Search Results (43)

Pastoral systems in New Zealand are under societal pressure due to their increasing negative environmental impact in terms of greenhouse gas emissions. This study was conducted to investigate the effects of supplementing a mixture containing hydrolysable and condensed tannins on the in vitro fermentation characteristics and gas production of three different forages, Lolium perenne, Medicago sativa, and Plantago lanceolata. Three fermentation runs of 48 h were conducted using the ANKOM gas production technique, with each pertaining to a particular forage with or without (control) tannin. Tannins were added to the fermentable substrate (i.e., forage) at a level of 0.3%. For each run, rumen fluid was collected from two fistulated Holstein Friesian × Jersey cows. The ANKOM RF gas production modules were used to monitor gas pressure and temperature every 5 min. At the end of each run, the pH of the fluid was measured, gas vials were taken for methane (CH₄) measurements and liquor samples were taken to measure volatile fatty acids (VFA) and NH₃ concentrations. The addition of tannins reduced the fractional rate of gas production for alfalfa (p ≤ 0.04) but increased it for ryegrass and plantain. There was a tendency for reduced gas production for ryegrass when tannins were added (p = 0.10). There was also a tendency for CH₄ production to reduce (p < 0.10) and N₂O to increase (p = 0.10) when tannins were added. Iso-butyrate tended to be lower for ryegrass control than to ryegrass with tannins (p = 0.08). Valerate concentration was lower for plantain control than to plantain with tannins. No effects were detected for gas composition (p > 0.05) or VFA concentrations (p > 0.05) when fermenting alfalfa. Under the condition of this study, these results may suggest that low-level tannin addition to the diet may affect rumen-fermentation pattern with a potential reduction of CH₄ production in Lolium perenne-based diets. Further research is required on the effect of low levels of tannin supplementation under ex vitro and in vivo conditions as tannin supplementation effects might be substrate-dependent. Full article

This study was conducted to compare the effects of hydrolysable versus condensed tannins on growth performance, nutrient digestion, and rumen fermentation in goats. A total of 27 Liaoning cashmere goats with similar initial body weights were randomly distributed into three groups: a basal diet, a basal diet +0.5% tannic acid (hydrolysable tannin, HT), or a basal diet +0.5% quebracho tannin (condensed tannin, CT), respectively. Compared to the control group, HT showed a decreased (p < 0.05) feed intake, while CT showed an increased (p < 0.05) feed intake and body weight gain. Digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber did not differ (p > 0.05) among groups. The HT group showed lower pH and acetic acid concentration in the rumen (p < 0.05), while the CT group showed a decrease (p < 0.05) in the abundances of Verrucomicrobia and Methanobrevibacter. Supplementation of CT decreased (p < 0.05) the levels of dihydrouracil, xanthosine, alpha-D-mannose, and L-tryptophan, while HT increased (p < 0.05) these metabolites. In conclusion, this study suggested that responses of ruminal microbiota and metabolite profiles to the type of tannins varied, and CT displayed a more positive effect on the growth performance of goats than HT when supplemented at the same level in the diets. Full article

Tannin-based foams have gained attention as a potential bio-based alternative to conventional synthetic foams. Traditionally, namely condensed tannins (CT) have been used, leaving the potential of hydrolysable tannins (HT) largely unexplored. This study compared the performance of chestnut (HT) and quebracho (CT) in tannin–protein-based foams at different tannin ratios. Using soy protein isolate (SPI) and hexamine under acidic conditions, a series of tannin foams were produced through a mechanical foaming method and analyzed for cell structure, compression strength, thermal conductivity, and chemical stability. Results show that chestnut tannin is viable in hexamine SPI formulations but is harder to process due to lower reactivity, further resulting in higher material densities compared to quebracho. Foams with higher quebracho content featured smaller, more interconnected cells, while increasing chestnut content led to larger, less interconnected cells. Compression strength decreased with higher chestnut content, while fire resistance and thermal conductivity were influenced by material density rather than tannin type. The ¹³C-NMR analysis revealed covalent bonding of hexamine with both tannins, but potential covalent bonds with SPI were undetectable. Overall, chestnut tannin can substitute quebracho tannin in hexamine-SPI foams, though with compromises in terms of specific material properties and processability. Full article

