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1.
J Food Sci Technol ; 60(3): 1153-1162, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36908358

RESUMO

Biodegradable films intend to replace polymers derived from petroleum. The effect of pectin and Tara gum on the properties of films prepared with rice starch and glycerol was studied in this context. FTIR analysis determined the presence of complex interactions between the components. SEM showed regular film surface with minor roughness. The evaluation of mechanical properties of the films proved the importance of pectin, Tara gum and glycerol concentration. When the proportion of pectin to Tara gum was 1:1, the tension at break, the elongation and the solubility reached the highest values while the water vapor permeability dropped to a minimum. Statistical analysis demonstrated non-linear behavior between composition and properties of the films and stated the importance of interactions between the components. Films produced from rice starch and glycerol in combination with pectin and Tara gum present competitive properties in terms of elongation, tensile stress, permeability to water vapor and solubility, displaying a uniform structure suitable for the packaging of food materials.

2.
Clin Oral Investig ; 22(9): 3071-3077, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29484546

RESUMO

OBJECTIVE: To evaluate retention of intraoral fluoride in biofilm and saliva, an experimental dentifrice containing hydrocolloid (tara gum) was used as a controlled-release system for fluoride (F). MATERIALS AND METHODS: In a triple-blind randomized crossover trial with washout, 18 individuals used the following different dentifrices for a week: 100-TGF (sodium fluoride NaF associated with tara gum, 1100 mg/L), 50-TGF (50% NaF associated with tara gum + 50% free NaF, 1100 mg/L), PC (free NaF, 1100 mg/L), TG (with tara gum and without F), and placebo (without F or tara gum). On the seventh day of dentifrice use, biofilm was collected at 1 and 12 h, and saliva was collected up to 60 min and 12 h after the last toothbrushing. F concentrations were determined by physico-chemical analysis of fluoride using the hexamethyldisiloxane-facilitated diffusion technique. Data were subjected to two-way analysis of variance (repeated measures) and Spearman's correlation coefficient (p < 0.05) testing. RESULTS: No significant difference was observed with the same dentifrice regarding F retention in biofilm at 1 and 12 h after toothbrushing for the 100-TGF, placebo, and TG groups (p > 0.05). The highest area under the curve values in saliva were found for the 50-TGF, 100-TGF, and PC groups. CONCLUSION: The dentifrice containing hydrocolloid as a controlled-release system for F promoted F retention in the oral cavity, even at 12 h after brushing. CLINICAL RELEVANCE: Hydrocolloid added to dentifrices as a controlled-release system for F might contribute to a higher anti-caries effect. TRIAL REGISTRATION: NCT02809014.


Assuntos
Biofilmes/efeitos dos fármacos , Cariostáticos/uso terapêutico , Preparações de Ação Retardada/uso terapêutico , Dentifrícios/química , Dentifrícios/uso terapêutico , Gomas Vegetais/uso terapêutico , Fluoreto de Sódio/uso terapêutico , Adulto , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Saliva/química , Escovação Dentária , Resultado do Tratamento
3.
Int J Biol Macromol ; : 134914, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39173805

RESUMO

The demand for UV-protective and biodegradable packaging materials has been increasing with greater awareness about environmental sustainability and human safety. In this work, the effect of incorporating riceberry phenolic extract (RPE) as well as combined RPE and green synthesized biogenic nano­silver (RPE-NS, into Tara gum/PVA (TP)-based matrix was evaluated on the physical, mechanical, functional, biocompatible and biodegradable attributes of the resultant composite films. Integration of RPE (2 wt%) and RPE-NS (0.8 wt%) resulted in nanocomposite (TP/RPE-NS) film with improved physical properties relative to the plain TP and TP/RPE films. The TP/RPE-NS film displayed a compact structure and homogenous distribution of the nano­silver. Increased molecular interactions, crystallinity and thickness was also observed for the nanocomposite film. Compared to plain TP film, TP/RPE-NS film exhibited improved water vapor barrier properties and surface hydrophobicity due to the extract and nanoparticles. The tensile strength and elongation-at-break of TP/RPE-NS were markedly higher (41.76 MPa and 37.40 %) compared to that of plain TP film (36.07 MPa and 20.80 %). Whereas TP/RPE film provided good UV protection (UPF value of 31.85) compared to the minimal protection by TP film (UPF value of 2.72), combination of RPE/RPE-NS ensured that TP/RPE-NS availed an excellent UV-barrier performance (UPF value of 61.09). Furthermore, TP/RPE-NS film exhibited significant antioxidant activity relative to TP film. Besides, all TP-based films were found to be compatible with rat erythrocytes and biodegradable. Taken together, these findings indicate that TP/RPE-NS holds good potential for the development of UV-protective and biodegradable packaging material.

