Presence Of Xanthan Gum Research Articles

A new approach in improving granular cold water swelling starch properties using xanthan gum and β-lactoglobulin/xanthan gum electrostatic coupled gel

Granular cold water swelling (GCWS) starches are capable of creating cold-set gels without any heat treatment. However, similar to their thermally gelatinized counterparts, there are some techno-functional challenges related to these physically modified starches. The main objective of this study was to investigate the probable improvement of physical and mucoadhesive properties of alcoholic-alkaline modified GCWS tapioca and corn starches (GCWSTS and GCWSCS, respectively) in the presence of xanthan gum (XG) or β-lactoglobulin-XG electrostatic coupled gel (βlg-XG ECG). Results showed that the viscosity, consistency, pseudo-plasticity, structure recovery, and cold storage stability were improved, and the turbidity development and susceptibility against temperature rise and successive freeze-thaw cycles decreased by increasing the XG to starch ratio from 1:99 to 10:90 in the XG/GCWSTS mixtures, and from 5:95 to 10:90 in XG/GCWSCS mixtures, compared to the respective GCWS starches. The XG to starch ratios of 1:99 and 2.5:97.5 negatively influenced the characteristics of GCWSCS, except for its mucoadhesion. The maximum work of adhesion was obtained at XG to TS ratio of 5:95. Partial substitution of the starch with βlg-XG ECG increased shear-thinning behavior, percent recovery, and work of adhesion, although to a lower degree compared with XG. In contrast, the ECG could substantially reduce the long-term retrogradation and after-five-cycles freeze-thaw syneresis of the GCWS starches much more than XG, despite having a lower concentration. The results of this study suggested that the XG and βlg-XG ECG are capable of extending the applications of GCWS starches in the heat-sensitive functional formulations and 3D printable foods.

Effect of xanthan gum on the quality of low sodium salted beef and property of myofibril proteins

The effects of xanthan gum (0 % and 0.3 %) on the quality of low sodium (2.0 %, 2.4 %, 2.8 %, 3.2 %, 3.6 % and 4.0 %) salted beef and property of myofibril proteins (MP) extracted from salted beef were researched. Changes in the salting absorptivity, cooking loss, shear force, color and sensory analysis showed that xanthan gum had a positive effect on the quality of salted beef with low salinity (2.0 %, 2.4 % and 2.8 %). MP of salted beef treated with xanthan gum had higher solubility, lower hydrogen bond than that without it (P < 0.05). The decrease of surface hydrophobicity and intrinsic fluorescence intensity indicated that the chromophore of protein was brought into a hydrophobic environment in the presence of xanthan gum. The electrophoresis showed that xanthan gum could improve the concentration of myosin heavy chain, paramyosin and actin after tumble-salting. The data suggested that salted beef and its MP treated with xanthan gum and 2.8 % salt (XS3) had the best properties. Together, xanthan gum could be considered as a sodium salt substitute for the development of low sodium meat products.

Surface chemical and selective flocculation studies on iron oxide and silica suspensions in the presence of xanthan gum

The changes in the surface chemical properties of iron oxide and silica suspensions consequent to the addition of xanthan gum were studied. The adsorption density of xanthan gum for iron oxide was found to be maximum at pH ~ 2, whereas almost nil adsorption was found for silica throughout the pH range investigated. The isoelectric points (i.e.p.) of iron oxide and silica were found to be located at pH ~ 8.4 and presumably less than pH 2 respectively. The addition of xanthan gum shifted the i.e.p. of iron oxide towards more acidic pH values, in proportion with the concentration of xanthan gum added, with a concomitant change in the zeta potentials to more electronegative or less electropositive values. The maximum flocculation of iron oxide (98%) was observed in the wide pH regime of 2–9 with the optimum dosage of xanthan gum (20–50 ppm). The electrokinetic and flocculation characteristics of the silica were not altered much by the addition of xanthan gum, akin to the adsorption result. FTIR spectral investigations provide evidence in support of hydrogen bonding and chemical interaction forces between iron oxide and xanthan gum. Maximum separation efficiency of 65% for iron oxide-silica mixture was observed in selective flocculation tests.

