Quebracho Tannin Research Articles

Safety and efficacy of a feed additive consisting of an extract of condensed tannins from Schinopsis balansae Engl. and Schinopsis lorentzii (Griseb.) Engl. (red quebracho extract) for use in all animal species (FEFANA asbl).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an extract of condensed tannins from Schinopsis balansae Engl. and Schinopsis lorentzii (Griseb.) Engl. (red quebracho extract) when used as a sensory additive in feed and water for drinking for all animal species. The EFSA Panelon Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive under assessment is safe up to the maximum proposed use levels of 400mg/kg for chickens for fattening and other growing poultry, 600mg/kg for laying hens and other laying/breeding birds kept for egg production/reproduction, 540mg/kg for turkeys for fattening, 720mg/kg for piglets, 860mg/kg for pigs for fattening and other growing Suidae, 1,050mg/kg for sows, 1,680mg/kg for veal calves (milk replacer), 1,580mg/kg for cattle for fattening and other growing ruminants, 1,030mg/kg for dairy cows and other dairy ruminants, 1,580mg/kg for sheep, goats, horses, 630mg/kg for rabbits, 1,810mg/kg for salmonids and other fin fish, 1,900mg/kg for dogs and 3,000mg/kg for ornamental fish. For cats, the calculated safe concentration in feed is 317mg/kg complete feed. For all the other minor species, the additive is considered safe at 317mg/kg complete feed. The FEEDAP Panelconsidered the use in water for drinking as safe provided that the total daily intake of the additive does not exceed the daily amount that is considered safe when consumed via feed. No concerns for consumers were identified following the use of the additive at the maximum proposed use level in feed. The extract under assessment is not an eye irritant but in the absence of data, no conclusion can be drawn on its potential to be a skin irritant and a dermal and respiratory sensitiser. The use of the extract under the proposed conditions of use in feed was not expected to pose a risk for the environment. Since quebracho and its preparations were recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

Using supplemental condensed tannin to mitigate tall fescue toxicosis in non-pregnant, non-lactating ewes consuming tall fescue silage

Tall fescue [Schedonorus arundinaceus (Shreb.)], the primary grazing forage in the mid-south, and has a symbiotic relationship with an endophytic fungus (Neotyphodium coenophialum) that produces ergot alkaloids that cause fescue toxicosis in grazing livestock. Some evidence indicates that condensed tannins (CT) can bind to ergot alkaloids and render them ineffective, thereby preventing symptoms of fescue toxicosis. Non-pregnant, non-lactating ewes [n = 20; 57 ± 1.3 kg initial body weight (BW)] were housed in individual pens (1 × 1.5 m) with metal grate flooring. Ewes were offered ad libitum access to either novel endophyte (NE) or toxic endophyte-infected tall fescue silage with no CT (E0), or CT at 10 (E10) or 30 (E30) g/kg of silage dry matter (DM). The CT used was Quebracho tannin (Schinopsis quebracho-colorado). All ewes received 4 g/kg BW liquid molasses, and this served as the carrier for the CT treatments. The study consisted of 2, 21-d periods with a 30-d washout between periods. A 14-d adaption was followed by 7-d of total fecal and urine collection in each period. Blood samples for prolactin analysis were taken on the last day of each period. Data were analyzed using individual ewe within period as the experimental unit, treatment was a fixed effect, and period and pen were random effects. Prolactin was lesser (P < 0.01) in endophyte infected silage treatments. Intake (DMI; g/kg BW) and neutral detergent fiber (aNDF) intake (g/kg BW) were greater (P = 0.05) in NE compared to other treatments. Dry matter digestibility (DMD; g/kg DMI) and aNDF digestibility (g/kg NDF) were greater (P = 0.01) in NE compared to other treatments and organic matter (OM) digestibility [(OMD, g/kg OM intake (OMI)] did not differ between NE and E10, but NE was greater (P = 0.01) than E0 and E30. Digestible DMI and OMI (g/kg BW) were greater (P = 0.01) from NE compared to other treatments. Apparent N absorbed (g/kg N intake) was greater (P = 0.03) in NE, E0, and E10 compared with E30. Fecal N (g/kg N intake) was greater in E30 compared to E0 and E10, but not different from NE. Nitrogen retained (g/kg N intake and N absorbed) did not differ (P ≥ 0.31) among treatments. Condensed tannin supplementation at 30 g/kg DM had negative impacts on DM and OM digestibility and did not prevent decreases in prolactin associated with tall fescue toxicosis.

