Persimmon Tannin Research Articles

Effects of Persimmon Tannin-Aloe vera Composite on Cytotoxic Activities, and Radioprotection Against X-rays Irradiated in Human Hepatoma and Hepatic Cells.

A persimmon tannin-Aloe vera composite powder (PT-A) was investigated for its capacity to protect against ionizing radiation. Human hepatic cells (L02 cells) and human hepatoma cells (HepG2 cells) were pretreated with different concentrations of PT-A or the single compounds (PT or Aloe vera) and radiated with X-rays. After radiation and post-incubation for 12 h or 24 h, the cell viability, apoptosis, and reactive oxygen species (ROS) production were analyzed by Cell Counting Kit 8 (CCK-8), 2',7'-dichlorfluorescein diacetate (DCFH-DA) staining, and Hoechst 33258 staining/flow cytometry, respectively. CCK-8 results illustrated that the optimal radiation dose L02 cells was 8 Gy for L02 cells, and the cell activity was 71.72% (IC50 = 412.1 μg/mL) after post-radiation incubation of 12 h. For HepG2 cells, the optimal radiation dose was 8 Gy, and the cell activity was 62.37% (IC50 = 213.0 μg/mL). The cell apoptotic rate was the lowest at a PT-A concentration of 200 μg/mL in L02 cells (4.32%, P < 0.05), and at 100 μg/mL in HepG2 cells (9.80%, P < 0.05). ROS production induced by radiation could be effectively inhibited by 200 μg/mL of PT-A in L02 cells, and by 100 μg/mL of PT-A in HepG2 cells. The PT-A composite has good radioprotective effects on cell vitality and apoptosis of X-rays radiation exposure towards L02 cells and HepG2 cells compared to the persimmon tannin or Aloe vera. Therefore, PT-A composite might be useful as a natural, harmless anti-ionizing radiation agent, and has various clinical application prospects in future.

Insight into the performance and mechanism of persimmon tannin functionalized waste paper for U(VI) and Cr(VI) removal

Herein, using dialdehyde waste paper (DAWP) as a cross-linking agent to immobilize persimmon tannin (PT) was first used to remove the U(VI) and Cr(VI) via the “waste control by waste” concept. The microscopic and macroscopic surface properties of the as-prepared adsorbent was characterized by the advanced characterization techniques. Factors that affected the elimination process such as variable pH, coexistence ions and equilibrium time were investigated by batch techniques. The results showed that the maximal removal capacities of U(VI) and Cr(VI) on DAWP-PT were 242.3 mg/g (pH = 6.0) and 178.7 mg/g (pH = 2.0) at 298 K, which exhibited competitiveness with most of the reported solid materials. Meanwhile, adsorption data were fitted perfectly to the Langmuir and Pseudo-second-order equations, which indicated that the monolayer and homogenous chemisorption dominated the removal process. The SEM-EDX, DFT and XPS analysis conformed that adsorption of U(VI) was mainly via surface complexation, while the elimination of Cr(VI) was a redox reaction process, and about 65.33% of Cr(III) and 34.67% of Cr(VI) co-existed onto the surface of DAWP-PT. Thus, this study would provide a high-efficiency and low-cost adsorbent for radionuclide and heavy metal treatment.

Inhibition of persimmon tannin extract on guinea pig skin pigmentation.

