Adsorption Of Tannic Acid Research Articles

Effects of tannic acid interfacial absorption on the physicochemical stability of algal oil-loaded emulsions and inhibition of fishy off-flavor

In the present study, the inhibition of fishy off-flavor and destabilization in algae oil-loaded emulsions by tannic acid (TA) adsorption on octenyl succinic anhydride (OSA) starch interfaces were investigated. The changes of typical fishy off-flavor components in the emulsion, physiochemical stability, and interaction between TA and OSA starch were analyzed. The TA fortification significantly prevented the production of fishy smell-related volatile components such as heptanal and (E, E)-3, 5-octadiene-2-one. The proportion of TA on the interface was more than 90 %, forming an interfacial film with the antioxidant function. The emulsions stabilized by OSA starch-TA complexes had better oxidative and physical stability. The isothermal titration calorimetry suggested that the interaction between OSA starch and TA included hydrogen bonding and van der Waals forces (ΔG = -13.272 kJ·mol−1·K−1, ΔH = -1.302 × 103 kJ·mol−1, ΔS = -4.326 kJ·mol−1·K−1). Altogether, these results provided application guidance for developing starch-based oil-in-water emulsion systems with antioxidant properties.

Improved Fire Retardancy of Cellulose Fibres via Deposition of Nitrogen-Modified Biopolyphenols.

Driven by concerns over the health and environmental impacts of currently used fire retardants (FRs), recent years have seen strong demand for alternative safer and sustainable bio-based FRs. In this paper, we evaluated the potential of nitrogen-modified biopolyphenols as FRs for cellulosic natural fibres that could be used in low-density cellulose insulations. We describe the preparation and characterisation of nitrogen-modified lignin and tannin containing over 10% nitrogen as well as the treatment of cellulose pulp fibres with combinations of lignin or tannin and adsorption-enhancing retention aids. Combining lignin or tannin with a mixture of commercial bio-based flocculant (cationised tannin) and anionic retention chemical allowed for a nearly fourfold increase in lignin adsorption onto cellulosic pulp. The nitrogen-modified biopolyphenols showed significant improvement in heat release parameters in micro-scale combustion calorimetry (MCC) testing compared with their unmodified counterparts. Moreover, the adsorption of nitrogen-modified lignin or tannin onto cellulose fibres decreased the maximum heat release rate and total heat release compared with cellulose reference by 15–23%. A further positive finding was that the temperature at the peak heat release rate did not change. These results show the potential of nitrogen-modified biopolyphenols to improve fire-retarding properties of cellulosic products.

Chemometric Evaluation of a Biodegradable Tannic Acid-Polyurethane System for the Removal of Pb(II) and Hg(II) Ions from Water

The industrialization has brought advances that have enabled a better quality of life for people and improved production stages and business models. However, some impacts still need to be resolved, such as water pollution. Industrial pollutants containing potentially toxic metal ions are expensive for the industry, so studying new materials and new processes has helped solve this problem. Adsorption processes using biodegradable adsorbent materials have been presented as relevant alternatives for reusing metallic ions from water bodies and sewage networks. In this perspective, tannic acid (TA) immobilization in biodegradable polyurethane (PU) foams based on vegetable oil (castor oil) was used to remove metal ions Hg (II) and Pb (II) from water. The preliminary study was carried out in TA's immobilization in PUs, with a 2k order factorial experimental design. The responses were obtained and evaluated by gravimetry and UV-Vis spectroscopy using Central Composite Design (CCD). The molar concentration of 0.1000 mol L-1 by TA solution at pH equal to 7 and 19 hours of contact time was defined as optimal conditions for TA adsorption in the PU. The optimized PU-TA system was evaluated for removing Pb (II) and Hg (II) ions in aqueous solutions, and the tests showed that 59.93% and 51.48% were removed from water, respectively. The use of the PU-TA adsorbent system for removing metals in water can be widely valuable in industrial plants that need water treatment.