Renewable Tannin-Based Adhesive from Quebracho Extract and Furfural for Particleboards

With increasing concerns about the production of sustainable materials, the field of wood-based materials still offers a critical challenge. Indeed, a close dependence on petroleum derivatives is still required, involving high consumption of non-renewable and toxic chemicals in the assembly of wooden parts. Herein, the aim of this research was to evaluate the potentiality of an entirely renewable tannin-based adhesive for particleboard production. Industrial quebracho (Schinopsis balansae) tannin powder was selected as a raw material and analyzed in terms of polyphenols, polysaccharides, and the total condensed amount. Furfural was proposed as a bio-sourced hardener to establish crosslinking between the flavonoid units and hence produce a resin. This formulation was analyzed in terms of viscosity and curing time and then applied to laboratory-scale single-layer particleboard production. The density, mechanical properties, and thickness swelling of the panels were investigated at different glue ratios and pressing conditions. It was observed that time has a higher impact than temperature on the internal bond, and panels pressed at 160 °C for a longer pressing time (&gt;7 min) performed better than the boards obtained at a higher temperature. The registered values at 160 °C for 11 min of pressing of internal bond (0.37 MPa) and modulus of elasticity (1417 MPa) met the required standards for P1 panels according to European norms EN 312 (2010). Conversely, the modulus of rupture (4.9 MPa) did not satisfy the requirements suggesting the need for the use of additive or post-treatments. Considering the results achieved, quebracho–furfural adhesives are an interesting base for bio-based adhesive formulations.

In vitro screening of the ruminal methane and ammonia mitigating potential of mixtures of either chestnut or quebracho tannins with blends of essential oils as feed additives

Tannins and essential oils (EOs) have been previously described for their properties to mitigate ruminal methane and ammonia. Their combination might be even more efficient, as they have different modes of action on rumen pathways. This study aimed to screen in vitro the mitigating properties of variously combining tannins with EO in a total of 48 treatments: 12 single additives, 10 mg of EO or 20 mg of tannins/g diet, to establish their basal efficiency; 36 combinations of 20 mg of tannins/g + 10–15 mg of EO. Quebracho (Q) and chestnut (C) tannins defined C, Q and C/Q groups of mixtures with EO blends, formulated with oregano, thyme and clove EO, citrus peel, carvacrol, thymol, eugenol, α-pinene, and bornyl acetate. Supplements were added to a control diet, which was also incubated alone as a basis for comparisons with supplemented treatments, in a total of six runs. Effects on rumen pH, protozoal count, and proportions of individual volatile fatty acids (VFA) were limited. The tannins extracts seemed to cause most of the mitigating effects by suppressing ammonia by up to 31% and methane yield by up to 15%, with the highest reductions obtained with tannins-based supplements. However, this occurred by contemporary affecting the feeding value of the substrate, as indicated by reductions in total VFA and in vitro organic matter digestibility. Overall, six mixtures of C and Q groups were the most efficient and they need further studies to understand the mechanisms of actions and the synergistic effects occurring among compounds. Highlights Combinations of tannins and essential oil compounds were screened in vitro Some combinations lowered methane yield and ammonia formation by up to 15 and 31% Essential oil compounds enhanced the mitigating properties of the tannins

Simple preparation of broadband UV filters based on TiO2 coated with aqueous extracts of native trees from the Chaco region of Argentina.

The nativeforest of northwestern Argentina,as part of the Chaco region, is a rich andunexploited source of phytochemical compounds for medicinal/cosmetic applications. In the present study, fruit, leaf, branch, and bark organs of the native trees Sarcomphalus mistol (Mistol, M) and Schinopsis lorentzii (Quebracho Colorado santiagueño, QC) were harvested, and aqueous plant extracts (PE) were prepared. The spectroscopic (UV-Vis absorbance, diffuse reflectance, ATR-FTIR) and antioxidant (TEAC, Folin-Ciocalteu) properties of PE were characterized and used as TiO2 coating material to obtain a series of TiO2@PE nanocomposites. These materials showed almost null photocatalytic activity compared to aqueous suspensions of bare TiO2, displaying yellowish to brownish coloration and high long-term stability in both freshwater and seawater model solutions. The loss of photocatalytic activity in TiO2@PE was associated with the combination of the internal filter effect and the antioxidant/radical capacity exerted by the phytochemicals of the PE coating,with higher broadband photoprotection for the nanocomposites prepared with QC extracts. Thus, this study shows the potential capacity of the forest resources of the Chaco region of Argentina for the development of new cosmetic and/or sun protection formulations.

