• Geomechanics and Engineering
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• v.12 no.5
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• pp.785-801
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• 2017

Biopolymer treatment of geomaterials to develop sustainable geotechnical systems is an important step towards the reduction of global warming. The cutting edge technology of biopolymer treatment is not only environment friendly but also has widespread application. This paper presents the strength and slake durability characteristics of biopolymer-treated sand sampled from Al-Sharqia Desert in Oman. The specimens were prepared by mixing sand at various proportions by weight of xanthan gum biopolymer. To make a comparison with conventional methods of ground improvement, cement treated sand specimens were also prepared. To demonstrate the effects of wetting and drying, standard slake durability tests were also conducted on the specimens. According to the results of strength tests, xanthan gum treatment increased the unconfined strength of sand, similar to the strengthening effect of mixing cement in sand. The slake durability test results indicated that the resistance of biopolymer-treated sand to disintegration upon interaction with water is stronger than that of cement treated sand. The percentage of xanthan gum to treat sand is proposed as 2-3% for optimal performance in terms of strength and durability. SEM analysis of biopolymer-treated sand specimens also confirms that the sand particles are linked through the biopolymer, which has increased shear resistance and durability. Results of this study imply xanthan gum biopolymer treatment as an eco-friendly technique to improve the mechanical properties of desert sand. However, the strengthening effect due to the biopolymer treatment of sand can be weakened upon interaction with water.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.363-368
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• 2013

The main attributes of yogurt that affect consumer satisfaction are taste, consistency, and a firm texture. This study evaluates the influence of xanthan gum, barley beta-glucan, and guar gum in concentrations of 0.05%, 0.1%, 0.2%, and 0.3% on probiotic yogurt. The set-type yogurt samples were prepared by using raw cow's milk. The statistical analysis showed that none of these gum additions had any marked effect on pH, titratable acidity, total solids content, and probiotic bacteria counts of yogurt samples. Evaluations for syneresis and water-holding capacity (WHC) in the yogurt samples were affected by the type and concentration of the stabilizer. Yogurts treated with 0.1% xanthan gum and 0.3% beta-glucan recorded the highest WHC and the least syneresis. The largest amount of gel firmness was recorded in yogurt samples treated with 0.2% xanthan gum and 0.3% beta-glucan. Yogurt samples treated with 0.1% xanthan gum and 0.3% beta-glucan were considered acceptable by trained panelists and gained the highest scores in sensory evaluations. The correlation coefficient between the amount of syneresis, WHC and stiffness of texture was significant compared to scores for sensory evaluation (p<0.01). Results for effects of guar gum on the tested parameters were contrary to the results expected from a gum. According to this study, the use of xanthan gum and beta-glucan are highly recommended for low-fat yogurt production.

• Transactions of Materials Processing
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• v.21 no.2
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• pp.138-143
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• 2012

A polishing method using magnetorheological (MR) fluid has been developed as a new precision technique to obtain a fine surface. The process uses a MR fluid that consists of magnetic carbonyl iron (CI) particles, nonmagnetic polishing abrasives, water and stabilizers. But the CI particles in MR fluids cause a severe corrosion problem. When coated with Xanthan gum, the CI particles showed long-term stability in corrosive aqueous environment. The surface roughness obtained from the MR polishing process was evaluated. A series of experiments were performed on fused silica glass using prepared slurries and various process conditions, including different polishing times. Outstanding surface roughness of Ra=2.27nm was obtained on the fused silica glass. The present polishing method could be used to produce ultra-precision micro parts.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.954-957
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• 2007

Gelation mechanism of xanthan-carob mixture (X/C) was investigated based on thermorheological behavior. Three X/C ratios (1:3, 1:1, and 3:1) were studied. Small amplitude oscillatory shear tests were performed to measure linear viscoelastic behavior during gelation. Temperature sweep ($-1^{\circ}C/min$) experiments were conducted. Using a non-isothermal kinetic model, activation energy (Ea) during gelation was calculated. At 1% total concentration, the Ea for xanthan fraction (${\phi}_x$)=0.25, 0.5, and 0.75 were 178, 159, and 123 kJ/mol, respectively. However, a discontinuity was observed in the activation energy plots. Based on this, two gelation mechanisms were presumed-association of xanthan and carob molecules and aggregation of polymer strands. The association process is the primary mechanism to form 3-D networks in the initial stage of gelation and the aggregation of polymer strands played a major role in the later stage.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.200-206
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• 2015