Use of thermodynamics in understanding drug release from xanthan gum matrices: The influence of clay-drug complexes

The aim of this study was to outline a novel way of understanding the controlled drug release from drug-clay-polymer matrices using isothermal calorimetry (ITC) as a complementary technique to dissolution studies. ITC results showed that the binding phenomenon between the model drug propranolol hydrochloride (PPN) and magnesium aluminium silicate (MAS) in the presence of xanthan gum (XG was spontaneous and enthalpically driven (negative enthalpy (ΔH) and small entropy (-T∆S)). This may be due to the competition for PPN due to the anionic nature of XG. Dissolution results showed that when using the MAS-PPN complexes, 10% w/w XG polymer level was enough to significantly reduce the burst release. When used together, ITC and dissolution studies may help a formulator understand and identify interactions which occur during dissolution studies and may be beneficial to the controlled drug delivery system.

Biomimetic silk fibroin and xanthan gum blended hydrogels for connective tissue regeneration

Combination of naturally occurring materials instead of chemically synthesized products has always been an attractive proposition in the field of tissue engineering. In this study, silk fibroin (SF) and xanthan gum(XG) were physically crosslinked to form biocompatible hydrogels. SF/XG hydrogels were prepared using ultrasonication, which induces β-sheets from random coils in SF solution and allows entrapment of heated XG chains homogeneously in the SF network. It is a novel way of blending SF and XG polymers which avoids the usage of chemical crosslinkers. SF/XG blended solutions were used at different ratios for the hydrogel formation. Scanning electron microscopy (SEM) and micro-computed tomography (MCT) were used for morphological analysis of the interconnected network and porosity of the scaffolds, respectively. Rheological studies were performed to understand the changes in mechanical properties due to the incorporation of XG into SF hydrogels. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of SF and XG moieties in the blend scaffolds. Additionally, thermal Analysis (TGA & DSC) established the homogenous mixture and presence of XG in the SF network without any phase separation. Furthermore, the MTT assay demonstrates the cytocompatibility of scaffolds using L929 fibroblast cells. Thus, fabricated SF/XG scaffolds could mimic natural cartilage ECM by exhibiting enhanced water swelling capacity and suitable porosity along with its cytocompatible studies, indicating its potential application in soft tissue engineering.

Protective effect and mechanism of action of xanthan gum on the color stability of black rice anthocyanins in model beverage systems

We investigated the effect and mechanism of action of xanthan gum (XG) on the color stability of black rice anthocyanins (BRA) in model beverage systems (pH 3.0) containing l-ascorbic acid under different conditions. The color stability of BRA was significantly enhanced in the presence of XG under accelerated storage conditions (40 °C), particularly at 0.25% (w/v). The degradation of BRA followed a first-order reaction rate (R2 > 0.89) during storage and thermal processing conditions. The addition of XG effectively improved the storage stability of BRA in the presence of l-ascorbic acid, particularly at 4 °C in the dark. Moreover, the thermal stability of BRA was enhanced by XG under thermal treatment (80 °C, 90 °C and 100 °C). The FTIR spectrum, X-ray diffraction and molecular simulation results showed that the interaction between XG and BRA was driven mainly by hydrogen bonds and hydrophobic interactions, leading to the increased stability of BRA. Our study demonstrated the benefits of using XG to improve the color stability of BRA in model beverage systems, further expanding the practical application of XG in anthocyanin-rich beverages.

Understanding the effect of the mesopore volume of ordered mesoporous carbons on their electrochemical behavior as Li-ion battery anodes

Abstract This work aims at understanding the effect of the mesopore volume of ordered mesoporous carbons (OMCs) on their behavior as anodes for Li-ion batteries. To that purpose, the hard-templating method was used as an enabling tool, with the controlled partial etching of the silica template to prepare a series of OMCs with a wide range of mesopore volumes. The formed carbon-silica hybrids were processed into electrodes using a water-based ink preparation route in the presence of xanthan gum as a binder, which retained access to the pores after formation of the electrodes. The pore texture of the latter was compared to that of the starting powders. A very good linear relationship could be evidenced between the mesopore volume of the electrodes and the first insertion capacity of Li-ions. The lithium de-insertion also followed a linear trend, but its behavior was dependent on the final applied potential. Indeed, the higher the mesopore volume, the higher the contribution of de-insertion at elevated voltages. This study further points out the importance of the textural characterization of electrodes (instead of just the starting material) as well as the conditions at which the electrochemical measurements are carried out, especially the maximum applied de-insertion voltage.

