Viscosity of guar gum and xanthan/guar gum mixture solutions

The viscosity of diluted guar gum solutions and the viscosity of xanthan and guar gum mixture solutions have been studied. Guar gum solutions showed pseudoplastic behaviour. Apparent viscosity increased with gum concentration and decreased with the temperature at which viscosity was measured. A maximum in the plot of viscosity versus increasing dissolution temperature was observed at 60 °C. This behaviour was related to differences in molecular structure of the polymers solved at different temperatures. Mixtures of xanthan and guar gum showed a higher combined viscosity than that occurring in each separate gum. This synergistic interaction was affected by the gum ratio in the mixture and dissolution temperature of both gums. The effect of polysaccharide concentration (1.0, 1.5 and 2.0 kg m⁻³), xanthan/guar gum ratio (1/5, 4/2, 3/3, 4/2 and 5/1) and dissolution temperature (25, 40, 60 and 80 °C for both gums) on the viscosity of solutions of mixtures were studied. The highest viscosities were observed when 2.0 kg m⁻³ gum concentration was used together with a ratio of xanthan/guar gum of 3/3 (w/w) and dissolution temperature of 40 and 80 °C for xanthan and guar gum, respectively. © 2000 Society of Chemical Industry     

Rheological interactions between Lallemantia royleana seed extract and selected food hydrocolloids

BACKGROUND: Lallemantia royleana (Balangu) is a mucilaginous endemic plant which is grown in different regions of world. The flow behaviour of Balangu seed extract (BSE) and its mixture with xanthan, guar and locust bean gums at 1:3, 1:1 and 3:1 ratios, in addition to control samples (0% BSE), were evaluated. To describe the rheological properties of samples, the power law model was fitted on apparent viscosity–shear rate data. To evaluate the interaction between BSE and selected hydrocolloids in dilute solutions, the relative viscosity was also investigated. RESULTS: There was no significant difference between the consistency coefficient of guar and locust bean solutions and their blends substituted with 250 g kg^?1 BSE. The BSE–xanthan mixture at 1:3 and 1:1 ratios had consistency index equal to xanthan solution. BSE–locust bean gum at all ratios, BSE–xanthan at 1:3 ratio and BSE–guar gum at 1:1 and 3:1 ratios indicated relative viscosity lower than values calculated assuming no interaction. The intrinsic viscosity value of BSE was determined 3.50 dL g^?1. CONCLUSION: The apparent viscosities of BSE, selected hydrocolloids and their blends were the same at a shear rate of 293 s^?1 and the commercial gums can be substituted by 250 g kg^?1 and 500 g kg^?1 BSE. Copyright © 2011 Society of Chemical Industry     

Study of emulsions stabilized with Phaseolus vulgaris or Phaseolus coccineus with the addition of Arabic gum, locust bean gum and xanthan gum

The properties of o/w emulsions stabilized with 1%w/v common bean (Phaseolus vulgaris L.), V or scarlet runner bean (P. coccineus L.), Coc extracted by isoelectric precipitation or ultrafiltration, at pH 7.0 and 5.5, with the addition of Arabic gum, locust bean gum, xanthan gum and a mixture of xanthan gum–locust bean gum (0.1 %w/v and 0.25 %w/v) are studied. The stability of emulsions was evaluated on the basis of oil droplet size, creaming, viscosity and protein adsorption measurements. The addition of Arabic gum, caused an increase in D[4,3] values and a decrease in the amount of protein adsorbed at the interface. The addition of locust bean gum in some emulsions reduced the amount of protein adsorbed. The addition of xanthan and to a less extend of the polysaccharide mixture, promoted a decrease in D[4,3]. So, emulsion stability was affected by the polysaccharide nature. Differences were also observed with respect to the protein nature, the method of its preparation and emulsion's pH. All polysaccharides enhanced the emulsions viscosity with xanthan and xanthan–locust bean gum exhibiting the higher values. V isolates and isoelectricaly precipitated isolates of both V, Coc showed higher viscosity values. The stability was enhanced by the increase of the viscosity of the continuous phase and the creation of a network, which prevents the oil droplets from coalescence.     

