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Xanthan Gum–Konjac Glucomannan Blend Hydrogel for Wound Healing

Xanthan Gum–Konjac Glucomannan Blend Hydrogel for Wound Healing

To accomplish the production of hydrogels, researchers have been using different natural polymers, like alginate [8], chitosan [9], collagen [10], dextran [11], hyaluronan [12], xanthan [13], and konjac [14], among others. Catanzano et al. produced a hydrogel composed of alginate and hyaluronan aiming to improve the wound healing process [8]. These authors verified that the produced hydrogels were able to promote cell migration as well as reduce the area of wounds previously induced on animal models. On the other hand, Miguel et al. developed a thermo-responsive hydrogel composed of chitosan and agarose that displayed excellent biocompatibility and was able to enhance the wound healing process [9]. Herein, a xanthan gum–konjac glucomannan blend was used for the first time to produce a wound dressing that was subsequently evaluated in physicochemical and biological assays. Konjac glucomannan (KGM) is a natural polysaccharide [15] extracted from the tubers of the Amorphophallus konjac plant [16]. It is composed of β-1,4-linked d-glucose units with glucose/mannose (G/M), with a G/M ratio around 1:1.6 [17–20]. KGM has been widely used in the food industry as a gelling agent or thickener due to its biocompatibility and biodegradability [21]. Nevertheless, KGM application in the production of wound dressings is restricted by the weak mechanical properties displayed in aqueous solutions. Such behavior occurs as a consequence of the high number of hydroxyl groups available in its polymeric chain [22]. To overcome this limitation, xanthan gum (XG) was used to upgrade the mechanical strength of the produced hydrogel. XG is a negatively charged and high molecular weight extracellular hetero-polysaccharide, with a cellulose-like backbone, obtained from Xanthomonas campestris [23–25]. It is composed of 1,4 linked β-d-glucose residues, with a trisaccharide side chain of β-d-mannose β-d-glucuronic acid-α-d-mannose attached to alternate d-glucose units of the main chain [23–25
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Obtaining process of interpolymeric complexes from lactalbumin, xanthan gum and pectin Processo de obtenção de complexos interpoliméricos a partir de lactoalbumina, goma xantana e pectina

Obtaining process of interpolymeric complexes from lactalbumin, xanthan gum and pectin Processo de obtenção de complexos interpoliméricos a partir de lactoalbumina, goma xantana e pectina

In this work, the optimization process of interpolymeric complexes formation between lactalbumin and the polysaccharides xanthan gum and pectin was studied in order to defi ne the optimum conditions for the complexes formation. For the experimental design, response surface methodology (RSM) for three independent variables was used. The optimum conditions for the complexes formation between lactalbumin and xanthan gum were: pH 6.6, NaCl concentration of 0.6 mol/L and xanthan gum concentration 0.083% w/v. And for the complexes formed between pectin and lactalbumin the conditions were: pH 6.6, NaCl concentration of 0.25 mol/L and pectin concentration of 0.113% w/v. The best fi tted model for the experimental data was that corresponding to the complex xanthan gum-lactalbumin, whose coeffi cient of determination (R²) was 0.97.
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Xanthan gum production by semissolid and submerged processes using potato peel as substrate / Produção de goma xantana por processos semissólidos e submersos usando casca de batata como substrato

Xanthan gum production by semissolid and submerged processes using potato peel as substrate / Produção de goma xantana por processos semissólidos e submersos usando casca de batata como substrato

Xanthan gum is an extracellular, water-soluble, anionic and branched heteropolysaccharide, produced by Xanthomonas campestris Gram-negative bacteria strains, with unique rheological properties, such as highly pseudoplastic behavior, where the viscosity of the solutions is almost unchanged at temperatures between 4 and 93 °C and pH between 1 and 13, which contributes to their applications as stabilizing agents, thickeners and emulsifiers in the petroleum, food, pharmaceutical, hygiene and cosmetic industries (Diniz et al., 2012; Menezes et al. , 2012).

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Biosynthesis of xanthan gum from pectin deriving from passion fruit peel extraction / Biossíntese de goma xantana de pectina derivada da extração de casca de maracujá

Biosynthesis of xanthan gum from pectin deriving from passion fruit peel extraction / Biossíntese de goma xantana de pectina derivada da extração de casca de maracujá