Salt Effects on Formation and Stability of Colloidal Gas Aphrons Produced by Anionic and Zwitterionic Surfactants in Xanthan Gum Solution

This work is devoted to the influence of NaCl salt concentration on the formation and stability of colloidal gas aphrons (CGA) produced by the anionic surfactant sodium dodecyl sulfate (SDS) and zwitterionic surfactant coco amido propyl betaine (CAPB) in the presence of xanthan gum (XG) as a stabilizer. Dynamic surface tension measurements as well as volume and half-life time of the produced foams are considered for stability analysis. A sharp decrease of the half-life time and volume of the CGAs at NaCl concentrations larger than 20,000 ppm was observed, which was attributed to the precipitation of SDS in the solution. The mentioned SDS precipitation altered the dynamic surface tension behavior, dilational surface elasticity, and turbidity of the solution. The main reason for the precipitation of SDS is the increased Krafft point caused by the addition of salt. However, for the zwitterionic surfactant CAPB, the effects of added NaCl on the interfacial properties required for CGAs production was negligible due to the simultaneous effects on the cationic and anionic head groups in the CAPB leading to negligible changes in the net repulsion forces. Yet, an overall reduction in the half-life time of CGAs with increasing salt concentration, even when we have no precipitation, was observed for both surfactants, which could be explained by the reduction in the ability of XG to increase the viscosity with increasing salt concentration.

Effect of heat-moisture treatment on the in vitro digestibility and physicochemical properties of starch-hydrocolloid complexes

The effect of heat-moisture treatment (HMT) on the in vitro digestibility and physicochemical properties of starch-hydrocolloid complexes of various structures was investigated, employing Gum Arabic, Xanthan Gum, and Guar Gum. HMT was performed at 120 °C for 4 h with a starch moisture content of 20%. HMT was shown to increase the slowly digestible starch content from 6.89% to 11.41%, and that of resistant starch from 7.02% to 18.04%. After blending with hydrocolloids, digestibility can be further reduced, with a Guar Gum-starch complex (1:40 ratio) showing the lowest rate of digestion. Scanning electron microscopy (SEM) and particle size analysis revealed that starch granules aggregated due to hydrogen bond interactions. Starch granules formed larger aggregates in the presence of Xanthan Gum or Guar Gum than Gum Arabic. SEM also demonstrated that the surface of starch granules became smoother after HMT. Rapid viscosity analysis and differential scanning calorimetry revealed that HMT significantly reduced the peak viscosity and setback of starch and significantly delayed gelatinization onset, peak, and conclusion temperatures. Finally, X-ray diffraction revealed that the A-type crystal form of the complexes was unaltered, but the relative crystallinity decreased. Overall, this study provides useful information for the development of healthful, low-GI, functional foods.

Rheological Properties of Methane Hydrate Slurry in the Presence of Xanthan Gum

Summary Methane hydrate formation in a xanthan-gum (XG) solution is an important problem for drilling in a deepwater environment. It not only alters the rheology of the drilling fluid in the wellbore but increases the risks of a hydrate blockage in the blowout preventer. The current work is performing groups of experiments to investigate the rheology of the hydrate slurry under XG concentrations of 0.15, 0.2, 0.25, and 0.3%, shear rates from 10 to 480 s−1, and hydrate concentrations from 1.01 to 9.12%. The experimental results show that the hydrate slurry with XG additives exhibits an obvious shear-thinning behavior, which is because the XG solution has strong pseudoplastic characteristics, and the inner structures of the flocculated hydrate particles suspended in the hydrate slurry are broken up during the hydrate-slurry flow. The increase of hydrate concentrations in the hydrate slurry can reduce the non-Newtonian fluid index and make the rheology of the hydrate slurry become more shear-thinning. However, as the XG concentration increases in the hydrate slurry, the influence of the hydrate concentration on the rheology of the hydrate slurry gradually weakens. Empirical Herschel–Bulkley-type equations are developed to describe the rheology of the hydrate slurry with XG for the current experimental condition, considering the shear rate, hydrate concentration, and XG concentration. In the proposed equations, the non-Newtonian factor and the consistency factor are expressed as functions of XG concentration empirically. Correction Notice:The preprint version of this paper was modified from its original version to correct Figs. 8 and 9 and Eqs. 6 through 9 on page 7. Errata explaining the corrections are included below as Supporting Information.