In daily life, excessive exposure to ultraviolet light can lead to pigmentation. This study is to determine the mechanism of persimmon tannin extract in inhibiting pigmentation, to investigate whether the effect of persimmon tannin extract is superior to that of arbutin, and to detect the optimal concentration. In this study, the guinea pig pigmentation model was established by ultraviolet B (UVB) irradiation. With arbutin as a positive control, Masson-Fontana silver staining was used to observe the effects of persimmon tannin extract on melanin distribution in guinea pigs' skin tissue. Then, the tyrosinase activity was measured, and an Enzyme-linked immunosorbent assay was used to investigate the contents of antioxidant enzymes, inflammatory factors, and signaling pathway inhibitors in guinea pigs' skin tissue. The results showed that compared with the model group, superoxide dismutase, catalase, glutathione peroxidase, DKK1 content of Wnt/-catenin signaling pathway inhibitors levels, and inhibitory tyrosinase activity were increased by 24.3%, 33.3%, 59.3%, 36.81%, and 17.16%, respectively. Meanwhile, the interleukin-6 and interleukin-8 expression were reduced by approximately 22.2% and 54%. The results also showed that persimmon tannin extract could significantly reduce melanin density. The differences in experimental results were statistically significant (P<.01). Compared with the arbutin group, the medium-dose group (persimmon tannin extract of 20%) had a more significant effect on inhibiting pigmentation. Persimmon tannin could serve as a promising agent for preventing skin pigmentation. It is expected to provide ideas for the development of deep-processed persimmon products related to functional foods and cosmetics.

Calculation and analysis of interaction between characteristic functional group of persimmon tannin and metal ions

Persimmon tannin has excellent adsorption efficiency of heavy metal ions, and epigallocatechin gallate (EGCG) is the key structural monomer of persimmon tannin to play its active role. In order to analyze the nature of the interaction between persimmon tannin and metal ions, in this paper the density functional theory (DFT) is used to calculate and analyze the interactions between EGCG and metal ions (Ag&lt;sup&gt;+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt;, Cu&lt;sup&gt;2+&lt;/sup&gt;, Fe&lt;sup&gt;2+&lt;/sup&gt;, In&lt;sup&gt;3+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt;, Au&lt;sup&gt;3+&lt;/sup&gt;), from the respects of EGCG-metal complex configuration, Mayer bond order, natural population analysis, binding energy, and weak interaction. In this paper, the B3LYP combined with DFT-D3 dispersion correction method is mainly used. For metal atoms, the Lanl2dz basis set is adopted. For H, C and O atoms, the 6-311G (d, p) basis set is adopted for optimizing the structure, and the more accurate 6-311+G (d, p) basis set is selected for calculating the single point energy. At the same time, the study adds the SMD solvation model with water as the solvent. All calculations are done by using the Gaussian 09 package. The method of reduced density gradient function is used to study the weak interactions between EGCG and metal ions. The results of research show that EGCG-Fe&lt;sup&gt;2+&lt;/sup&gt; complex is adsorbed mainly by chelating bond. However, the EGCG adsorbs mainly Ag&lt;sup&gt;+&lt;/sup&gt;, Hg&lt;sup&gt;2+&lt;/sup&gt; ions through electrostatic attraction. The configurations of the complexes show that In&lt;sup&gt;3+&lt;/sup&gt;, Al&lt;sup&gt;3+&lt;/sup&gt; and Au&lt;sup&gt;3+&lt;/sup&gt; ions with EGCG form unique “luminal structure” metal complexes, so there is not only electrostatic attraction, but also aromatic ring stacking between these three metal ions and D ring 4&lt;i&gt;"&lt;/i&gt;O, 5&lt;i&gt;"&lt;/i&gt;O. The calculated Mayer bond order indicates that the bond order of the composite bond is formed by Fe&lt;sup&gt;2+&lt;/sup&gt; ion and the EGCG is the largest in the seven metal complexes, and the bond order is formed by In&lt;sup&gt;3+&lt;/sup&gt; ion, and EGCG is smallest. The compound of Cu&lt;sup&gt;2+&lt;/sup&gt; ion and EGCG have chelation, electrostatic attraction and aromatic ring stacking. By observing the binding energy, it can be found that the more charges the metal ions have, the easier the charge transfer will be and the stronger the electrostatic attraction of EGCG may be. These results will provide enlightenment for further studying the mechanism of persimmon tannin's adsorption of metal ions.