4.
Polymers (Basel) ; 16(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38543443

RESUMO

Tara gum, a natural biopolymer extracted from Caesalpinia spinosa seeds, was investigated in this study. Wall materials were produced using spray drying, forced convection, and vacuum oven drying. In addition, a commercial sample obtained through mechanical methods and direct milling was used as a reference. The gums exhibited low moisture content (8.63% to 12.55%), water activity (0.37 to 0.41), bulk density (0.43 to 0.76 g/mL), and hygroscopicity (10.51% to 11.42%). This allows adequate physical and microbiological stability during storage. Polydisperse particles were obtained, ranging in size from 3.46 µm to 139.60 µm. Fourier transform infrared spectroscopy characterisation confirmed the polysaccharide nature of tara gum, primarily composed of galactomannans. Among the drying methods, spray drying produced the gum with the best physicochemical characteristics, including higher lightness, moderate stability, smaller particle size, and high glass transition temperature (141.69 °C). Regarding rheological properties, it demonstrated a non-Newtonian pseudoplastic behaviour that the power law could accurately describe. The apparent viscosity of the aqueous dispersions of the gum decreased with increasing temperature. In summary, the results establish the potential of tara gum as a wall material applicable in the food and pharmaceutical industries.

5.
Food Res Int ; 181: 114119, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38448102

RESUMO

Tara (Caesalpinia spinosa, Leguminosae) seed germ (TSG), a by-product of tara gum (E417) extraction, has been used as a protein- and polyphenol-rich food ingredient for human and animal nutrition. Nevertheless, TSG is the alleged culprit for a recent foodborne outbreak of even severe acute illnesses that have affected hundreds of individuals in the USA, perhaps triggered by nonprotein amino acids such as baikiain. Herein, the composition of TSG has been characterized at molecular level, with a focus on proteins, phenolics, lipids, and mineral composition. TSG contains 43.4 % (w/w) proteins, tentatively identified for the first time by proteomics, and 14 % lipids, consisting of 83.6 % unsaturated fatty acids, especially linoleic acid. Ash is surprising high (6.5 %) because of an elevated concentration of P, K, Ca, and Mg. The detection of a rare earth element such as gadolinium (Gd, 1.6 mg kg-1), likely sourced from anthropogenic pollution, suggests alternative hypotheses for the origin of TSG hazards.


Assuntos
Caesalpinia , Farinha , Animais , Humanos , Polifenóis , Sementes , Ácido Linoleico
6.
Int J Biol Macromol ; 242(Pt 1): 124645, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37119886

RESUMO

The main purpose of this paper is to synthesize a new kind of green and environmental protection emulsion, which can be used as water erosion resistant materials. Here, a non-toxic polymer was prepared by grafting acrylic acid (AA) and methyl methacrylate (MMA) onto the long chains of tara gum (TG) to synthesize a copolymer emulsion (TG-g-P (AA-co-MMA)). The structure, thermal stability, morphology and wettability of the polymer were characterized by conventional methods, and the effects of key synthesis conditions on the performance of the emulsion (viscosity) were optimized. The erosion resistance and compressive strength of polymer-treated loess and laterite soils were evaluated under laboratory conditions. The results showed that the successful grafting of AA and MMA monomers onto TG improved its thermal stability and viscosity. In soil performance tests with low amounts of polymer additive, a 0.3 wt% application of TG-g-P (AA-co-MMA) to loess could resist continuous precipitation for >30 h with an erosion rate of 2.0 %. The compressive strength of the laterite treated with 0.4 % TG-g-P (AA-co-MMA) was 3.7 MPa, which was about three times that of the untreated soil. The results from this study suggest that TG-g-P (AA-co-MMA) emulsions have good potential for soil remediation applications.