α-Amylase inhibition of a certain dietary polyphenol is predominantly affected by the concentration of α-1, 4-glucosidic bonds in starchy and artificial substrates

To elucidate why the inhibitory activity of one same polyphenol against α-amylase varies in different works. Seven starchy and three artificial substrates, and a polyphenolic competitive inhibitor, tannic acid (TA) were applied to study the enzyme inhibition in different digestion systems. The results showed that the IC50 values of TA were similar for all starches at the same starch concentration, although there existed difference in starch physiochemical properties, like branching degree, amylose chain distribution, viscosity, and digestion rate. However, the IC50 values significantly decreased with the substrate concentration decreasing, regardless of substrate types. Notably, TA had a similar competitive inhibition constant (Kic) for all the starches, despite the difference in substrate concentration, indicating that the fixed constant unconditionally describes the inhibitor-enzyme binding property. In the TA/amylase/starch system, the physical adsorption of TA with starch was much weaker than the specific binding of TA with α-amylase that was driven by hydrogen bondings and π-stackings. Therefore, it was the substrate, i.e., α-1,4-glucosidic bond concentration, rather than the existing matrix of the bonds, that predominantly affected the inhibitory activity of a polyphenol, because of the competitive action between α-1,4-glucosidic bond and the polyphenol regarding binding with the enzyme.

Preparation of Amino-Functionalized Mesoporous SBA-15 Nanoparticles and the Improved Adsorption of Tannic Acid in Wastewater.

Ordered mesoporous Santa Barbara amorphous (SBA-15) materials have high surface areas and are widely used in adsorption, separation, filtration, and heterogeneous catalytic processes. However, SBA-15 surfaces contain hydroxyl groups that are unsuited to the adsorption of organic pollutants; thus, SBA-15 must be chemically modified to promote its adsorption activity. In this study, amino-functionalized nanoporous SBA-15 was fabricated by employing sodium silicate as a precursor. The structural characteristics of the prepared composites were examined using thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectrometry, field-emission scanning electron microscopy, transmission electron microscopy, and surface area analysis. The prepared SBA-15 had a large pore size (6.46–7.60 nm), large pore volume (1.037–1.105 cm3/g), and high surface area (546–766 m2/g). Functionalization caused a reduction in the SBA-15 pore volume and surface area, whereas amino groups that promoted an interaction between adsorbates and solids facilitated solute adsorption. The adsorption of tannic acid (TA) onto amino-modified silica composites (SBA-15 and 3-aminopropyltriethoxysilane (SBA-15/APTES) and SBA-15 and pentaethylenehexamine (SBA-15/PEHA)) was studied. Their adsorption capacities were affected by solution temperature, solution pH, agitation speed, adsorbent dosage, and initial TA concentration. The maximum adsorption capacities for SBA-15/APTES and SBA-15/PEHA were 485.18 and 413.33 mg/g, respectively, with SBA-15/APTES exhibiting ultrafast removal of TA (98.61% removal rate at 15 min). In addition, this study explored the thermodynamics, adsorption isotherms, and kinetics. A comparison of two types of amino-functionalized SBA-15 was used for the first time to adsorb TA, which providing valuable information on TA adsorption on high adsorption capacity materials in water media.

Understanding the electrosteric dispersion of α-alumina particles using a sulfonated tannin of natural origin

This work explores the stabilization effect of a sulfonated tannin (black wattle extract) on water-suspended α-alumina particles. Results showed that first additions lead to particle agglomeration. A minimum of 0.5 wt% tannin (relative to the alumina content) is required to cover the whole particle surface. Suspensions regain stability at ca. 1.0 wt% tannin (ca.1 mg tannin/m2 alumina surface area), due to a high negative ζ-potential (−60 mV, pH = 8.0). Both ζ-potential and particle hydrodynamic diameter are then close to those in electrostatically dispersed alumina particles. Changes in ionic strength cause changes in ζ-potential and hydrodynamic diameter but hardly affect the tannin adsorption. The electrosteric stabilization results from the repulsion provided by the ~15 nm thick adsorbed tannin layer (steric effect) and the enveloping electric double layer, which remains sensitive to the suspension ionic strength (electrostatic effect). Changes in hydrodynamic diameter can be used to infer the electric double layer thickness.

