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Wastewaters, as the major waste stream of the wine industry, are usually disposed in crude form due to the lack of sustainable treatments, which poses rising environmental threat. Considering biodegradability, nutrients content and other specific characteristics, winery wastewaters are suitable for utilization in xanthan production. In this study, the screening of local wild-type Xanthomonas euvesicatoria strains, isolated from pepper leaves, for xanthan production on medium containing wastewaters from rose wine industry, with initial sugar content of 25 g/L, was performed. Bioprocess success was estimated based on the quantity and quality of separated biopolymer. Additionally, composition of collected wastewaters was determined, and the obtained data indicate the importance of their proper management. The results of screening experiments suggest that applied X. euvesicatoria isolates have a statistically significant effect on xanthan concentration in cultivation medium, its molecular weight, as well as on apparent viscosity of xanthan aqueous solution. According to the obtained results, xanthan concentration varied from 4.0 g/L to 10.0 g/L, while the values of average molecular weight of xanthan and apparent viscosity of its solution ranged from 2.5 ∙ 105 g/mol to 8.5 ∙ 105 g/mol and from 40 mPa ∙ s to 60 mPa ∙ s, respectively. The results from this study suggest that X. euvesicatoria PL2 isolate showed the greatest potential for xanthan production on medium containing wastewaters from rose wine industry because of determined quantity of good-quality biopolymer. Further research is necessary in order to improve proposed bioprocess as sustainable biotechnological solution for winery wastewaters utilization. [ABSTRACT FROM AUTHOR]

This study examines five benzyl alcohol derivatives and three chemically similar compounds and compares them against benzyl alcohol in gelled emulsions for the removal of overpaint during cleaning of oil paintings. Comparative cleaning tests using xanthan gels, Pemulen® TR-2 gels, and neat solvent were made on overpaint on fragments of a seventeenth-century test painting. This approach demonstrated that molecular changes to a benzyl alcohol core resulted in enhanced control during the cleaning process. In some cases a benzyl alcohol derivative enabled selective removal of non-original material, when benzyl alcohol appeared to affect the original paint. Select derivatives were also tested in an area of overpaint on a sixteenth-century oil on panel painting by Jan van Scorel in the Rijksmuseum Collection through modifying the chemical activity of benzyl alcohol. Finally, two GC-MS-based methods were used to monitor benzyl alcohol retention and possible oxidation in paint layers post-treatment. [ABSTRACT FROM AUTHOR]

The antifungal agent, ketoconazole, and the anti-inflammatory drug, piroxicam, were incorporated into matrices of xanthan or oleic acid-esterified xanthan (Xn) and polyurethane (PU), to develop topical drug delivery systems. Compared to matrices without bioactive compounds, which only showed a nominal compressive stress of 32.18 kPa (sample xanthan–polyurethane) at a strain of 71.26%, the compressive resilience of the biomaterials increased to nearly 50.04 kPa (sample xanthan–polyurethane–ketoconazole) at a strain of 71.34%. The compressive strength decreased to around 30.67 kPa upon encapsulating a second drug within the xanthan–polyurethane framework (sample xanthan–polyurethane–piroxicam/ketoconazole), while the peak sustainable strain increased to 87.21%. The Weibull model provided the most suitable fit for the drug release kinetics. Unlike the materials based on xanthan–polyurethane, those made with oleic acid-esterified xanthan–polyurethane released the active ingredients more slowly (the release rate constant showed lower values). All the materials demonstrated antimicrobial effectiveness. Furthermore, a higher volume of piroxicam was released from oleic acid-esterified xanthan–polyurethane–piroxicam (64%) as compared to xanthan–polyurethane–piroxicam (44%). Considering these results, materials that include polyurethane and either modified or unmodified xanthan showed promise as topical drug delivery systems for releasing piroxicam and ketoconazole. [ABSTRACT FROM AUTHOR]

This study delves into the properties and behavior of xanthan TNCS-ST, a specialized variant designed for enhanced oil recovery (EOR) purposes. A notable aspect of this polymer is its transparency and capability to dissolve in high salt concentrations, notably up to 18% total dissolved solids. Various laboratory methods are employed to assess the polymer's distinctive traits, including transparency, salt tolerance, and high pyruvylation. These methods encompass preparing xanthan solutions, conducting filtration tests, assessing energy consumption, and measuring rheological properties. The findings highlight the influence of salt concentration on xanthan's filterability, indicating increased energy requirements for dissolution with higher salt and xanthan concentrations. Additionally, this study observes temperature-dependent viscosity behavior in different solutions and evaluates the shear stability of xanthan. A significant and novel characteristic of TNCS-ST is its high salt tolerance, enabling complete dissolution at elevated salt concentrations, thus facilitating the filterability of the xanthan solution with sufficient time and energy input. Core flooding experiments investigate fluid dynamics within porous rock formations, particularly sandstone and carbonate rocks, while varying salinity. The results underscore the substantial potential of the new xanthan polymer, demonstrating its ability to enhance oil recovery in sandstone and carbonate rock formations significantly. Remarkably, the study achieves a noteworthy 67% incremental recovery in carbonate rock under the high salinity level tested, suggesting promising prospects for advancing enhanced oil recovery applications. [ABSTRACT FROM AUTHOR]

The extracellular heteropolysaccharide xanthan, synthesized by bacteria of the genus Xanthomonas, is widely used as a thickening and stabilizing agent across the food, cosmetic, and pharmaceutical sectors. Expanding the scope of its application, current efforts target the use of xanthan to develop innovative functional materials and products, such as edible films, eco-friendly oil surfactants, and biocompatible composites for tissue engineering. Xanthan-derived oligosaccharides are useful as nutritional supplements and plant defense elicitors. Development and processing of such new functional materials and products often necessitate tuning of xanthan properties through targeted structural modification. This task can be effectively carried out with the help of xanthan-specific enzymes. However, the complex molecular structure and intricate conformational behavior of xanthan create problems with its enzymatic hydrolysis or modification. This review summarizes and analyzes data concerning xanthan-degrading enzymes originating from microorganisms and microbial consortia, with a particular focus on the dependence of enzymatic activity on the structure and conformation of xanthan. Through a comparative study of xanthan-degrading pathways found within various bacterial classes, different microbial enzyme systems for xanthan utilization have been identified. The characterization of these new enzymes opens new perspectives for modifying xanthan structure and developing innovative xanthan-based applications. Key points: • The structure and conformation of xanthan affect enzymatic degradation. • Microorganisms use diverse multienzyme systems for xanthan degradation. • Xanthan-specific enzymes can be used to develop xanthan variants for novel applications. [ABSTRACT FROM AUTHOR]

The primary aim was to observe the effect of processing type and compositional change on the antioxidant activity of the aqueous phase of O/W nano-emulsions during freeze-drying microencapsulation. So, olive oil-in-bitter orange juice nano-emulsions (O/W) were microencapsulated by freeze-drying with chia gum and xanthan gum. Physical (microstructure, droplet size, particle size distribution) and chemical (total antioxidant activity, total phenolic content, and structural characterization; FTIR spectroscopy) properties of different processed nano-emulsions were investigated. Solely freeze-drying of Tween80/Span20, Tween80/SMP, and Tween80/SL nano-emulsions caused a 39%, 13%, and 19% decrease in antioxidant activity accompanied by 65%, 52%, and 64% decrease in phenolic content, respectively. Microencapsulation with xanthan gum increased antioxidant activity of Tween80/Span20, Tween80/SMP, and Tween80/SL nano-emulsions by 17%, 47%, and 120% accompanied by a 5.8, 7.2, and 5.9 times rise in phenolic content, respectively. Microencapsulation with chia gum produced a 7.5, 7.13, and 9.3 times increase in antioxidant activity along with a 9.3, 12.4, and 10.1 times rise in phenolic content of Tween80/Span20, Tween80/SMP, and Tween80/SL nano-emulsions, respectively. Freeze-drying microencapsulation with chia gum and xanthan gum can be an effective method for increasing the antioxidant activity of the aqueous phase of O/W nano-emulsions. [ABSTRACT FROM AUTHOR]