刺槐豆胶与黄原胶复配体系的流变性

研究刺槐豆胶/黄原胶复配体系的流变性,并采用流变学的Cross模型进行拟合分析。结果表明:刺槐豆胶与黄原胶复配可以产生协同作用,当刺槐豆胶与黄原胶的复配体积比为4∶6时,复配体系的黏度最大,触变测试中形成的滞后环面积最大,并且在黏弹性测试中储能模量G’表现出最大值。因此,刺槐豆胶与黄原胶的最佳复配比例为体积比4∶6。对最佳比例复配体系进行不同温度处理后测试可知,最佳复配体系的最适处理温度为80℃,得到的复配体系黏度最大;复配体系的p H值在6.0~10.0之间时,其黏度变化较小,保持相对稳定。     

黄原胶与其它食品胶协同增效作用 及其耐盐稳定性的研究

以黄原胶、羟丙基淀粉、ＣＭＣ－Ｎａ、瓜尔豆胶、刺槐豆胶、魔芋精粉等为主要研究对象,系统地研究了黄原胶与其它食品胶２种或３种之间的协同增效作用及其耐盐稳定性。研究结果表明：黄原胶与羟丙基淀粉、ＣＭＣ－Ｎａ复配无协同增效作用,黄原胶与刺槐豆胶、魔芋精粉、瓜尔豆胶有良好的协同增效作用,两者或三者按适当比例配合后,耐盐稳定性显著提高,用量比任一单一胶少,而且使用成本大幅度降低,因此复配食品胶在高盐食品中使用具有明显的优越性和广阔的应用前景。     

黄原胶与其它食品胶协同增效作用及其耐盐稳定性的研究

以黄原胶、羟丙基淀粉、ＣＭＣ－Ｎａ、瓜尔豆胶、刺槐豆胶、魔芋精粉等为主要研究对象,系统地研究了黄原胶与其它食品胶２种或３种之间的协同增效作用及其耐盐稳定性。研究结果表明：黄原胶与羟丙基淀粉、ＣＭＣ－Ｎａ复配无协同增效作用,黄原胶与刺槐豆胶、魔芋精粉、瓜尔豆胶有良好的协同增效作用,两者或三者按适当比例配合后,耐盐稳定性显著提高,用量比任一单一胶少,而且使用成本大幅度降低,因此复配食品胶在高盐食品中使用具有明显的优越性和广阔的应用前景。     

Rheology and modelling of aqueous gum solutions commonly used in the food industry

Rheological properties of solutions prepared using xanthan (XG), locust bean (LBG) or sodium carboxymethyl cellulose (CMC) gums, and their binary mixtures were studied. The influence of shear rate, total gum content, measurement time and temperature on the apparent viscosity was investigated. In the binary mixtures, the presence of different gum ratios at several total gum content was also analysed. XG solutions were always the most stable, providing high viscosity values which rose notably with increasing gum content. XG/LBG and CMC/XG mixtures depicted high values of viscosity for very low gum amounts. Viscosity did not change with measurement time in mixtures containing XG, whereas varied with measurement temperature. This variation was lower for samples with larger total gum content. The viscosity was also modified when different gum ratios were tested. A mathematical model was proposed to evaluate the combined effect of temperature, concentration and shear rate on the apparent viscosity.     

黄原胶与几种胶复配对花生乳稳定性的影响

研究了黄原胶分别与刺槐豆胶、瓜尔豆胶、魔芋胶复配对花生乳稳定性的影响,通过分析样品沉淀率、油脂析出率、粘度及高温稳定性观察,结果表明,黄原胶与瓜尔豆胶复配时花生乳稳定性最好,最佳复配比例为黄原胶:瓜尔豆胶=1:2,最佳复配用量为0.05 %.     

The viscosity of dilute solutions of guar gum and locust bean gum with and without added sugars

The apparent viscosities of dilute solutions of guar and locust bean gums have been measured. The intrinsic viscosity [n] of guar gum solution is greater than that of locust bean gum solution, but the interaction coefficient k of guar gum solutions is less than that of locust bean gum. Addition of glucose, sucrose, or glucose syrup increases the apparent viscosity of the gum solution. The intrinsic viscosity of the gum solution is decreased but the interaction coefficient is increased.     

Effects of gelatinisation level, gum and transglutaminase on the quality characteristics of rice noodle

The aim of the present study was to investigate the effects of gelatinisation level, gum (locust bean gum, xanthan gum, 3%) and/or transglutaminase (TG, 0.5%) on quality characteristics of rice noodle. In order to improve the dough forming ability, rice flour was gelatinised at levels of 15%, 20%, 25% and 30%. Noodle samples were evaluated in terms of cooking loss, total organic matter (TOM), water absorption, swelling volume, maximum force, colour, sensory properties, pasting properties. Noodle sample with a gelatinisation level of 25% had better cooking and sensory properties. Gum and/or TG were added to this noodle formula. The noodle samples including xanthan gum had better cooking and sensory properties. TG caused a significant decrease in TOM. The samples including locust bean gum had significantly higher maximum force values. Xanthan gum caused decreases in some Rapid ViscoAnalyzer viscosity values of the noodle samples, while locust bean gum caused increases.     