Assuntos
Polímeros , Água , Metilmetacrilato , Emulsões , Metacrilatos/química
7.
Int J Biol Macromol ; 253(Pt 5): 127176, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37783254

RESUMO

The present research was undertaken to develop semi-IPN hydrogel matrix tablets of tara gum (TG) and carboxymethyl TG (CMTG) for sustained gastrointestinal delivery of highly water soluble tramadol hydrochloride (TH). The matrix tablets were developed by a hybrid process of wet granulation and direct compression technique. Carboxymethyl TG was crosslinked with dual cross-linking ions (Al3+/Ca2+). The uncross-linked component of the semi-IPN matrix was either incorporated within the granules (intragranular TG) or incorporated outside the granules (extragranular TG), prior to compression. The effect of intragranular/extragranular TG on the swelling, erosion and TH release characteristics from the semi-IPN hydrogel matrix tablets was investigated. The key finding of the investigation indicated that intragranular TG expedited TH release, while extragranular TG sustained TH release. Moreover, the effect of cross-linking ions on viscosity, rigidity, cross-link density and TH release behavior from hydrogel matrices was investigated. In-vivo pharmacokinetic performance of the optimized extragranular TG semi-IPN hydrogel matrix (F15) indicated sustained TH release in gastrointestinal milieu.


Assuntos
Hidrogéis , Tramadol , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Comprimidos , Fármacos Gastrointestinais , Íons
8.
Int J Biol Macromol ; 232: 123448, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-36709815

RESUMO

Tara gum (TG) was derivatized to carboxymethyl TG (CMTG) and then cross-linked with Al3+/Ca2+ ions to prepare Al/Ca cross-linked CMTG matrices for sustained delivery of Tramadol Hydrochloride (TH), a highly water-soluble drug. The effect of Al3+/Ca2+ ions concentration on swelling, erosion, and drug release behavior from Al/Ca-CMTG matrices was investigated. Al-CMTG matrices had greater cross-linking density, produced a more rigid and denser hydrogel layer than Ca-CMTG matrices. The rate of swelling, erosion, and in vitro drug release from Al-CMTG matrices was slower than from Ca-CMTG matrices. The most important finding of our study indicated that at the same concentration of cross-linking ions, the release of TH from Al-CMTG matrices was slower compared to Ca-CMTG matrices. The optimized formulation containing 9 % w/w AlCl3 in CMTG matrices released TH in a sustained manner up to 12 h in the gastrointestinal milieu. Moreover, it was observed that the prepared optimized formulation exhibited a more sustained release of TH compared to the marketed product.


Assuntos
Tramadol , Hidrogéis , Comprimidos , Íons , Preparações de Ação Retardada
9.
Int J Biol Macromol ; 227: 1001-1014, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36464192

RESUMO

Galactomannans are reserve carbohydrates in legume plants and are primarily extracted from their seeds. They contain galactose side chains throughout the mannose backbone and have unique features such as emulsifying, thickening, and gelling together with biodegradability, biocompatibility, and non-toxicity, which make them an appealing material. Guar gum and locust bean gum mainly are used in all galactomannan needed applications. Nonetheless, tara gum and fenugreek gum have also attracted considerable attention in recent decades. Despite the increased usage of galactomannans in the textile-related fields in recent years, there is no review article published yet. To fill this gap and to demonstrate the striking and increasing importance of galactomannans, a concise summary of the properties of common galactomannans and their comparisons is given first, followed by an account of recent developments and applications of galactomannans in the textile-related fields. The associated potential opportunities are also provided at the end of this review.


Assuntos
Galactanos , Gomas Vegetais , Gomas Vegetais/química , Galactanos/química , Mananas/química , Galactose/química , Manose/análise , Sementes/química , Têxteis
10.
Polymers (Basel) ; 15(19)2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37836034

RESUMO

Iron deficiency leads to ferropenic anemia in humans. This study aimed to encapsulate iron-rich ovine and bovine erythrocytes using tara gum and native potato starch as matrices. Solutions containing 20% erythrocytes and different proportions of encapsulants (5, 10, and 20%) were used, followed by spray drying at 120 and 140 °C. Iron content in erythrocytes ranged between 2.24 and 2.52 mg of Fe/g; microcapsules ranged from 1.54 to 2.02 mg of Fe/g. Yields varied from 50.55 to 63.40%, and temperature and encapsulant proportion affected moisture and water activity. Various red hues, sizes, and shapes were observed in the microcapsules. SEM-EDS analysis revealed the surface presence of iron in microcapsules with openings on their exterior, along with a negative zeta potential. Thermal and infrared analyses confirmed core encapsulation within the matrices. Iron release varied between 92.30 and 93.13% at 120 min. Finally, the most effective treatments were those with higher encapsulant percentages and dried at elevated temperatures, which could enable their utilization in functional food fortification to combat anemia in developing countries.