The extracellular heteropolysaccharide xanthan, synthesized by bacteria of the genus Xanthomonas, is widely used as a thickening and stabilizing agent across the food, cosmetic, and pharmaceutical sectors. Expanding the scope of its application, current efforts target the use of xanthan to develop innovative functional materials and products, such as edible films, eco-friendly oil surfactants, and biocompatible composites for tissue engineering. Xanthan-derived oligosaccharides are useful as nutritional supplements and plant defense elicitors. Development and processing of such new functional materials and products often necessitate tuning of xanthan properties through targeted structural modification. This task can be effectively carried out with the help of xanthan-specific enzymes. However, the complex molecular structure and intricate conformational behavior of xanthan create problems with its enzymatic hydrolysis or modification. This review summarizes and analyzes data concerning xanthan-degrading enzymes originating from microorganisms and microbial consortia, with a particular focus on the dependence of enzymatic activity on the structure and conformation of xanthan. Through a comparative study of xanthan-degrading pathways found within various bacterial classes, different microbial enzyme systems for xanthan utilization have been identified. The characterization of these new enzymes opens new perspectives for modifying xanthan structure and developing innovative xanthan-based applications. Key points: • The structure and conformation of xanthan affect enzymatic degradation. • Microorganisms use diverse multienzyme systems for xanthan degradation. • Xanthan-specific enzymes can be used to develop xanthan variants for novel applications. [ABSTRACT FROM AUTHOR]

A framework was developed to evaluate and compare cleaning systems and cleaning system delivery methods, collectively referred to as varnish removal methods, within art conservation practice. This framework was applied to two water-based cleaning systems, optimised for the removal of dammar varnish from an artificially aged brown earth oil paint, including the surfactant-containing microemulsion, Polar Coating B (from the Nanorestore Cleaning series) delivered via the chemical gel, Higher Water Retention (HWR) (from the Nanorestore Gel Dry series), and a surfactant-free microemulsion delivered via the microfiber cloth, Evolon. In addition, two water-based systems and one organic solvent were used to remove dammar varnish from an artificially aged lead white oil paint sample, including a xanthan gum-stabilised emulsion delivered via a synthetic brush, a surfactant-free microemulsion delivered via cotton swab rolling, and 2-propanol solvent delivered via cotton swab rolling. The evaluation framework was thus applied to two different oil paints, with different sensitivities to cleaning. Through this work, the comparative advantages and disadvantages of the varnish removal methods were demonstrated. Notably, cleaning system compatibility with multiple delivery methods afforded greater versatility, including for reducing unwanted interactions between the cleaning system and oil paint. In addition, a surfactant-free microemulsion proved to be a promising, clearance-free, inexpensive, and modifiable option within current offerings for largely water-based methods for varnish removal. [ABSTRACT FROM AUTHOR]

Photodynamic therapy using delta-aminolevulinic acid is considered a promising option in the treatment of oral lichen planus. In the present work, three emulgel compositions prepared from natural polysaccharide gums, tragacanth, xanthan and gellan, were preliminarily tested for oromucosal delivery of delta-aminolevulinic acid. Apart from cytotoxicity studies in two gingival cell lines, the precise goal was to investigate whether the presence of the drug altered the rheological and mucoadhesive behavior of applied gelling agents and to examine how dilution with saliva fluid influenced the retention of the designed emulgels by oromucosal tissue. Ex vivo mucoadhesive studies revealed that a combination of xanthan and gellan gum enhanced carrier retention by buccal tissue even upon dilution with the saliva. In turn, the incorporation of delta-aminolevulinic acid favored interactions with mucosal tissue, particularly formulations comprised of tragacanth. The designed preparations had no significant impact on the cell viability after a 24 h incubation in the tested concentration range. Cytotoxicity studies demonstrated that tragacanth-based and gellan/xanthan-based emulgels might exert a protective effect on the metabolic activity of human gingival fibroblasts and keratinocytes. Overall, the presented data show the potential of designed emulgels as oromucosal platforms for delta-aminolevulinic acid delivery. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) recently has been shown as a promising option in the treatment of premalignant lesions of the soft oral tissues. Effective delivery of photosensitizer is challenging due to poor drug adherence to the oromucosal epithelium. In the present work, emulgels composed of natural polysaccharide gums (tragacanth, xanthan and gellan) were evaluated as novel oromucosal platforms of delta-aminolevulinic acid (ALA) for PDT. Apart from mucoadhesive and textural analysis, the specific steps involved studies on drug penetration behavior and safety profile using a three-dimensional human oral epithelium model (HOE). All designed emulgels presented greater mucoadhesiveness when compared to commercial oromucosal gel. Incorporation of ALA affected textural properties of emulgels, and tragacanth/xanthan formulation with greater hardness and cohesiveness exhibited a protective function against the mechanical tongue stress. Permeability studies revealed that ALA is capable of penetrating across oromucosal epithelium by passive transport and all formulations promoted its absorption rate when compared to a commercial topical product with ALA. Importantly, the combination of tragacanth and xanthan profoundly enhanced photosensitizer retention in the buccal epithelium. Tested samples performed negligible reduction in cell viability and moderately low IL-1β release, confirming their non-irritancy and compatibility with HOE. Overall, the presented findings indicate that tragacanth/xanthan emulgel holds promise as an oromucosal ALA-carrier for PDT strategy. [ABSTRACT FROM AUTHOR]

Recently, degradable biopolymers have become increasingly important as potential environmentally friendly biomaterials, providing a wide range of applications in various fields. Bacterial exopolysaccharides (EPSs) are biomacromolecules, which due to their unique properties have found applications in biomedicine, foodstuff, textiles, cosmetics, petroleum, pharmaceuticals, nanoelectronics, and environmental remediation. One of the important commercial polysaccharides produced on an industrial scale is xanthan. In recent years, the range of its application has expanded significantly. Bacterial cellulose (BC) is another unique EPS with a rapidly increasing range of applications. Due to the great prospects for their practical application, the development of their highly efficient production remains an important task. The present review summarizes the strategies for the cost-effective production of such important biomacromolecules as xanthan and BC and demonstrates for the first time common approaches to their efficient production and to obtaining new functional materials for a wide range of applications, including wound healing, drug delivery, tissue engineering, environmental remediation, nanoelectronics, and 3D bioprinting. In the end, we discuss present limitations of xanthan and BC production and the line of future research. [ABSTRACT FROM AUTHOR]

This study aims to produce fat‐reduced cream cheese using the different levels (0.25%–0.5%) of basil seed and xanthan gum by a RSM method. The basil seed, xanthan gum, and fat levels did not significantly influence the cream cheese's pH and acidity. With the fat reduction, textural properties were lost; for example, hardness, gumminess, and adhesiveness increased, and cohesiveness decreased. In addition, low‐fat cream cheese's sensory score (taste, mouthfeel, and overall acceptance score) was lower. However, adding basil seed and xanthan gum could improve water holding capacity (WHC), hardness, gumminess, cohesiveness, adhesiveness and scores of mouthfeel, and overall acceptance. Basil seed gum had a better impact than xanthan on fat‐reduced cream cheese properties among the two gums. In general, results showed that adding 0.5% basil and 0.5% xanthan into cream cheese could manufacture a product with a reduced‐fat level (19.04%). At the same time, its physicochemical, sensory, and textural attributes were similar to cream cheese with high fat (24%). In addition, the price of the obtained product was lower. [ABSTRACT FROM AUTHOR]

Xanthan is an extracellular heteropolysaccharide produced by the bacteria Xanthomonas campestris. Due to its unique properties, the polysaccharide and its derivatives are widely used in many industries, from food to biomedicine and oil production, that demands an efficient xanthan depolymerization method to adapt this polysaccharide for various applications. Unlike the known chemical approaches, biological methods are considered to be more environmentally friendly and less energy intensive. In laboratory conditions, we have isolated a bacterial community capable of reducing the xanthan viscosity. Identification of the individual isolates in the microbial community and their testing resulted in the consortium LE-C1, consisting of two microorganisms Paenibacillus phytohabitans KG5 and Cellulosimicrobium cellulans KG3. The specific activities of the overall xanthanase and auxiliary enzymes that may be involved in the xanthan depolymerization were as follows: xanthanase, 19.6 ± 0.6 U/g; β-glucosidase, 3.4 ± 0.1 U/g; α-mannosidase, 68.0 ± 2.0 U/g; β-mannosidase, 0.40 ± 0.01 U/g; endo-glucanase, 4.0 ± 0.1 U/g; and xanthan lyase, 2.20 ± 0.07 U/mg. In order to increase the efficiency of xanthan biodegradation, the LE-C1 whole cells were immobilized in a poly(vinyl alcohol) cryogel. The resulting regenerative biocatalyst was able to complete xanthan depolymerization within 40 cycles without loss of activity or degradation of the matrix. [ABSTRACT FROM AUTHOR]