Removal, Recovery and Recycle of Gold (III) from Aqueous Solution Using Persimmon Tannin Gel

Removal, Recovery and Recycle of Gold (III) from Aqueous Solution Using Persimmon Tannin Gel

Selective enrichment and separation of Ag(I) from electronic waste leachate by chemically modified persimmon tannin

A 2,5-dimercapto-1,3,4-thiadiazole (DMTD)-immobilized and persimmon tannin (PT)-based biosorbent, DMTD-PT, was synthesized via a one-pot method and used for selective enrichment of Ag(I) from electronic waste (e-waste) leachate. Batch adsorption revealed that both PT and DMTD-PT had a weaker affinity for co-existing metal cations. However, DMTD-PT and PT adsorbed 98.7% and 20.7% of Ag(I), respectively, with a dose of 5.0 g L−1 each at pH 3.0 from e-waste leachate that contained 117.3 mg L−1 of Ag(I) at room temperature. These observations indicate that the selectivity of DMTD-PT is superior to that of PT. The column adsorption further proved that DMTD-PT can be used to separate Ag(I) from e-waste leachate. The adsorption of Ag(I) on DMTD-PT fit the Langmuir isotherm well with a maximum adsorptive capacity of 50.7 mg g−1. A thermodynamics study further indicated that the adsorption was spontaneous and was dominated by chemisorption. The two mass transfer models of homogeneous solid diffusion model (HSDM) and a Linear Driving Force (LDF) model were used to study the kinetics and generally well fitted the experimental data. Analyses of Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) of fresh and Ag(I)-adsorbed DMTD-PT further revealed that the plausible adsorption mechanism was principally attributable to the complexation of N and S on the diazole ring. Also, DMTD-PT exhibited better reusability and qualified durability without a distinct decrease in Ag(I) adsorption even after 5 repeated cycles.

Persimmon tannin functionalized polyacrylonitrile fiber for highly efficient and selective recovery of Au(III) from aqueous solution

An efficient fibrous adsorbent (PANF-TETA-PT) was prepared via grafting triethylenetetramine (TETA) on polyacrylonitrile fiber (PANF), followed by persimmon tannin (PT) immobilizing. Detailed characterization certified that plenty amounts of amino and phenolic hydroxyl groups existed on the surface of PANF-TETA-PT, which would provide excellent active sites for Au(III) adsorption. The batch characteristic results found that the adsorption equilibrium data could be fitted well with Langmuir equation, while the obtained kinetic data were consistent with the Pseudo-second-order equation. The maximum equilibrium adsorption capacity of PANF-TETA-PT towards Au(III) (801.2 mg/g) was apparently superior than that of the reported adsorbents, and the competitive adsorption showed that PANF-TETA-PT had a good preference to adsorption Au(III) in spite of some coexisting pollutants. The characterization analysis of Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer spectrum (XRD) revealed that the electrostatic attraction and chelation dominated the uptake of Au(III) on PANF-TETA-PT, in which a part of loaded Au(III) was reduced to Au particles with the help of reductive functional groups. Thus, this adsorbent could be as a promising candidate to separation and preconcentration of Au(III) from wastewater.

Hydroxyl‐assisted nitrogen‐containing group modified persimmon tannin with enhanced recovery capacity for Mo(VI) in aqueous solution