Comparison of the effects of gums on dynamic rheological properties of acetylated sweet potato starch

Dynamic rheological properties of acetylated sweet potato starch (ASPS) pastes mixed with 3 commercial gums (guar gum, locust bean gum, and xanthan gum) were investigated at different gum concentrations. The dynamic moduli of the ASPS-gum mixtures were higher than those of the control, and they increased with an increase in gum concentration. In particular, the G′ value of xanthan and G″ value of guar gum at a 0.6% gum concentration were much higher as compared to those of other mixtures. Tan δ values of ASPS-xanthan mixtures were much lower than those of other samples, indicating that the elastic properties in the ASPS-gum mixture systems were strongly affected by the additions of xanthan. These results suggest that the presence of gums in ASPS modifies the viscoelastic properties, and that these modifications are dependent on the gum type and gum concentration.     

Effect of Gums on Low-Fat Meat Batters

The effects of adding Iota-carrageenan, kappa-carrageenan, guar gum, locust bean gum, xanthan gum, methylcellulose, and a locust bean gum/kappa carrageenan mixture to low-fat, high moisture meat batters were investigated. The methylcellulose treatment showed an increase in weight losses between 60° and 70°C, while other treatments remained similar throughout heating. Xanthan gum and guar gum at 0.2% altered textural parameters as determined by texture profile analysis. Increasing the concentration of xanthan gum decreased batter hardness without affecting batter stability. Sensory evaluation indicated that low-fat frankfurters (11–12% fat) were as acceptable as control frankfurters (27% fat).     

黄原胶的特性、生产及应用进展

黄原胶是Xanthomnas.sp分泌的胞外水溶性多糖,由于其有突出的高粘性和水溶性、独特的流变特性、优良的温度稳定性和pH稳定性、极好的兼容性以及安全环保等特性,已被广泛于石油开采、食品工业、纺织和化妆品等诸多行业。主要综述了黄原胶的分子结构、分子特性、生产以及应用的研究进展。     

Thermally stable hydrogels from enzymatically oxidized polysaccharides

Polysaccharides guar galactomannan (guar gum), locust bean galactomannan (locust bean gum) and tamarind galactoxyloglucan were selectively oxidized by galactose oxidase. The degrees of oxidation of the products were 18-28% for guar galactomannan, 10-16% for locust bean galactomannan and 12-14% for tamarind galactoxyloglucan, calculated from the ratio of oxidized galactose units and total carbohydrates. The rheological properties of the unoxidized and oxidized polysaccharide solutions were investigated by determining their viscosities, storage and loss moduli, and temperature dependence of moduli from 20 °C to 90 °C. All the studied oxidized polysaccharides formed hydrogels throughout the entire temperature range. Concentration (0.2-1% w/v) and degree of oxidation had an effect on the gel formation. The oxidized galactomannans formed stable gels already in low concentrations, such as 0.2-0.4% w/v, while oxidized galactoxyloglucan required a concentration of 0.8% w/v to be stable up to 90 °C. The oxidized polysaccharide hydrogels are highly potential materials for food and medical applications requiring thermal stability.     

Rheological behaviour of pullulanase-treated guar galactomannan on co-gelation with xanthan

The present study involves the use of non-specific enzyme pullulanase (from Bacillus acidopullulyticus) to remove galactose residues from guar galactomannan to obtain modified guar galactomannan mimicking the functional properties of locust bean gum. The modified guar galactomannan blended with xanthan exhibited the rheological behaviour of elastic modulus (G′) greater than viscous modulus (G″) with a decrease in tan δ value similar to locust bean gum/xanthan blend. Also a twofold increase in the magnitude of elasticity compared to xanthan alone suggested the synergistic interaction with formation of three dimensional networks. The modified guar galactomannan with galactose content of 21% and M:G ratio 1:3.8, almost akin to locust bean gum, showed a better interaction with xanthan. Dynamic stress sweep study of modified guar galactomannan/xanthan blend with increased yield stress of 800 dynes/cm² also indicated the synergistic behaviour. Modified guar galactomannan also revealed the maximum synergistic interaction with xanthan at a mixing temperature of 60 °C than at 20 °C, 30 °C, 40 °C and 50 °C, respectively. Modification of guar galactomannan by pullulanase is an alternative route to produce galactose-depleted guar galactomannan with enhanced rheological functionalities on co-gelation with xanthan, as a cost effective replacement to locust bean gum.     