This investigation was carried out to study the effect of three types of gums namely: Arabic gum (AG), guar gum (GG) and xanthan gum (XG) as well as different water amounts on the physical, sensory, and textural properties of glutenfree pan bread (GFPB). The gluten-free composite flour as base formulation consists of 47.5g rice flour, 47.5g cornstarch, and 5g skim milk powder. Firstly, AG, GG and XG were tested, separately, with constant concentration (2g) and at three different amounts of water (90, 100, and 110 ml). The results indicated that the use of XG significantly increase the specific volume, High/Width ratio and yield of GFPB whereas the baking loss decrease with increasing of water amount used. However, these parameters were diminished in the case of AG and GG by using high amount of water (110 ml). The texture profile analysis (TPA) data indicated that hardness and cohesiveness decreased, while springiness and resilience increased with increasing the water amount. Secondly, three different concentrations 2, 3 and 4g of each gum, separately, were tested with a constant amount of water (110 ml). The obtained results showed that the increase of AG or GG concentration led to enhancement of GFPB specific volume. In contrast, the increase of XG from 2 to 4g with the water amount of 110 ml caused decrease in the specific volume. The TPA data showed that higher doses of gum tended to produce breads with higher hardness, gumminess, chewiness and lower springiness. Moreover, the increasing in water amount resulted in softer, spongier and more resilient crumbs. Good physical, textural and sensory acceptable was obtained with formulation supplemented with 2g XG and 110 ml water. [ABSTRACT FROM AUTHOR]

Heparin (Hep), with its anticoagulant activity, antiangiogenic and apoptotic effects, and growth factor binding, plays an important role in various biological processes. Formulations as drug delivery systems protect its biological activity, and limit the potential side effects of faulty administration. The objective of this study was to develop novel xanthan-based materials as a delivery carrier for heparin. The materials exhibited remarkable elastic behavior and toughness without any crack development within the network, which also support their application for tissue engineering. It was found that all materials possessed the ability to control the release of heparin, according to the Korsmeyer–Peppas release model. All Hep-containing materials caused significant exchanges of the activated partial thromboplastin time (aPTT) and prothrombin time (PT) parameters, indicating that formulated natural/natural synthetic polymeric networks conserved heparin's biological activity and its ability to interrupt the blood coagulation cascade. The obtained results confirmed that developed materials could be carriers for the controlled release of heparin, with potential applications in topical administration. [ABSTRACT FROM AUTHOR]

To date, due to the low accessibility of enzymes to xanthan substrates, the enzymolysis of xanthan remains deficient, which hinders the industrial production of functional oligoxanthan. To enhance the enzymatic affinity against xanthan, the essential role of two carbohydrate binding modules—MiCBMx and PspCBM84, respectively, derived from Microbacterium sp. XT11 and Paenibacillus sp. 62047—in catalytic properties of endotype xanthanase MiXen were investigated for the first time. Basic characterizations and kinetic parameters of different recombinants revealed that, compared with MiCBMx, PspCBM84 dramatically increased the thermostability of endotype xanthanase, and endowed the enzyme with higher substrate affinity and catalytic efficiency. Notably, the activity of endotype xanthanase was increased by 16 times after being fused with PspCBM84. In addition, the presence of both CBMs obviously enabled endotype xanthanase to produce more oligoxanthan, and xanthan digests prepared by MiXen-CBM84 showed better antioxidant activity due to the higher content of active oligosaccharides. The results of this work lay a foundation for the rational design of endotype xanthanase and the industrial production of oligoxanthan in the future. [ABSTRACT FROM AUTHOR]

The increase in the need for starch in the food processing industry has led to the recognition of the effect of other food compounds on the processing of starch-based foods. Xanthan and sugar are commonly used as hydrocolloids and sweeteners, respectively, in starch-based foods. These constituents can affect the structural, thermal, adhesive (dough) and rheological properties of these types of foods. The purpose of this study is to analyze the effect of sucrose and xanthan on the physicochemical, rheological and morphological characteristics of starch pastes. In addition, the comparison of the effect of the combination of xanthan and sucrose on corn and wheat starch pastes has been done in this study. In this research, the concentration of xanthan was 1% by weight and sucrose was 5% by weight, and the mixtures were prepared based on starch (corn or wheat starch). The results showed that in the presence and absence of xanthan 1% by weight and sucrose 5% by weight, the starch dough had a significant difference in terms of solubility, swelling power, water absorption, and dough transparency (p < 0.05). Rheological tests revealed that all pastes exhibited shear thinning behavior. By adding xanthan and sucrose, the apparent viscosity, storage modulus and loss modulus of starch pastes increased. Fourier transform infrared spectra showed the change in the intensity and wavelength of absorption peaks due to the addition of xanthan and sucrose. The measurements of scanning electron microscope and X-ray diffraction proved that as a result of adding xanthan and sucrose during gelatinization, changes were made in the network structure. The results of this study can improve processing and find optimal processing conditions to produce food based on Starch like baby food, bread, sweets, etc. help. [ABSTRACT FROM AUTHOR]

This study developed an innovative fish burger using Atlantic bonito, an abundant but undervalued species rich in lipids and protein. The burger was enriched with chickpea, seaweed (Spirulina and Fucus vesiculosus), and hydrocolloids (xanthan and carrageenan). Using a Taguchi design, the effects of varying concentrations of these ingredients on the physicochemical properties, texture, phenolic content, and antioxidant activity (DPPH, ABTS) were evaluated. The optimal formulation (2 g/100 g Spirulina, 3 g/100 g Fucus vesiculosus , 0 g/100 g xanthan, 4 g/100 g carrageenan) increased fiber by 1.5 times, protein by 2.8 times, antioxidant activity (ABTS) by 1.2 times, and phenolic content by 3.4 times compared to the control. Seaweed concentration was linked to increased burger hardness, while cohesiveness, adhesiveness, and gumminess were unaffected by hydrocolloid concentration. No significant changes were observed in moisture content or DPPH antioxidant activity. The study demonstrates the potential of using undervalued fish species like Atlantic bonito to create nutritionally enhanced, sustainable food products. • Atlantic bonito (Sarda) is an abundant but undervalued fish species. • Assessing the bonito burger enriched with chickpea, seaweed, and hydrocolloids. • Hydrocolloids, such as xanthan and carrageenan, were evaluated. • Spirulina, Fucus, and hydrocolloids improved nutritional and functional properties. • Consumers preferred burgers containing seaweed. [ABSTRACT FROM AUTHOR]

• Experiments are presented detailing particle migration in inertial Taylor–Couette flow of complex fluids. • Particles are observed to migrate oppositely within Taylor vortices with inelastic and elastic fluids. • A weaker elastic fluid shows a transition between an initial migration to the center of the Taylor vortices, switching to migration to the perimeter of the vortices as rotation rate is increased. • A preliminary numerical Euler-Euler calculation using a White–Metzner constitutive model captures the migration. A drilling process comprises a drill-pipe rotating within a borehole where fluid is pumped down the pipe and returns, with drilled cuttings, along the annulus. Predominantly the axis of the system is horizontal. Thus, in the absence of axial flow the process geometry is that of a Taylor–Couette flow. Formulated drilling fluids themselves are usually regarded as Bingham or Hershel-Bulkley in nature, but nevertheless encompass elastic behaviour. We have thus studied the distribution of dense (i.e. sedimenting) non-Brownian solid particles in Taylor–Couette flow of model drilling fluids as a function of center body rotation speed. In all cases Taylor vortices are formed above some critical, fluid dependent, Taylor number. However, depending on the fluid properties, particles decorate the vortices differently: particles in a polymeric fluid move to the centroids of the vortices, whereas in a colloidal fluid they move to the outer periphery of the vortices, as previously observed for Newtonian fluids. With a mixed fluid, a clear transition between the two regimes is found. We postulate that this behaviour is a result of a balance between elastically derived lift forces and inertially driven Saffman lift forces acting antagonistically on the particles. [ABSTRACT FROM AUTHOR]