AbstractBACKGROUNDPersimmon tannin, extracted from young astringent persimmons, is a cheap waste biomass material. The abundant phenolic hydroxyl groups in persimmon tannin are known to display excellent affinity to Mo(VI). In addition, ligands containing N donor atoms, as brilliant adsorption groups, can strongly interact with Mo(VI) when the groups are protonated under acidic conditions. Therefore, the introduction of nitrogen‐containing groups in persimmon tannin may be an effective method to improve the recovery capacity of biosorbent for Mo(VI) in aqueous solution. In this work, a series of adsorbents were prepared by immobilizing ethylenediamine or methylamine on the surface of persimmon tannin.RESULTSDue to the abundant nitrogen‐containing groups and hydroxyl groups, the ethylenediamine modified persimmon tannin exhibited excellent maximum uptake capacity to Mo(VI) (478.02 mg·g−1), which was superior to that of methylamine modified persimmon tannin. Further, the results of XPS and FT‐IR confirmed that Mo(VI) was adsorbed on the hydroxyl‐assisted nitrogen‐containing group modified persimmon tannin via coordination and electrostatic interaction.CONCLUSIONFurthermore, 99% of Mo(VI) was selectively recovered from coexisting ions by en‐CPT under appropriate acidic conditions (pH 1). Pseudo‐second‐order kinetic model best represented the adsorption process of Mo(VI) onto the en‐CPT. The adsorption equilibrium was achieved in a relatively short time (no more than 1 h). High recovery efficiency and excellent selective adsorption made the en‐CPT an ideal candidate for Mo(VI) recovery in practical applications. © 2020 Society of Chemical Industry (SCI)

Persimmon tannin changes the properties and the morphology of wheat gluten by altering the cross-linking, and the secondary structure in a dose-dependent manner

The effects of persimmon tannin (PT) on the texture, viscoelasticity, thermal stability, and morphology of gluten were studied and the underlying mechanisms were also explored. The results showed that PT increased the hardness and viscoelasticity but lowered the cohesiveness and extensibility of gluten in a dose-dependent manner. Additionally, PT increased the denaturation temperature and enthalpy of gluten, and induced the formation of gluten with compact structure. High concentration of PT (8%) significantly increased the hardness and viscoelasticity of gluten, and induced the formation of compact structure of gluten by disturbing the conformation of gluten, and interfering gluten cross-linking through decreasing disulfide bonds, free sulfydryl groups, and free amino groups. In contrast, low concentration (0.25%) of PT slightly altered the gluten properties and morphology. Our work extended the study on the supplementation of phenolic compounds in wheat flour-based products.

Persimmon tannins as biosorbents for precious and heavy metal adsorption in wastewater: a review

Over the years, adsorption has proved to be an effectual technique in the recovery of a variety of substances from aqueous solution. In response to the call for environmental and economic sustainability, much attention has been placed on biosorbents. Persimmon tannin-based adsorbents (PTBAs), in particular, have shown promise in terms of recovering metals from wastewater. PTBAs are universally occurring, low-cost biological polymers that can be easily obtained and transformed into non-soluble tannin gels or immobilized onto various carriers. This study provides an overview of available literature (2002–2020) regarding the application of PTBA for remediating water containing heavy and precious metals. The adsorption capacity of several PTBAs (modified and unmodified) was summarized and this reflected the efficacy of PTBAs as a biosorbent. Gold was the most common target of PTBAs with the highest recorded maximum adsorption capacity of 15.36 mol/kg of Au3+. The uptake mechanisms of precious and heavy metals Au, Pd, Pt, V, and Cr(VI) unto PBTAs were also discussed. Furthermore, the factors influencing adsorption of metals by PTBAs, particularly pH, were identified. The effect of pH on metal adsorption onto PTBAs from previous studies is compiled and discussed.

Persimmon highly galloylated-tannins in vitro mitigated α-amylase and α-glucosidase via statically binding with their catalytic-closed sides and altering their secondary structure elements.