11.
Foods ; 12(9)2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37174411

RESUMO

Ethanolic extracts of propolis and bee honey contain substances beneficial to human health. Mixtures of wall materials were compared in spray-drying microencapsulation of ethanolic extracts of propolis and bee honey rich in bioactive compounds. Maltodextrin and tara gum were used to obtain microencapsulates A, and modified native potato starch and tara gum were used for microencapsulates B. High values of phenolic compounds, flavonoids, and antioxidant capacity were obtained in microcapsules A and B, and the results obtained in terms of encapsulation efficiency, yield, hygroscopicity, solubility, moisture, Aw, bulk density, and color were typical of the spray-drying process. On the other hand, spherical and elliptical microparticles of sizes between 7.83 and 53.7 µm with light and medium stability were observed. Thermogravimetric properties were similar in both microencapsulates; total organic carbon, SEM-EDS, and FTIR analyses corroborated the encapsulation. X-ray diffractogram exhibited amorphous structures, and the release kinetics of phenolic compounds presented high values from 8.13 to 12.58 mg GAE/g between 7 and 13 h. Finally, modified potato starch is a better encapsulant than maltodextrin because it has better core protection and controlled release of the encapsulated bioactive compounds.

12.
Curr Res Food Sci ; 5: 718-725, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35497774

RESUMO

Iron deficiency is one of the main causes of anemia in the world, especially in children and women, so food fortification through microencapsulation is a viable alternative to combat this deficiency. The present work aimed to encapsulate iron in a water-in-oil-in-water double emulsion (W1/O/W2), which was formed with whey protein isolate and polyglycerol polyricinoleate as the emulsifying agents, tara gum as a thickening agent, and sucrose as an osmotic active substance. The double emulsion formed with 12% whey protein isolate, 0.8% tara gum, and 2% sucrose presented high encapsulation efficiency (96.95 ± 1.00%) and good stability (up to 7 days). Additionally, after the in vitro gastrointestinal simulations, the bioaccessibility was high for adults (49.54 ± 5.50%) and infants (39.71 ± 2.33%). Finally, the study show that double emulsions can form stable systems with high iron bioaccessibility even in infant gastric systems, which indicates the possibility of using double emulsions to fortify food with iron.

13.
Foods ; 11(2)2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-35053891

RESUMO

Olive mill wastewater, a high polyphenols agro-food by-product, was successfully exploited in an eco-friendly radical process to synthesize an antioxidant macromolecule, usefully engaged as a functional ingredient to prepare functional puddings. The chemical composition of lyophilized olive mill wastewaters (LOMW) was investigated by HPLC-MS/MS and 1H-NMR analyses, while antioxidant profile was in vitro evaluated by colorimetric assays. Oleuropein aglycone (5.8 µg mL-1) appeared as the main compound, although relevant amounts of an isomer of the 3-hydroxytyrosol glucoside (4.3 µg mL-1) and quinic acid (4.1 µg mL-1) were also detected. LOMW was able to greatly inhibit ABTS radical (IC50 equal to 0.019 mg mL-1), displaying, in the aqueous medium, an increase in its scavenger properties by almost one order of magnitude compared to the organic one. LOMW reactive species and tara gum chains were involved in an eco-friendly grafting reaction to synthesize a polymeric conjugate that was characterized by spectroscopic, calorimetric and toxicity studies. In vitro acute oral toxicity was tested against 3T3 fibroblasts and Caco-2 cells, confirming that the polymers do not have any effect on cell viability at the dietary use concentrations. Antioxidant properties of the polymeric conjugate were also evaluated, suggesting its employment as a thickening agent, in the preparation of pear puree-based pudding. High performance of consistency and relevant antioxidants features over time (28 days) were detected in the milk-based foodstuff, in comparison with its non-functional counterparts, confirming LOWM as an attractive source to achieve high performing functional foods.

