• Applied Biological Chemistry
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• v.33 no.3
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• pp.223-230
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• 1990

Gelatinization properties of heat-moisture treated Olchal(japonica) and Hankangchalbyeo(j x indica) waxy rice starches were compared. The blue value, light transmittance of starch suspension and viscosity in sodium hydroxide solution were similar between two starches. Olchal starch showed lower water binding capacity, swelling power md peak viscosity by amylograph than Hankangchalbyeo starch. Upon heat-moisture treatments all above parameters were decreased. The critical sodium hydroxide concentration for gelatinization was increased by treatments. The initial pasting temperature of Olchal starch was higher than that of Hankarlgchalbyeo. All amylograph reference points increased by the treatments, except the maximum viscosity or 2l% moisture-treated Olchal starch. Starches treated at 18% moisture level showd the highest value of consistency index. The activation energy of consistency index for gelatinized Olchal starch was lower than that for Hankangchalbyeo starch. The heat-moisture treatments had no effect on activation energy.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.141-145
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• 1982

Busuge is conventional snack food in Korea which is made from steeped glutinous rice. The effect of the steeping time on total acidity, viscosity, canons, phosphorus and raising power of glutinous rice was investigated. Total acidity was increased from 0.3 to 1.02% by steeping for 20 days at $10^{\circ}C$. Viscosity was increased from 25.5 to 32.4 cP after 14 days steeping and thereafter decreased to 23.5 cP. K, Na, Ca, Mg and P were leached 68, 67, 85 and 16% on 20 days steeping, respectively. K, Na and P were leached in the initial period, and Ca, Mg in the middle period of steeping. Raising power was increased according to the acidity increase and leaching of Ca, Mg and inorganic phosphorus during steeping. However, influence of the former on raising power was greater than the after.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.272-275
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• 2007

Red yeast rice flour, which is a natural functional material, was used in muffin production at different concentrations ranging from 0 to 10%. The initial pasting temperature was not affected by the addition of red yeast rice flour, whereas peak viscosity and final viscosity decreased with increasing concentrations. The lightness value of the muffins decreased, however, the redness value increased with increasing amounts of red yeast rice flour. The bulk of the muffins was generally reduced by the addition of red yeast rice flour. At the 10% concentration, hardness and viscosity were similar to the control, and there were no changes in springiness or cohesiveness. For the sensory evaluation, parameters such as appearance, color, texture, taste, and overall acceptability increased significantly from the control at the 3% concentration of red yeast rice flour, but flavor decreased with increasing amounts of red yeast rice flour. Based on these results and the sensory evaluation specifically, the optimal amount of red yeast rice flour added to the muffins was the 3% concentration.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.3
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• pp.261-275
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• 2012

This paper presents numerical analysis of the mud cake infiltration behaviour which is influenced tunnel face stability during excavation by slurry shield TBM. This analysis method can make useful data to select proper shield TBM type and to set up the construction plan. But effective analysis did not proposed until now. In this paper, we carried out numerical analysis using by $PFC^{2D}$ fluid coupling simulation which is suitable for sandy soil modelling. As a analysis result, we checked that the slurry infiltration behaviour varied with soil permeability and slurry characteristic(specific weight, viscosity etc). This analysis method is helpful safety excavation through anticipating the proper slurry viscosity at the design stage and verifying the slurry quality at initial excavation stage.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.379-385
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• 1991

Morphological changes of starch granules from 12 different varieties of rice were examined by scanning electron microscopy during heating at 2.5% (w/v) concentration. Rice starch granules proceeded through a similar pattern of progressive morphological changes daring heating, regardless of variety. Rice starch granules began to swell radially in the initial stage of gelatinization and then undergo radial contraction and random tangential expansion to form complex structures in the latter stage of gelatinization temperature range. At higher temperatures, starch granules softened and melted into thin flat discs, and then stretched into thin filaments to form three-dimensional networks. These progressive morphological changes were reflected in the changes of swelling power, solubility and amylograph viscosity of starch. During the transition of melting or softening, swelling power, solubility and amylograph viscosity increased rapidly. The time of loss of granular structure of starch depended on gelatinization temperature range. The ratio of amylose to amylopectin was largely responsible fur the rate of melting or softening and the fineness of a three-dimensional filamentous network above the gelatinization temperature range. Therefore, both the gelatinization temperature range and amylose content of starch affect the rate of cooking, and amylose content of starch affects the final texture of cooked starch paste.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.618-624
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• 1988

