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PubMed1988

[Detection of the intercellular borders of the endothelium using scanning electron microscopy].

Three different approaches for studying aorta endothelial cells by scanning electron microscopy (SEM) were compared to expose cell border lines and surface shape simultaneously. Staining of aorta probes with silver nitrate leads to more specific silver deposits at cell junctions, but unsatisfactory image resolution obscures any detail of cell junctions and other fine structural features. Endothelium impregnated with tannin-osmium showed enhanced cell junction detail, but this method resulted in formation of presumably artificial structures. Osmium tetraoxide was most optimal for impregnation of aorta probes, as it exposed well cell border lines, excluded artifacts of tannin-osmium staining, provided a good image resolution in SEM, and allowed to analyse the ultrastructural features of cell surface.

Animals↗
PubMed1988

[Production of an diagnostic erythrocyte agent from Pseudomonas aeruginosa exotoxin A].

The sensitization of formolized sheep red blood cells with exotoxin A by means of chromium chloride or glutaraldehyde is more effective with respect to their sensitivity in the passive hemagglutination test than loading by means of amidol, tannin and rivanol. The use of chromium chloride decreases the consumption of exotoxin A 2, 8, 16 and 16 times in comparison with the use of amidol, tannin, rivanol or glutaraldehyde respectively. The high specificity of erythrocyte diagnosticum obtained from exotoxin A by means of chromium chloride is indicated in the study of hyperimmune sera to 22 different antigens of enteric bacteria and staphylococci in the passive hemagglutination test and to 10 different enterobacterial and staphylococcal antigens in the antibody neutralization test.

ADP Ribose Transferases↗
PubMed1988

[Characterization of the nutritional potential of tepari bean (Phaseolus acutifolius) grown in Mexico].

The chemical, physical, antiphysiological and biological quality of the protein of three varieties (white, brown and black) of tepary bean (Phaseolus acutifolius) were studied. Its proximate composition was determined, as well as water absorption, hardness of the seed, tannin content, trypsin inhibitors and lectins. Beans were also submitted to differential scanning calorimetry of the starch. The biological quality of its proteins was also established, based on the protein efficiency ratio (PER) and protein apparent digestibility. It was found that the protein content of the bean was high (25%). The white variety had the highest water absorption and the lowest hardness of the seed when compared with the other varieties (p less than 0.05). The black variety had a lower starch gelatinization energy and a higher cooking time than the white and brown varieties. The tannin content of the three varieties was low, particularly in the white one. The trypsin inhibitor and lectin content were relatively high in the raw beans, but disappeared almost totally during cooking. The biological quality of the tepari proteins was higher than that of the common bean cultivated under the same conditions, More evidently so in the white bean (PER = 1.48 as compared to 1.23 in pinto bean). It can be concluded that the tepary bean is a potentially good protein source and has also a great potential ad donor of genes for the obtention of better bean varieties from the culinary, nutritional and toxicological points of view.

Analysis of Variance↗
PubMed1988

[Evaluation of the protein quality of legume flours obtained by roasting in heated beds].

Roasted flours from cowpea, canavalia and washed lupin were prepared by a thermic treatment in fluid sand beds at 150, 200 and 250 degrees C for 2.0 and 2.5 minutes, followed by dehulling and grinding. A flour produced by pressure cooking at 121 degrees C for 30 min followed by drying was used as reference. The flours were evaluated through residual levels of antitryptic activity, tannin content, available lysine, NPR and protein digestibility. The roasting and the pressure cooking processes increased NPR values. Nevertheless, the NPR values of all legume flours were significantly lower than the NPR casein values. The roasting process carried out under the conditions indicated inactivated trypsin inhibitor activity significantly. A small decrease in tannin content was also observed, with small insignificant changes in available lysine. The protein digestibility of all products was high with lupin, digestibility being equal to that observed for casein. The roasting process in a fluid granular bed allows the production of products of acceptable protein quality with low levels of antiphysiological factors.

Animals↗
PubMed1987

[Effect of processing and amino acids supplementation on the protein quality of amaranth (Amaranthus caudatus)].