14.
Int J Biol Macromol ; 206: 521-533, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35231534

RESUMO

This work proposed a one-pot green route for the development of a biocompatible Tara gum-Riceberry phenolics­silver nanosphere hybrid nanocomposite (TG/RiPE-SNG) with manifold biological potentialities. The reaction system comprised of AgNO3 as nanosilver precursor, Riceberry phenolic extract as the green in situ reductant, and Tara gum as stabilizing and anchoring agent. TG/RiPE-SNG was extensively characterized using UV-vis spectroscopy, FTIR, RAMAN, TEM, FESEM, EDX, DLS/zeta potential, XRD, and TGA analyses. Small, stable, spherical, well-dispersed SNP with an average particle size of 13.01 nm and λmax of 421 nm were synthesized in situ, and uniformly distributed within the gel-like TG/RiPE composite. The prepared nanocomposite demonstrated superior antibacterial properties (MIC of 12.5 µg/mL) against S. aureus and S. epidermidis compared to the gum or extract. Additionally, TG/RiPE-SNG exhibited strong light barrier, tyrosinase inhibitory and antioxidant functionalities. TG/RiPE-SNG also exhibited high stability at different pH and was more thermally stable relative to the plain TG/RiPE composite. Furthermore, TG/RiPE-SNG showed good biocompatibility towards mouse L929 fibroblasts and rat erythrocytes. The obtained findings revealed a simple, benign, and inexpensive approach using only natural ingredients for the preparation of gum-based biopolymer-nanosilver hybrid nanocomposite and underscored the strong attributes of TG/RiPE-SNP as a nanomaterial with desirable biomedical potentials.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Camundongos , Testes de Sensibilidade Microbiana , Nanogéis , Extratos Vegetais/química , Gomas Vegetais , Polietilenoglicóis , Polietilenoimina , Ratos , Prata/química , Staphylococcus aureus
15.
Int J Biol Macromol ; 150: 189-199, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32050084

RESUMO

Interest in galactomannans and its derivatives as a functional health supplement is growing based on physicochemical properties. In this work, the optimized conditions of sulfated tara gum (STG) with a maximum DS of 0.66 by box-behnken design (BBD) were obtained as following: ratio of chlorosulfonic acid/pyridine 3:1, reaction time 4 h and reaction temperature 40 °C. The structure features of STG such as the degree of substitution (DS), substitution position, weight average molar mass (MW), monosaccharide components and chain conformation were investigated. Decreasing of MW, the increasing of Z-average radius of gyration (〈S2〉Z1/2) and specific volume for gyration (SVg) were obtained by SEC-MALLS. In addition, the structural properties of four sulfated galactomannans were comparatively investigated and analyzed based on our earlier reports of sulfated fenugreek gum, guar gum and locust bean gum. A conclusion was drown that higher galactose branch could enhance steric hindrance, which was inferred as one of the significant factors for the derivatization efficiency, thus affecting the DS, MW and conformational transition of sulfated galactomannans. This study will provide valuable information for further research on the comparison of bioactivities and medical application of galactomannans family.


Assuntos
Modelos Químicos , Gomas Vegetais/química , Sulfatos/química , Algoritmos , Estrutura Molecular , Peso Molecular , Monossacarídeos/química , Gomas Vegetais/síntese química , Reprodutibilidade dos Testes , Análise Espectral , Temperatura
16.
Food Chem ; 325: 126964, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32387994

RESUMO

Edible films are popular for the development of food packaging. The suitable additive is the key point for the improvement of edible film performance. In this study, edible films (LTEFs) based on blends of ellagitannins (ET) from the unripe fruits of Rubus chingii Hu, low methoxyl pectin (LMP) and tara gum (TG) were characterized and evaluated. The results showed that the thickness and water resistance were increased with the addition of TG and ET. The content of TG and ET obviously influenced its mechanical properties. FT-IR and SEM results suggested that there were interactions between ET and the film substrates, which modified its structure and connection mode. Moreover, the LTEF showed effective antioxidant activity and antimicrobial activity. These results suggested that TG and ETs had the potential to improve the performance of the pectin film and the LTEF could be used as a functional edible film for application in food industries.