Sustainable utilization of rice husk waste for preparation of ordered nanostructured mesoporous silica and mesoporous carbon: Characterization and adsorption performance

Rice husk has a high heating value, making it an attractive source of renewable energy. Rice husk ash (RHA) forms after the combustion of rice husk to heat energy. The recovery and reuse of RHA is a sustainable strategy in a circular economy. In this research, RHA was used as the raw material for the preparation of mesoporous silica, Santa Barbara Amorphous (SBA-15). Ordered mesoporous carbon, carbons mesostructured from Korea–3 (CMK-3), was synthesized utilizing SBA-15 as a template by injecting it with sucrose. According to transmission electron microscopy (TEM) images, both SBA-15 and CMK-3 consisted of high order and hexagonal arrays of mesopores. SBA-15 and CMK-3 contained large pore volumes of 1.260 and 1.185 cm3/g, high surface areas of 820 and 1005 m2/g, and uniform pore sizes of 6.41 and 3.44 nm, respectively. The amino-groups were successfully grafted on the SBA-15 surface. The amino-modified SBA-15 and CMK-3 revealed excellent adsorption of tannic acid. The effects of adsorption conditions, namely the solution temperature, adsorbent dosage, solution pH, and initial tannic acid concentration, were examined. Amino-modified SBA-15 and CMK-3 exhibited maximum adsorption capacities of 278.9 and 488.9 mg/g, respectively. Thermodynamic parameters were also investigated. The results indicated that the tannic acid adsorption was an exothermic process. Kinetic behaviors and adsorption equilibrium optimally matched the pseudo-second-order model and Langmuir isotherm. Overall, recovered RHA was useful in the preparation of mesoporous adsorbents for removing chemicals containing tannic acid from liquid waste.

Impact of the variety on the adsorption of anthocyanins and tannins on grape flesh cell walls.

During winemaking, after extraction from the skins, anthocyanins and tannins adsorb onto the pulp flesh cell walls. The present study aimed to quantify the amounts adsorbed and their impact on wine composition, the impact of variety and ethanol on adsorption, and whether the presence of anthocyanins plays a role and impacts tannin adsorption. Anthocyanin and tannin fractions obtained by mimicking winemaking conditions were mixed with fresh flesh cell walls of two varieties: Carignan and Grenache. Adsorption isotherms were measured. Adsorption of tannins was higher with Carignan than with Grenache and decreased when the ethanol content increased. In comparison, anthocyanins were adsorbed in small amounts, and their mixing with tannins had no impact on their adsorption. The differences were related to differences in pulp cell wall composition, particularly in terms of extensins and arabinans. Adsorption of tannins, which can reach 50% of the initial amount, depends on the pulp cell wall composition. This needs to be investigated further. © 2021 Society of Chemical Industry.

The behaviour of tannic acid adsorption on fluorite surface: Isotherm, kinetic and thermodynamic studies

The behaviour of tannic acid adsorption on fluorite surface: Isotherm, kinetic and thermodynamic studies

Encapsulation of Chlamydomonas reinhardtii into a metal-phenolic network

Single-cell encapsulation using metal-phenolic networks (MPNs) is an emerging technique to protect cells from stressors. Until now, the MPN coatings have been only applied to some bacteria, yeast, and mammalian cells. To further demonstrate their versatility, we herein coat Chlamydomonas reinhardtii with the network consisting of tannic acid and iron(III). The encapsulation served as a mechanical barrier, which delayed proliferation of the coated cells. Furthermore, we investigated the adsorption of tannic acid onto the surface of C. reinhardtii and identified the optimum concentration to achieve partial coverage on the algae's surface. Finally, we explored the effect of MPN coating for flocculation-enhanced algae harvesting. Overall, the results demonstrate that the cell encapsulation technique using metal-phenolic networks is applicable to the C. reinhardtii, which is promising for the surface engineering of the green algae for energy harvesting and biomedical applications.

