• Food Science of Animal Resources
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• v.31 no.3
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• pp.366-371
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• 2011

Viscosity is critically important for bulgogi sauce. However, exposure to irradiation may decrease the rheological properties of bulgogi sauce. This study was conducted to compare the effects of gamma irradiation (0-9 kGy) on viscosity, molecular weight, pH, reducing end level, and water solubility of xanthan gum, guar gum, and locust bean gum as thickening agents/stabilizers in bulgogi sauce. The physicochemical properties of all samples changed (p<0.05) from 3965 to 0 cP (viscosity), from 6048 to 28 kDa (molecular weight), from 5.79 to 4.62 (pH), from 0.13 mg/mL to 1.72 mg/mL (reducing end level), and from 6% to 87% (water solubility) following gamma irradiation. Viscosity after irradiation was most stable (p<0.05) in xanthan gum (from 1249 to 92 cP) compared with guar gum (from 3965 to 0 cP) and locust bean gum (from 1631 to 0 cP). The sensory properties (texture and taste) of bulgogi sauce prepared with xanthan gum (1%, w/w) were highly maintained (about 7.0-5.0) after high-dose irradiation of up to 40 kGy. These results indicate that xanthan gum can be effectively used as a thickening agent/stabilizer in bulgogi sauce, which had low viscosity after irradiation.

• Textile Coloration and Finishing
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• v.32 no.1
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• pp.44-50
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• 2020

In this study, pre-treatment was performed on kapok, a hydrophobic fiber, to compare dyeability by hydrophilization. The pretreatment conditions of kapok fiber were used with different amounts of sodium oleate(NaO), a fatty acid-based anionic surfactant, and xanthan gum(XG) as a natural thickener. At this time, NaO and XG were separately or mixed treated with 0.01%, 0.1%, 1% aqueous solution at 80℃ for 30 min. Hydrophilicity through dyeing was confirmed using Sappan wood extract. Therefore, SEM observation was performed to investigate the surface change of kapok fiber according to the conditions. The surface color difference was also analyzed. Pretreated kapok fibers were made from nonwoven fabrics and the contact angles were measured to determine their hydrophilization. The surface of the fiber after pretreatment was found to be cracked when NaO and NaO were mixed with XG. The surface color was the highest in a^⁎ and K/S values after the simultaneous treatment of NaO and XG, followed by NaO pretreatment and XG pretreatment. The contact angle of kapok fiber made of nonwoven fabric was slightly lower at 300g/㎡ than the fabric weight of 150g/㎡. Such hydrophilized nonwoven kapok fiber are expected to be used in various fields.

• Geomechanics and Engineering
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• v.17 no.5
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• pp.475-483
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• 2019

Vegetation cover plays a vital role in stabilizing the soil structure, thereby contributing to surface erosion control. Surface vegetation acts as a shelterbelt that controls the flow velocity and reduces the kinetic energy of the water near the soil surface, whereas vegetation roots reinforce the soil via the formation of root-particle interactions that reduce particle detachment. In this study, two vegetation-testing trials were conducted. The first trial was held on cool-season turfgrasses seeded in a biopolymer-treated site soil in an open greenhouse. At the end of the test, the most suitable grass type was suggested for the second vegetation test, which was conducted in an environmental control chamber. In the second test, biopolymers, namely, starch and xanthan gum hydrogels (pure starch, pure xanthan gum, and xanthan gum-starch mixtures), were tested as soil conditioners for improving the water-holding capacity and vegetation growth in sandy soils. The results support the possibility that biopolymer treatments may enhance the survival rate of vegetation under severe drought environments, which could be applicable for soil stabilization in arid and semiarid regions.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.209-215
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• 1990

For the improvement of the nutritive value of extruded noodles, soybean flour(SF) was mixed with wheat flour. The effects of the addition of SF on the viscosity of wheat flour and the quality of cooked noodles were evaluated. As the proportion of SF addition was increased, 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% SF, Na-alginate, Na-car-boxymethyl cellulose, guar gum, crude gluten and xanthan gum were added. Then, the noodlemaking characteristics were examined. The viscosity increased with the increase in the concentration of additives and xanthan gum was the most effective. The texture of noodles supplemented by Na-alginate 2.0%, Na-carboxymeihyl 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 instrumental tests.

• Korean journal of food and cookery science
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• v.14 no.2
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• pp.140-147
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• 1998

The rheological properties of dough made from composite flour containing 30% of buckwheat flour with 80% of extraction rate and 70% of wheat flour, with addition of vital wheat gluten and/or gums, were studied for the development of buckwheat bread. From the farinograph data, water absorption, development time, and stability of the dough decreased as the amount of buckwheat flour increased. However, the addition of gluten increased the water absorption and development time but decreased the weakness of the dough. The use of xanthan gum showed a stability-increasing effect. From the extensograph data, extension and strength of the dough decreased with increasing amount of buckwheat flour, but resistance to extension increased. The addition of gluten increased the extension and strength of the dough, but decreased the resistance to extension. Guar and xanthan gum added at 0.2% level had little effect on extensograph data of the dough. Overall, addition of, vital wheat gluten improved the properties of buckwheat bread dough better than water-soluble gums.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.538-544
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• 1996

A highly viscous biopolymer from alkali-tolerant Bacillus sp. was purified and its rheological properties were studied. 1% (w/v) solution of purified biopolymer showed pseudoplastic fluid behavior with the yield stress similar to those of xanthan and guar gum, and its consistency index was exponentially dependent on concentration and temperature. The concentration dependency of consistency index exhibited two rectilinear plots with different slopes at 1% concentration and pseudoplastic property increased with the increase of biopolymer concentration. The biopolymer solution exhibited a low temperature dependency and the activation energy of flow was 1.16 kacl/g mol. The apparent viscosity was very dependent on the change of pH and the addition of salt. However, no organic solvent effects were observed effects of viscosity synergism with the addition of viscosifier were not observed.

