Quebracho Tannin Research Articles

Dietary supplementation of chestnut and quebracho tannins mix: Effect on caecal microbial communities and live performance of growing rabbits

The interest in antimicrobial compounds as feed additives is currently increasing. Among different options, tannins seem to have several beneficial effects when employed in animals diet. The present study aimed at investigating the influence on caecal microbial communities of the supplementation of a chestnut and quebracho tannins mix in meat rabbit's diet, also considering animals live performances. Four groups of rabbits were fed with a different diet: a control diet (C); a control diet with coccidiostat (CC), and two experimental diets with 0.3% (T0.3) and 0.6% (T0.6) chestnut and quebracho tannins mix. For microbial analysis, culture-dependent and culture-independent methods were employed. Live performances were not significantly affected by tannins mix supplementations, as well as culturable microbial loads of E. coli, Enterobacteriaceae, Bacteroides spp. and Bifidobacterium spp. C. perfringens was always under the detection limit. A consistent result was obtained by qPCR. As for PCR-DGGE analysis, the Richness and evenness (Shannon-Weiner index) of bacterial communities in caecum resulted significantly higher in control samples (C and CC) than in those from rabbit fed with tannin-containing diets. Sequencing analysis revealed that the phylum Firmicutes was less represented in samples from control groups. As for the methanogen archaeal DGGE, no significant differences were found in richness and diversity among different groups, all dominated by Methanobrevibacter spp.. This work highlights the potential antimicrobial effect of chestnut and quebracho tannins mix in an in vivo system revealed by molecular analysis.

The influence of dietary chestnut and quebracho tannins mix on rabbit meat quality.

Tannins were recently evaluated as feed additives in order to increase antioxidant compounds in animal diet, mainly to enhance resistance to lipid oxidation in meat. Rabbit meat is one of the most susceptible animal products, thus the main aim of this study was to evaluate the capacity of tannins to elongate shelf life of rabbit meat. Ninety hybrid rabbits were fed with three different diets: basal diet (control, C) and basal diet supplemented with 0.3% or 0.6% of tannins mix. Meat samples were refrigerated as raw at 4°C up to 11 days and analysed both as raw and cooked for physical-chemical characteristics, fatty acids profile, lipid oxidation and antioxidant capacity. Results showed that dietary tannins affected meat colour of raw samples (mostly yellowness). Lipid peroxidation (TBARS) of raw samples was lower in tannins group than C group; a further inhibition of peroxidation was showed also in cooked samples only by the highest dose of tannins mix. Moreover, antioxidant capacity (ABTS) of raw samples increased with the percentage of tannins. In conclusion, supplementation with 0.6% of tannins mix seems to positively affect the lipid peroxidation and antioxidant capacity of meat without modifying the intrinsic characteristics of rabbit meat.

Primers based on tara and quebracho tannins for poorly prepared steel surfaces

Steel panels must be protected during storage and transportation because they can corrode. This protection used to be afforded by chromate primers, but nowadays tannin-based primers are being studied. These primers are not only used as protection but also as adhesion promoter if the steel surface was not well prepared (presence of oxides or low roughness).The objective of this work was to prepare lanthanum “tannate”, employing tara and quebracho tannins. The “tannates” were incorporated in primers formulation and applied on steel SAE 1010 panels (previously exposed to the humidity chamber or with 6 μm of roughness depth). These primed panels were exposed to humidity chamber where corrosion and blistering degrees were evaluated. Adhesion test were done. Electrochemical assays such as ionic resistance and corrosion potential measurements were carried out.Results showed that the adhesion and the barrier properties of the primers were good. Besides, on low roughness steel, the primers diminished the corrosion current.Results were compared with traditional zinc tetroxychromate primer.