The inefficient decomposition of polysaccharides, particularly branched polysaccharides limits their large-scale industrial applications. Further understanding and modification of glycoside hydrolases (GHs) processivity is expected to overcome this limitation. Here, a novel xanthan-binding CBM (Mi XBM), which was supposed to alter the processivity of GHs, was systematically characterized. Phylogeny and structure analyses indicated that Mi XBM is closely related to putative polysaccharide side chain-binding modules. Quantitative binding assays further revealed that Mi XBM probably has a high affinity for xanthan side chain via a variable loop site. Moreover, catalytic performance demonstrated that xanthanase chimeras containing Mi XBM promote highly efficient hydrolysis of xanthan because of improved substrate accessibility. Notably, Mi XBM was observed to enhance the processivity of xanthanase, owing to its high substrate affinity to the repeating unit xanthan. Furthermore, sequential hydrolysis of xanthan by xanthanases with varying processivity resulted in significantly increased hydrolytic efficiency and focused oligoxanthans array. These results expand understanding of CBM-substrate recognition and shed light on efficient degradation of other regularly branched polysaccharides using modified GHs. [Display omitted] [ABSTRACT FROM AUTHOR]

Biopolymers like guar and xanthan gums are considered to be sustainable soil stabilisers that can improve engineering properties of earthen construction materials. Recent studies indicate that water-based soil washing has achieved partial success in recycling these materials. In this study, β-mannanase was used in the washing process for recycling. An engineered soil mixture was stabilised using these biopolymers and then recycled in two stages, initially with water and then with β-mannanase. The impact of recycling was ascertained in terms of particle size distribution and Atterberg limits. The recycled soil was subsequently used to produce earthen construction materials, and their mechanical performance was evaluated. Two recycling cycles were conducted to explore the potential of recycling after repeated cycles of biopolymer amendment. Using β-mannanase proved effective in recovering more original material than washing with water and notably more effective for guar gum. Mechanical tests indicated that the recycled material was suitable for earthen construction. [Display omitted] • The study uses β-mannanase to recycle guar and xanthan gum stabilised earthen construction materials. • Two cycles of recycling have been undertaken to compare between water-based and β-mannanase based washing. • β-mannanase has been more effective for guar than xanthan in retrieving original soil particles and plasticity. • Xanthan gum's regenerative capabilities revive mechanical properties after recycling ensuring its reuse. [ABSTRACT FROM AUTHOR]

Synergistic interaction gels (SIGs) hold immense promise for applications in 3D printing, colonic drug delivery, and sustained release. The amalgamation of xanthan and tamarind gum (TMG) gives rise to SIGs through molecular interaction; however, the intricacies of their assembly behaviors remain elusive. This work elucidates that in xanthan-rich systems, the predominant formation of xanthan aggregations shapes network assembly structure, with TMG clusters adhering to them. Conversely, in TMG-rich systems, TMG clusters actively participate in creating a "sea-island" assembly structure enveloped by xanthan aggregations. Higher concentration of TMG contributes to augmenting the association extent of TMG and xanthan. The heightened binding between TMG and xanthan correlates with an increase in chain distance in scatters and the compactness of scatter arrangement. These favor the development of micro-structures with a relatively larger mesh size and the enhancement of gel hardness. This study serves to facilitate the design and production of SIGs-based artificial gel foods with the requisite performance characteristics, such as artificial sea cucumber and porcine back fat. [Display omitted] • Xanthan aggregation shapes network structure in xanthan-rich system. • "Sea-island" structure is formed in tamarind gum (TMG)-rich system. • Higher TMG content increases association extent of xanthan and TMG. • Higher association extent causes higher gel hardness of TMG/xanthan SIGs. [ABSTRACT FROM AUTHOR]

Synergistic interaction gels (SIGs) have become attractive in food industry due to their ability to modify rheology features, realize safe swallowing and apply as fat simulants. Locust bean gum (LBG) and xanthan give rise to SIG, however, their assembly process remain elusive. This work demonstrated that, in xanthan-rich system, xanthan chains transformed into helical structure and aggregated into thick bundles upon cooling. Subsequently they bound with LBG clusters, constructing a xanthan-like 3D gel network. However, in LBG-rich system, LBG chains gradually dissociated from clusters and associated into helical structure during cooling ("dissociation-association" process), forming an LBG-like "sea-island" structure. With further cooling, LBG continued to undergo "dissociation-association" process, along with specifically binding by xanthan chains (helical structure or thick bundles), generating thick grid contour lines and larger sparse gel network. The enthalpy change values indicated that with the decrease of xanthan content, synergistic binding extent was increased and then decreased, reaching the maximum at LBG: xanthan ratio of 7:3. This was responsible for the increment of G ′, gel hardness, and capacity to accumulate energy for the weak shear-induced structure for LBG/xanthan SIGs. This study serves to facilitate the design and production of SIGs with the requisite performance characteristics. [Display omitted] • "3D" network structure was generated in xanthan-rich system. • Sparse network with larger grid was formed in LBG-rich system. • Ratio of 7:3 (LBG: xanthan) was a well-defined stoichiometry for synergistic bind. • Higher association extent caused higher gel strength of LBG/xanthan SIGs. [ABSTRACT FROM AUTHOR]

Background Mycophenolate mofetil as an immunosuppressive agent is widely administered in patients with kidney disorders and following organ transplantation. The amounts of xanthan gum and sorbitol, as two excipients of mycophenolate mofetil, are influential on the final quality and stability of the suspension. Objective In this experimental study, we aim to optimize the levels of xanthan gum and sorbitol in the Mycophenolate mofetil powder. Methods A Central composite design was used to prepare the formulations. The amounts of xanthan gum and sorbitol were considered as independent variables while the sedimentation volume (F value) and concentration of active pharmaceutical ingredient (API) after preparation and after 3 months of storage at 45 Cͦ were considered as dependent variables. The samples were prepared through wet granulation process. Chromatography analysis and determination of F value and API were then performed. Results Analysis of variance showed that the increase in the amounts of xanthan up to 75 mg provided higher F value and better protection of API after 3 months by 98%, while the increase of sorbitol from 10 to 25 g had no significant effect on these variables. Optimized sample composed of 16.69 g sorbitol and 68.81 mg xanthan gum. Predicted error was desirably less than 5%. Conclusion The proposed formulation of mycophenolate mofetil powder for oral suspension with optimum amounts of xanthan gum and sorbitol has good stability. High level of xanthan gum and moderate level of sorbitol are recommended for preparing an optimal product. [ABSTRACT FROM AUTHOR]

In this paper, a novel ionogel with semi-interpenetrating poly (ionic liquids)/xanthan gum (PIL/XG) polymer network (semi-IPN) was prepared by using a simple one-pot method. The structure and the pressure sensing performance have been systematically investigated. It was found that introducing a low content (0.3–3.1 wt%) of XG significantly promoted the mechanical performance of ionogels with little effect on the ionic conductivity. The optimized PIL/XG containing 2.2 wt% XG exhibited high compression strength (761.0 kPa) and ionic conductivity (0.63 S/m at 25 °C). Such ionogels showed a liner response (0–100 kPa) and high sensitivity value of 6.86 kPa−1 in a capacitive mode. Meanwhile, as a resistive sensor, PIL/XG exhibited a wide response range to dynamic pressure ranges with stable repeatability. Furthermore, this ionogel exhibited excellent bactericidal properties against both gram-positive bacteria and gram-negative bacteria. This research provides a potential approach for developing ionogels based on semi-IPN with pressure-sensitive and anti-bacterial properties. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, the effect of cultivation time on xanthan biosynthesis by different Xanthomonas campestris and Xanthomonas euvesicatoria strains, isolated from crucifers and pepper leaves, respectively, was examined. Xanthan was produced by submerged cultivation on crude glycerol-based medium at a laboratory level under aerobic conditions at 30 °C and 150 rpm for 168 h and 240 h. Bioprocess efficacy was estimated based on the xanthan concentration in media at the end of bioprocess and its average molecular weight. According to the obtained results, Xanthomonas strains have statistically significant effect on xanthan concentration in cultivation media when biosynthesis is performed by X. euvesicatoria strains, and cultivation time has significant effect on this parameter only when bioprocess is performed by X. campestris strains. The combination of Xanthomonas strains and cultivation time has a statistically significant effect on xanthan concentration in medium for both groups of isolates. The obtained results show that all applied Xanthomonas strains and cultivation time as well as their combination have statistically significant effect on average molecular weight of xanthan produced in applied experimental conditions. It is found that X. euvesicatoria strains produce higher amount of xanthan in a shorter period of time (168 h) when compared to the X. campestris strains. Xanthan of higher average molecular weight was produced when cultivation of both groups of isolates was performed for 240 h in applied experimental conditions. Results obtained in this research suggest that X. euvesicatoria strains have the greatest potential for application in biotechnological production of xanthan on crude glycerol-based medium. [ABSTRACT FROM AUTHOR]