• Geomechanics and Engineering
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• v.17 no.5
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• pp.453-464
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• 2019

Soft marine soil has high fine-grained soil content and in-situ water content. Thus, it has low shear strength and bearing capacity and is susceptible to a large settlement, which leads to difficulties with coastal infrastructure construction. Therefore, strength improvement and settlement control are essential considerations for construction on soft marine soil deposits. Biopolymers show their potential for improving soil stability, which can reduce the environmental drawbacks of conventional soil treatment. This study used two biopolymers, an anionic xanthan gum biopolymer and a cationic ${\varepsilon}-polylysine$ biopolymer, as representatives to enhance the geotechnical engineering properties of soft marine soil. Effects of the biopolymers on marine soil were analyzed through a series of experiments considering the Atterberg limits, shear strength at a constant water content, compressive strength in a dry condition, laboratory consolidation, and sedimentation. Xanthan gum treatment affects the Atterberg limits, shear strength, and compressive strength by interparticle bonding and the formation of a viscous hydrogel. However, xanthan gum delays the consolidation procedure and increases the compressibility of soils. While ${\varepsilon}-polylysine$ treatment does not affect compressive strength, it shows potential for coagulating soil particles in a suspension state. ${\varepsilon}-Polylysine$ forms bridges between soil particles, showing an increase in settling velocity and final sediment density. The results of this study show various potential applications of biopolymers. Xanthan gum biopolymer was identified as a soil strengthening material, while ${\varepsilon}-polylysine$ biopolymer can be applied as a soil-coagulating material.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.367-372
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• 2016

To understand the effects of adding different gums (guar, xanthan, and locust bean gums) on naked barley flour (NBF), the rheological and pasting properties of NBF-gum mixtures were measured at different gum concentrations (0, 0.3, and 0.6% w/w). Steady shear rheological properties were determined by rheological parameters for power law and Casson models. All samples showed a clear trend of shear-thinning behavior (n=0.16~0.48) and had a non-Newtonian nature with yield stress. Consistency index, apparent viscosity, and yield stress values increased with an increase in gum concentration. Storage modulus values were more predominant than loss modulus values with all concentrations of gums. There is a more pronounced synergistic effect of elastic properties of NBF in the presence of xanthan gum. Rapid visco analyser pasting properties showed that the addition of gums resulted in a significant increase in the peak, breakdown, setback, and final viscosities, whereas the pasting temperature decreased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.586-591
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• 2000

This study was conducted to investigate the effect on quality of low fat pork patties containing various hydrocoloids such as sodium alginate, carboxymethy1 cellulose (CMC) and zanthan gum. Moisture contents of raw, cooked and reheated patties of control patty (20% fat) were lower than those of the hydrocolloids-added patties, and fat content patties was higher than other patties. Colors of raw and reheated patties were not different among four kinds of patties, but L-value of cooked patty adding sodium alginate and b-value of control patty were low significantly in comparison with other patties. Cooking and final yield of hydrocolloids-added patties was high significantly in comparison with control patty. Fat retention of cooked control patty was lower than hydrocolloids-added patties, and fat retentions of retention four kinds of patties were 89.7~93.1%. Hardness of cooked and reheated patties adding xanthan gum was low significantly in comparison with other patties, and chewiness was high in theorder of control patty, CMC, sodium alginate and xanthan gum. In case of water holding capacity, cooked and reheated hydrocolloids-added patties, and juiciness was superior in the order of xanthan gum, sodium alginate, CMC and control patty. On the whole, textural and sensory characteristics of patties containing hydrocolloids were superior to control patty.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.589-594
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• 2006

The effect of five commercial gums (carboxylmethylcellulose, CMC; guar gum, GG; hydroxypropylmethyl-cellulose, HPMC; locust bean gum, LBG; and xanthan gum) at a concentration of 0.25% on the rheological properties of rice flour (RF) dispersions was investigated in steady and dynamic shear. The steady shear rheological properties showed that RF gum mixture dispersions (5%, w/w) at $25^{\circ}C$ had high shear-thinning flow behavior (n=0.20-0.31) exhibiting a yield stress. Magnitudes of consistency index (K), apparent viscosity (${\eta}_{a,100}$), and Casson yield stress (${\sigma}_{oc}$) of RF-gum mixtures were much higher than those of RF dispersion with no added gum (control). Activation energy values (6.67-10.8 kJ/mole) of RF-gum mixtures within the temperature range of $25-70^{\circ}C$ were lower than that (11.9 kJ/mole) of the control. Dynamic rheological data of log (G', G") versus log frequency (${\omega}$) of RF-gum mixtures had positive slopes (0.15-0.37) with G' greater than G" over most of the frequency range (0.63-63 rad/sec), demonstrating a frequency dependency. Tan ${\delta}$ (G"/G') values of RF-gum mixtures, except for xanthan gum, were much higher than that of the control.