The interplay between exposure and preference for unpalatable foods by lambs

Herbivores satiate on single foods ingested too frequently or in excess. We hypothesized that exposure to the same unpalatable food too frequently or in excess causes satiety, which in turn would reduce subsequent use and preference for this food when alternatives become available. In each of three experiments, twenty-four lambs were randomly assigned to three treatment groups (8 lambs/group), where they received high (Ad libitum), intermediate (100–200 g/d) or low exposure (20–40 g/d) to three unpalatable foods: The invasive weed medusahead (Experiment 1), an alfalfa:quebracho tannin ration (70:30; QT) (Experiment 2), or wheat straw (Experiment 3). After exposure, all groups in Experiments 1 and 3 received a simultaneous offer of the unpalatable food and a novel food that changed across four consecutive preference tests: Grape pomace (Test 1), barley straw (Test 2), tall fescue hay (Test 3), and beet pulp (Test 4). Lambs in Experiment 2 received a simultaneous offer of each of these novel foods and the same novel food containing 30% quebracho tannins. During exposure, lambs in Experiment 1 showed a low and cyclic pattern of medusahead intake, and the group with intermediate level of medusahead exposure showed greater intake values than the Ad libitum group, followed by the group with the lowest level of exposure (P < 0.05). For the rest of the experiments, intake was Ad libitum > intermediate > low level of exposure (P < 0.05). During preference tests, lambs with the least level of exposure to the unpalatable foods tended to consume more medusahead (35% to 37%; P = 0.11) or wheat straw (15 to 30%; P = 0.10) than lambs that received greater levels of exposure. In contrast, differential exposure to QT did not influence subsequent preference for tannin-containing foods (P = 0.33), but animals with the greatest level of exposure to QT consumed 24% more alternatives (i.e., non-tannin containing foods) than lambs that had received the lowest level of QT exposure (P < 0.05). Intake of alternative novel foods during preference tests increased with increments in nutritional quality from grape pomace and barley straw to tall fescue hay and beet pulp (P < 0.05), suggesting that lambs discriminated the nutritional value of the novel foods. In conclusion, repeated exposure to unpalatable foods has the potential to further reduce their utilization when alternatives –even when novel– become available. This effect appeared to be influenced by the chemical characteristics of the unpalatable food and it has implications for the coexistence of plant species in grazed communities.

Optimal Depressants and Collector Dosage in Fluorite Flotation Process Based on DoE Methodology

Alternative processes have been proposed for selective separation of fluorite and gangue minerals (carbonates and silicates) present in fluorspar ores. Calcination and gravity separation processes are methods that have low efficiency and high cost. Flotation is a chemical process that becomes important when high ore grades are required; however, the selectivity is inhibited by the superficial similarity of the chemical composition of minerals. Accordingly, interactions between dissolved ionic species of fluorite, carbonates, and silicates with some reagents under determinate conditions obstruct the flotation process. In order to optimize the flotation process of a Spanish fluorite ore, this research uses a mathematical model. In this study, the variables were the dose of potato starch, quebracho tree, white dextrine, oleic acid, and sodium silicate. On the other hand, the factors studied were the law of carbonates, silica, and fluorite, in addition to the metallurgical recovery of fluorite. The statistical technique of factor analysis that relates the variables and factors allowed to the optimization of the reagent dosage. Maximum metallurgical recovery was achieved without sacrificing the fluorite grade. The mathematical model adjusts satisfactorily to the results with a correlation coefficient of 91.58% for metallurgical recovery and 98.51% for fluorite grade. Optimizing the process 60.45% of metallurgical recovery and 68.99% of fluorite grade are achieve in the roughing step, using a dosage of 1.68 g·kg−1 of potato starch, 0.86 g·kg−1 of quebracho tree, 1.25 g·kg−1 of dextrin, 3 g·kg−1 of oleic acid, and 0.85 g·kg−1 of water glass.

Dietary supplementation of quebracho and chestnut tannins mix in rabbit: effects on live performances, digestibility, carcase traits, antioxidant status, faecal microbial load and economic value

The effects of dietary supplementation of tannins mix (quebracho and chestnut) in rabbit diet were evaluated for productive performances, health parameters and digestibility in order to quantify their practical utilisation in the rearing system. One-hundred and twenty Martini group hybrid rabbits of 30 days old were fed four different diets for 60 days. The diets were formulated as: basal diet (negative control, C), basal diet supplemented by 0.3% of tannins mix (T0.3), basal diet supplemented by 0.6% of tannins mix (T0.6) and basal diet supplemented with coccidiostat (positive control, CC). Live performances did not show any significant differences, moreover, no significant differences were observed for all carcase traits except for gastrointestinal tract (p = .015, lowest values for T0.3 diet). Also, digestibility of the feed and faecal microbial load was not influenced by tannins addition. Slight differences between the diets were detected in catalase and glutathione peroxidase concentrations in plasma, as a common trend was revealed with higher values of C than the other diets. From an economical point of view, T0.3 diet showed to be more profitable than CC and T0.6. Tannins addition might be taken into account as potential feed additive in rabbit feeds, as it does not affect negatively the productive performances, digestibility and induce a slight increase of antioxidant status.HighlightsOn an economical point of view tannin diet showed to be more profitable than a diet added with coccidiostat.Addition of tannins in rabbits’ feed did not affect negatively productive performances and digestibility.Tannins represent a valuable feed additive in rabbit farming as a slightly increase of antioxidant status was induced.