Relationship between sensory saltiness intensity and added oil in low-viscosity and high-viscosity polymer solutions

Generally, the foods we usually eat are not only aqueous solutions, but also viscous solutions and solids. Therefore, it is interesting for us to explore how taste components are perceived in a viscous polymer solution. The relationship between the sensory evaluation of saltiness intensity, amount of added oil, and apparent viscosity was clarified in low-viscosity and high-viscosity polymer solutions. The study was conducted using samples containing corn oil, sodium chloride, and [xanthan gum] or [xanthan gum + locust bean gum] as a thickener. Oil was added to the viscous polymer solutions regardless of whether they were low- or high-viscosity, and saltiness intensity was evaluated as compared with a reference solution. The low-viscous polymer solutions with [xanthan gum] were perceived to be saltier than the high-viscous polymer solutions with [xanthan gum + LBG] as the amount of oil increased. The shear stress value gradually increased as the amount of oil increased in both the low-viscosity and the high-viscosity polymer solutions, as derived from the fluid constitutive equation. There was a correlation between saltiness intensity and apparent viscosity in both high- and low-viscosity polymer solutions. A coefficient of determination (R²) of 0.918 was obtained between saltiness intensity and “apparent viscosity” for the samples using [xanthan gum] and that of 0.683 between saltiness intensity and “apparent viscosity” for the samples using [xanthan gum+LBG]. The low-viscosity polymer solutions showed a saltier intensity as the amount of oil increased and a greater correlation with apparent viscosity, as compared with the high-viscosity polymer solutions.     

Dielectric and Thermal Properties of Rice Cake Formulations Containing Different Gums Types

In this study, dielectric properties of rice cake formulations containing different gum types (xanthan, guar, locust bean, HPMC, and kappa-carrageenan) were determined at temperatures between 25 and 90°C at 2450 MHz. Moreover, thermal properties of these formulations were determined by using differential scanning calorimeter (DSC). Dielectric properties of cake batters were found to be dependent on cake formulation. Xanthan and guar gum containing cake batters had the highest dielectric constant and loss factor values at 25°C. Temperature dependence of dielectric properties was not significant until temperature of 85°C. Gelatinization enthalpy of batter increased with the addition of gums.     

Conformational Role of Xanthan in its Interaction with Locust Bean Gum

ABSTRACT: Texture analysis and Ubbelohde capillary viscometry were used to investigate the effects of chain conformational changes of xanthan or deacetylated xanthan on its interaction with locust bean gum (LBG). The stability of xanthan helical structure or xanthan chain flexibility played a critical role in interacting with LBG. Destabilization of xanthan helical structure by deacetylation and heating facilitated the intermolecular binding between xanthan and LBG. Xanthan conformational change was noted in the presence of LBG, even when its helical structure was stabilized by salt. However, this conformational change was not observed for deacetylated xanthan, presuming deacetylated xanthan was in the exact conformation to bind LBG.     

盐及非盐物质对常用低浓度食品胶溶液粘度影响的研究

对饮料生产中常用的食品胶－黄原胶、海藻酸钠、瓜尔胶和琼脂在低浓度水相体系中外加盐（阴、阳离子）、乙醇、蔗糖及柠檬酸对溶液粘度的影响作了探讨性研究,结果表明四种胶溶液（０．１０％黄原胶、０．３０％海藻酸钠、０．２５％瓜尔胶、０．１０％琼脂）中、瓜尔胶溶液对盐的耐受性最好,即大多数阴阳离子都不会对其粘度产生影响,而常用金属盐阳离子及Ｃｌ＾－、ＳＯ３＾２－对黄原胶溶液粘度的影响与阴阳离子对海藻酸钠和琼脂     

Optimization of Gum Combination in Prebiotic Instant Hot Chocolate Beverage Model System in Terms of Rheological Aspect: Mixture Design Approach

Mixture design was used to investigate the effects of four different gums (xanthan gum, guar gum, alginate and locust bean gum) and their combinations on the rheological properties of a prebiotic model instant hot chocolate beverage (including 3.5% inulin) and to determine their interactions in the model beverage. Simplex centroid mixture design was applied to predict the physicochemical (soluble solids, pH, colour properties) and rheological parameters (consistency index (K), flow behaviour index (n) and apparent viscosity (η ₅₀)) of the samples. In the model, the optimum gum combination was found by simplex centroid mixture design as 59% xanthan gum and 41% locust bean gum, and the highest K value was 33.56 Pa s ⁿ . The increase of guar gum and alginate in the gum mixture caused a decrease in the K value of the sample.