Using multiple heart-cutting valves and stop-flow operation to enable variable second dimension gradient times in online comprehensive two-dimensional liquid chromatography

Online comprehensive two-dimensional liquid chromatography (LC×LC) is the preferred method currently for the separation of highly complex mixtures of non-volatile compounds. With fully automated commercial instrumentation and software making the method appealing to both researchers and industry, the demand for systems with improved separation capabilities for highly complex mixtures such as those found in natural products or proteomics has increased. In this study we report an approach that enables variable second dimension analysis times based on the use of multiple heart-cutting valves and stop-flow operation to circumvent the requirement for very fast second dimension (2D) analyses in online LC×LC. As application, the HILIC×RP-LC analysis of condensed tannins (proanthocyanidins) in cocoa, grape seed and quebracho extracts is used to demonstrate the performance on the proposed methodology. The method offers increased flexibility compared to conventional online LC×LC separations in that longer 2D gradients can be used to accommodate more complex portions of the chromatogram, while shorter 2D gradients can be used in sections containing fewer peaks, while largely maintaining the benefits of comprehensive separation. We present an evaluation of the performance of the variable gradient time stop-flow HILIC×RP-LC method compared to a comparable, conventional online HILIC×RP-LC system in terms of practical peak capacities using established 2D-LC theory. The improved separation of especially low-level intermediate molecular weight proanthocyanidin oligomers by the former method demonstrates the benefits of the developed approach.

Comparing carriers as a support media of white-rot fungi in natural tannins removal

• The growth of white-rot fungi was tested on polyethylene carriers containing cellulose; • Basidiomycetes could cover fully the carriers with the highest cellulose percentage; • B. adusta could grow up to 60% of carrier surface in not-sterile conditions; • B. adusta growth was associated with 25±4% Quebracho tannin sCOD removal; • B. adusta and A. tubingensis could grow together and remove Quebracho sCOD up to 15±4% In the last decades, White-rot Fungi bioremediation potential has been widely investigated, providing remarkable results toward several recalcitrant molecules. However, full-scale applications based on fungi are not employed yet and little is known about their optimal operating conditions, such as i) their ability to grow without sterile conditions, ii) co-substrate requirements and iii) the accurate carrier design for fungal growth. In this study, several batch tests were performed as preliminary steps to evaluate the possible design of a pilot-scale reactor based on fungal biomass to be operated under not-sterile conditions in the removal of Quebracho natural tannin. The tests were performed to verify fungal affinity, including Basidiomycetes and Ascomycetes for innovative cellulose-containing carriers compared to commonly employed PolyUrethane Foam Cubes. In particular, four fungi, including three Basidiomycetes White-rot Fungi, Bjerkandera adusta, Phanerochaete chrysosporium and Tyromyces chioneus and the Ascomycota strain Aspergillus tubingensis , were employed. As a first step, fungi were tested to evaluate their ability to attach and grow onto 12 types of innovative carriers made by High-Density PolyEthylene and containing cellulose in different percentages. Other tests were performed without sterile conditions. In particular, fungal abilities i) to attach and grow onto two different types of support, including cellulose-containing carrier and polyurethane foam cubes and ii) to biotransform recalcitrant molecules (Quebracho natural tannin) iii) to grow and operate synergistically in a consortium of two fungi, were evaluated. The main parameters evaluated were soluble Chemical Oxygen Demand (sCOD) reduction and dry weight increase. Basidiomycetes showed high affinity for cellulose-containing carrierswith the highest cellulose percentage (7%) achieving full colonization and 60% coverage, in sterile conditions and not- sterile conditions, respectively. These results were associated with a Quebracho sCOD removal of 25±4%, without sterility. When combined, the two selected strains, Bjerkandera adusta and Aspergillus tubingensis were able to grow on carriers and to remove up to 15±4% of tannins recalcitrant sCOD. This study provides evidence of i) Basidiomycetes high affinity for cellulose-containing carriers that could favour fungi attachment in sterile and not-sterile conditions, t .and ii) the feasibility of a combined use of Ascomycetes and Basidiomycetes in bioremediation.