Water resistance improvement by polyethyleneimine of tannin-furfuryl alcohol adhesives

ABSTRACTIn this research furfuryl alcohol (FA) and polyethyleneimine (PEI) in different ratio were added to a tannin based adhesive in order to improve its moisture resistance. In order to characterize the functional groups involved, Fourier-transform infrared spectroscopy (FTIR) was used. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to study the thermal behaviour of the formulations. FTIR spectroscopy indicated the reaction of quebracho tannin with FA and PEI. The results of the TGA showed that the added FA and PEI increased the resistance to thermal degradation. DSC analysis showed that the added FA and PEI reduced the heat absorption peak. According to the tensile shear strength of the formulations, the adhesive formulation T1 F0.75 P20 (mixing proportion: Tannin 1, FA 0.75, PEI 20%) was able to satisfy the standards requirements (BS 1204-2) as a moisture resistant adhesive. Furthermore, this formulation presented the best tensile shear tests results and the least number of delaminated samples.

Ultrastructural study of adult Haemonchus contortus exposed to polyphenol-rich materials under in vivo conditions in goats.

This study assessed the ultrastructural changes caused in adult Haemonchus contortus obtained from goats fed fodder based on polyphenol-rich plants Lysiloma latisiliquum or Onobrychis viciifolia or from goats drenched with quebracho extract, Schinopsis spp. The H. contortus were obtained from artificially infected goats used as models to investigate the anthelmintic effect of feeding or drenching with the polyphenol-rich materials. Nematode populations were exposed to polyphenol-rich plant materials by feeding host goats for 8 consecutive days (D28 to D35 post-infection) with (a) L. latisiliquum fodder at 800 g fresh basis/day, (b) O. viciifolia fodder offered ad libitum, and (c) drenched with a solution containing quebracho extract (90 g/day). Meanwhile, control H. contortus were obtained from goats fed polyphenol-free diets. The H. contortus specimens were recovered from the goats on D36 post-infection, and transmission electron microscopy (TEM) was used to identify ultrastructural changes. In vivo exposure to different polyphenol-rich plant materials caused vacuolization of the nematodes’ intestinal, muscular and hypodermal cells. These alterations represent the first evidence of cell damage caused in H. contortus when hosts were fed or drenched with polyphenol-rich materials. Ultrastructural changes affecting several types of cells could explain modifications in worm motility and nutrition, eventually affecting H. contortus reproductive success. This study contributes to our understanding of the mechanisms of action of polyphenol-rich plants against H. contortus when given as nutraceuticals to goats.

Effects of tannin-containing diets on performance, gut disease control and health in broiler chicks

The emergence of antibiotic-resistant bacteria in the intestinal microbiota of broiler chickens, and the possibility of antibiotic residues in meat and meat products are seen as a threat to animal and human health. The search for alternatives to conventional drugs, including natural compounds, is an interesting approach to prevent the adverse effects of antibiotics. Therefore, the aim of the present study was to evaluate whether the addition of tannin (as a quebracho extract) in the diet of broiler chickens could be used to replace in-feed antimicrobials and coccidiostatic drugs, to exert positive effects on animal health and performance. The use of tannin in the diet of broiler chicks as an additive (at 0.5% for 1–10-day-old birds; and 1.0% for 11–42-day-old broiler chickens) enhanced their bodyweight, weight gain and daily weight gain on Day 42 of life, compared with the untreated control group (P &amp;lt; 0.05). However, these findings were not observed when tannin was added at 0.5%. Moreover, broiler chickens fed with an extract containing tannins showed higher erythrocyte counts, as well as haemoglobin and haematocrit concentrations than did those in the control group, whereas counts of total leukocytes and lymphocytes were lower (P &amp;lt; 0.05). The use of a diet with tannins did not influence meat quality compared with a diet containing zinc bacitracin and salinomycin, which altered some parameters associated with meat colour. Moreover, the diet with tannins reduced (P &amp;lt; 0.05) the number of oocysts of Eimeria sp. (36-day-old broilers) and the total faecal bacterial counts (42-day-old broilers) compared with the control group. Finally, intestinal histopathology showed that the addition of tannins minimised the degree of lesions (Degree 1) compared with the control group (Degree 3). On the basis of these results, we concluded that the use of quebracho extract containing tannins can be a suitable approach to improve the performance of broiler chickens, replacing in-feed antibiotics and coccidiostatic drugs. The use of tannins did not change meat quality; however, it caused positive effects on the immune system, and exerted potent bactericidal and coccidiostatic properties, reinforcing its use as a replacement for conventional drugs.