The present study was undertaken to evaluate the effect of thermic processing on the protein quality of amaranth (A. caudatus). It was also intended to establish the order of essential amino acid deficiencies suggested by the chemical score as limiting protein quality. The A. caudatus grain was cooked in water in the autoclave at 15 lb pressure during 0, 10, 20, 30, 40, 50 and 60 min. Once cooked, the samples were dehydrated with hot air at 60 degrees C and ground into flours. These were analyzed for: tannins, trypsin inhibitors, hemagglutinins (with cow, sheep, and human erythrocytes), damaged starch, available lysine, protein quality (by the NPR method), and true digestibility. Results indicated that the flours (0 to 60 min cooked) did not contain trypsin inhibitors and that their small tannin content, expressed as catechin, disappeared after 30 min of cooking. The quantities of these antiphysiological substances in the raw material are so small that they do not constitute a factor that may cause a decrease of the product's quality. A positive response was obtained for hemagglutinins, stronger with human erythrocytes, which disappeared with cow's and sheep's erythrocytes after 10 min of cooking and with human erythrocytes, after 20 min. As expected, cooking time increased the damaged starch and a slight increase was observed in available lysine, a finding which was impossible to explain satisfactorily. There were no important changes in true protein digestibility with respect to cooking time. Once again, results demonstrated the positive effect thermic treatment had on protein quality, suggesting the presence of antiphysiological active substances or a low nutrient bioavailability in raw samples. Longer cooking times did not alter substantially the protein quality (NPR and digestibility) and it was concluded that 10 min of cooking is an adequate time for the type of processing used. A sample of processed A. caudatus was utilized for the supplementation studies carried out with threonine, methionine, leucine, individually, or with the three amino acids together at 8.0, 9.5 and 1.0% protein in the diet. According to the results obtained, higher NPR values were observed with 9.0 and 9.5% protein content in the diet. No clear effects were detected when the amino acids were added, but there was an interaction between protein in the diet and amino acids. No effect occurred when leucine was added, suggesting that it is not a limiting amino acid. Possibly, threonine is a more limiting amino acid, but the effects were not as high, probably due to the level added to the diets.(ABSTRACT TRUNCATED AT 400 WORDS)

Amaranthus↗
PubMed1987

[Effects of treatment with polyvinylpyrrolidone on nutritional quality of sorghum].

The purpose of this paper was to show that a high polyphenolic compound content in the sorghum grain (Sorghum saccharatum, var sugar drip) has an unfavorable influence on the nitrogen absorption. In order to arrive at this conclusion, the tannin content in sorghum flour was reduced by means of a treatment with polyvinylpyrrolidone (PVP) as a complexing agent. Several biological experiments were performed with non-treated flour (S) and with PVP-treated flour (S + PVP). Treatment improved true digestibility (D), having obtained the following values: for S = 31 +/- 2.67, and for S + PVP = 55.8 +/- 3.48 (significance P less than 0.001). The tannin evaluation yielded the following results: S = 1.90 g/100 g, and S + PVP = 0.85 g/100 g reported as tannic acid. The digestibility increase induced a better nitrogenous utilization, the net protein utilization (NPU) values being from 19 +/- 1.58 to 37 +/- 3.36 for S, and S + PVP, respectively.

Animals↗
PubMed1983

Inhibitory effect of betel nut extracts on endogenous nitrosation in humans.

Extracts of betel nut (Areca catechu) were tested for their capacity to inhibit the endogenous formation of nitrosamines by measurement of the amount of urinary N-nitroso-L-proline (NPRO) following ingestion of sodium nitrate (300 mg) and L-proline (300 mg) by 2 volunteers. A water extract of the dried nuts, an ether extract containing mainly (+)-catechin and (-)-epicatechin, and a caffeine-precipitated n-butyl alcohol extract containing primarily proanthocyanidins (tannins) strongly reduced the endogenous formation of NPRO. An average of 14.7 and 10.9 micrograms NPRO (8 expts per individual) was excreted in the urine of the 2 volunteers over a 24-hour period following the intake of sodium nitrate and L-proline. The water extract and the proanthocyanidin (tannin)-containing extract, both of which contain the dose equivalent of one-quarter of a nut, reduced the excreted NPRO to background levels, which varied from 0.5 to 3.6 micrograms and from 0.6 to 2.1 micrograms (6 expts) in 24-hour urine samples from the 2 volunteers. These results may exemplify the way in which naturally occurring phenolics, which are ingested daily in relatively large quantities, could affect the endogenous formation of carcinogenic nitrosamines.

Anthocyanins↗
PubMedDate not supplied

Phytochemical screening of Nigerian medicinal plants II.

A total of 47 plant extracts representing 132 genera and 172 species of plants distributed over 59 families were collected from various parts of Nigeria. The plant extracts were screened for the presence of alkaloids, saponins, tannins, phlobatannins and anthraquinones. The number of positive tests obtained was 176 (32.18%) for alkaloids, 242 (44.24%) for saponins, and 435 (79.52) for tannins. A few were positive for phlobatannins and anthraquinones.

Alkaloids↗
PubMed1978

The analysis of cider phenolics.