The use of gums in processed foods manufactured in Korea was investigated in this study. The information about gums added to each food was collected from the ingredient claimed on the food packaging. A total of 272 food items were found to use gums as a thickener, stabilizer, and/or emulsifier. Among them, carrageenan was the most frequently found in 110 items (40%), followed by xanthan gum in 87 items (32%), guar gum in 67 items (25%), arabic gum in 50 items (18%), and gellan gum in 28 items (10%). Application of more than two different gums to food items was also observed, presumably based on the synergistic interaction between gums for a specific physical property. Of nine food categories classified by the Korea Food Code, gums were used most frequently in beverages, noodles, and meat products. Foods for children which include confectioneries, beverages, and chocolates were found to frequently use arabic gum, carrageenan, xanthan gum, guar gum, or gellan gum. These results indicate that gums have been widely using in a variety of Korean processed foods in order to improve their physical properties. Considering potential health concern of some gums such as carrageenan, further study to estimate daily intake of gum is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1060-1067
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• 2001

Effect of various thickening agents on kakdugi fermentation was investigated by measuring physicochemical and sensory properties during fermentation at 2$0^{\circ}C$. Paste of seven kinds of thickening agents (wheat flour (WF), waxy rice flour (WR), corn starch (CS), acid modified starch (AM), aretylated distarch adipate (AA), hydroxypropyl distarch phosphate (PP) and xanthan gum (XG) ) at 0.25% concentration was added to kakdugi. Total acidity during fermentation was not different among thickening agents, but slightly lower in XG than control at the 7th day of fermentation. At 0 day of fermentation, free sugar amount were higher in thickening agent addition groups than control, but rapidly decreased to below control at the 7th day of fermentation, except XG. Glucose and fructose which were the major free sugars, decreased rapidly during fermentation, whereas mannitol increased in all samples. Viscosity of kakdugi liquid was much higher in thickening agent addition groups than control at 0 day of fermentation, but rapidly decreased from 1 day of fermentation. However, initial viscosity was maintained only in XG. Hardness at the 7th day of fermentation was higher in WR, PP, XG than control. The result of sensory evaluation shows that there were no significant difference in sour odor, sour taste and savory taste among samples. Moldy odor was higher in WR, WF and AM, but was not significantly different in XG, PP, AA compared to control. Viscosity of XG and PP, and starchy taste of XG were higher than those of control. Overall preference of XG, AM, PP were not significantly different from that of control. Xanthan gum was considered to be a good thickening agent for kakdugi but it is necessary to find a minimum concentration for kakdugi since starch taste of xanthan gum.

• Korea-Australia Rheology Journal
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• v.18 no.2
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• pp.67-81
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• 2006