From a circular bio-economy perspective, biomass valorization requires the implementation of increasingly efficient extraction techniques to ensure the environmental and economic sustainability of biorefining processes. This research focuses on optimizing the specialized metabolite extraction of Turkey oak chips from Quercus cerris L. by applying a 3 levels Full Factorial Design (FFD). The goal is to obtain an extract with the highest antioxidant activity [evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP) assays] and specialized metabolites content [measured as total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and hydrolysable tannins content (THC)]. With this objective, three different variables were investigated and compared: temperature (20 °C, 50 °C, 80 °C), solvents EtOH/H₂O (0%, 20%, 40%), and time (3 h, 6 h, 24 h), resulting in 27 different extracts. Following the FFD analysis, the optimal extractive conditions were determined to be 80 °C, 40% EtOH/H₂O, and 19.8 h. Finally, the prediction ability of FFD was compared with that of artificial neural network (ANN) for DPPH scavenging activity, FRAP, and TPC data based on the coefficient of determination (R²), mean absolute error (MAE), and root mean square error (RMSE). The results indicated that ANN predictions were more precise than FFD ones; however, both methods were useful in optimizing the extraction process as they returned comparable optimized extraction parameters. Full article

This research identified the bioactive compounds and antioxidant capacity of the extractable (EP) and non-extractable (NEP) polyphenol fractions of berrycactus (BC). Additionally, the effects of BC and its residue (BCR) on preventing AOM/DSS-induced early colon carcinogenesis were evaluated in vivo. Male Sprague Dawley rats were randomly assigned to six groups (n = 12/group): healthy control (C), AOM/DSS, BC, BCR, BC+AOM/DSS, and BCR+AOM/DSS. NEP was obtained through acid hydrolysis using H₂SO₄ and HCl (1 M or 4 M). The HCl-NEP fraction exhibited the highest total phenolic and flavonoid content, while condensed tannins were more abundant in the H₂SO₄-NEP fraction. A total of 33 polyphenols were identified by UPLC-QTOF-MSE in both EP and NEP, some of which were novel to BC. Both NEP hydrolysates demonstrated significant total antioxidant capacity (TEAC), with HCl-NEP exhibiting the highest ORAC values. The BC+AOM/DSS and BCR+AOM/DSS groups exhibited fewer aberrant crypt foci (p < 0.05), reduced colonic epithelial injury, and presented lower fecal β-glucuronidase activity, when compared to AOM/DSS group. No differences in butyric acid concentrations were observed between groups. This study presents novel bioactive compounds in EP and NEP from BC that contribute to chemopreventive effects in early colon carcinogenesis, while reducing fecal β-glucuronidase activity and preserving colonic mucosal integrity. Full article

Numerous strategies have been developed for the corrosion protection of steel; however, most of them have a significant environmental impact and employ toxic compounds. Tannins are a green and promising solution for sustainable corrosion protection strategies. In this context, this work was focused on natural (condensed and hydrolysable) tannin layers as a possible corrosion protection strategy for carbon steel. The impact of the tannins’ dissolution medium (ultrapure water or Phosphate-Buffered Saline), surface pre-treatment (acid pickling or plasma), and deposition technology (dipping or spin coating) on layer homogeneity and adhesion has been evaluated. The effects of these parameters on coating formation, homogeneity, and adhesion have been investigated by means of visual inspections, swabbing, Fourier Transformed Infrared spectroscopy (FTIR), Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) and tape adhesion tests. Preliminary electrochemical corrosion tests have been performed on the most promising material (carbon steel acid pickled and coated with a hydrolysable tannin solved in water by spin coating) to estimate the protective ability of the developed layers and highlight the main criticisms to be overcome. Full article

In this study, we present data on the effects of condensed tannins (CTs) and hydrolysable tannins (HTs), polyphenols extracted from plants, at different concentrations on zebrafish development to identify the range of concentrations with toxic effects. Zebrafish embryos were exposed to CTs and HTs at two different concentration ranges (5.0–20.0 μgL⁻¹ and 5.0–20.0 mgL⁻¹) for 72 h. The toxicity parameters were observed up to 72 h of treatment. The uptake of CTs and HTs by the zebrafish larvae was assessed via HPLC analysis. A qRT-PCR analysis was performed to evaluate the expressions of genes cd63, zhe1, and klf4, involved in the hatching process of zebrafish. CTs and HTs at 5.0, 10.0, and 20.0 μgL⁻¹ were not toxic. On the contrary, at 5.0, 10.0, and 20.0 mgL⁻¹, HTs induced a delay in hatching starting from 48 h of treatment, while CTs showed a delay in hatching mainly at 48 h. The analysis of gene expression showed a downregulation in the group exposed to HTs, confirming the hatching data. We believe that this study is important for defining the optimal doses of CTs and HTs to be employed in different application fields such as the chemical industry, the animal feed industry, and medical science. Full article