The synergistic interaction gels of locust bean gum (LBG) /xanthan show great potential for application in the food industry, such as 3D printing and taste/texture simulation. Including 1, 2-propanediol (PDO) significantly promoted the gel-related properties of LBG/xanthan gels. The synergistic interaction between LBG and xanthan was enhanced with the presence of small amounts of PDO (≤ 20 %) due to the dehydration effect of PDO and the resulting promotion of the molecular association. As a result, this further improved the gel network and the gel strength (G ' value and gel hardness). However, more significant amounts of PDO (20 %–40 %) imposed adverse effects with the weakened gel structure and the reduced strength, which was related to the excessive hydration effect and the decreased association of LBG with xanthan. These findings favor the design and development of the synergistic interaction gels with the improved gel structure, gelling temperature, and mechanical strength. [Display omitted] • The presence of 1, 2-propanediol (PDO) postponed the phase transition of xanthan. • Small amounts of PDO enhanced the binding of locust bean gum (LBG) and xanthan. • Small amounts of PDO improved the microstructure and the strength of LBG/xanthan gels. • More significant amounts of PDO caused the excessive self-association of LBG. [ABSTRACT FROM AUTHOR]

Motivated by sustainability and environmental protection, great efforts have been paid towards water purification and attaining complete decolorization and detoxification of polluted water effluent. Textile effluent, the main participant in water pollution, is a complicated mixture of toxic pollutants which seriously impact human health and the entire ecosystem. Developing effective materials for potential removal of the water contaminants is urgent. Recently, cryogels have been applied in wastewater sectors due to their unique physiochemical attributes(e.g. high surface area, lightweight, porosity, swelling-deswelling, and high permeability). These features robustly affected the cryogel's performance, as adsorbent material, particularly in wastewater sectors. This review serves as a detailed reference to the cryogels derived from biopolymers and applied as adsorbents for the purification of textile drainage. We displayed an overview of: the existing contaminants in textile effluents (dyes and heavy metals), their sources, and toxicity; advantages and disadvantages of the most common treatment techniques (biodegradation, advanced chemical oxidation, membrane filtration, coagulation/flocculation, adsorption). A simple background about cryogels (definition, cryogelation technique, significant features as adsorbents, and the adsorption mechanisms) is also discussed. Finally, the bio-based cryogels dependent on biopolymers such as chitosan, xanthan, cellulose, PVA, and PVP, are fully discussed with evaluating their maximum adsorption capacity. [Display omitted] [ABSTRACT FROM AUTHOR]

Galactomannans are the main component of locust bean gum from the fruit of the carob tree, Ceratonia siliqua L. They are a reserve of polysaccharides, found in the translucent endosperm of the seeds. They are designated as the best gels with thickening capacity and are, therefore, widely used as a natural food additive (E410) in many food, pharmaceutical and cosmetic preparations. In this study, we aim to exploit this gelling property of carob galactomannans in the microencapsulation of lactic bacteria in order to protect them from the negative effects of simulated digestive conditions. Two beneficial bacteria are used: Lactobacillus rhamnosus LBRE-LSAS and Bifidobacterium animalis subsp. lactis Bb12. Their survival in the free state or encapsulated in pure carob galactomannan gel combined with xanthan, was determined after residence in simulated in vitro digestive conditions (gastric: pH 2, pepsin 3 g/l and intestinal: bile 0.3%: W/V, pH 6.5. The results obtained show that gel encapsulation of carob galactomannans combined with xanthan improves the survival of these two beneficial strains to simulated digestive hostilities. the loss under gastric conditions 36.79% (3.55 log CFU/mL) for the non-encapsulated cells and only 12% (1.2 log CFU/mL) for the encapsulated ones. However, galactomannans alone do not appear to be effective in keeping a minimum of 106 bacterial cells viable when confronted with the hostile conditions of the digestive tract where they will be called upon to exert their positive effect on health. [ABSTRACT FROM AUTHOR]

The influence of agave fructans (AF) (1–10%) and xanthan (from 0.03% to 0.25%) in combination with sodium caseinate (SC) at 1% on the rheological and physicochemical properties of aqueous phases and emulsions was evaluated. Steady‐state flow behavior, particle size distribution, and stability studies were used to characterize the systems. The aqueous systems displayed the shear‐thinning behavior characteristic of xanthan solutions; however, this behavior was modified by the presence of SC and AF due to interactions between AF–SC and AF–xanthan based on predominant hydrogen bonding because of the hydroxyl groups on AF. In emulsions, an increase in viscosity due to the effect of the AF concentration reflects a probable association of fructan aggregates on the surface of SC particles that reinforce the interfacial layer of SC, while xanthan contributes to an increase in the viscosity of the continuous phase, which effectively prevents coalescence and floc formation even at higher concentrations, despite the possible existence of a depletion flocculation effect attenuated by the interaction between AF–SC and AF–xanthan. Practical Application: These results can be of use, in an important way, in the design of stable functional emulsions in which there is an application for agave fructans recognized as dietary fiber, also considering their peculiar way of interacting with xanthan favoring its stabilizing functionality. [ABSTRACT FROM AUTHOR]

This study presents new drug delivery systems based on xanthan, unmodified or modified by esterification with oleic acid, and alginate for controlled release of bioactive substances with anti-inflammatory (piroxicam) and antifungal properties (ketoconazole). The mechanical properties of the developed drug carriers showed that their compressive strength was affected by the encapsulation of the bioactive principles. When ketoconazole was added into the xanthan/alginate matrix, an increment in the mechanical strength was recorded (66.68% compression). The release of the active principles from the materials was best described by the Korsmeyer-Peppas model, with non-Fickian or Fickian diffusion (the values of the exponent of release are between 0.29 and 0.75), depending on the composition of the polymeric matrix. The release rate constant presents smaller values for the materials based on chemically modified xanthan (between 0.89 and 20.11) as compared with materials based on the unmodified form (between 4.27 and 25.00). All materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The designed systems prove to have antimicrobial and anti-inflammatory activity. The findings make prone these biomaterials for the manufacture of transdermal drug delivery systems. [ABSTRACT FROM AUTHOR]

Phosphorus nutrition appears to be very important in the xanthan production, next to carbon and nitrogen. Various studies indicated that xanthan production is controlled by phosphorus concentration in cultivation medium and that phosphorus is generally added in the form of phosphate salts. This paper presents an analysis of the effect of various K2HPO4 concentrations (0-3.00 g/L) in waste glycerol-based medium on xanthan production using Xanthomonas strain PL 4 isolated from pepper leaves. The bioprocess success was assessed based on the values of xanthan concentration in media at the end of biosynthesis, average molecular weight of the polymer, degree of glycerol conversion into xanthan and degree of total phosphorus conversion. The obtained results show that the increase of K2HPO4 concentration in medium from 0 g/L to 2.50 g/L significantly contributes to the rise in xanthan amount and its molecular weight, while further increase of phosphorus source concentration has a statistically insignificant effect on the values of these parameters. The greatest bioprocess success is achieved when the concentration of K2HPO4 in medium was 2.50 g/L. Cultivation of producing strain on medium with optimal K2HPO4 concentration resulted in high production of xanthan (13.26±0.20 g/L) of good quality (3.38±0.14·105 g/moL) along with a relatively high degree of phosphorus conversion (73.62±0.02%). [ABSTRACT FROM AUTHOR]