The Influence of Xanthan Gum on Rheological Properties and In Vitro Digestibility of Kudzu (Pueraria lobata) Starch

AbstractThe study describes the effects of xanthan gum (0.5–2.0%) on the in vitro digestibility and rheological and pasting properties of kudzu (Pueraria lobata) starch pastes. The flow behavior index (n) shows a decrease in trends (from 0.43 to 0.31) as the xanthan gum concentration increases, indicating pseudoplastic behavior. Dynamic viscoelasticity analysis indicate that the elastic (G′) and viscous (G″) moduli increase in the presence of xanthan gum, suggesting a strong interaction between xanthan gum and kudzu starch in the composite system. All concentrations of xanthan gum result in increased elasticity (G′ &gt; G″). Pasting properties reveal that the peak and final viscosity of the xanthan gum–kudzu starch dispersion decreases with the increasing concentration of xanthan gum, highlighting the importance of xanthan gum in controlling overall viscosity. The addition of xanthan gum also decreases the hydrolysis of kudzu starch during in vitro digestion.

Influence of xanthan gum on the short- and long-term retrogradation of potato starches of various amylose content

Effect of the 0.05 and 0.20% (w/w) admixture of xanthan gum (XG) upon short and long-term retrogradation of 4, 5 and 6% potato starch gels was studied in relation to the amylose/amylopectin ratio in the starches. Recorded mechanical spectra, gel texture, syneresis, resistant starch content and x-ray patterns of the normal and waxy potato starch gels revealed that XG promoted the formation of a three-dimensional gel network independently on the amylose/amylopectin ratio. It meant that XG favored the short-term retrogradation after samples preparation. Simultaneously, the presence of XG in admixture with potato starch hindered and promoted long-term retrogradation of the gels of normal and waxy starch gels, respectively.

Biomimetic mineralisation of calcium carbonate using xanthan gum as morphology control agent

Biomimetic synthesis of calcium carbonate (CaCO 3 ) with various sizes and morphologies using organic matrix has become an interesting hotspot. CaCO 3 was synthesised by the reaction of Na 2 CO 3 and CaCl 2 in the presence of xanthan gum (XG). The results showed that the fresh mineralised CaCO 3 /XG were microspheres with large surface area and porosity. The original CaCO 3 /XG microspheres transformed to brick-like CaCO 3 after ageing 7 days at 4°C. During the morphology transformation, CaCO 3 spheres rearranged by attaching to XG molecular, and transformed from a macroscopic view of CaCO 3 microspheres to a hexahedral structure related with the XG uncoiled single chains re-associating into loose several-fold helix. The study demonstrated that environmental effect coupled XG could be one feasible approach to regulate the structure of CaCO 3 .

Effect of Hydrophobic and Hydrophilic Metal Oxide Nanoparticles on the Performance of Xanthan Gum Solutions for Heavy Oil Recovery.

Recent studies revealed higher polymer flooding performance upon adding metal oxide nanoparticles (NPs) to acrylamide-based polymers during heavy oil recovery. The current study considers the effect of TiO2, Al2O3, in-situ prepared Fe(OH)3 and surface-modified SiO2 NPs on the performance of xanthan gum (XG) solutions to enhance heavy oil recovery. Surface modification of the SiO2 NPs was achieved by chemical grafting with 3-(methacryloyloxy)propyl]trimethoxysilane (MPS) and octyltriethoxysilane (OTES). The nanopolymer sols were characterized by their rheological properties and ζ-potential measurements. The efficiency of the nanopolymer sols in displacing oil was assessed using a linear sand-pack at 25 °C and two salinities (0.3 wt % and 1.0 wt % NaCl). The ζ-potential measurements showed that the NP dispersions in deionized (DI) water are unstable, but their colloidal stability improved in presence of XG. The addition of unmodified and modified SiO2 NPs increased the viscosity of the XG solution at all salinities. However, the high XG adsorption onto the surface of Fe(OH)3, Al2O3, and TiO2 NPs reduced the viscosity of the XG solution. Also, the NPs increased the cumulative oil recovery between 3% and 9%, and between 1% and 5% at 0 wt % and 0.3 wt % NaCl, respectively. At 1.0 wt % NaCl, the NPs reduced oil recovery by XG solution between 5% and 12%, except for Fe(OH)3 and TiO2 NPs. These NPs increased the oil recovery between 2% and 3% by virtue of reduced polymer adsorption caused by the alkalinity of the Fe(OH)3 and TiO2 nanopolymer sols.