Cistus spp. have been traditionally used for inflammatory and infectious disorders, including gastrointestinal ailments, in the Mediterranean area. Among them, Cistus × incanus L. is one of the most frequently cited species in the literature for a variety of biological activities which include inflammatory diseases. Cistus spp. aerial parts are rich in polyphenols such as condensed and hydrolysable tannins, procyanidins, and flavonoids, which show gastroprotective activities. The purpose of the present study is to investigate the biological activities of a hydroalcoholic extract from Cistus × incanus L. aerial parts in gastric epithelial cells (GES-1) infected with H. pylori. The extracts inhibited IL-8 and NF-κB induced by H. pylori and showed antibacterial activity after simulated digestion. Since our previous paper reported interesting results on the ability of Castanea sativa Mill. leaf extract to decrease inflammatory conditions in H. pylori-infected gastric cells, the combination of Castanea sativa and Cistus × incanus extracts was also investigated, showing strong anti-inflammatory activity and inhibition of bacterial adhesion. This association of botanicals is proposed herein as a novel food supplement capable of counteracting gastric inflammatory conditions. Full article

Cascalote pods are an important source of phenolic compounds, mainly recovered using solvent extraction methods. To find a sustainable alternative to these methods, this study aimed to evaluate solid-state fermentation (SSF) in order to enhance the extractability of total phenolic compounds (TPC) with antioxidant activity (AA) from cascalote pods. Aspergillus niger GH1 was selected based on the amount of TPC released and AA measured (ABTS, DPPH, FRAP) in a short period of time. Moreover, moisture, temperature, inoculum size, and mineral composition were evaluated. The largest amount of TPC released was 124.17 mg/gdw (g of dry weight) after 12 h of culture, which significantly correlated with the AA (Pearson’s R = 0.94). Moisture and KH₂PO₄ concentration were the main influencing factors of TPC release. Treatment 6 (1 × 10⁷ spores/gdw, 30 °C, 60% moisture, mineral composition (g/L): KH₂PO₄, 1.52; NaNO₃, 7.65; and MgSO₄, 1.52) was selected due to the highest values of both TPC and AA. SSF-assisted extraction allowed for an increase of 118% and 93% in TPC and AA values, respectively. Corilagin, lagerstannin, geraniin, and ellagic acid were the main phenolic compounds identified by RP-HPLC-ESI-MS in the cascalote extracts. The results obtained demonstrate the feasibility of SSF-assisted extraction as a biotechnological alternative for the recovery of important bioactive molecules from this underutilized material. Full article

The genus Dipteryx, to which the cumaru tree belongs, contains neotropical species native to Central and South American countries. They are used both in the sale of timber and seeds and for the extraction of the active compound coumarin, used as a flavoring agent. This study evaluated the phytochemical profile and antioxidant activity of extracts of leaves, branches, and fruits (residues and seeds) of the species Dipteryx punctata. The plant material for analysis was collected in five seed-producing areas, in Mojuí dos Campos, Pará, Brazil. The extracts were obtained via Soxhlet extractor using 92.8% distilled ethanol as the solvent and operated till exhaustion (8 h). Chromatographic analyses were performed by thin-layer chromatography (TLC) and gas chromatography coupled to mass spectrometry (GC-MS), followed by phytochemical determination of phenolics and flavonoids and analysis of antioxidant activity (TLC and free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH). The highest extract yields were obtained from D. punctata fruit residues and seeds from all areas, with maximum values of 26.1% and 47.2%, respectively, in Boa Fé (area 3). In the evaluation by TLC, the extracts of leaves, branches, and residues presented the classes of terpenes, condensed and hydrolysable tannins, and flavonoids; coumarin (1,2-benzopyrone) was identified only in residue and seed extracts. The major constituents highlighted in the collection areas were: lupeol in leaves (34.4% in area 5), 4-O-methylmannose in branches and residues (85.5% in area 2 and 90.6% in area 5, respectively), and coumarin in seeds (99.3% in area 3). The best results for the antioxidant action were obtained for extracts from leaves and residues, requiring a concentration of 117.6 µg.mL⁻¹ of the extract from the leaves and 160.4 µg.mL⁻¹ of the extract from the residues to reduce the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical by 50%. This phytochemical study contributes to reducing the scarcity of information on D. punctata. The chemical classes and compounds identified corroborate the antioxidant activity and add value to the species, and the data obtained reinforce the importance of reusing fruit residues, which are chemically rich but discarded in the environment. Full article

Twenty oenotannins from different botanical origins were studied in model wine solution (1 g/L, 12% ethanol, pH 3.5). An original device was created for measuring Oxidation–Reduction potential (ORp) of the solutions at 20 °C in strict anoxic condition by the electrochemical method of the platinum electrode zero-current potential. Reactivity against proteins and antioxidant properties were related to the chemical structure and, consequently, to the botanical origin of the oenotannins. The highest turbidity after BSA addition (ΔNTU > 1000) values were measured for the gallic hydrolysable tannins. The ORp versus standard hydrogen electrode ranged from 420 to 260 mV. The ellagitannins had the highest antioxidant power (AP%), followed by condensed tannins and gallotannins, highlighting a correlation with the phenolic profile. Based on these findings, two formulations were prepared as a blend of some of the tested oenotannins, with the ability to increase (MIX1) and decrease (MIX2) the ORp of the model wine. Full article

