PlI and probing depth did not show obvious changes. These results indicate that the tannin-fluoride preparation reduces gingival inflammation around abutment teeth.

Adolescent↗
PubMed1996

A comparison of topical tannic acid versus iontophoresis in the medical treatment of palmar hyperhidrosis.

This is a report comparing the efficacy of tannic acid lotion (an astringent) and iontophoresis in the medical treatment of idiopathic hyperhidrosis. Ten patients with long-standing symptomatic idiopathic palmar hyperhidrosis were recruited into the study. One palm was treated with daily tannic acid (20%) lotion and the opposite palm with iontophoresis. Visual scoring using a visual analog scale by patients and assessors showed the mean score to be significantly lower on the iontophoresis treated palm than the tannic acid treated palm. There was significant reduction in the severity of hyperhidrosis on the iontophoresis treated palm after treatment. There was also a significant reduction in transepidermal water vapour loss on the iontophoresis treated palms. The study indicated that iontophoresis is an effective medical treatment for idiopathic hyperhidrosis. The disadvantage of iontophoresis is its short-lived effect. Patients need to undergo the treatment weekly to achieve euhidrosis.

Administration, Topical↗
PubMed1997

A case of fibrin sealant application for closing benign trachea-esophageal fistula (TEF).

Surgical treatment of upper airway-esophageal communications are frequently lead to failure. Having previous experience of thoracic administration of Tissucol fibrin glue authors attempted the local application in a case of TEF. A young lady suffering from myasthenia gravis required longstanding artificial ventilation. Not surprisingly a TEP developed in the area of the tracheostomy. There was no room for surgical repair of the TEF. Two administrations of rapid acting form of Tissucol was needed following local astringent therapy and enzymatic debridement to achieve a complete and permanent closure of a tracheobronchial sinus in a diameter of 5 mm. In addition of meticulous technique and of general supporting therapy special attention was paid to the followings: 1/healthy wound edges 2/ local infection control 3/dry environment 4/patient building up strategy.

Adult↗
PubMed1998

Chemical synthesis and characterization of the sweet protein mabinlin II.

The sweet protein mabinlin II isolated from the seeds of Capparis masaikai consists of the A chain with 33 amino acid residues and the B chain composed of 72 residues. The B chain contains two intramolecular disulfide bonds and is connected to the A chain through two intermolecular disulfide bridges. The A chain was synthesized by the stepwise fluoren-9-ylmethoxycarbonyl (Fmoc) solid-phase method in a yield of 5.9%, while the B chain was synthesized by a combination of the stepwise Fmoc solid-phase method and fragment condensation in a yield of 6.0%. Disulfide formation and combination of the A and B chains followed by purification by ion-exchange high-performance liquid chromatography (HPLC) gave mabinlin II in a yield of 47.4%. The characterization of the synthetic mabinlin II by HPLC, electrospray ionization mass spectrometry, amino acid analysis, and disulfide bond determination fully supported the expected structure. A 0.1% solution of the synthetic mabinlin II had an astringent-sweet taste.

Amino Acid Sequence↗
PubMed1998

Effect of edible oils and oil emulsions on the perception of basic tastes.

The intensity of sweet, bitter or astringent tastes is reduced by consumption of edible oil or oil emulsions immediately before the ingestion of test solutions. The basic taste substances were dissolved in 30% aqueous ethanol, flavoured with plant extracts. The time-intensity dependence was influenced similarly. The sensitivity of taste receptors returned to the original value within 15-20 min. Intensities of acidic or salty tastes were not affected.

Catechin↗