Effect of Select Tannin Sources on Pathogen Control and Microbial Nitrogen Metabolism in Composted Poultry Litter Intended for Use as a Ruminant Crude Protein Feedstuff.

Poultry litter is a good crude protein supplement for ruminants but must be treated to kill pathogens before feeding. Composting effectively kills pathogens but risks loss of ammonia due to uric acid degradation. The objectives of this study were to test the ability of tannins to reduce pathogens and preserve uric acid during poultry litter composting. In two experiments, poultry litter was mixed with phosphate buffer and distributed to 50-ml tubes (three tubes/treatment per sample day) amended with 1 ml buffer alone or buffer containing pine bark, quebracho, chestnut, or mimosa tannins. Treatments achieved 0.63% (wt/wt) quebracho, chestnut, or mimosa tannins in experiment 1, or 4.5% pine bark or 9% quebracho, chestnut, or mimosa tannins in experiment 2. Tubes were inoculated with a novobiocin- and nalidixic acid-resistant Salmonella typhimurium, closed with caps, and incubated at successive 3-day increments at 22, 37, and 42°C, respectively. In experiment 1, bacterial counts in contents collected on days 0, 6, and 9 revealed a treatment by day effect (p < 0.03), with the Salmonella challenge being 1.3 log10 CFU/g higher in quebracho-treated composts than in untreated controls after 6 days of composting. After 9 days of composting, Salmonella, wildtype Escherichia coli, and total aerobes in untreated and all tannin-treated composts were decreased by about 2.0 log10 CFU/g compared to day 0 numbers (3.06, 3.75, and 7.77 log10 CFU/g, respectively). Urea and ammonia concentrations tended (p < 0.10) to be increased in chestnut-treated composts compared to controls and concentrations of uric acid, urea, and ammonia were higher (p < 0.05) after 9 days of composting than on day 0. Despite higher tannin application in experiment 2, antibacterial effects of treatment or day of composting were not observed (p > 0.05). However, treatment by time of composting interactions was observed (p < 0.05), with quebracho- and chestnut-treated composts accumulating more uric acid after 24 h and 9 days of composting and chestnut-, mimosa- or quebracho-treated composts accumulating less ammonia than untreated composts. Results demonstrate that composting may effectively control pathogens and that tannin treatment can help preserve the crude protein quality of composting poultry litter.

Antibacterial Potency for Mimosa, Quebracho and Essential Oils of Origanum Species against Acinetobacter pittii, Klebsiella pneumonıae and Bacillus cereus from Diabetic Foot Patient

The diabetic patients may sometime suffer from foot lesions, foot ulcers and amputation that adversely affect their quality of life. In this respect, good footwear has a critical significance for diabetic foot patients. The aim of this study to evaluate the potential efficacy of mimosa, quebracho, and essential oils of Origanum onites, Origanum onites oleum, and Origanum minutiflorum, against Acinetobacter pittii, Bacillus cereus, and Klebsiella pneumoniae, which was isolated from diabetic foot patient. According to our results, the mimosa extracts were slightly more efficient when compared to quebracho extracts to control the bacterial growth of A. pittii (8.77±0.58-35.12±8.41% inhibition for three doses), and K. pneumoniae (21.40±0.48-47.04±0.51% inhibition) except B. cereus (71.1±0.31-23.51±1.66% inhibition). But these inhibition percentages remained at lower levels. On the other hand, essential oil samples of O. onites, O. onites oleum, and O. minutiflorum at tested doses have considerably high antibacterial effects against A. pittii, B. cereus, and K. pneumoniae. The tested essential oils almost completely inhibited B. cereus with percentages of inhibition ranging from 96.18±2.98-100±0.00. Also, the bacterial growth of K. pneumoniae and A. pittii was inhibited by 88.01±2.36 to 100±0.00% and 71.42±12.57 to 100±0.00%, respectively. Moreover, the essential oils of O. onites, O. onites oleum, and O. minutiflorum, had bactericidal activity against A. pittii, and K. pneumoniae but bacteriostatic activity against B. cereus. This potency for essential oil of Origanum species may be evaluated for diabetic footwear. More detailed technical studies are required for the application of Origanum species to leather footwear.

Quebracho Tannin Bio-Based Adhesives for Plywood.