The aim of this work was to examine relations between instrumental and sensory parameters in a texture modified food matrix, with and without saliva. Nine pureed carrot samples (eight thickened and a control) were developed with starch (0.4 and 0.8% wt/wt), xanthan (0.2 and 0.4% wt/wt) or starch–xanthan blends that met International Dysphagia Diet Standardisation Initiative (IDDSI) Level 4 guidelines using fork and spoon tests. Rheological and tribological tests were conducted on the food and simulated bolus prepared by adding fresh stimulated saliva to the food (1:5, saliva:food) to mimic oral processing. Perceived sensory properties were identified using a temporal dominance of sensations (TDS) test (n = 16) where panelists were given a list of nine attributes. The area under the curve was extracted from TDS curves for each attribute/sample and this was correlated with rheological (viscosity at 10 s−1, G′, G″, and tan δ at 1 Hz) and tribological (friction coefficient in three regimes) data. The viscosity of the control sample decreased after adding hydrocolloids (except Starch_0.8%) and with saliva incorporation. G′ and G″ either increased or were similar for xanthan and blends and decreased for starch‐thickened samples. Hydrocolloid addition increased friction for all samples and was higher with saliva addition. Sensory results showed that samples with starch were perceived as thick and grainy while xanthan was perceived as smooth and slippery. A greater number of sensory attributes correlated with viscoelastic parameters compared to friction coefficients. Correlations were highest with the saliva added samples, further highlighting the importance of including saliva during instrumental testing. [ABSTRACT FROM AUTHOR]

The present work is focused on developing new eco‐friendly materials based on xanthan gum (XG) and cobalt ferrite (CF) nanoparticles with adsorptive properties. CF powder was prepared by the co‐precipitation method. Esterification of XG was performed in order to improve its hydrophobic character, resulting in xanthan acrylate (XGAC). Thin films were prepared and characterized. The influence of pH and materials' composition on their water uptake capacity was investigated. Batch adsorption experiments were performed to evaluate the dye adsorption capacity of the materials. Materials comprising CF showed the highest values of dye removal percentage (up to 83%). The adsorption capacity of XGACCF for Methyl Blue (MB) was 65.56 mg g−1, while the same material retained 63.35 mg g−1 of Basic Fuchsine (BF) dye solution. Equilibrium adsorption data were well fitted to two (Langmuir and Dubinin–Radushkevich) isotherm models. The adsorption kinetics were analyzed by the pseudo‐first‐order model, pseudo‐second‐order model, and Elovich model. A spontaneous endothermic physisorption process was recorded for MB adsorption, while BF retention was evaluated as an exothermic process. [ABSTRACT FROM AUTHOR]

Nitrogen doping with carbon material substantially enhances the electrochemical properties in lithium and sodium batteries. However, direct treating at high temperature fails to create high nitrogen content, thus limiting the morphological as well as electrochemical performances. Herein, a hydrophilic material xanthan and acid‐treated melamine are doped by a dual process of hydrothermal and carbonization, enabling high nitrogen content (28%) carbon spheres. The highly defected nanosphere structures (ID/IG = 1.14) enable the high specific surface area of 388 m2 g−1, which facilitates a large number of lithium/sodium ions and gives rise to remarkable electrochemical performances. When applied as an anode, the nitrogen‐doped porous sphere xanthan (NPS‐XAN) delivers a superior discharge capacity of 390 mAh g−1 after 1000 cycles at a current density of 1 A g−1 for lithium anode and maintains a discharge capacity of 262 mAh g−1 after 2800 cycles at 1 A g−1 for sodium anode. This work signifies superior capacity anodes for Li/Na‐ion batteries and contributes to the long‐life cycling energy application. [ABSTRACT FROM AUTHOR]

The inclusion of double-walled carbon nanotubes in carboxymethyl xanthan-based hydrogels was developed in order to improve both mechanical and drug release (diclofenac) properties of these nanocomposites for potential application in the biomedical field. The synthesis of carboxymethyl xanthan was carried out by an esterification reaction between xanthan gum and monochloroacetic acid, and the grafting was confirmed by FTIR analysis. The obtained carboxymethyl derivatives exhibited higher hydrophilicity degrees of substitution compared to the native xanthan gum. The nanocomposites prepared using either raw or modified xanthan gum were characterized in terms of physical properties, and we evidenced both an increase in viscoelasticity by one order of magnitude and an improved distribution of the nanotubes within the hydrogel matrix in the case of the carboxymethyl xanthan. The trapping efficiency of diclofenac was improved by the addition of the nanotubes, reaching up to 74 wt %. While the nanotubes also allowed a slower release of the molecule. An in-vitro study was carried out to ensure that the CNTs grafted onto the modified CMX were not released during the diffusion of the active ingredient. [ABSTRACT FROM AUTHOR]

Background and objectives: Dairy Spreads are solid and spreadable food products that are merely made from milk or milk products containing 10 to 80% milk fat. Samanou is a traditional Iranian dessert prepared by cooking a mixture of wheat flour and green malt extract. This study aimed to assess the effect of adding xanthan gum (0, 0.5 and 1%) and chia seed flour (0, 0.5 and 1%) on physical stability, textural and rheological properties of dairy spread containing Samanou powder. Material and methods: In the present study, the frequency sweep rheological test was performed by a rheometer. During this test, first the linear viscoelastic range is determined and then in the frequency range of 0.1 to 100 Hz, the temperature of 10 °C and the constant strain of 1%, the rheological properties of the spread including storage modulus (G′), loss modulus (G′′) and loss tangent (G′′ /G′) were measured. Emulsion stability was measured using a centrifuge based on oil separation (g). Textural properties were performed by backward extrusion and spreadability tests with a texture analyzer to determine the firmness (N), cohesiveness (N), consistency (Ns), and spreadability (N) parameters. Results: The results showed that the effect of adding xanthan gum and chia seed flour on increasing the cohesiveness, consistency, firmness and reducing the spreadability of the produced spread was significant (P<0.05). Increasing the concentration of xanthan gum and chia seed flour to 1% increased the cohesiveness and firmness and reduced the spreadability of the produced spread compared to the control sample. The treatment containing 1% xanthan gum and 1% chia seed flour had the highest firmness and the least spreadability, respectively. Spreads containing xanthan gum were more consistent than spreads containing chia seed flour, so the highest and lowest consistency was in the treatment containing 1% xanthan gum without chia seed flour (67.53±12.66 N.s) and the treatment prepared from 1% Chia seeds flour without xanthan of (37.36±17.5 Ns), respectively. The lowest and highest cohesiveness were in the treatment containing 0.5% xanthan (-0.05±0.22 N) and the treatment containing 1% xanthan and 0.5% chia seed flour with a score of -0.31±0.39 N, respectively. Spreads containing xanthan gum and chia seed flour were more stable than the control sample. In this regard, the highest oil separation and the lowest physical stability (0.476±0.13 gr) were observed for control. In the frequency sweep test, 1% strain was determined as the best strain corresponding to the linear viscoelastic range (LVR). Also, the amount of G′, G′′ and G′′ /G′ decreased by a simultaneous increase in the concentration of xanthan gum and chia seed flour. Unlike xanthan gum, the presence of chia seed flour in the spread formulation increased the amount of G′ and G′′. However, the maximum amount of G′ and G′′, as a result of the highest elasticity, consistency and firmness was belonged to the treatment containing 0.5% xanthan gum and the treatment containing 1% xanthan gum + 0.5% chia seed flour had the lowest amount of G′ and G′′. Conclusion: Minimum concentrations of xanthan gum (0.5%) and chia seed flour (0.5%) improved the textural properties of dairy spreads containing Samanou powder. Increasing the concentration of chia seed flour, unlike xanthan gum, weakened the internal bonds and reduced the consistency of the product. The presence of xanthan gum compared to chia seed flour had a greater effect on preventing phase separation and increasing the stability of dairy spread containing Samanou powder. In all frequency ranges, the amount of storage modulus was greater than the drop modulus, and the spreads produced behaved like a gel viscoelastic solid. [ABSTRACT FROM AUTHOR]

