• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.233-239
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• 2009

The effects of guar gum (GG) and xanthan gum (XG) at different concentrations (0, 0.2, 0.4, and 0.6% w/w) on the rheological properties of Korean waxy rice starch (WRS) pastes were evaluated under both steady and dynamic shear conditions. The flow properties of WRS-gum mixtures were determined from the rheological parameters of the power law model. The addition of GG and XG to WRS resulted in an increase in the apparent viscosity ($\eta_{a,100}$) and consistency index (K) values obtained from power law model. The flow behavior index (n) values of the WRS-XG mixtures decreased with an increase in gum concentration while there was only a marginal difference between n values for the WRS-GG mixtures. Dynamic moduli (G', G", and $\eta^*$) values in the WRS-gum mixture systems also increased with an increase in gum concentration. WRS-XG mixtures had higher dynamic moduli and lower tan $\delta$ (ratio of G"/G') values than WRS-GG mixtures, indicating that the higher dynamic rheological properties of WRS-XG can be attributed to an increase in the viscoelasticity of the continuous phase in the starch-gum mixture systems, which was due to the higher viscoleastic properties of XG compared to GG. The dynamic ($\eta^*$) and steady shear ($\eta_a$) viscosities of the WRS-XG paste at a 0.2% gum concentration followed the Cox-Merz superposition rule.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1324-1332
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• 2016

The effects of different hydrocolloids, including hydroxypropyl methylcellulose (HPMC), xanthan gum (XG), guar gum (GG), and glucomannan (GM), on bread quality characteristics were investigated. The composite flour used for bread production consisted of 80% bread flour and 20% rice flour with 1% different hydrocolloids based on baker's%. Loaf volume, specific loaf volume, baking and cooling loss rate, moisture content, crumb texture and color, and sensory evaluation were determined. Breads containing HPMC and GM showed the highest loaf volumes, but the difference was not significant. Bread containing GM showed the lowest baking and cooling loss rate (7.03 and 7.78%, respectively), and the highest moisture content. Breads containing HPMC and GM showed increased springiness and decreased hardness based on texture profile analysis. Cohesiveness, chewiness, and gumminess of breads containing GM and HPMC showed their lowest values, whereas breads containing XG revealed their highest values. Bread with HPMC showed lightest coloured crumbs. In the sensory evaluation, bread containing GM and HPMC presented their highest scores, whereas bread containing XG showed the lowest scores. Overall, HPMC and GM significantly and positively affected quality characteristics of bread.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11a
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• pp.30-36
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• 1999

• 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.

• 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.

• Food Engineering Progress
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• v.13 no.4
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• pp.320-325
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• 2009

The effects of adding additives such as vital gluten, gum, emulsifier, and enzyme to rice flour on baking quality were examined. The effects of different gums on the pasting and dough properties of rice flour containing vital gluten were studied using a Rapid Visco Analyzer (RVA) and a Brabender farinograph. The RVA peak, breakdown, and final viscosities decreased with the addition of gums, while setback viscosity increased. The farinogram showed that rice flour supplemented with gums such as tara gum, guar gum, and locust bean gum (LBG) increased water absorption and dough stability, yielding strengthened dough similar to wheat flour dough. The addition of guar or tara gum/sodium stearoyl lactylate (SSL)/fungal $\alpha$-amylase (AMYL) or glucose oxidase (GO) blend improved the volume and reduced the crumb firmness of rice bread prepared from rice flour containing 14% vital gluten. Therefore, the combined addition of gum, emulsifier and enzyme into rice flour significantly improved the rice bread quality, allowing the decrease of the vital gluten level in rice bread formula.

• Korean journal of food and cookery science
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• v.24 no.5
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• pp.636-644
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• 2008

The principal objective of this study was to assess the effects of hydrocolloids(xanthan gum, guar gum, sodium alginate, k-carrageenan, carboxy-methyl cellulose) on the suppression of retrogradation in the bread. The pasting properties of the doughs and the sensory properties were determined in the bread samples, to which xanthan gum, guar gum, sodium alginate, k-carrageenan, and CMC, were added at different ratios(0.2%, 0.6%, 1%). CMC and k-carrageenan with 0.6% level were selected for the further retrogradation studies. Changes in the firmness of the bread samples at room temperature for 15 days were assessed using a texture analyzer, and the type of retrogradation was calculated via the Avrami equation. The thermal properties of the samples were also determined via differential scanning calorimetry (DSC). The addition of hydrocolloids was shown to increase the viscosities of the doughs. Setback and breakdown viscosity were reduced significantly via the addition of CMC(0.6%, 1%), xanthan gum(1%), and k-carrageenan(1%). Sensory hardness was significantly increased when 1% hydrocolloids were added. Our textural analysis showed that the addition of CMC reduced the firmness of the bread, whereas k-carrageenan didn't. However, the retrogradation rate was reduced via the addition of k-carrageenan, as was also demonstrated in the results of our DSC analysis.

• 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.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.239-245
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• 2003

This study is to research on printing method by use of colorants extracted from Sappan wood. As for the research, the stability of paste added by mordants, steaming condition, optimal mordant concentration, change of surface color and colorfastness were measured. The experiment showed that guar gum were stability among the sodium-alginate, modified starch, guar gum. And the surface color was best when the streaming time was 60 minutes, mordant concentration 3g/l. And for colorfastness experiment, colorfastness to drycleaning was good, but colorfastness to light and colorfastness to washing showed no desirable result.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.4
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• pp.7-15
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• 2002

It is of critical importance to understand the characteristics of papermaking additives and their reaction mechanisms to fully utilize the benefits they provide. Among the papermaking additives, retention aids play critical roles in improving productivity, product quality and process economy. Diverse research efforts to understand the reaction mechanisms between cationic polymers and anionic microparticles have been made since microparticle retention systems were introduced into the market. And it is most commonly accepted that flocs formed by the addition of cationic polymers are dispersed by shear force and the broken flocs are reflocculated instantly with the addition of microparticles. There are still many unanswered questions, however, on the reaction phenomena between cationic polymers and anionic microparticles. In this study, several cationic polymers including waxy maize starch, com starch and guar gum were used to investigate their retention efficiency when they were used along with anionic colloidal silica.