Wood-based products are traditionally bonded with synthetic adhesives. Resources availability and ecological concerns have drawn attention to bio-based sources. The use of tannin-based adhesives for engineered wood products has been known for decades, however, these formulations were hardly used for the gluing of solid wood because their rigidity involved low performance. In this work, a completely bio-based formulation consisting of Quebracho (Schinopsis balancae) extract and furfural is characterized in terms of viscosity, gel time, and FT-IR spectroscopy. Further, the usability as an adhesive for beech (Fagus sylvatica) plywood with regard to press parameters (time and temperature) and its influence on physical (density and thickness) and mechanical properties (modulus of elasticity, modulus of rupture and tensile shear strength) were determined. These polyphenolic adhesives presented non-Newtonian behavior but still good spreading at room temperature as well as evident signs of crosslinking when exposed to 100 °C. Within the press temperature, a range of 125 °C to 140 °C gained suitable results with regard to mechanical properties. The modulus of elasticity of five layered 10 mm beech plywood ranged between 9600 N/mm2 and 11,600 N/mm2, respectively, with 66 N/mm2 to 100 N/mm2 for the modulus of rupture. The dry state tensile shear strength of ~2.2 N/mm2 matched with other tannin-based formulations, but showed delamination after 24 h of water storage. The proposed quebracho tannin-furfural formulation can be a bio-based alternative adhesive for industrial applicability for special plywood products in a dry environment, and it offers new possibilities in terms of recyclability.

Comparing the Effects of a Pine (Pinus radiata D. Don) Bark Extract with a Quebracho (Schinopsis balansae Engl.) Extract on Methane Production and In Vitro Rumen Fermentation Parameters

Simple SummaryLivestock production systems are responsible for 37 and 64% of total anthropogenic methane (CH4) and ammonia (NH3) overall planet emissions, respectively. Due to the growing demand for meat and milk, mitigating their environmental impact is a major concern. A novel tannin-rich phenolic extract from radiata pine bark (PBE) has the potential to reduce CH4 and NH3 nitrogen (NH3-N) production and modulate rumen fermentation but has not been compared with other commercial phenolic extracts. This study compared PBE with a quebracho extract (QTE). Both extracts decreased butyrate proportion, CH4, total volatile fatty acids, NH3-N production, and increased acetate proportion. Inclusion of QTE increased the propionate proportion but decreased DM disappearance. Results indicate that PBE has the potential to contribute to sustainable livestock production; however, further in vivo studies are needed to verify our results.The aim of this study was to compare the effects of a pine (Pinus radiata D. Don) bark extract (PBE) with a quebracho (Schinopsis balansae Engl.) extract (QTE) on methane (CH4) production and in vitro rumen fermentation parameters. A forage diet supplemented with PBE or QTE (0, 2 and 4% dry matter (DM) basis) was incubated for 24 h to determine in vitro DM disappearance (IVDMD), CH4, volatile fatty acids (VFA), and ammonia nitrogen (NH3-N) production. Differences were analyzed using Tukey’s test, orthogonal contrasts, hierarchical clustering heatmap (HCH), and principal component analysis (PCA). Both extracts (4% DM) decreased butyrate (Bu; p = 0.001), CH4 (p = 0.005), total VFA (p < 0.001), and NH3-N (p = 0.006) production and increased acetate (Ac; p = 0.003) without affecting the partitioning factor (p = 0.095). Propionate (Pr; p = 0.016) was increased, whereas IVDMD (p = 0.041) was decreased with QTE (4% DM). The inclusion of QTE (2% DM) decreased CH4 production (p = 0.005) and the (Ac + Bu)/Pr ratio (p = 0.003), whereas PBE (2% DM) decreased the NH3-N (p = 0.006) and total VFA production (p < 0.001). The HCH and PCA indicate a negative correlation (r = −0.93; p < 0.001) between CH4 production and tannins. In conclusion, PBE shares many of the effects generated by QTE on ruminal fermentation, although the magnitude of these effects depends on concentration. The PBE could be used as an additive in ruminant diets to reduce CH4 and NH3-N production without reducing IVDMD or increasing propionate, but further in vivo studies are required to clarify its effects on animal production.