Four classes of phenolic compounds may be distinguished in ciders: 1. Phenolic acids; 2. Phloretin derivatives; 3. Catechins; 4. Procyanidins. Only the procyanidins can be classed as true tannins and only they make any contribution to the bitterness and astringency of the product. Traditional methods of tannin analysis, however, fail to estimate the procyanidins as a separate group from the other phenolics. It is now possible to isolate the procyanidin fraction from bittersweet ciders by adsorption onto Sephadex LH-20 and then to separate the individual procyanidins by counter-current distribution between ethyl acetate and water. In this way sufficient material may be obtained to allow structural studies, and we can now show that ciders contain a range of procyanidin polymers probably up to heptameric, based mostly on epicatechin. Tasing panel work on these fractions shows that bitterness is predominantly associated with oligomeric procyanidins and astringency with polymeric procyanidins. Analytical chromatography on Sephadex LH-20 in a water-methanol gradient also shows, for instance, the selective loss of up to 20% of organoleptically significant procyanidins during gelatin fining, and the useful gain in procyanidins which can occur with DDS diffuser extraction. These results are important because a certain amount of bitterness and astringency is considered desirable in blended English ciders, but the true bittersweet apples are in very short supply.

Alcoholic Beverages↗
PubMed1993

[Hemagglutinating properties of Acinetobacter calcoaceticus].

Hemagglutinating activity was tested in 309 strains of Acinetobacter calcoaceticus with fresh and tannine human, horse, sheep, bovine, chicken and guinea pig erythrocytes. Determinations were performed with 0.1% D-mannose and without it, both in temperature 37 and 22 degrees C. Hemagglutinating activity was exhibited by 75-85% of strains, more frequently cultured at 22 degrees C A. calcoaceticus var. anitratus equally frequently was agglutinating both types of erythrocytes. Strains of A calcoaceticus var. lwoffii were agglutinating only chicken erythrocytes, but were agglutinating all tannin treated erythrocytes. The observed agglutination was mannose-resistant.

Acinetobacter calcoaceticus↗
PubMed1976

[Indirect hemagglutination via glutaraldehyde-treated erythrocytes for determining anti-anthrax antibodies].

The so-called passive hemagglutination reaction is used in this country to determine the serum level of anthrax antibodies in immunized individuals. Use is made of an erythrocyte diagnostic means prepared from formalin- and tannin-treated sheep erythrocytes that have been sensibilized with a protective anthrax antigen. An attempt has been made to replace this means by another one obtained by treating the same erythrocytes with glutaric aldehyde. Comparative studies reveal that the new diagnostic means is equally effective in the passive hemaglutination reaction as is the classic method using formalin- and tannin-treated erythrocytes. The suggested method of erythrocyte treatment proves more feasible, and, according to preliminary data, the new diagnostic means has longer shelf-life.

Aldehydes↗
PubMed1993

Inhibitory effects of crude drug components on the proliferation of cultured human mesangial cells.

The effects of a component of an Oriental medicine and green tea plants utilized for the traditional beverage on the proliferation of mesangial cells were determined in terms of the 3H-thymidine uptake. When magnesium lithospermate B was added to the medium of the mesangial cell culture, it suppressed the proliferation of mesangial cells at a concentration of 50 micrograms/ml. The 3H-thymidine uptake began to display an inhibitory action from the 6.25 micrograms/ml (-)-epicatechin 3-O-gallate, (-)-epigallocatechin 3-O-gallate or green tea tannin mixture, showing a more conspicuous inhibition at 50 micrograms/ml that did the magnesium lithospermate B at the corresponding concentration. In particular, (-)-epigallocatechin 3-O-gallate, the predominant component of the green tea tannin mixture, exerted an inhibitory effect at a relatively low concentration.

Catechin↗
PubMed1996

Antimutagenic effects of polyphenols isolated from Terminalia bellerica myroblan in Salmonella typhimurium.

Antimutagenic effect of 2 polyphenolic fractions isolated from T. bellerica in TA98 and TA100 strains of S. typhimurium against 2AF, NPD and 4NQNO has been characterized. Both the fractions were significantly effective against S9-dependent 2AF; less effective against NPD and almost not effective against 4NQNO in TA100 strain. Using 13C-NMR spectral analysis, the TB-3 fraction, which was significantly more effective against 2AF compared to TB-4, was found to be a mixture of 3 tannins while TB-4 was non-tannin fraction. Interaction of polyphenols with S9 proteins may be the probable cause of inhibitory effect of these polyphenols, though the possibility of other mechanisms cannot be ruled out.

Antimutagenic Agents↗
PubMed1979

[Design of stable immunoglobulin erythrocyte diagnostica. 1. Erythocyte fixation and their sensitization by specific immunoglobulins].