Reticence of α-amylase (α-Amy) and α-glucosidase (α-Glu) is needed due to their mitigation potency on the glucose absorption. In this study, the anti-amylolytic effects of persimmon tannins (PT) on α-Amy and α-Glu and their interaction mechanisms were investigated. It was found that PT inhibited α-Amy and α-Glu with the half inhibitory concentration (IC50 ) values of 0.35 and 0.24mg/ml, respectively. Fluorescence and FT-IR spectrometry results showed that PT could bind to enzymes and alter their conformations. Molecular docking showed that the structural units of PT interacted with the key sites (amino acids Glu233, Asp197, and Asp300) of α-Amy by H-bonds and π-π interactions, while they bound to the residues closed to the active sites of α-Glu. The whole results implied that PT was a promising mitigator of α-Amy and α-Glu. It might help to understand mechanisms of glycemic response inhibition of PT and develop certain therapeutic strategies against diabetes. PRACTICAL APPLICATIONS: α-Amy and α-Glu are the crucial starch digestive enzymes associated with type II diabetes mellitus in humans. Persimmon is an excellent source of bio-functional tannins which potentially mitigate the type II diabetes. This study showed that PT beneficially decreased the action of the carbohydrate digestion-related enzymes, namely α-Amy and α-Glu via interaction simultaneously, which could be used to formulate a functional food and natural medicine.

Preparation and application of iron oxide/persimmon tannin/ graphene oxide nanocomposites for efficient adsorption of erbium from aqueous solution

Rare earth elements (REEs) are used for the development of new energy materials owing to their intrinsic physicochemical property. However, excess REEs in water threaten the safety of animals, plants and humans. An efficient way to separate REEs from the water is therefore needed. In this study, a biosorbent consisting of iron oxide (Fe3O4), persimmon tannin (PT), and graphene oxide (GO) as Fe3O4/PT/GO was prepared, and the adsorption of trivalent erbium (Er3+) ions from aqueous solution was investigated. The adsorption process for Er3+ ions conforms to pseudo-second order kinetic and the Langmuir isotherm model behavior. Thermodynamic studies indicate that the adsorption process is spontaneous and endothermic. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) analysis, and vibrating sample magnetometer (VSM) were used to assess the adsorption mechanism of Er3+ ions onto the Fe3O4/PT/GO biosorbent. A combination of electrostatic interactions, redox reactivity and chelation are responsible for adsorption of Er3+ ions on the Fe3O4/PT/GO biosorbent. The magnetic Fe3O4/PT/GO biosorbent can be easily separated under the magnetic field for effective recycle of Er3+ ions from aqueous solution. Therefore, this new biomass composite holds great promise for wastewater treatment.

Protecting HaCaT cells from ionizing radiation using persimmon tannin-Aloe gel composite

Context Persimmon tannin (extract of Diospyros kaki L.f [Ebenaceae]) and Aloe gel (extract of Aloe vera (L.) Burm.f. [Asphodelaceae]) are known as anti-radiation agents. However, radiation resistance of the persimmon tannin-Aloe gel composite remains inconclusive. Objective To investigate the capacity of the persimmon tannin-Aloe gel composite to protect against ionising radiation at the cellular level. Materials and methods HaCaT (human epidermal keratinocytes) cells were pre-treated with PT-A-1 (the mass ratio of persimmon tannin and Aloe gel was 2:1) or the single component (persimmon tannin or Aloe gel) at various concentrations (0, 50, 100, 200, 400, 800 μg/mL. Control group: medium with no HaCaT cells), and then radiated with X-rays (radiation dose: 4, 8, 12, 16, and 20 Gy). Cell viability, cell apoptosis, and radiation-induced intracellular reactive oxygen species (ROS) generation were analysed by CCK-8, Hoechst 33258 staining/flow cytometry, and 2′,7′-dichlorfluorescein diacetate (DCFH-DA) assay, respectively, for 12 or 24 h incubation after radiation. Results The optimal radiation dose and post-radiation incubation period were determined to be 8 Gy and 12 h. CCK-8 activity detection showed that the cell activity was 77.85% (p < 0.05, IC50 = 55.67 μg/mL). The apoptotic rate was the lowest (4.32%) at 200 μg/mL of PT-A-1 towards HaCaT cells. ROS production was the most effectively suppressed by 200 μg/mL PT-A-1 towards HaCaT cells. Discussion and conclusions The persimmon tannin-Aloe gel composite has good radioprotective effect, and which will facilitate its clinic application as a potential natural anti-radiation agent in future.