Quebracho-Based Wood Preservatives: Effect of Concentration and Hardener on Timber Properties

Tannin polyphenols are produced by plants to protect themselves against natural decay. It is expected that impregnating low-durable timber with tannin extracts of more durable species such as quebracho (Schinopsis balansae) will enhance the durability of the specimens. This biomimetic approach combined with the in situ polymerization of quebracho–hexamine formulations can be a valid alternative to synthetic wood preservatives. In this work, we aim to evaluate the impregnation mechanism as well as the impact of tannin and hardener concentration on the mechanical and leaching resistance properties of treated wood. Compression resistance, surface hardness and leaching resistance of four different common non-durable wood species: spruce (Picea abies), pine (Pinus spp.), poplar (Populus alba) and beech (Fagus sylvatica) impregnated with different concentrations of extract and hexamine are presented. The results show that the mechanical properties of tannin-impregnated timber are enhanced, especially for timber with lower densities. Tannin and hardener concentrations tendentially do not contribute significantly to further increase MOE (modulus of elasticity), MOR (modulus of rupture) and Brinell hardness. Similar results are also obtained when the specimens are tested against leaching: tannin is significantly more water-resistant when cured with hexamine, but higher amounts of hardener do not further improve its water resistance. These findings suggest that quebracho tannin–hexamine formulations are already effective at low concentrations (5 to 10% extract with 2.5 to 5% hexamine).

Relative impact of oenological tannins in model solutions and red wine according to phenolic, antioxidant, and sensory traits

Oenological tannins (OETs) are winemaking processing aids used to facilitate stabilization and fining, to increase the antioxidant capacity, and to promote colour stability of grape juice and wine. A wide variability of pure or mix formulates are available for winemaking purposes, including hydrolysable tannins (gallotannins and ellagitannins), proanthocyanidins from grape skins and seeds (prodelphinidins and procyanidins), and from exotic wood (prorobinetinidins and profisetinidins). In this study, seventeen OETs pure and mix formulates were characterized in terms of polyphenolic content and antioxidant capacity in a model wine and in a red wine after one-month storage, as well as aroma, astringency, and bitterness sensory characteristics in water and red wine. Colour-related features were also analysed in the added red wine after one-month storage. For the first time, correlations among the obtained results in the different matrices were investigated to understand the most suitable OETs for winemaking applications. The results showed a great variability among the formulates studied in terms of phenolic content, which was strictly correlated to their antioxidant capacity. Regarding origin, hydrolysable tannins had the highest antioxidant ability, followed by exotic wood formulates. A strong and positive correlation was found in antioxidant capacity of OETs in model wine and red wine after one-month storage, in particular for ellagitannins, which confirmed also their ability to increase pigments polymerization. By contrast, quebracho tannins resulted the bitterest and most astringent when tasted in water (0.4 g/L), although in-mouth and aromatic descriptors of OETs tasted in water were not correlated with the ones of the added red wine. Therefore, the choice of OETs formulate and its optimal dose requires a characterization in terms of polyphenolic content and antioxidant capacity because these properties were well correlated with those of the added wines in a short storage period, whereas the sensory impact at oenological range doses is mainly dependent on wine features.

Impact of gelatine coating on the performance of tannin-loaded pectin microbeads obtained through external gelation

One of the limitations of external gelation for microencapsulation is that small water-soluble compounds tend to diffuse out of the microbeads, resulting in low encapsulation efficiencies. In this work we propose a one-step approach for hydrogel microbead formation and simultaneous coating using external gelation. We explored amidated pectin as the encapsulation matrix for two different tannin-rich extracts (from chestnut and quebracho). The inclusion of tannin extracts contributed to the improvement of the structure of the microbeads through their interactions with pectin. By adding gelatine to the gelling bath, the microbeads were coated with the protein. This led to a significant increase in microencapsulation efficiency, which in some cases almost doubled compared to non-coated microbeads. Thanks to the binding of tannins with gelatine, coated microbeads loaded with the greatest amount of tannin extracts (20% w/w) presented the best retention of the bioactive compounds. A 14-days storage release study showed that these microencapsulation systems only experienced a slight loss of tannins during this period, with quebracho extract exhibiting greater retention than chestnut extract. Overall, by exploiting interactions in the pectin/tannins/gelatine ternary system, the proposed strategy for microbead production and coating in a single step allowed the development of a simple and more efficient microencapsulation approach for tannin extracts through external gelation.

A Study of Concept to Prepare Totally Biosourced Wood Adhesives from Only Soy Protein and Tannin.