The work presents the results of developing the method of fixation of erythrocyte constituting the cellular base of immunoglobulin erythrocytic diagnostic preparations and the sensitization of erythrocytes with immunoglobulin preparations of various specificity. Based on Ingraham's method, modified method of erythrocyte stabilization has been developed; it consists in the treatment of 50% cell suspension with 4% formaldehyde solution in the presence of 0.5% sucrose (erythrocyte suspension and formaldehyde solution being in the ratio 1 : 2.5). An economic and highly productive technique of sensitizing erythrocytes with immunoglobulin preparations has been developed. The essence of this technique lies in the interaction between 6% suspension of erythrocytes treated with formalin and tannin and the equal volume of sensitin taken in a working dose. The work also presents the method of synthesizing the bifunctional compound fluoro-borate bis-daizonium complex (obtained from benzidine) and discusses the comparative possibilities of the methods of developing immunoglobulin erythrocytic diagnostic preparations by sensitization of tannin-treated erythrocytes and by chemical conjugation.

Allergens↗
PubMed1995

[Effect of growing location on sensory properties and nutritional characteristics of black beans (Phaseolus vulgaris L.)].

The present research consisted of an evaluation of five genotypes harvested from six growing locations. Variables of sensory properties, cooking quality and nutritional characteristics were determined. Genotype with longer cooking time was BV which also present hard shell. Those of shorter cooking time were FMB and PV. In Calera frosting during pod filling, drastically reduced cooking time, sensory properties and tannins. Taking this location off, the analysis show little effect of genotype or growing location in regard to determined properties. The genotypes with lower content of tannins were PV and BV. The content of lectins were in general low for all samples and the diferences between genotypes were not statistically significant (p<0.05) but they did for growing location.

Analysis of Variance↗
PubMedDate not supplied

Ascorbyl radical scavenging activity of polyphenols.

A variety of tannin and lignin-related compounds were compared for their ability to modify the ascorbyl radical intensity of sodium ascorbate. Hot-water extracts prepared from green tea, black tea and pine cone (Pinus parviflora Sieb. et Zucc.), and various wines potently scavenged ascorbyl radical intensity. Low molecular weight tannins and phenylpropenoid monomers showed the greatest scavenging activity, whereas the dehydrogenation polymers of phenylpropenoids were much less active. On the other hand, natural lignified materials, protein-bound polysaccharide (PSK) and positively-charged glucans enhanced the ascorbyl radical intensity. Lignin sulfonate stimulated the sodium ascorbate-induced cytotoxicity in human promyelocytic leukemic HL-60 cells. These data suggest that the ascorbyl radical scavenging activity of polyphenols depends on molecular weight, the functional group and the presence of polysaccharides in the molecule.

Ascorbic Acid↗
PubMed1996

[Polyphenolic composition of the leaf of bilberry].

Dried leaves of 14 harvested batches and one batch from commercial origine of Vaccinium myrtillus L present a similar polyphenolic pattern. The mean levels of the harvested batches and the levels of the commercial batch were respectively: total polyphenol compounds 12.98 and 10.62%, tannins 7.84 and 7.43%, total flavonoid compounds 2.98 and 2.20% (spectrophotometry), 1.41 and 1.16% (HPLC), quercetin 3-glucuronide 1.02 and 0.83%, hyperoside 0.22 and 0.16%, chlorogenic acid 3.66 and 1.58%. The levels were higher in young leaves and lower in old leaves. A specific chromatographic profile of the flavonoid compounds and a determination method of the tannin or the total polyphenol content were proposed in a standardization purpose.

Chromatography, High Pressure Liquid↗
PubMed1995

[Chemical characteristics of the pulp and oil of the annona tree (Annona coriaceae)].

Belonging to the Annonaceae family, marolo (Annona coriaceae) is a native species of the Brazilian "cerrado" región (Minas Gerais, Goiás and Distrito Federal) and can be found in South American tropical zones. Its fruits are highly consumed by local people and commercialized in markets or street stalls. There is, however, a tendency for the extinction of marolo due to deforestation and the large scale plantation of monocultures instead of native plants. The literature still offers no data on the chemical composition of the proximate composition and vitamin C, A and tannin contents were carried out on the yellow marolo pulp as well as the determination of the physico-chemical characteristics of the seed oil. Five batches of fruit from the Alfenas region--south of Minas Gerais State--were analysed in this work and their average composition were: humidity 77%, total sugar 15%, reducing sugar 11%, crude protein 1%, lipids 3%, fiber 5% and fixed mineral residue 1%. The contents of vitamin C and A were 8.2 mg/100g and 117.5 RE/100g, respectively, and the tannin content was 245 mg/100g. The results showed high fiber and lipid contents of marolo pulp in comparison with many other tropical fruit pulps. The vitamin C contents were equivalent to those found in avocado, pineapple and watermelon, while the vitamin A contents were equivalent to papaya, peach, guava and several other tropical fruits. Marolo seed contains 45% of oil on a dry basis. Its composition and physico-chemical characteristics showed the possibility of producing a good quality oil, with great potential for the fine oil market. However the presence of alkaloids in the oil needs to be further studied. Their elimination could be done by refining or extraction in a continuous press. The results exalt the high quality of marolo pulp, showing that the preservation of native species should be stimulated.

Alkaloids↗