Rapid construction of hierarchically porous metal–organic frameworks by a spray‐drying strategy for enhanced tannic acid adsorption

AbstractMetal–organic frameworks (MOFs) have attracted much attention owing to their tailored pore environment and surface functionality. However, most of the currently reported MOFs are confined to small pore sizes (<5 nm), limiting their practical applications. Here, a facile and versatile strategy for rapid construction of hierarchically porous MOFs (HP‐MOFs) by spray‐drying is reported, in which presynthesized nanosized MOFs (N‐MOFs) can be assembled to form MOF microspheres with meso/macropores resulting from the interspace among closely arranged N‐MOFs. This strategy enables the construction of multicomponent HP‐MOFs with various functions. As a proof of concept, we show that the adsorption for tannic acid (TA) can be significantly enhanced using HP‐MIL‐101(Cr). Particularly, HP‐MIL‐101‐30 (30 represents the primary nanoparticle size) exhibits a record‐high adsorption capacity (1175 mg g−1), and the adsorption rate of HP‐MIL‐101‐30 is increased by 50% compared to that of N‐MIL‐101‐30. These findings have important implications for the rapid construction of HP‐MOFs, which is beneficial for the adsorption of large molecules.

Mechanistic understanding of the discrete morphology formed by multi-cycle assembly of tannic acid with Poloxamer 188 on silicon using QMC-D

Formation of discrete microdome-shaped features on planar silicon surfaces through multi-cycles of alternate adsorption of tannic acid (TA) and Poloxamer 188 of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (P188) has been reported recently. To further our understanding of the underlying fundamentals, we turned to quartz crystal microbalance with dissipation (QCM-D) for non-invasive monitoring of the process using SiO 2 -coated quartz crystals. Different concentrations of TA and P188 solutions were used for the step-by-step assembly, and the corresponding QCM-D responses were investigated. Additional TA-P188 assemblies were prepared on silicon substrates using the same concentration settings and subjected to surface morphology characterizations before and after drying. The results showed that increasing the concentration of P188 causes increased restructuring of the constructs during the assembling process, and leads to the formation of well-hydrated but less spherically shaped morphology with more continuity in coverage. In contrast, increasing TA concentration helps the assembled discrete features grow in size without inducing drastic change in morphology, and the large dissipation shift recorded is most likely related to water trapped in between the features. Furthermore, the study revealed that, besides the amphiphilic nature of P188 and the right solution concentration of TA, the surface of the underlying silicon substrate being hydrophilic is also instrumental in achieving discrete features of TA-P188 assembly. Collectively, findings reported herein allow for further tailored design of functional surfaces using TA and P188 as building blocks.

The Relative Contributions of Complexation, Dispersing, and Adsorption of Tannic Acid to the Dissolution of Copper Oxide Nanoparticles

The Relative Contributions of Complexation, Dispersing, and Adsorption of Tannic Acid to the Dissolution of Copper Oxide Nanoparticles

Tribology and QCM-D approaches provide mechanistic insights into red wine mouthfeel, astringency sub-qualities and the role of saliva

Wine mouthfeel and astringency play an important role in shaping the organoleptic quality and have been associated with tannin-salivary protein colloidal interactions. The mechanistic drivers of wine mouthfeel, especially those creating distinct astringency sub-qualities percepts, are yet to be fully realised due to the lack of appropriate measures. This study researched the friction behaviours of saliva-wine interactions, that allow inference of insights into the physicochemical origins of several important wine mouthfeel attributes. The red wine sample sets were created by doctoring various levels of ethanol, tannin, pH and mannoprotein on a Malbec. Samples were profiled sensorily and chemically. The friction behaviours of wine-saliva interaction and salivary viscoelasticity were investigated by soft-tribological protocols plus quartz crystal microbalance with dissipation. The sensory scores of mouthfeel attributes were modelled by physicochemical parameters using partial least squares regression. Results suggested that burning and resalivation are non-frictional-derived sensations driven by ethanol and acidity, respectively. Drying, grippy and rough are driven by tannin's adsorption on salivary film, which cause poor lubricity and a film strip-off thus exhibit as high boundary friction in tribology. Pucker is not directly driven by tannin but the weak viscoelasticity of salivary film, which is exhibited as the fast rate of friction increase in tribology. Smoothness is driven by less salivary protein precipitation, a highly viscoelastic salivary film, or the viscosity effects from mannoprotein. Fullness is driven by high viscosity by high ethanol. These models support the theory that wine mouthfeel attributes have dissimilar physicochemical origins that lead to distinct sensory experiences.