Cake batter is a camplen emulsion of air babbles and oil droplets in which the egg plays a key role in foam formation, absorption of air molecules and volume in the cake. However, regular consumption of eggs due to high levels of cholesterol and saturated fatty acids, increases cardiovascular disease and can lead to allergies for some people. Barly aquafaba is a thick liquid obtained form cooking barly, which stabilizes the foam due to significant amounts of active compounds and proteins. The purpose of this study was to investigate the effect of different levels of barly aquafaba (0, 25, 50 and 100%) and xanthan gum (0, 0.25 and 0.5%) as an egg replacer on physical, chemical, rheological and organoleptic properties of oily cake. According to the obtained results, barly aquafaba had an acceptable foaming property due to high protein quality cake samples containing barly aquafaba upto 50% had similar characteristics to control cake samples. However, increasing the replacement of 75 and 100% of eggs with barly aguafaba led to a significant decrease (p<0.05) in physical. Chemical, rheological and sensory properties of eggless cake samples. 0.5% of xanthan gum resulted in improved sensory properties of eggless cake samples, increased moisture content and reduced firmness in the cake samples replaced with 50% barly aquafaba. The results showed that barly aquafaba can be used as a partial replacer for eggs up to 50% while maintaining the sensory, physical and rheological properties if the oily cake. [ABSTRACT FROM AUTHOR]

The aim of this study was to produce vanilla ice cream containing suitable emulsifier and favorable homogenition pressure. In present study, ice cream containing 0.5% of carboxymethyle cellulose and xanthan separately, fat at levels of 10 and 14%, and pressure of homogenization at two levels 140 and 180 bar were prepared and physicochemical, textural and sensory properties of each sample were measured. Data were analyzed by SPSS.The results obtained from physicochemical traits showed that A7 and A10 treatments had the highest pH. Dry matter of samples containing 14% fat was significantly higher than others. Samples containing Xanthan gum had lower volume comparisons with the control sample and samples containing carboxymethyle cellulose gum(p<0.05). The viscosity of the A6 sample was significantly higher than other treatments. The results of texture profile analyzer showed that samples of (A3), (A4), (A7) and (A8) have maximum hardness. Also, the adhesiveness of samples containing Xanthan gum was higher than those of carboxymethyl cellulose contents. The lowest cohesiveness and springiness were attributed to A8. The results of sensory evaluations showed that there was no significant difference in odor, taste and color of the samples. A8 treatment was introduced as superior treatment. [ABSTRACT FROM AUTHOR]

The effect of some hydrocolloids on the quality of common carp fish fingers were evaluated during frozen storage for six months. Sodium alginate (ALG), carrageenan (CGN), hydroxyl propyl methylcellulose (HPMC), xanthan gum (XG), and chitosan (CH) were used as additives (5g/kg) in common carp fish fingers, and the proximate composition and physical, chemical, microbiological, and sensory properties were evaluated at regular intervals in common carp fish fingers. The results showed that, the moisture, protein, lipid, and ash of minced common carp fish samples, raw common carp fish fingers, and pre-fried common carp fish fingers were 75.15, 18.55%, 4.01%, and 4.30; 71.80%, 17.75%, 2.56%, and 5.90%, and 66.29%, 17.30%, 5.95%, and 6.28%, respectively. The changes in chemical composition between fresh common carp fish, fish fingers, and pre-fried fish fingers were found significant (P< 0.05). The values of pH, total volatile basic nitrogen, trimethylamine, thibarbituric acid total bacterial count, psychrophilic bacteria, and yeast & molds counts increased significantly during the storage period, but the values were within the acceptable limits. Organoleptic evaluation revealed that, the different added hydrocolloids didn’t significantly affect the flavor of common carp fish fingers, while chitosan and carrageenan improved the taste, textures, and appearance of common carp fish fingers significantly in comparison to the control and other trails. In conclusion, different types of fish fingers were acceptable even at the end of the storage period; also, different hydrocolloids were effective in retaining the quality properties of treated fish fingers and showed better performance than the control. [ABSTRACT FROM AUTHOR]

Industrial processing of tomato includes its cutting and mincing, thermal treatments, and the addition of ingredients, which might induce changes in physicochemical properties of the final products. In this frame, the impact of texturing/thickening [xanthan gum (X) or potato fiber (F)] on the macroscopic, mesoscopic and molecular properties of tomato double concentrate (TDC) was investigated to determine if F can efficiently substitute X, in association with small solutes (sugar and salt) and thermal treatment (cold and hot). At a macroscopic level, multivariate statistics (MANOVA) underlined that color change (ΔE) was increased by X and F addition contrary to heating and the addition of salt and sugar. MANOVA revealed that texture was greatly enhanced through the use of F over X. 1H NMR molecular mobility changes were more controlled by texturing agents (F and X) than thermal treatment and small solutes. Particularly F increased the more rigid population indicating stronger interaction with water molecules resulting in shear-thinning flow. However, adding X contributed into the increase of the dynamic and mobile populations. Therefore, F can be a valid "clean label" substitute of X in modulating tomato products properties. [ABSTRACT FROM AUTHOR]

Nowadays, gums are used in cereal and flour products to replace gluten by optimizing physicochemical and rheological properties. In this study, with the aim of improving the rheological properties of the dough compared to the control sample, the effect of different concentrations of guar gum, xanthan and pectin gums (0.3, 0.6 and 0.9%) in terms of weight / weight percentage based on rice flour of Nemat and Neda cultivars was examined. Based on the results of the viscosity properties, the highest Peak viscosity is in Nemat and Neda cultivars with the addition of guar (0.9%) and the lowest Peak viscosity is in Nemat cultivar without adding gum or control sample. The results show that with increasing guar and increasing the concentration of added guar, the tendency to absorb water increases and the volumetric expansion of the dough will increase. The greatest effect on the rate of breakdown viscosity was observed in Nemat cultivar with the addition of xanthan gum and the highest rate of breakdown viscosity was observed in Neda cultivar with increasing guar (0.9%). Due to the decreasing trend on the rate of breakdown, we find that xanthan is not a suitable hydrocolloid to improve the rheological properties of rice flour paste of Nemat cultivar. The highest rate of setback viscosity was observed in both Nemat and Neda cultivars with an increase of 0.3% and the lowest rate was in the control sample. Comparison of the average of statistical data shows that the highest final viscosity in both Nemat and Neda cultivars with an increase in guar 0.9% and the lowest in the control sample. It can be concluded that increasing the gums used in this study increases the tendency of the final product or product to dry after cooling. [ABSTRACT FROM AUTHOR]

PAM is a good flocculant, and XG is a good tackifier. When the two solutions are mixed, the PAM/XG mixed solution has good viscosity and can be used as a foam stabilizer in foam drilling fluids, and it can also be used as a coupling agent for sand-fixation serous fluid. When metal cations enter the PAM/XG system, it will destroy the overall rheology and stability of the PAM/XG system. This article uses the DV3T-LV rheometer to test the rheology of different types of PAM (HPAM/CPAM/AMPAM/NPAM) and XG mixed solutions, and get the optimal test ratio. Then add various metal cations (Na+, K+, Ca2+, Mg2+) to the mixed solutions of HPAM/XG, CPAM/XG, AmPAM/XG, NPAM/XG respectively. We know divalent metal cations have greater impacts on the shear stress of the PAM/XG composite system, which is likely to cause its shear dilution. Finally, through mechanism analysis, it is concluded that it provides a good preliminary foundation for the research of foam drilling fluid and sand-fixation serous when the metal ion destroys the molecular structure of the PAM/XG composite system. [ABSTRACT FROM AUTHOR]

The creation of environmentally friendly polymeric materials able to decompose at the end of their service life under the environment, in particular, by replacing the original nonrenewable components with natural ones, is a promising way to decrease the impact of polymer wastes on the environment. The article examines the effect of natural components (castor and palm vegetable oils, xanthan exopolysaccharide), the mass fraction of which amounts to 70 wt.% on the structure, thermal and viscoelastic properties of water-based polyurethanes. The structure - properties relationship was confirmed by wide and small-angle X-rays scattering, DMA, TGA and DSC analysis. The presence of components of natural origin have been shown to affect the structure, viscoelastic behavior and thermal properties of studied polyurethanes. The data obtained made it possible to conclude the possibility of obtaining stable polyurethanes with an adjustable set of properties depending on the amount and nature of the renewable raw materials. [ABSTRACT FROM AUTHOR]