17.
Int J Biol Macromol ; 163: 2113-2126, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32950525

RESUMO

Galactomannans are naturally occurring biocompatible and biodegradable nonionic polysaccharides comprised of mannose and galactose residues. They are under investigation for the design of various drug delivery carriers such as matrix tablets, microparticles, nanoparticles/nanocomposites, polymeric micelles, hydrogels, as well as pharmaceutical excipients. Amongst galactomannans, guar gum, locust bean gum, and fenugreek gum are the biomaterials mostly investigated for their potential utility as nanocarriers for various purposes, either in their native or modified forms. The galactomannan-based nanomaterials have been fabricated by adopting various strategies. These galactomannan nanomaterials have been tested for oral vaccination, oral insulin delivery, cancer cell & macrophage targeting, controlled drug delivery, heavy metal extraction and wound dressing applications. The galactomannan has attracted the attention of researchers as reducing agents for the green synthesis of metal nanoparticles as well. These nanometals have shown improved antimicrobial, antioxidant and anticancer activities. In vitro toxicity of the nanomaterials is also assessed in some instances. Others such as cassia gum, tara gum, Delonix, Leucaena leucocephala, Punica granatum galactomannans are amongst the least studied materials for biological applications. This review describes various strategies adopted for the synthesis of galactomannan-based nanomaterials, their properties and applications, especially in the field of drug delivery.


Assuntos
Materiais Biocompatíveis/química , Mananas/química , Nanoestruturas/química , Polissacarídeos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/uso terapêutico , Sistemas de Liberação de Medicamentos , Galactanos/síntese química , Galactanos/química , Galactose/análogos & derivados , Humanos , Mananas/síntese química , Mananas/uso terapêutico , Gomas Vegetais/síntese química , Gomas Vegetais/química , Polissacarídeos/síntese química , Polissacarídeos/uso terapêutico , Trigonella/química
18.
Prev Nutr Food Sci ; 23(3): 254-259, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30386754

RESUMO

The present study was performed to investigate the influence of tara gum (TG) addition on the steady and dynamic shear rheological properties of rice starch (RS) isolated from the Korean rice variety 'Boramchan' flour. From X-ray diffraction and Fourier transform infrared spectra of RS, it was found that RS was purely isolated. All RS+TG pastes (4.7:0.3, 4.5:0.5, and 4.3:0.7, w/w) showed shear-thinning fluid characteristics. Adding TG significantly increased the values of apparent viscosity and consistency index of RS. In the dynamic shear rheological analysis, the dynamic moduli and complex viscosity of RS+TG pastes were significantly greater than those of the RS paste, indicating that RS+TG pastes had significantly higher viscoelastic properties than the RS paste. Light microscopy images of RS+TG pastes showed that the addition of TG can inhibit the RS granule from swelling.

19.
Polymers (Basel) ; 10(9)2018 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-30960870

RESUMO

Tara gum/silver composite superabsorbent polymers were synthesized with tara gum grafted poly(acrylic acid), using K2S2O8 (KPS) as an initiator and N,N'-methylenebisacrylamide (MBA) as a cross-linker. The products were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the silver ions were partially reduced to Ag° and the amorphous nanoparticles containing Ag° and Ag2O were around 10~50 nm in size The tara gum/silver composite superabsorbent polymers exhibited an interconnected porous structure with strong water absorption capacity. The swelling ratio of each product could reach 473 g/g in distilled water and 62 g/g in 0.9% NaCl solution. The antimicrobial activity of the samples against Staphylococcus aureus and Escherichia coli increased with the addition of AgNO3 from 0 to 125 mg. This work indicates that the developed tara gum/silver composite superabsorbent polymers can be potentially used for biomedical applications.

20.
Polymers (Basel) ; 10(7)2018 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-30960621

RESUMO

An antibacterial superabsorbent polymer was prepared by graft polymerization of acrylic acid onto tara gum polysaccharide, by adding N,N-dimethyl-N-2-propenyl-2-propen-1-aminium chloride and a polymer with 2-propenamide (polyquaternium-7, PQ7) as an antibacterial agent. The effects of the amount of PQ7 in the hydrogel on its swelling ratio were investigated and maximum swelling ratios of 712 g/g and 68 g/g, in distilled water and 0.9 wt % NaCl solution were attained with 0.5 g PQ7 per gram of tara gum. The superabsorbent hydrogel was characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermal gravimetric analysis. The results showed that poly (acrylic acid) was successfully grafted onto tara gum and a three-dimensional network structure formed with PQ7 chains penetrated in the networks. The antibacterial properties of these superabsorbent hydrogels against Staphylococcus aureus and Escherichia coli improved with increasing PQ7 content. This study demonstrates a method of preparing novel functional superabsorbent hydrogels.

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