Study of Equilibrium and Kinetics of Pb(II) in Solution Using Persimmon Tannin Gel as an Adsorbent

Heavy metals concentrations exceeding the recommended threshold are hazardous for the environment, so there is a need for handling it safely. The purpose of this research was to determine the adsorption capacity and kinetics of adsorption. This research uses an adsorption method in the process of removing Pb(II) heavy metal ions using persimmon tannin gel. Besides the influence of contact time, pH, and the concentration of Pb(II) metal ions on adsorption, a kinetics study was also carried out. The adsorption rate is obtained through the adsorption rate constant (K) and the reaction order generated from the kinetics model. Based on the results of the research, showed the optimum adsorption process, which is 20 minutes and at a pH of 5. The maximum adsorption capacity of 17.62 mg/g with the value of the standard energy changes of Gibbs adsorption (-ΔG° = -14.274 kJ/moll) indicates that the adsorption takes place through physical interaction. The kinetic adsorption gives the adsorption rates a constant of, k = 0.008231 g/mg.min.

Adsorption behavior of Au(III) and Pd(II) on persimmon tannin functionalized viscose fiber and the mechanism

A novel bio-adsorbent (DAVF-PT) was prepared by the introduction of persimmon tannin (PT) on the surface of viscose fiber (VF) through condensation reaction. The adsorbent was applied to the adsorption of Au(III) and Pd(II) from aqueous solution. Batch adsorption experiment found that the adsorption performance of DAVF-PT for Au(III) and Pd(II) was closely related to pH of solution, initial metal ion concentration as well as co-existing metal ions. The adsorption isotherms data of Au(III) and Pd(II) on DAVF-PT could be best explained by the Langmuir equation, and the fitted maximum adsorption amounts for Au(III) and Pd(II) were 535 mg/g and 214 mg/g, much higher than those similar adsorbents reported in the literatures. The thermodynamic study revealed that adsorption reaction was an endothermic, spontaneous and entropy increase process. Furthermore, the kinetics data of Au(III) and Pd(II) adsorption on DAVF-PT obeyed the Pseudo-second-order equation, indicating that the chemical adsorption was the mainly rate-limiting step. The EDS, XPS and XPD analysis confirmed that the gold and palladium ions were reduced to metallic state following adsorption, while the phenolic group was simultaneously converted into quinone group, indicating the potential use of this novel fiber-based adsorbent in the recovery of precious metal ions from wastewater.

Transcriptomic and metabolomic analyses reveal antibacterial mechanism of astringent persimmon tannin against Methicillin-resistant Staphylococcus aureus isolated from pork

Persimmon tannin (PT) exhibits antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) isolated from retail pork. The involved molecular mechanisms were investigated for the first time using transcriptome and metabolome in this study. Results showed that subinhibitory concentration of PT (0.5 mg/ml) induced significant changes in MRSA at both transcriptional and metabolic levels, as 370 genes and 19 metabolites were differentially expressed. Bioinformatic analysis revealed that the varying genes and metabolites were mainly involved in pathways of membrane transport, amino acids, carbohydrate, and energy metabolism. The highlighted changes were those related to osmotic regulation, intracellular pH regulation, amino acid synthesis and metabolism, glycolysis, TCA cycle and iron metabolism, suggesting the multifaceted effects including cell membrane damage, amino acids limitation, energy metabolism disorder and iron deprivation induced by PT. The results provided insight into the anti-MRSA mechanism of PT, which is useful for PT’s development and application in food safety.

Efficient adsorption of methylene blue from aqueous solution by graphene oxide modified persimmon tannins.