Biopolymer-Based Minimal Formulations Boost Viability and Metabolic Functionality of Probiotics Lactobacillus rhamnosus GG through Gastrointestinal Passage.

The delivery of probiotic microorganisms as food additives via oral administration is a straightforward strategy to improve the intestinal microbiota. To protect probiotics from the harsh environments in the stomach and small intestine, it is necessary to formulate them in biocompatible carriers, which finally release them in the ileum and colon without losing their viability and functions. Despite major progresses in various polymer-based formulations, many of them are highly heterogeneous and too large in size and hence often "felt" by the tongue. In this study, we established a new formulation for probiotics Lactobacillus rhamnosus GG (LGG) and systematically correlated the physicochemical properties of formulations with the functions of probiotics after the delivery to different gastrointestinal compartments. By reducing the stirring speed by 1 order of magnitude during the emulsification of polyalginate in the presence of xanthan gum, we fabricated microparticles with a size well below the limit of human oral sensory systems. To improve the chemical stability, we deposited chitosan and polyalginate layers on particle surfaces and found that the deposition of a 20 nm-thick layer is already sufficient to perfectly sustain the viability of all LGG. Compared to free LGG, the colony-forming units of LGG in these formulations were by factors of 107 larger in stomach fluid and 104 larger in small intestine fluid. The metabolic functionality of LGG in polymer formulations was assessed by measuring the amount of lactate produced by LGG in a human gastrointestinal simulator, showing 5 orders of magnitude larger values compared to free LGG. The obtained results have demonstrated that the minimal formulation of LGG established here boosts not only the viability but also the metabolic functionality of probiotics throughout oral uptake, passage through the gastrointestinal tract, and delivery to the ileum and colon.

On turbulence decay of a shear-thinning fluid

An experimental investigation of turbulent flow in a shear-thinning fluid is presented. The experimental flow is a boundary-free, uniformly sheared flow at a relatively high Reynolds number (i.e., Reλmax=275), which decays in time. As just one example of decaying turbulence, the experiment can be thought of as a simple model of bulk turbulence in large arteries. The dimensionless parameters used are Reynolds, Strouhal, and Womersley numbers, which have been adapted according to the characteristics of the present experiment. The working fluid is a solution of aqueous 35 ppm xanthan gum, a well-known shear-thinning fluid. The velocity fields are acquired via time-resolved particle image velocimetry in the streamwise/cross-stream and streamwise/spanwise planes. The results show that the presence of xanthan gum not only modifies the turbulent kinetic energy and the dissipation rate but also significantly alters the characteristics of the large-scale eddies.

Drag reduction behavior of hydrolyzed polyacrylamide/polysaccharide mixed polymer solutions—effect of solution salinity and polymer concentration

Anionic polyacrylamide is a hydrolyzed form of polyacrylamide (HPAM), which suffers from mechanical degradation at turbulent flow rates. In order to investigate the possibility of improving the shear resistance of HPAM, various polyacrylamide/polysaccharide mixtures as well as single xanthan gum (XG) and guar gum (GG) polymer solutions were prepared and drag reduction (DR) measurements were performed in a closed flow loop. It was found that the DR efficiencies of both XG and GG solutions were directly proportional to polymer concentration and both solutions exhibited excellent mechanical resistance at turbulent conditions. The presence of XG in concentrated HPAM/XG solutions (C > 450 wppm) significantly improved both DR efficiency and shear resistance of the solutions (6–8% decline after shearing for 2 h). GG solutions exhibited smaller DR efficiencies than XG solutions. Due to small molar mass and low flexibility, GG was not as good a friction reducer as XG and HPAM; therefore, the presence of GG did not improve the DR behavior of the binary solutions. Another issue associated with HPAM is sensitivity to the presence of salt ions in the solution. The effect of salt on the DR behavior was verified by addition of 2% KCl to single and binary solutions. Drag reduction efficiencies of HPAM/XG/KCl solutions were 28 and 20% compared to 10% DR of 1000 wppm HPAM/KCl solution. It was found that the presence of XG in binary solutions significantly reduced the negative effect of salt ions on HPAM molecules.