419 Effect of Differing Rates of Quebracho (Schinopsis balansae) Extract provided in a Limit-Fed High Roughage Total Mixed Ration Upon Digestibility and Nitrogen Balance.

419 Effect of Differing Rates of Quebracho (Schinopsis balansae) Extract provided in a Limit-Fed High Roughage Total Mixed Ration Upon Digestibility and Nitrogen Balance.

Effects of lespedeza condensed tannins alone or with monensin, soybean oil, and coconut oil on feed intake, growth, digestion, ruminal methane emission, and heat energy by yearling Alpine doelings.

Fifty-four Alpine doelings (initial BW and age of 31.7 ± 0.38 kg and 306 ± 1.9 d, respectively) were allocated to nine treatments individually fed for ad libitum intake of 25% concentrate and 75% forage diets (DM basis). Alfalfa was the forage in the control diet. Other diets contained Sericea lespedeza as the forage, with 1.25% DM of quebracho extract included in the concentrate fraction for a dietary condensed tannin level of 8.4%. Lespedeza treatments were no additive (L) and inclusion of monensin (I) at 22 mg/kg DM (L-I), soybean oil at 3% (L-S), coconut oil at 3% (L-N), I and 3% soybean oil (L-I-S), I and 3% coconut oil (L-I-N), 1.5% soybean oil and 1.5% coconut oil (L-S-N), and I, 1.5% soybean oil, and 1.5% coconut oil (L-I-S-N). The experiment was 12 wk with two 6-wk periods. Gas exchange was determined in weeks 6 and 12, and other measures occurred in weeks 5 and 11. The control diet offered averaged 2.67% nitrogen, 43.8% neutral detergent fiber, and 8.8% acid detergent lignin, and the L diet offered averaged 2.03% nitrogen, 42.8% neutral detergent fiber, and 13.2% acid detergent lignin. There were no treatment × period interactions for digestibilities (P ≥ 0.770) or methane emission (P ≥ 0.324). There were differences (P < 0.001) between the control treatment and diets with lespedeza in intake of DM (1.46, 1.23, 1.30, 1.18, 1.32, 1.10, 1.02, 1.20, and 1.01 kg/d; SEM = 0.059), digestibility of OM (57.4%, 50.9%, 51.8%, 52.7%, 50.3%, 52.1%, 52.1%, 51.9%, and 49.8%; SEM = 1.42), and digestibility of nitrogen (59.1%, 31.2%, 32.5%, 37.1%, 31.6%, 38.3%, 30.4%, 38.4%, and 34.1% for control, L, L-I, L-S, L-N, L-I-S, L-I-N, L-S-N, and L-I-S-N, respectively; SEM = 2.21). Ruminal methane emission was less (P < 0.001) for diets with lespedeza than for the control in MJ/d (1.36, 0.76, 0.84, 0.71, 0.71, 0.66, 0.65, 0.68, and 0.68; SEM = 0.048) and relative to intake of gross energy (5.92%, 3.27%, 3.49%, 3.19%, 2.84%, 2.91%, 3.20%, 3.20%, and 3.27%; SEM = 0.165) and digestible energy (11.19%, 6.98%, 7.40%, 6.38%, 5.90%, 5.69%, 6.37%, 6.38%, and 6.70% for control, L, L-I, L-S, L-N, L-I-S, L-I-N, L-S-N, and L-I-S-N, respectively; SEM = 0.400). In conclusion, the magnitude of effect of condensed tannins from lespedeza and quebracho extract on ruminal methane emission by Alpine doelings did not diminish over time and was not markedly influenced by dietary inclusion of monensin, soybean oil, or coconut oil.