Using a strain-controlled rheometer, the dynamic viscoelastic properties of aqueous xanthan gum solutions with different concentrations were measured over a wide range of strain amplitudes and then the linear viscoelastic behavior in small amplitude oscillatory shear flow fields was investigated over a broad range of angular frequencies. In this article, both the strain amplitude and concentration dependencies of dynamic viscoelastic behavior were reported at full length from the experimental data obtained from strain-sweep tests. In addition, the linear viscoelastic behavior was explained in detail and the effects of angular frequency and concentration on this behavior were discussed using the well-known power-law type equations. Finally, a fractional derivative model originally developed by Ma and Barbosa-Canovas (1996) was employed to make a quantitative description of a linear viscoelastic behavior and then the applicability of this model was examined with a brief comment on its limitations. Main findings obtained from this study can be summarized as follows: (1) At strain amplitude range larger than 10%, the storage modulus shows a nonlinear strain-thinning behavior, indicating a decrease in storage modulus as an increase in strain amplitude. (2) At strain amplitude range larger than 80%, the loss modulus exhibits an exceptional nonlinear strain-overshoot behavior, indicating that the loss modulus is first increased up to a certain strain amplitude(${\gamma}_0{\approx}150%$) beyond which followed by a decrease in loss modulus with an increase in strain amplitude. (3) At sufficiently large strain amplitude range (${\gamma}_0>200%$), a viscous behavior becomes superior to an elastic behavior. (4) An ability to flow without fracture at large strain amplitudes is one of the most important differences between typical strong gel systems and concentrated xanthan gum solutions. (5) The linear viscoelastic behavior of concentrated xanthan gum solutions is dominated by an elastic nature rather than a viscous nature and a gel-like structure is present in these systems. (6) As the polymer concentration is increased, xanthan gum solutions become more elastic and can be characterized by a slower relaxation mechanism. (7) Concentrated xanthan gum solutions do not form a chemically cross-linked stable (strong) gel but exhibit a weak gel-like behavior. (8) A fractional derivative model may be an attractive means for predicting a linear viscoelastic behavior of concentrated xanthan gum solutions but classified as a semi-empirical relationship because there exists no real physical meaning for the model parameters.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.323-331
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• 2020

Objective: The present work was undertaken to determine the possibility of using xanthan and guar gums as stabilizers to enhance the yogurt quality. Methods: Yogurt was manufactured from standardized milk (3.5% fat, 8.5% solid-not-fat contents) with the addition of 2% to 3% starter culture. Enzyme-hydrolyzed xanthan gum (0.1%, 0.5%, 1.0%) and guar gum (0.1%, 0.5%, 1.0%) were added to the yogurt as stabilizers. Prepared yogurt samples were kept at refrigeration temperature (4℃±2℃) for 21 days and various quality and sensory parameters were studied at regular intervals (7 days). Results: Results showed that yogurt with 0.5% xanthan gum (T5) was best in terms of preventing syneresis and improving the viscosity, water holding capacity and texture of the product. Additionally, adding gums did not adversely affect the sensorial attributes of the product. Conclusion: Modified gums were found useful in augmenting yogurt quality and therefore addition of gums is highly recommended for manufacturing yogurt.

• Korean journal of food and cookery science
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• v.14 no.2
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• pp.168-176
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• 1998

The breadmaking characteristics of composite flour containing 30% of buckwheat and 70% of wheat with the addition of vital wheat gluten and water-soluble gums, were studied to establish the optimum formula for the development of buckwheat bread. The addition of vital wheat gluten or/and gums led to successful formation of buckwheat bread, giving loaf volume increase and improvement of sensory quality, especially texture determined by QDA (Quantitative Descriptive Analysis). Among those additives, xanthan gum showed the best volume expansion. Synergistic effects on bread quality were observed when the vital wheat gluten and xanthan gum or guar gum were used together. As buckwheat flour was substituted for wheat flour, gelatinization started early and the maximum viscosity increased measured by an amylography. The addition of gluten and gums caused the initial gelatinization to occur at a higher temperature and maximum viscosity to decrease.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.216-222
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• 1990

For the improvement of the nutritive value of extruded noodles, dry soymilk residue flour (DSRF) was mixed with wheat How. The effects of the addition of DSRF on the viscosity of wheat flour and the quality of cooked noodles were evaluated As the proportion of DSRF addition was in-creased the viscosity of composite flour was decreased And so were the texture and cooking quality of noodles. To improve noodle-making characteristics of extruded noodles with 10% DRFF, Na-alginate, Na-carboxymethyl cellulose, guar gum crude gluten and xanthan gum were added. Then, the noodle-making characteristics were examined. The viscosity increased with the increase in the concentration of additives and Bnnthan gum was the most effective. The texture of noodles supplemented by Na-alginate 2.0%, Na-carboxymethyl cellulose 2.0%, guar gum 2.0%, xanthan gum 1.0% was similar to that of wheat flour noodles. The results of sensory test (color and texture) was coincidal with the results of instumental tests.