Edible coatings application to the food prior to drying by infrared system is another potential pretreatment to drying. Edible coatings are thin layers of an edible material applied to the surface of the food and creating a selective barrier to the gas transport. The aim of this study was to investigate the color and area changes of coated apricot slices with xanthan and balangu seeds gums during drying in the infrared system. In this study, apricot slices in cylinder form with a thickness of 0.5 cm were coated using xanthan and balangu seeds gum (concentration of 0.6%) and then placed in an infrared dryer and the effect of radiation power (150, 250 and 375 W) on the appearance characteristics were examined. To examine the color and area changes of the samples, samples image were taken continuously during drying time. Color indexes including brightness (L*), redness (a*), yellowness (b*) and color changes (ΔE) as well as changes in the samples area during drying time were calculated. The calculated L* index for the drying process of apricot samples showed that the coated samples were brighter in terms of brightness and the coated apricots with balangu seed gum had higher L* values. In terms of color change index (ΔE), coated apricots with balangu seed gum showed the lowest color changes during drying time and the average values of ΔE for the control sample, coated with xanthan gum and coated with balangu seed gum were equal to 21.30, 16.89 and 13.92, respectively. For modeling the color change index, the quadratic model had less error than the power model. The results showed that the coating with balangu seed gum maintained the appearance of the dried product and also the least area changes in the total drying time and at different irradiation powers were observed in these samples. [ABSTRACT FROM AUTHOR]

A new, highly efficient xanthan-producing strain, Xanthomonas campestris M 28, was obtained. It produces up to 28 g/L of the polysaccharide on a molasses medium, which is almost two times higher than the productivity of the NRRL B-1459 strain. Whole-genome sequencing of the strain was performed with the Illumina method and nanopore sequencing. The genome of X. campestris M 28 contained one chromosome of 5 102 828 nucleotides with an average G + C content of 65.03%. The structure and physicochemical and rheological properties of the obtained xanthan were studied. It was found that the addition of xanthan to the bentonite dispersion led to the formation of primary clay particles (70 nm) and aggregates of ~190 nm without the formation of a precipitate. This indicated the interaction of macromolecules with particles and aggregates with the formation of polymer-clay bridging structures. This ensures the stability of clay dispersions and makes it possible to achieve the required rheological properties of drilling fluids based on xanthan obtained in a molasses medium, thereby reducing its cost. [ABSTRACT FROM AUTHOR]

The objective of this study was to formulate hydrophilic matrices for a controlled delivery of Piroxicam using carboxymethyl xanthan gum derivatives (CMX). CMXs with various degrees of substitution (DS = 0.22, 1.70 and 2.85) were synthesized by an etherification reaction, and their characterization was realized by FT-IR spectroscopy, X-ray diffraction, and scanning electron microscopy. Different tablets were prepared using the direct compression method. The powder mixtures were characterized by the determination of their angle of repose, compressibility index and Hausner ratio, whereas weight uniformity, hardness, friability, drug content, and in-vitro drug dissolution were employed to test the tablets under simulated gastric and intestinal conditions. The obtained results indicated that the drug release rate increases with the CMX ratio. The matrices based on CMX2 (DS = 1.7) were found to be the best candidates in controlling the release profile, where the optimal formulation contains 40% of CMX2 (F9). The dissolution data showed that all matrices fit well with Korsmeyer–Peppas model, whereas the release kinetics of F9 followed non-Fickian type release. The highest mean dissolution time value was obtained for F9. Finally, these results revealed that CMXs are suitable excipients for the sustained release dosage forms for as long as 20 h. [ABSTRACT FROM AUTHOR]

• Semi-contineous production of X. campestris xanthan in biofilm reactor was studied. • SEM showed high immobilzation of cells on stainless-steel and polyethylen supports. • Xanthan recovery in the biofilm reactor with stainless-steel support was increased. • High elasticity of the xanthan produced using Xanthomonas campestris was observed. Semi-continuous production of xanthan gum using self-immobilized Xanthomonas campestris cells in biofilm reactors was studied. Fermentation was carried out using two different designs of biofilm reactor equipped with a) stainless-steel support (SSS) and b) polyethylene support (PES). Fermentation was performed in three cycles with refreshing the media at the beginning of each: cycle 1, 0−27 h; cycle 2, 27−54 h; and cycle 3, 54–78.5 h. Results showed that the glucose consumption and the pH reduction in the PES biofilm reactor was faster compared to the SSS biofilm reactor. Scanning electron microscopy showed that the SSS was capable to immobilize more cells during the growth of X. campestris. The maximum concentration of xanthan gum in the SSS biofilm reactor obtained after 27 h (3.47 ± 0.71 g/L), while the maximum concentration of xanthan in the PES biofilm reactor obtained after 78.5 h (3.21 ± 0.68 g/L). Thermal stability analysis of xanthan using differential scanning calorimetry showed the presence of two fractures attributed to dehydration and degradation of polymer. The thermogram represented both endothermal and exothermal behaviour of xanthan polymer. Furthermore, the functional groups and molecular structure of the xanthan produced in this study was evaluated using Fourier transform infrared spectrometry and also proton nuclear magnetic resonance. in addition, the surface tension of (0.2 %, w/v) xanthan gum solution was in a range of 52.16–56.5 mN/m. Rheological analysis of xanthan showed that the G′ values were higher than the G″ in all frequencies demonstrating a relatively high elasticity of the produced xanthan gum. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this article is to study the possibility of xanthan usage as a polymer additive in silicate-gel solutions when creation compositions for enhancing oil recovery. The dependence of the time of gel formation of the silicate-polymer compositions and the pH of the gel-forming solution from various concentrations of xanthan and polyacrylamide was analyzed. Research methods: Direct and reverse titration, potentiometric titration, pH-metry, determination of the dynamic viscosity on a rotational viscometer, axial compression method to determine the elastic modulus were used to determine the possibility of xanthan usage as a polymer additive instead of polyacrylamide. Results: Such investigations as determination the influence of polymer type and concentration on the elastic modulus and syneresis of compositions in the gel state have been performed to determine the possibility of xanthan usage as a polymer additive of gel-forming composition and influence of this polymer on the dynamic viscosity of gel-forming compositions, gel strength, stability in time, the possibility of gel destruction. Discussion: Xanthan investigation as an alternative polymer has shown the perspective of its usage in the oil recovery industry. The environmental friendliness of technologies developed with the use of xanthan, which is safe for the environment, does not lead to an irreversible change in the reservoir properties of the formation. The lower molecular weight of xanthan in comparison with synthetic polymers determines the improved filtration properties of xanthan solutions, especially in low permeability conditions, which also makes it possible to carry out deeper treatments of the formation. [ABSTRACT FROM AUTHOR]

The incorporation of aluminum anodes in metal-air galvanic cells is very interesting due to its intrinsic physico-chemical properties that include a high theoretical specific capacity (2.98 Ah g−1) compared to lithium (3.86 Ah g−1), low density, negative standard potential versus the standard hydrogen electrode (SHE), high abundance in the earth's crust, recyclability, and environmental friendliness. In this report, various hydrogels based on xanthan are described that were prepared at different pH values in order to produce solid electrolytes characterized by high ionic conductivity. These electrolytes have been characterized in aluminum-air galvanic cells using Pt/C based air cathodes. The performance of the cells was characterized by discharge tests performed at constant currents across the range from 3 to 6 mA/cm2. The ability of recharging the cells was evaluated by determining the electrolyte electrochemical window using cyclic voltammetry (CV) measurements. The ionic conductivity of the hydrogels was determined by electrochemical impedance spectroscopy (EIS). The results evidenced the superior performance of acidic hydrogels in terms of cell capacity and anodic efficiency, due to the capability of xanthan as self-corrosion inhibitor, but the rechargeability was hindered because of the current consuming hydrogen reduction. A larger electrochemical window was observed for neutral hydrogels, but with low cell voltage, and by alkaline electrolytes, but at the expense of the anodic efficiency. [ABSTRACT FROM AUTHOR]