Involvement of Quebracho tannins in dietalters productive and reproductive efficiency of postpartum buffalo cows.

This study was conducted to investigate the effects of 10 weeks supplementation of Quebracho tannins (QT; 0 [control], 100 [QT100] or 200 g/[cow·d] [QT200]) to 30 multiparous postpartum buffalo cows (10 cows per group) on milk yield and composition, blood metabolites and reproductive performance. Supplementation of QT100 had no significant effect on milk yield, whereas QT200 decreased (P < 0.05) this trait. Compared with the control group, both QT levels decreased (P < 0.05) fat-corrected milk (FCM) yield, but no significant effects were found on percentages of milk fat and protein. Contrariwise, yields of milk fat, lactose and milk protein were decreased (P < 0.05) when QT200 was supplemented. The solids nonfat (SNF) percentage and yield were decreased (P < 0.05) with QT100 supplementation. Moreover, QT tended to numerically reduce total number of ovarian follicles, number of small follicles, peripheral progesterone concentration and conception rate. Supplementation of QT200 numerically increased number of large follicles, mean diameter of large follicle, number and diameters of corpora lutea. The inclusion of QT200 shortened days open (DO) and decreased number of services per conception. Contrariwise, QT did not show significant effects on serum total protein, albumin, globulin, glucose, cholesterol and triglycerides concentrations. Supplementation of QT100 caused an increase (P < 0.05) of serum urea compared with that in control and QT200 groups. Generally, QT decreased (P < 0.05) serum creatinine concentration. Therefore, the supplementation of a commercial QT to early lactating Egyptian buffalo cows displayed negative consequences on their productive and reproductive performances.

Removal of Quebracho and Tara tannins in fungal bioreactors: Performance and biofilm stability analysis

Tannins are polyphenolic compounds produced by plants that are used in the vegetable tanning of leather at industrial scale. Quebracho tannin and Tara tannin are intensively used by the tanning industry and are two of the most recalcitrant compounds that can be found in tannery wastewaters. In this study two reactors fed with Quebracho tannin and Tara tannin, respectively, were inoculated with polyurethane foam cubes colonized with a fungal strain biofilm of Aspergillus tubingensis MUT 990. A stable biofilm was maintained in the reactor fed with Quebracho tannin during 180 days of operation. Instead, biofilm got detached from the foam cubes during the start-up of the reactor fed with Tara tannin and a bacterial-based suspended culture was developed and preserved along the operational period (226 days). Soluble chemical oxygen demand removals up to 53% and 90% and maximum elimination capacities of 9.1 g sCOD m−3 h−1 and 37.9 g sCOD m−3 h−1 of Quebracho and Tara tannins, respectively, were achieved in the reactors without the addition of co-substrates. Next generation sequencing analysis for bacteria and fungi showed that a fungal consortium was developed in the reactor fed with Quebracho tannin while fungi were outcompeted by bacteria in the reactor fed with Tara tannin. Furthermore, Quebracho and Tara tannins were successfully co-treated in a single reactor where both fungi and bacteria were preserved.

¿Qué madera es buena para leña? Conocimiento botánico local en “leñeras” del partido de La Plata (Buenos Aires, Argentina)

El presente estudio se llevó a cabo en el partido de La Plata, Buenos Aires, Argentina. El área es diversa, con zonas urbanas y periurbanas, abundante arbolado urbano, vegetación espontánea en zonas periurbanas, mientras que en los alrededores del partido se encuentran bosques y matorrales ribereños, talares y bosques implantados. En el marco de una investigación de etnobotánica urbana, se registraron 13 sitios de venta de leña (“leñeras”) y se realizaron entrevistas a los expendedores con el objetivo de relevar el conocimiento botánico local sobre las especies comercializadas, las consideradas más adecuadas, procedencia, forma de obtención, modo de reconocimiento y clasificación. Se halló un total de 32 etnotaxa comercializados como leña, entre los cuales los más vendidos son: “quebracho colorado”, “itín” y “eucalipto”. El principal destino de la leña es para la calefacción de hogares y, en segundo lugar, para la cocción de los alimentos. Se destaca el amplio conocimiento que posen los entrevistados acerca del tema, así como también la diversidad de prácticas relevadas en torno al uso de la leña, las estrategias de aprovisionamiento y la elevada variedad de especies utilizadas.