With the rapid development of dye and textile industry, the pollution of dye wastewater has aroused widespread public concern due to the potential risk to human health. Therefore, it is of significance for the removal of dye pollutants from wastewater. In this work, a green and efficient bio-adsorbent, graphene oxide modified persimmon tannin (PT-GO), has been fabricated through glutaraldehyde crosslinking method for efficient adsorption of methylene blue (MB) from aqueous solutions. The prepared PT-GO bio-adsorbent was analyzed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectra (XPS) and Brunauer-Emmett-Teller (BET) analysis. The adsorption behavior of the PT-GO bio-adsorbent towards MB dye in a batch adsorption process was investigated. The maximum MB adsorption capacity achieved 256.58 mg g-1 with MB concentration of 35 mg L-1 at 323 K. The Freundlich equilibrium isotherm and the pseudo-second order model fit the adsorption behavior very well. Thermodynamics data revealed that the adsorption of MB onto PT-GO bio-adsorbent was feasible, spontaneous and endothermic. Redox reactions, electrostatic interactions and π-π interactions dominated the adsorption of MB onto PT-GO bio-adsorbent. In addition, the regeneration of the PT-GO was efficiently achieved and MB removal efficiency remained high (88.3%) after fifth cycles. All these results indicated that PT-GO bio-adsorbent could be a promising biomass adsorbent for the removal of organic dye contaminants with non-toxic, efficient and low cost.

Effect of persimmon tannin on the physicochemical properties of maize starch with different amylose/amylopectin ratios.

The effects of persimmon tannin (PT) on the physicochemical properties of maize starch with different amylose/amylopectin ratios were studied. The results showed that PT remarkably altered the physicochemical properties of the starch. And the effects were dependent both on the concentration of PT and the amylose/amylopectin ratios. DSC analysis showed that PT slightly increased the gelatinization temperature of low-amylose (LAC) and intermediate-amylose maize starch (IAC), whereas the Tc and Tp of high-amylose maize starch (HAC) were decreased strikingly. XRD and SEM analysis demonstrated that PT retarded the retrogradation of the three kinds of starch. The hardness and adhesiveness values of the three kinds of starch decreased with increasing the PT concentration. The cohesiveness and springiness value of LAC starch gel were decreased by PT, whereas that of HAC starch gel were slightly increased by PT addition. Dynamic rheology analysis demonstrated that PT improved the viscoelasticity of LAC paste, but lowered the viscoelasticity of HAC and IAC paste. Taken together, PT had greater effects on the physicochemical properties for HAC starch than on LAC, revealing that PT has stronger interaction with amylose than with amylopectin. Our results indicated that PT might have a potential use in improving the quality of starch-based food.

Novel magnetic graphene oxide decorated with persimmon tannins for efficient adsorption of malachite green from aqueous solutions

Dyeing effluent is one of the main sources of textile wastewater, which has a seriously destructive impact on human health. A simple and effective way to remove dyes from the environment is required. In this paper, a new adsorbent, magnetic graphene oxide decorated with persimmon tannins (Fe3O4/PT/GO) composites, has been prepared by one-step hydrothermal method for efficient adsorption of malachite green (MG) from aqueous solutions. The microstructure and composition of the Fe3O4/PT/GO adsorbent were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) analysis, X-ray powder diffraction (XRD) and vibrating sample magnetometer (VSM). The Fe3O4/PT/GO adsorbent had excellent adsorption ability with the maximum adsorption capacity of 560.58 mg/g at 308 K and pH 6.0. The adsorption capacity maintained 85.9% after five cycles. The adsorption process of MG conformed to the Langmuir isotherm model and pseudo-second order kinetic equations. In addition, the thermodynamic studies indicated that the adsorption process is spontaneous and endothermic. All the experimental results showed that the Fe3O4/PT/GO adsorbent had good adsorption capacity for removing MG from wastewater and can be quickly extracted from water under an external magnetic field.

Functionalization of persimmon tannin with chitosan for the removal of cationic and anionic dyes from aqueous solutions

Functionalization of persimmon tannin with chitosan for the removal of cationic and anionic dyes from aqueous solutions