The Physical Adsorption of Gelatinized Starch with Tannic Acid Decreases the Inhibitory Activity of the Polyphenol against α-Amylase.

The effects of mixing orders of tannic acid (TA), starch, and α-amylase on the enzyme inhibition of TA were studied, including mixing TA with α-amylase before starch addition (order 1), mixing TA with pre-gelatinized starch before α-amylase addition (order 2) and co-gelatinizing TA with starch before α-amylase addition (order 3). It was found that the enzyme inhibition was always highest for order 1 because TA could bind with the enzyme active site thoroughly before digestion occurred. Both order 2 and 3 reduced α-amylase inhibition through decreasing binding of TA with the enzyme, which resulted from the non-covalent physical adsorption of TA with gelatinized starch. Interestingly, at low TA concentration, α-amylase inhibition for order 2 was higher than order 3, while at high TA concentration, the inhibition was shown with the opposite trend, which arose from the difference in the adsorption property between the pre-gelatinized and co-gelatinized starch at the corresponding TA concentrations. Moreover, both the crystalline structures and apparent morphology of starch were not significantly altered by TA addition for order 2 and 3. Conclusively, although a polyphenol has an acceptable inhibitory activity in vitro, the actual effect may not reach the expected one when taking processing procedures into account.

Preparation and characterization of calcite for tannic acid adsorption: Optimization by response surface methodology coupled by Box-Cox transformation procedure

Preparation and characterization of calcite for tannic acid adsorption: Optimization by response surface methodology coupled by Box-Cox transformation procedure

Insights into the adsorption mechanism of tannic acid by a green synthesized nano-hydroxyapatite and its effect on aqueous Cu(II) removal.

The polyphenolic tannic acid (TA) has been widely used in the stabilization and surface modification of nanomaterials. The interaction mechanism of TA with the biogenic nano-hydroxyapatite (nHAP) and its environmental importance, however, are poorly understood. This study explored the adsorption of TA using the green synthesized, eggshell-derived nHAP and implications of this process for the removal of aqueous Cu(II) via batch adsorption experiments, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) investigations. TA adsorption by nHAP was a complex pH-dependent process and significantly correlated with TA molecule speciation and amphoteric properties of nHAP via multiple adsorption modes including surface complexation, electrostatic attraction, and hydrogen bond. The maximum TA adsorption amount was found to be 94.8mg/g for less crystalline nHAP with lower calcination temperature. In the ternary Cu-TA-nHAP systems, TA promoted Cu(II) adsorption at pH<5 and reduced Cu(II) uptake at pH>5. Further studies of the effects of ionic strength and addition sequences, as well as Raman, FTIR, and XPS analyses revealed Cu(II) adsorption on nHAP was mainly dominated by inner-sphere surface complexation. These results can shed light on not only the utility of biogenic nHAP for TA and Cu(II) adsorption but also the evaluation of the effect of TA on the environmental behavior of heavy metals.