Heteropolysaccharide obtained from the bacteria Xanthomonas fermentation, xanthan gum is widely used in the food, petrochemical, oil, agrochemical and pharmaceutical industries. This work evaluates the process of this polysaccharide production from pectin extracted from passion fruit peel, in the proportion of 1.5% (m/V), with and without sucrose supplementation, compared to the standard medium (YM). The fermentation process was carried out in an orbital shaker at 200 rpm and 28 °C for 72 hours. The gum yields obtained with pectin as carbon source were higher than that found with the standard medium, where with only pectin reached 13.83 g/L, while with pectin and sucrose it reached 18.87 g/L and in the standard medium the maximum yield was 9.76 g/L.
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Some Qualitative and Rheological Properties of Virgin Olive Oil- Apple Vinegar Salad Dressing Stabilized With Xanthan Gum

Some Qualitative and Rheological Properties of Virgin Olive Oil- Apple Vinegar Salad Dressing Stabilized With Xanthan Gum

with 0.75% xanthan gum had the highest values of G and tan δ, suggesting that it had the greatest stability during the 90 days of storage in this study, but sauces with 0.5% of gum had the lowest change between the first day and 90th day parameter; as a result, passage of time had the least effect on this sample (Figure 3a,c). These results agreed with those reported by Franco et al, who found out that the tan δ value was related with the emulsion stability, which means that a higher tan δ value was linked with a more stable emulsion product. 26 Also,
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Biosynthesis of xanthan gum from the fermentation of milk whey: productivity and viscosity.

Biosynthesis of xanthan gum from the fermentation of milk whey: productivity and viscosity.

O presente trabalho teve por objetivos avaliar o rendimento da produção de goma xantana por diferentes linhagens nativas de Xanthomonas campestris , utilizando como[r]

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Effect of Different Hydrocolloids on Pasting Behavior of Native Water Chestnut (Trapa bispinosa) Starch

Effect of Different Hydrocolloids on Pasting Behavior of Native Water Chestnut (Trapa bispinosa) Starch

Th e pasting behavior of native Water Chestnut Starch – hydrocolloids mixtures was studied. Th e eff ect of Xanthan, Guar, Carboxy Methyl Cellulose and Acacia on Water Chestnut Starch was examined by using micro Viscoamylograph. It was noticed that all hydrocolloids greatly modify the pasting properties of water chestnut starch. Results showed that gelatinization temperature of water chestnut starch was increased by the addition of gum acacia at 0.3 % concentration, whereas guar gum decreased at the same concentration as compared to native water chestnut starch. Xanthan gum and guar gum signifi cantly increased peak viscosity at 0.1 – 0.3 %, but gum acacia at only 0.3 % addition. Th e breakdown was greatly enhanced by the addition of xanthan gum at 0.1-0.3 % concentrations, but the retrogradation was mostly infl uenced due to the presence of guar gum at 0.3 %. Th ese results showed that hydrocolloids modify the properties of native water chestnut starch, which can provide a great potential for use in diff erent food products.
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Polímeros  vol.23 número5

Polímeros vol.23 número5

The cells were first separated from the fermented medium by centrifugation at 9625 x g at 4 °C for 15 minutes. Ethyl alcohol was then added to the supernatant at a rate of 3 parts of alcohol to 1 part of supernatant (fermented broth). Precipitated gum was collected and transferred to previously weighed Petri dishes. The gums obtained were dried in an incubator at (30 ± 2 °C) to constant mass, and the xanthan gum yields measured by a gravimetric method, the values being expressed in g.L –1 .

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Braz. J. Chem. Eng.  vol.30 número4

Braz. J. Chem. Eng. vol.30 número4

Thus, Xanthomonas can also be employed to convert crude glycerin and this strategy was patented by our research group (Brandão et al., 2007). The objective of this work was to produce and character- ize the xanthan gum synthesized by X. campestris mangiferaeindicae 2103 in batch fermentation in a shaker from crude glycerin, which is an co-product of biodiesel with lower cost and higher availability compared to sucrose. The present study is the first paper presented in the literature that explores the use of crude glycerin as a feedstock to produce non- food-grade xanthan of lower cost for applications in drilling fluids and EOR.
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Thermodynamic properties of Buriti (Mauritia flexuosa) tree gum

Thermodynamic properties of Buriti (Mauritia flexuosa) tree gum

Based on the behavior of the curves (Figure 1), all isotherms are classified as type OO (sigmoid-like isotherms) (Brunauer et al., 1940) and, in particular, they were more consistent with Langmuir-like type-OO isotherms according to the quantitative criterion proposed by Yanniotis & Blahovec (2009). Type-OO behavior was observed by Torres et al. (2012) for adsorption isotherms of carboxymethyl cellulose, guar gum, locust gum, tragacanth gum, and xanthan gum at different temperatures (20-65 °C). Melo et al. (2011) also observed type-OO sorption isotherms for the skin, pulp, and fibrous part of buriti (Mauritia flexuosa).
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Locust bean gum: exploring its potential for biopharmaceutical applications