The goal of this study was to develop a sustainable, tannin-based option for silver-based and other current antimicrobial solutions for hospital privacy curtains. Commercial tree-derived tannins were characterized and their in vitro antibacterial properties against Staphylococcus aureus and Escherichia coli were determined. Hydrolysable tannins showed greater antibacterial efficacy than condensed tannins but differences in antibacterial efficacy between any of the tannins could not be attributed to their functional group content or molar mass. Outer membrane disruption was not a significant factor in antibacterial efficacy of tannins against E. coli. In a hospital field study, draw patches coated with hydrolysable tannins and affixed to privacy curtains reduced total bacteria count by 60% over eight weeks compared to their matching uncoated reference sides. In a follow-up laboratory study with S. aureus, very light spraying with water improved contact between bacteria and coating, enhancing the antibacterial effect by several orders of magnitude. Full article

This study examined the potential of hydrolysable tannin in comparison to condensed tannins for the production of furanic foams. The results indicate that chestnut tannin presents lower reactivity and requires a stronger acid for the polymerization. Additionally, foamability and density were found to be dependent on both surfactant concentration and tannin type, allowing lower densities for mimosa tannin and lower thermal conductivities for chestnut-based foams. Mimosa tannin was found to have the highest compression strength, followed by quebracho and chestnut, promising thermal conductivity of around 50 mW/m·K for 300 kg/m³ foams, which suggests that chestnut foams have the potential to performing highly when the density is reduced. Chemical analysis revealed that the methylene moieties of the furanics are non-specific and produces new covalent bonds with nucleophilic substrates: -OH groups and free-positions in the flavonoids. Overall, this study opens new perspectives for the application of hydrolysable tannins in polymer and material science. Full article

The chestnut tree (Castanea sativa, Mill.) is a widespread plant in Europe whose fruits and wood has a relevant economic impact. Chestnut wood (CW) is rich in high-value compounds that exhibit various biological activities, such as antioxidant as well as anticarcinogenic and antimicrobial properties. These metabolites can be mainly divided into monomeric polyphenols and tannins. In this piece of work, we investigated a sustainable protocol to isolate enriched fractions of the above-mentioned compounds from CW residues. Specifically, a sequential extraction protocol, using subcritical water, was used as a pre-fractionation step, recovering approximately 88% of tannins and 40% of monomeric polyphenols in the first and second steps, respectively. The optimized protocol was also tested at pre-industrial levels, treating up to 13.5 kg CW and 160 L of solution with encouraging results. Ultra- and nanofiltrations were used to further enrich the recovered fractions, achieving more than 98% of the tannin content in the heavy fraction, whilst the removed permeate achieved up to 752.71 mg GAE/g_ext after the concentration (75.3%). Samples were characterized by means of total phenolic content (TPC), antioxidant activity (DPPH· and ABTS·), and tannin composition (hydrolysable and condensed). In addition, LC-MS-DAD was used for semiqualitative purposes to detect vescalagin/castalagin and vescalin/castalin, as well as gallic acid and ellagic acid. The developed valorization protocol allows the efficient fractionation and recovery of the major polyphenolic components of CW with a sustainable approach that also evaluates pre-industrial scaling-up. Full article

Gastrointestinal nematodes (GINs) is a limiting health factor for dairy goats, and the integration of the diet with fodder containing condensed tannins (CT) is becoming increasingly important to control GINs. To preliminary evaluate their potential role as part of GIN control in goat breeding, the in vitro anthelmintic efficacy of the CTs of Silvafeed BYPRO (SBP), Silvafeed Q powder (SQ), and sainfoin hay (SH) was evaluated, and the untargeted metabolomics profiling of the selected formulations was performed. CTs were extracted in water and in ethanol, their concentration was determined, and their chemical characterization was conducted using High-Performance Liquid Chromatography (HPLC) coupled to High-Resolution Mass Spectrometry (HRMS) platform. The in vitro anthelmintic activity of the extracts was evaluated using the Eggs Hatch Test (EHT) and the Larval Migration Inhibition Test (LMIT) using different extract concentrations (150, 300, 600, and 1200 μg/mL). The metabolomic profile of the ethanol extract showed a high number of flavonoids, while the water extract showed higher levels of hydrolysable tannins. The ethanol extracts were effective on both eggs hatching and larvae migration at low concentrations (150 μg/mL) for the three analyzed samples, while the water extracts showed more varied results: SH showed the greatest ovicidal efficacy (concentration 150 μg/mL, %IH = 40.9), while SBP and SQ were more effective against the larvae migration (concentration 600 μg/mL, %LMI = 69.7% and 88%), respectively. The integration of CT-rich fodder into the diet may be considered for the control of GIN infection in goats. Full article