This is a study of concept on the initial application for wood adhesives totally biosourced from the covalent reaction between soy protein isolate (SPI) and a commercial flavonoid tannin, namely quebracho tannin. The adhesive is composed exclusively of the two vegetable biomaterials mentioned and thus is totally biosourced and non-toxic, as tannin has been classified as being not at all toxic by the European Commission REACH program. The pre-reaction between the two yielded the best plywood bonding results when limited to a temperature of 40 °C, final cross-linking being achieved during the plywood higher temperature hot pressing procedure, as for any other thermosetting adhesive. Pre-reaction at higher temperatures, namely 60 °C and 80 °C, achieved extensive premature cross-linking that lost any activity to cross-link further when hot pressed for preparing plywood. The reaction was followed by thermomechanical analysis, by matrix assisted laser desorption ionization time of flight (MALDI ToF) mass spectrometry, and by plywood shear strength tested dry, after a 24 h cold water soak and 1 h in boiling water. The adhesive of this approach lends itself to be further reinforced by the multitude of approaches on soy resins already developed by several other research groups.

11 Inclusion of Quebracho Tannin as a Silage Additive in Tall Fescue Silage: Effects on Fermentation

Abstract Tall fescue (Schedonurus arundinaceus) is commonly grazed in the mid-south, but also has potential use for spring silage. During ensiling, protein can be converted to ammonia, but condensed tannins such as those in Quebracho (Schinopsis quebracho-colorado) can reduce this conversion. However, acid production may also be reduced. Quebracho tannin was added to chopped tall fescue and ensiled at different moisture concentrations to determine those effects on ammonia and silage fermentation products. Tall fescue was harvested with a Carter harvester at 1000 h, spread on concrete, mixed thoroughly, and dried for 1 and 2 h to achieve 67 and 44% moisture (high moisture (HM) and low moisture (LM), respectively). Quebracho tannin was either not applied, or was mixed with distilled water 48 h prior to packaging and applied at 1 and 2% of the total silage dry matter (DM) to both moisture treatments. Laboratory silos were pressed to achieve a packing density of 192 kg/m3 and stored at room temperature (23.7 ℃) for 60 d, after which sub-samples were removed and analyzed for fermentation parameters. Post-ensiling crude protein (CP) was greater (P &amp;lt; 0.05) from LM vs. HM, but did not differ among tannin treatments (P = 0.11). Ammonia concentrations (%CP equivalent) were greatest in 0% tannin (P &amp;lt; 0.05). A moisture by tannin interaction affected acetic acid, with greater concentrations in HM silages with 0 and 2% tannin compared to LM with 2% tannin. Lactic acid (%) was greater (P &amp;lt; 0.05) in 0 compared to 2% tannin, but 1% did not differ from either 0 or 2% tannin. Butyrate was greater (P &amp;lt; 0.05) in HM, and in silos with 2% tannin, but not 1% tannin. Overall, total acids (%) were greatest (P &amp;lt; 0.05) in HM but did not differ (P = 0.54) among tannin treatments. Therefore, ensiling tall fescue with tannins reduced proteolysis regardless of moisture concentration, and did not reduce fermentation up to 2% tannin inclusion.

Effects of a blend of chestnut and quebracho tannins on gut health and performance of broiler chickens.

Antimicrobial restrictions prompted the search for cost and biologically effective alternatives to replace antimicrobial growth promoters (AGPs) in food-producing animals. In addition, the efficacy of this alternatives needs to be contrasted in field/commercial trials under different challenge conditions. However only a few studies describing the impact of tannins or others AGP-alternatives in commercial poultry production conditions are actually available. The aim of the present work is to study how the inclusion of a blend of chestnut and quebracho tannins can affect broiler productive performance and health under commercial conditions. Three experiments with different approaches were conducted: (1) a trial comparing the effects of both additives (tannins vs AGP) on different commercial farms at the same time; (2) the follow-up of one farm during an entire productive year; and (3) an experimental trial using a C. perfringens challenge model in broiler chickens. Although productive results from field trials were similar among treatments, evaluations of gut health indicators showed improvements in the tannins treated flocks. Frequency and severity of intestinal gross lesions were reduced in jejunum (42% vs 23%; p<0.05–1.37 vs. 0.73; p<0.01, respectively) and ileum (25% vs. 10%; p<0.0.5–1.05 vs. 0.58; p<0.01) in tannins treated birds. Results from 16S studies, show that cecal microbiota diversity was not differentially affected by AGPs or tannins, but changes in the relative abundance of certain taxa were described, including Lactobacillus and Bifidobacterium groups. Results from experimental C. perfringens necrotic enteritis showed that tannins treated birds had reduced incidence of gross lesions in jejunum (43.75 vs. 74.19%; p<0.01) and ileum (18.75% vs. 45.16%; p<0.05) compared with control. These results suggest that AGPs can be replaced by tannins feed additives, and contribute in the implementation of antimicrobial-free programs in broilers without affecting health or performance.