Study of antioxidant capacity and metabolization of quebracho and chestnut tannins through in vitro gastrointestinal digestion-fermentation

Quebracho (QUE) and chestnut (CHE) are natural sources of tannins, but there are no connection between QUE, CHE and human health. The study investigated the antioxidant response and metabolization of tannin extracts trough in vitro digestion-fermentation. The FRAP assay pointed a higher reducing capacity of CHE than QUE (6.90 vs. 5.07 mmol Trolox/g), in contrast to a stronger scavenging activity of QUE (8.16 mmol Trolox/g vs 6.70 mmol Trolox/g). The results obtained showed a decrease of the antioxidant capacity of tannins after microbial fermentation, but a high prebiotic activity through release of short-chain fatty acids of both CHE (11.14 mmol/g) and QUE (4.79 mmol/g) was observed. The UPLC-MS investigations on digested and fermented tannins gave an identification and semi-quantification of 18 compounds, including hydrolysable and condensed tannins and their metabolites. The results represent a valid basis for further studies on the potential use of these wood extracts in human diet.

Síntesis y caracterización de “tanatos” de lantano como inhibidores de la corrosión

RESUMEN Los taninos son polifenoles sintetizados por las plantas. Se encuentran en la madera del Quebracho (Schinopsis balansae), los frutos de la Tara (Caesalpinia spinosa), etc. Han sido incorporados en la industria de la pintura como agentes “antifouling” y como inhibidores de la corrosión en soluciones ácidas. Por otra parte, las soluciones de lantano han presentado un efecto inhibidor muy satisfactorio sobre probetas de acero SAE 1010. El objetivo del presente trabajo fue el de obtener dos tipos de “tanato” de lantano de baja solubilidad, a fin de que puedan ser incorporados como inhibidores de la corrosión en recubrimientos protectores temporarios, que protegen el metal durante su traslado y almacenamiento y, eventualmente, en pinturas anticorrosivas. En este trabajo se presenta la obtención de los “tanatos”, su caracterización y ensayos electro-químicos en solución de NaCl. Se prevé que si estos ensayos son satisfactorios, los “tanatos” puedan ser incorporados en protectores temporarios. Se obtuvieron 2 “tanatos”, empleando taninos de tara y de quebracho comerciales y solución de La(NO3)3x 6H2O 0,1 M. Los pigmentos se caracterizaron mediante espectrometría infrarroja con transformada de Fourier (FTIR) y su solubilidad fue determinada mediante una técnica colorimétrica utilizando el reactivo de Folin-Denis, mientras que el La+3 soluble se determinó por una técnica gravimétrica con oxalato. La acción protectora de los “tanatos” sintetizados, frente a la corrosión del acero SAE 1010 fue evaluada mediante curvas de polarización y medidas de potencial de corrosión en solución de NaCl. La película protectora formada sobre el acero inmerso en la solución fue observada mediante microscopía electrónica de barrido (MEB) y caracterizada mediante espectroscopía de dispersión de rayos X (EDS). Ambos “tanatos” desplazaron el potencial de corrosión del acero hacia valores más positivos y la resistencia a la polarización resultó uno o dos órdenes de magnitud mayor, con respecto al blanco (solución sin inhibidor) y a soluciones que contenían el tanino comercial correspondiente en diferentes concentraciones. Por otro lado, las determinaciones de la solubilidad de los pigmentos hacen preveer que no serán lixiviados de los recubrimientos prematuramente y que podrán ejercer su acción protectora durante un tiempo adecuado.

Up-scaling of tannin-based coagulants for wastewater treatment: performance in a water treatment plant.