Purification and characterization of hydrolysable tannins extracted from Coriaria nepalensis bark using macroporous resin and their application in gallic acid production

As an indispensable chemical raw material, tannins are widely used in industrial production. The crude tannins extracted from plants are difficult to be used directly because of their low purity. Therefore, tannins purification are particularly important. In this study, an economical and efficient method was developed for the purification of novel vegetable tannin resources from Coriaria nepalensis bark by macroporous resin. The purity of the obtained tannin was increased significantly from 32.5%–70.6% by optimal adsorption and desorption process conditions with D101 macroporous resin. The isothermal adsorption results illustrated by Langmuir and Freundlich equations showed that the adsorption of tannin with macroporous resin was in accordance with the exothermic process. Furthermore, the structure of the purified tannins was investigated by MALDI-TOF MS. The results indicate that the main structural compositions of the obtained tannins were Tri-O-galloylglucose, Tetra-O-galloylglucose, Penta-O-galloylglucose and Hexa-O-galloylglucose. The hydroxyl and DPPH radical scavenging rates of the purified tannins at a concentration of 256 μg mL−1 increased to 86.33% and 89.08%, respectively. When the concentration was 512 μg mL−1, the reducing ability of ferricyanide to the ferrous form reached to 0.88. Moreover, the minimal inhibitory concentrations for Staphylococcus aureus and Escherichia coli were 32 μg mL−1, which is superior to commercial tannic acid. In addition, further application experiment results show that Coriaria nepalensis bark tannins can be effectively hydrolyzed under the action of tannase to obtain a high yield of gallic acid (53.2%).

The Influence of Hydrolytic Enzymes on Tannin Adsorption-Desorption onto Grape Cell Walls in a Wine-Like Matrix.

This study evaluates the capacity of four hydrolytic enzymes to limit the interactions between grape cell-walls and tannins and/or to favor tannin desorption. Adsorption and desorption tests were conducted by mixing a commercial seed tannin with purified skin cell-walls from Syrah grapes, in the presence or absence of hydrolytic enzymes, in a model-wine solution. The effects of the enzymes were evaluated by measuring the tannins in solution by High Performance Liquid Chromatography (HPLC) and the changes in the cell wall polysaccharide network by Comprehensive Microarray Polymer Profiling (COMPP) while the polysaccharides liberated from cell walls were analyzed by Size Exclusion Chromatography (SEC). The results showed that the enzymes limited the interaction between tannins and cell walls, especially cellulase, pectinase and xylanase, an effect associated with the cell wall structural modifications caused by the enzymes, which reduced their capacity to bind tannins. With regards to the tannin desorption process, enzymes did not play a significant role in liberating bound tannins. Those enzymes that showed the highest effect in limiting the adsorption of tannins and in disorganizing the cell wall structure, cellulase and pectinase, did not lead to a desorption of bound tannins, although they still showed a capacity of affecting cell wall structure. The results indicate that enzymes are not able to access those polysaccharides where tannins are bound, thus, they are not a useful tool for desorbing tannins from cell walls. The practical importance implications of these findings are discussed in the manuscript.

New insights into the different adsorption kinetics of gallic acid and tannic acid on minerals via 1H NMR relaxation of bound water

The slower adsorption of lower molecular weight organic molecules remains poorly understood. This study investigated the adsorption kinetics of gallic acid (GA) and tannic acid (TA) on kaolinite (Kao), montmorillonite (Mon) and hematite (Hem), with an emphasis on the role of the bound water on the minerals. The lower adsorption of TA and GA on Kao than on Mon attributed to the lower specific surface area of Kao. Because of the electrostatic attraction, the adsorption of TA and GA on Hem was higher than that on Mon, even the specific surface area of the former was much lower than that of the later. The adsorption rates of TA on the three minerals were generally two orders of magnitude higher than those of GA. The adsorption kinetics of GA was strongly diffusion dependent; however, the diffusion process had limited influence on TA adsorption kinetics. The decreased c values of the intraparticle diffusion model of GA with increasing ionic strength provided additional direct evidence for the diffusion-dependent adsorption and the reduced hindrance by bound water via hydration layer compression. However, hydration layer compression had no effect on TA adsorption kinetics. The reduced 1H NMR relaxation rate of bound water indicated that the bound water quantity on minerals decreased with increasing ionic strength, which proved the occurrence of hydration layer compression. This study highlighted the importance of bound water and the relative sizes of organic molecules in the adsorption kinetics of organic compounds on minerals, which should be carefully considered for their environmental fate studies.