This study was conducted to observe the effects of partial replacement of mungbean starch(MB) with dent(DT) or cross-linked(CL) corn starches, and of added hydrocolloids on the characteristics of mungbean starch and the mook. The replacement with CL caused less changes compared to that with DT in phase transition enthalpy of MB measured with defferential scanning calorimeter. The viscosity of MB paste cooled to $50^{\circ}C$ after heating was also affected less with CL than with DT. The addition of hydrocolloids to mixed starches of MB and CL did not affect initial viscosity increase but resulted in marked increase in viscosity at later stage of heating. Mixed monks with CL were more similar to MB monks than those with DT. Hydrocolloids added to MB-CL mixture further decreased the gap between monks with and without CL.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.99-104
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• 1990

The effects of concentrations of sulfur dioxide (0.16-0.20%) and steeping times (25-50hr) at $52^{\circ}C$ on the changes in pH of steep water and weight and volume of corn and starch properties were investigated. The pH of steep water increased and remained constant after steeping time of 20 hours. The degree of weight or volume gain decreased as the concentration of sulfur dioxide increased. The protein content of starch increased as the concentration of sulfur dioxide increased. Water·binding capacity of starch showed the highest value at the steeping time of 35 hours. Swell ins power and solubility decreased as cocentration of sulfur dioxide and steeping time increased. The initial pasting temperature and peak viscosity were increased and decreased, respectively, as the concentration of sulfur dioxide increased. At the same concentration of sulfur dioxide, the peak viscosity was increased and then decreased. Viscosity of starch in sodium hydroxide solution tended to decrease as the concentration of sulfur dioxide and sleeping time increased. The gel volume of starch in 3M KSCN solution was not affected by concentration of sulfur dioxide and steeping time.

• Applied Biological Chemistry
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• v.22 no.1
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• pp.42-50
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• 1979

The viscosity coefficient of mucilage of Abelmoschus manihot, MEDIC root decrease under the influence of temperature and the other various physical and chemical factors. The rate of viscosity change of the mucilage have been measured at $5^{\circ}{\sim}50^{\circ}C$ in aqueous state under the various conditions. The results are as follows: 1. Relationship between rate of viscosity change of mucilage and temperature can be represent as Andrade equation. 2. Their activation energies of viscosity change of Abelmaschus maihot, MEDIC root A, B, C, D, E, F and G observed are 11.9, 12.1, 11.4, 12.1, 11.6, 13.8 and 13.2 Kcal/mole, respectively. And other activation parameters arc evaluated. 3. The activation energy of naturally mucilage are smaller than that of sterilized mucilage.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.25-32
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• 2010

High performance shotcrete has been recently researched partly as a result of high consensus on high strength and durability. However, they are very initial step compared from the advanced countries. For instance, they has been mainly on high strength or durability without any consideration on pumpability and shootability which are very crucial on workability. The purpose of this dissertation was to make a high performance wet-mix shotcrete (high workability) which would solve the general problems of wet-mix process in Korea. For this, the main experimental variables were selected to be silica fume(0.0, 4.5, 9%), air entrained agent(0.0, 0.005%). Rheology with IBB rheometer was measured for evaluating pumpability and shootability as well as pump pressure, rebound rate and build-up thickness. The conclusions from a series of experiments were as follow: The results of analyzing the effects of AE agent and silica fume on rheology indicated that AE agent reduced both of flow resistance(G) and torque viscosity(H) and silica fume increased flow resistance (G) and reduced torque viscosity(H). An increase in the value of torque viscosity(H) produces an increase in the requried pumping pressure. These result indicated that the reduction of torque would work better at improving pumpability. And an increase flow resistance(G) improved shootability(increase build-up thickness and reduce rebound).

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.193-199
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• 2002

The Job's tear gruels were prepared by various mixing ratios, particle size and soaking times of Job's tear and rice flours, and the physical and sensory properties of these gruel samples were measured by using a Brabender visco-amylograph and sensory evaluation. Also, the changes in the pH and viscosity of the gruel samples stored for 14 days at 4$\^{C}$ were measured as the parameters of gruel quality. The results showed that the peak viscosity was decreased by increasing the ratio of Job's tear flours. The values of peak viscosity and consistency of rice and Job's tear flours increased as the particle size decreased. As the soaking time of rice and Job's tear flours increased, the initial pasting temperature decreased. In sensory characteristics, the nutty taste was increased as the Job's tear flour levels increased. Overall acceptability of Job's tear gruel was the highest in the one of rice and Job's tear flours at 50:50 ratio. During 14 days of storage, the pH and viscosity of Job's tear gruels were increased till the sixth day, and then decreased slightly.