Intake and performance of growing lambs supplemented with quebracho tannins.

Tannins can modulate rumen fermentation and increase the bypass protein; however, the use of different doses and sources of condensed tannins (CT) in animal diets has divergent results. The aim of this study was to evaluate the effect of different levels of dietary quebracho extract inclusion, as a CT source, in the performance and carcass characteristics of growing lambs. Forty-eight weaned lambs (Texel, Suffolk, and Hampshire Down crossbred) were homogenously blocked into four groups and supplemented at 0, 10, 30, and 60g tannins/kg dry matter intake (DMI) (CONT, T1%, T3%, and T6%, respectively). The DMI, the roughage to concentrate ratio, the feed conversion rate (FCR), the average daily gain (ADG), and the body condition score (BCS) were evaluated. After the trial, animals were slaughtered, and the cold carcass weight, carcass yield, and subcutaneous fat thickness (SFT) were determined. Higher levels of CT in T3% and T6% reduced (P < 0.001) the total DMI and intake of concentrate without impacting (P = 0.071) the roughage intake (% body weight). ADG was the lowest for T6%, although the total weight gain and BCS were the lowest also for T3% (P < 0.001). FCR was worst for T6% (P < 0.001). Regarding carcass characteristics, T6% had the lowest weight of carcass (P = 0.003) and SFT (P = 0.021) compared to CONT. Carcass yields were similar among all the groups (P = 0.247). T1% did not differ from CONT to any parameter (P > 0.05). Supplementing quebracho CT at a low dose did not show beneficial effects; moreover, higher doses of CT led to detrimental effects in intake and animal performance.

Tannins as interphase corrosion inhibitors for aluminum in near‐neutral chloride solutions

AbstractThe addition of tara and quebracho colorado tannins remarkably reduces the corrosion rate of aluminum in near‐neutral and naturally aerated NaCl solutions. The experimental results (potentiodynamic polarization curves, corrosion potential measurements, scanning electron microscopy–energy‐dispersive X‐ray spectroscopy [SEM‐EDS] analysis on exposed surfaces) show that both tannins behave as a mixed‐type corrosion inhibitor of aluminum. In the absence of tannins, the SEM‐EDS analysis of the exposed samples demonstrates the accumulation of corrosion products and the existence of chlorinated compounds adsorbed on the metal surface. In the samples immersed in both tannins solutions, a more homogenous and compact layer is formed over the aluminum surface. Furthermore, in these layers chlorine was not found, revealing a high blocking capacity of the chloride adsorption when the tannins are present. Taking into account these findings, an inhibitory mechanism of aluminum corrosion is proposed. This mechanism is interphase inhibition, which involves the adsorption and incorporation of tannin molecules during the corrosion products passive layer formation, resulting in a protective three‐dimensional structure that retards both anodic and cathodic reactions.

Extract of Trema Orientalis (L.) Stem Bark: A Potential Source of Environmentally Friendly Tanning Agent for Leather Industry

Researchers around the world are in continuous endeavor to develop environment friendly tanning agent due to adverse effect of conventionally used chromium during leather tanning. Recent trend of tanning is thus heading to chrome-free and greener chemical processing options. Vegetable tanning is an exoteric leather processing technique because of their lower pollution load on the environment. Considering the inadequacy and high costing for the commercialized tannins, development of alternative tannins from locally available plants and their characterizations are important. In this research, the stem barks of Trema Orientalis (L.) were extracted at different temperatures employing water solvent with or without additives (sodium hydroxide or sodium sulphite) to attain phenolic-rich extractives. To ascertain appropriateness as a vegetable tanning agent, the obtained extracts were thereafter characterized in respect to yield, total phenolic content, tannin content and molecular structure. The extraction yield for all extracts improves and the quality remains nearly unchanged with temperature rising. The elevated concentration of chemical additives enhances the extraction yield but lessens the quality of extracts. In terms of extraction yield and the quality of extracts the best condition for extraction was discerned at 80°C with water solvent. This water extract has a decent extent of phenolic and tannin content of 266.13 mg Gallic acid equivalent/ gm of dry extract and 30.12 % respectively. The final extract exhibits excellent leather retanning tendency comparable to the commercial quebracho tannins.