Tannin extracts from the bark of Acacia mearnsii and wood of Schinopsis balansae, commonly known as Quebracho, were employed. These were modified at laboratory sale via the Mannich aminomethylation with formaldehyde and dimethylamine hydrochloride. Some reaction conditions were varied, namely the formaldehyde dosage and reaction time, while keeping the Mannich solution activation time constant, and their influence on the shear viscosity of the created bio-coagulants was evaluated. The effect of the final pH of the products on their shear viscosity was also analyzed. Up-scaling of the Mannich reaction for tannin from South Africa was performed and the procedure developed at 1-L scale was reproducible in upscaled conditions. One example of a modified South Africa tannin and the modified Quebracho tannin was subsequently selected for the treatment of an industrial wastewater and tested for color and turbidity reduction in jar tests. The effluent treatment was carried out in a single and dual system with cationic synthetic flocculation agents of different charge degree. Good turbidity and decoloration results (93 and 89% reduction, respectively) were obtained with the simultaneous introduction of a cationic, 40% charged polyacrylamide, with minimal dosage (5ppm) of the latter additive. The tannin-based coagulant from Acacia mearnsii was successfully applied in dual system with cationic polyacrylamide flocculant for industrial wastewater treatment at pilot plant scale. It was shown to satisfactorily treat the water and generate less sludge.

Removal of Hexavalent Chromium from Aqueous Solutions Using Biopolymers

AbstractTwo biopolymers were prepared by reaction of chestnut and quebracho tannins with gelatin extracted from untanned hide wastes. Obtained biopolymers were evaluated as adsorbents for removing ...

Fungi from industrial tannins: potential application in biotransformation and bioremediation of tannery wastewaters.

Tannins are a complex family of polyphenolic compounds, widely distributed in the plant kingdom where they act as growth inhibitors towards many microorganisms including bacteria, yeasts, and fungi. Tannins are one of the major components of tannery wastewaters and may cause serious environmental pollution. In the present study, four different tannins (the hydrolysable chestnut ellagitannin and tara gallotannin and the condensed quebracho and wattle tannins) were characterized from a mycological point of view with the aim of selecting fungal strains capable of growing in the presence of high tannin concentration and thus potentially useful in industrial biotransformations of these compounds or in the bioremediation of tannery wastewaters. A total of 125 isolates of filamentous fungi belonging to 10 species and four genera (Aspergillus, Paecilomyces, Penicillium, and Talaromyces) were isolated from the tannin industrial preparations. Miniaturized biotransformation tests were set up with 10 fungal strains and the high-performance liquid chromatography (HPLC) analysis pointed out a strong activity of all the tested fungi on both chestnut and tara tannins. Two strains (Aspergillus tubingensis MUT 990 and Paecilomyces variotii MUT 1125), tested against a real tannery wastewater, were particularly efficient in chemical oxygen demand (COD) and tannin removal (> 60%), with a detoxification above 74%. These results indicate that these fungi are potentially exploitable in the treatment of tannery wastewaters.

Effect of Dietary Supplementation of a Mix of Chestnut and Quebracho Tannins on Intestinal Morphology, Bacterial Load, Eimeria spp oocyst Excretion and Immune Response after Vaccination in Rabbits

Among plant products, tannins exhibited a strong antioxidant activity and their employment was studied as food or feed addictive with positive effects. Nevertheless, their health-enhancing properties remain to be completely clarified, particularly in rabbits. The aim of the present study was to investigate the influence of a mix of chestnut and quebracho tannins as supplementation in rabbit diet on intestinal morphology, as well as bacterial loads and Eimeria spp coccidial oocyst excretion and humoral immune response after vaccination. Rabbits were fed four different diets: basal diet (negative control, group CN), basal diet with anticoccidial supplementation (positive control, group CP) and basal diet with tannins mix 0.3% (group T0.3) or 0.6% (group T0.6). Samples of intestine, liver, spleen thymus, mesenteric lymph nodes, kidney and heart were submitted to histopathologic investigations. Morphometric analyses were performed on portion of duodenum, jejunum and ileum. Intestinal contents were analyzed by flotation test for Eimeria spp. oocysts excretion and by microbiological assays for Clostridium perfringens and Escherichia coli. Rabbits belonging to the four experimental groups were vaccinated by means of a live attenuated myxomatosis virus and sera were collected individually at three time points to determine antibody response.The obtained results demonstratedthe absence of toxic effects of the tannin mix on examined organs, particularly on liver and kidney and any negative influence on the growth performance. A relevant anti-inflammatory effect on the intestinal tract, a reduction of Eimeria spp. oocysts excretion and a positive immunomodulatory and antibacterial effects were also observed. Diets supplemented with the tannins mix affected also the morphology of examined intestinal tracts, particularly duodenum and ileum.