Sol-gel derived xanthan gum/silica nanocomposite—a highly efficient cationic dyes adsorbent in aqueous system

A sol-gel synthesis of nanocomposite adsorbent materials by dehydroxylation condensation of tetraethoxysilane (TEOS) in the presence of xanthan gum (XG) using base catalyst and ethanol as co-solvent is discussed. The synthesized nanocomposite material was evaluated for their ability to adsorb cationic dyes—methylene blue (MB) and bismarck brown Y (BB) from an aqueous solution. The XG/SiO2 nanocomposite shows the ordered macro- and meso-porous structures and also exhibited large surface area, excellent chemical/mechanical stability and high binding capability for MB and BB dyes. Different parameters such as pH, adsorbent dose and initial concentration were studied. The adsorption behaviour of the nanocomposite was investigated by performing both kinetics and equilibrium studies under batch conditions. The maximum adsorption capacity (Qmax) of the nanocomposite for MB and BB was found to be significantly high (432.90mgg−1 and 448.43mgg−1, respectively). The time taken for the removal of 99.4% of MB and 87.2% of BB from 100mgL−1 of dye solutions is only 35min. Thus, the proposed XG/SiO2 nanocomposite is a very promising adsorbent for the fast and efficient removal of dye from aqueous solutions.

Influence of xanthan, guar, CMC and gum acacia on functional properties of water chestnut (Trapa bispinosa) starch

This study was performed to determine the effect of xanthan, guar, CMC and gum acacia on functional and pasting properties of starch isolated from water chestnut (Trapa bispinosa). Morphological properties of water chestnut starch with CMC were studied by scanning electron microscopy (SEM). The addition of hydrocolloids significantly enhanced the solubility of water chestnut starch (WCS) while reduced swelling power and freeze–thaw stability. The hydrophilic tendency of WCS was increased by xanthan gum; however, with addition of gum acacia it decreased significantly. Starch was modified with guar and gum acacia exhibited highest% syneresis. Guar gum was found to be effective in increasing the clarity of water chestnut starch paste. The addition of CMC significantly reduced the pasting temperature of WCS indicating ease of gelatinization. The setback was accelerated in the presence of xanthan gum but gum acacia delayed this effect during the cooling of the starch paste. Only xanthan gum was found to be effective in increasing breakdown showing good paste stability of WCS.

Rheological Differences of Waxy Barley Flour Dispersions Mixed with Various Gums.

Rheological properties of waxy barley flour (WBF) dispersions mixed with various gums (carboxyl methyl celluleose, guar gum, gum arabic, konjac gum, locust bean gum, tara gum, and xanthan gum) at different gum concentrations were examined in steady and dynamic shear. WBF-gum mixture samples showed a clear trend of shear-thinning behavior and had a non-Newtonian nature with yield stress. Rheological tests indicated that the flow and dynamic rheological parameter (apparent viscosity, consistency index, yield stress, storage modulus, and loss modulus) values of WBF dispersions mixed with gums, except for gum arabic, were significantly higher than those of WBF with no gum, and also increased with an increase in gum concentration. In particular, konjac gum at 0.6% among other gums showed the highest rheological parameter values. Tan δ values of WBF-xanthan gum mixtures were lower than those of other gums, showing that there is a more pronounced synergistic effect on the elastic properties of WBF in the presence of xanthan gum. Such synergistic effect was hypothesized by considering thermodynamic compatibility between xanthan gum and WBF. These rheological results suggest that in the WBF-gum mixture systems, the addition of gums modified the flow and viscoelastic properties of WBF, and that these modifications were dependent on the type of gum and gum concentration.