Locust bean gum: exploring its potential for biopharmaceutical applications

Excipients have traditionally been included in drug formulations as inert substances whose role mainly relies on aiding the manufacturing process. Nevertheless, in the last decades they have been increasingly included in dosage forms to fulfill specialized functions aimed at improving drug delivery. LBG is being used in biopharmaceutical applications with several distinct functions, varying from controlled release excipient to tablet disintegrant. In most cases, the polysaccharide is associated with a second material, benefiting from strong synergies, and fields of application are varied, comprising oral, buccal and colonic delivery, but also ocular and topical applications have been described. A substantial amount of research remains to be conducted to unveil the real potential the polysaccharide might possess. Considering the available works, it seems to be particularly interesting in the case of synergies established with other polysaccharides, namely xanthan gum and carrageenan.
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Efeitos da redução de açúcar nas características estruturais de bolos tipo esponja

Efeitos da redução de açúcar nas características estruturais de bolos tipo esponja

ABSTRACT - The consumption of reduced-calorie cakes has been increasing, however this has presented challenges to be overcome concerning the formation of their structure when the sucrose is substituted by alternative sweeteners, gums or thickening agents. The present study evaluated the internal characteristics of cakes with a reduction in sucrose, and the effects of its substitution on starch gelatinisation. Starting with a pre-established formulation, the sucrose was gradually substituted by a 1.0% mixture of sucralose in a 1.5% xanthan gum solution. In the substituted cake mix, the apparent viscosity and its thermal properties were evaluated using differential scanning calorimetry (DSC). Specific volume (SV) and cell count (CC) were evaluated in the cakes. As the sucrose content decreased (52.17 to 10.00%), the specific volume (1.94 to 0.7 mL/g), cell count (36.2 to 4.0 cell/cm²) and the apparent viscosity of the batter (337.56 to 631.40 cP) were also reduced. The results showed that substituting the sucrose contributed greatly to the formation of defects in the cake structure (holes). From the data obtained, and thermograms of standard cake batters and those with a reduction in sucrose, it can be concluded that sucralose reduced the temperature of starch gelatinisation, speeding the process and causing compaction of the cake structure during baking, favouring the formation of bubbles throughout the batter.
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J. Braz. Chem. Soc.  vol.22 número7

J. Braz. Chem. Soc. vol.22 número7

A characteristic of the Xanthomonas genus is the copious production of exopolysaccharide (EPS), xanthan gum, released by the cells as slime in medium. The EPS is involved in cell protection, but its role in the protection mechanism against heavy metals is not well established. The xanthan gum is a 1,4 linked β- D -glucose polymer. Every alternated glucose contains a negative charged trisaccharide side chain with an internal mannose, glucuronic acid and a terminal mannose. The internal mannose can be acetylated in the O(6) position and the terminal one can be derived by a pyruvic acid moiety, joined by a ketal linkage in the O(4) and O(6) positions, leaving a free carboxylic acid group. The derivation of mannoses is dependent on species, environment (nutrients, pH and temperature) and age. 8
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Effect of ph on the stability of red beet extract (Beta vulgaris l.) microcapsules produced by spray drying or freeze drying

Effect of ph on the stability of red beet extract (Beta vulgaris l.) microcapsules produced by spray drying or freeze drying

Red beets is rich in phenolic acids and has high antioxidant capacity, and can be used to produce a natural dye. This study evaluated the effect of pH (3 to 6) on the stability of red beet extract microcapsules, dried by freeze drying and spray drying and stored at room temperature. The microcapsules were produced using a combination of maltodextrin and xanthan gum as encapsulating agents and stored for 7 days. For all evaluated microcapsules, a degradation of betanin was observed, however, that degradation was independent of pH, with the exception of the sample with maltodextrin and dried by spray drying. The freeze dried products showed lower degradation constants and higher half-life (t 1/2 ) when comparing with the spray dried samples. The microcapsules containing maltodextrin and xanthan gum, dried by spray drying, showed the highest change in the content of phenolic compounds after storage for 7 days. The color parameters showed a reduction for a*, and increase in b* and L*, for all samples during the storage time. In general, the microcapsules produced using maltodextrin and xanthan gum, and dried by freeze dryer, showed higher stability in terms of betanin content, phenolic compounds and color parameters during storage at different pHs.
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J. Braz. Chem. Soc.  vol.27 número5

J. Braz. Chem. Soc. vol.27 número5

Results found in this work are very relevant because the difficulties usually encountered in the xanthan gum digestion have been overcome, allowing the complete degradation of the samples in the presence of a single acid. Our studies demonstrated the applicability of the use of the reflux system adapted to the digester block. This system enabled the heating of samples under reflux, not presenting loss of concentrated nitric acid due to volatilization in the digestion step, which usually occurs in conventional procedures with open system. Consequently, fewer reagents are consumed, reducing the risk of contamination. Moreover, the elimination of the use of percloric acid was also possible, resulting in greater safety at work. The results found for Ca, Cu, K, Mg, Na and Zn were accurate and precise. Thus, this methodology is appropriate for routine analysis of analytes studied in xanthan gum samples.
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Effect of complexation conditions on microcapsulation of Lactobacillus acidophilus in xanthan-chitosan polyelectrolyte complex gels

Effect of complexation conditions on microcapsulation of Lactobacillus acidophilus in xanthan-chitosan polyelectrolyte complex gels

Preparation of chitosan and xanthan solutions Chitosan with a minimum of 80~95% deacetylation and a molecular weight of γ70 000 was purchased from Sigma-Aldrich Chemicals (St. Louis, MO). The chitosan was dissolved in 1N HCl by agitating, and adjusting the different chitosan concentration to 0.5%, 0.7%, 0.9% and 1.1%. The desired solution pH was adjusted by 1M NaOH and deionized (ŹI) water was added to bring it to the fi nal volume, and the pH was adjusted to 4.5, 5, 5.5 and 6. Xanthan gum with a mo- lecular weight of 1.0β million was kindly supplied by Zibo Zhongxuan biological chemistry company. Xan- than gum was dissolved in ŹI water under heating and agitation, and the xanthan concentration was adjusted to 0.5%, 0.7%, 0.9% and 1.1%. It was autoclaved (110°C, 15 min) before use.
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Mat. Res.

Mat. Res.

The screening step was a fractional factorial design 2 (4-1) with a center point. The screening input variables were the concentrations of xanthan gum (XG), sodium (NaCl) and calcium (CaCl 2 ) chlorides and the temperature (T). The output variables were the low consistency (k) and low behavior (n) indexes (rheological parameters) and the initial and inal gels forces (thixotropic parameters). This process was made in order to minimize the number of complete analysis experiments 7 .

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Rheological Characterization of Bentonite Dispersions with Xanthan for Oil Well Drilling Fluids

Rheological Characterization of Bentonite Dispersions with Xanthan for Oil Well Drilling Fluids

After selection of variables, a full factorial design 2³ showed that both consistency and flow behavior indexes are influenced by temperature, xanthan gum and sodium chloride concentrations, as well as some of their first order interactions. The increase of temperature and sodium chloride concentration resulted in an increase in “n”, reducing the fluid pseudoplasticity and caused a decrease in “k”. Increasing xanthan gum concentration caused the opposite effect: a reduction in “n” and a increasing in “k”.

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Braz. J. Pharm. Sci.  vol.50 número4

Braz. J. Pharm. Sci. vol.50 número4

Rational design of vaginal drug delivery formulations requires special attention to vehicle properties that optimize vaginal coating and retention. The aim of the present work was to perform a screening of mucoadhesive vaginal gels formulated with carbomer or carrageenan in binary combination with a second polymer (carbomer, guar or xanthan gum). The gels were characterised using in vitro adhesion, spreadability and leakage potential studies, as well as rheological measurements (stress and frequency sweep tests) and the effect of dilution with simulated vaginal luid (SVF) on spreadability. Results were analysed using analysis of variance and multiple factor analysis. The combination of polymers enhanced adhesion of both primary gelling agents, carbomer and carrageenan. From the rheological point of view all formulations presented a similar behaviour, prevalently elastic and characterised by loss tangent values well below 1. No correlation between rheological and adhesion behaviour was found. Carbomer and carrageenan gels containing the highest percentage of xanthan gum displayed good in vitro mucoadhesion and spreadability, minimal leakage potential and high resistance to dilution. The positive results obtained with carrageenan-xanthan gum-based gels can encourage the use of natural biocompatible adjuvants in the composition of vaginal products, a formulation ield that is currently under the synthetic domain.
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Properties of Extruded Xanthan-Starch-Clay Nanocomposite Films

Properties of Extruded Xanthan-Starch-Clay Nanocomposite Films

Xanthan gum addition affected mechanical properties of starch films, improving their elongation. Films produced with xanthan (2.0 g/100 g starch) and nanoclays (2.5 or 5.0 g/100 g starch) presented the better combination of mechanical properties, with high stress and strain at break values. Nanoclays addition at 2.5 w% was sufficient to decrease water vapor permeability and water sorption capacity and to increase the stress at break of produced films. These materials are a valid answer to produce low cost, highly competitive and pioneering environmentally friendly materials. Moreover, because of the increasing concerns about the sustainable development, as well as the escalating prices and global demand and for saving the fossil resources, agro-based materials now represent an interesting option to replace the conventional plastics.
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