• Journal of Ginseng Research
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• v.5 no.2
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• pp.122-131
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• 1981

An aqueous extract s of fresh ginseng roots was heated at loot for 64 hrs. and the changes of color intensity, pH and the amount of free sugars and amino acids during the various intervals of the heating time were investigated. Color intensity and absorbance of the solution at 490nm were increased in proportion to the length of the heating time. Most of brown pigments produced during the treatment were water soluble, and pH 5.1 at initial stage of the solution, was slightly decreased at the final stages of the reaction. Sucrose, glucose and fructose were major free sugars in ginseng roots, and the amounts of sucrose was over 90 % of total free sugars. Sucrose. was largely decreased approximately 50%, by 64 hrs of the treatment, whereas sharp increase in the amount of glucose and fructose was observed during the reaction in the solution. The observed increase in reducing sugars, glucose and fructose was presumed due to hydrolysis of sucrose. Evidently, glucose and fructose were not important factor to control the browning reaction of the solution. Most of free amino acids and peptides except alanine and isoleucine especially arginine, serine and threonine, were sharply decreased up to 40 : 50% of the original concentration within 2 hrs. Accordingly, the content of free amino acids and peptides seems to be extremely important factor to control the browning reaction in ginseng. A free amino acid, presumed to be nor-leucine, was found in fresh ginseng root on the basis of re mention on liquid chromatography. Kinetic analysis of the browning reaction indicated a pseudo second order with respect to amino acid concentration at the initial stage.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.68-74
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• 2002

This study was performed to examine the availability of electrolysis for removal of remaining biologically refractoty humus and residual color of leachate which is biologically pretreated in domestic waste matter sanitary landfill by recycling to landfill. The obtained results were as follows; 1) The electrolysis of leachate through covered bed represented that the removal efficiency of CODcr and color range from 70~80%, in color removal the only electrolysis for a treatment of leachate meet the critia of effluent. 2) The highest removal efficiency was represented in pH 7~8. 3) At anode used Al, Fe, Stainless the removal efficiency of CODcr and color was high in order of Fe, Al, stainless, in considering the settled ability of reaction product in economic or after electro coagulation the removal efficiency was highest when anode was the Fe electrode. 4) In this study conditions for removed both CODcr and Color ar the same time represented thar anode was used Fe, electrode-distance was 2cm and reaction time was 40min in 8volts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.349-354
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• 1983

A study on the color changes of fish meat during drying was conducted using fishes with different lipid contents, such as Alaska pollack as lean fish, conger eel as white fleshed fatty fish, and sardine as dark fleshed fatty fish. The fish meat was dried in a forced air dryer for 20 hours at 40, 55 and $70^{\circ}C$, The air velocity was 0.4 m/sec and the relative humidity of air was controlled to a constant value in the range of 10 to $50\%$. The color changes were evaluated with the brown color densities developed by lipid oxidation and Maillard reaction. The predominant reaction for the brown color developed during drying was lipid oxidation, The more the lipid content of fish and the higher the drying temperature were, the more violent the oxidative reaction of Lipid was. The rate of lipid oxidation during drying at 40 and $55^{\circ}C$ was affected by the relative humidity of air and was the slowest around $30\%$. But no remarkable influence of relative humidity on the rate of lipid oxidation could be confirmed during drying at $70^{\circ}C$. It seemed that the rate of lipid oxidation at higher temperature was more sensitive to the temperature than the relative humidity of air. Maillard reaction showed not so significant influence on the color changes of fish meat during drying. The rate of reaction was increased with increasing relative humidity of air in the range of 10 to $50\%$.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.161-165
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• 1994

It was aimed to investigate the effects of caffeic acid on the rates of Maillard reaction. The rates of browning reaction increased as the browning temperature increased. The color intensity of the browning mixtures indicated to depend on the amino acid rather than reducing sugar. Also, the color intensity of the browning mixtures increased more rapidly in the presence of caffeic acid. The increase in color intensity seemed to depend mainly to the polymerization of o-quinones formed from caffeic acid. The caffeic acid, furthermore, appeared to enhance the color intensity of the browning mixtures through the interaction with amino acid, especially methionine and phenylalanine. The activation ener-gies of the browning reaction without caffeic acid were 108∼130 J/mol, and Q10 values were 2.6∼3.2. The activation energies and Q10 values of browning mixtures decreased in the presence of CA. The activation energies of the browning mixtures with caffeic acid were 90∼101J/mol, and Q$\_$10/ values were 2.0∼2.6.

• Journal of Environmental Science International
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• v.13 no.11
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• pp.987-991
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• 2004

The purpose of this research is to evaluate the removal efficiencies of COD$\_$Cr/ and color for the dyeing wastewater by the different dosages of ferrous solution and H$_2$O$_2$ in Fenton process. In the case of H$_2$O$_2$ divided dosage for the Fenton's reagent 7:3 of H$_2$O$_2$ was more effective than 3:7 to remove COD$\_$Cr/ and color. The results showed that COD$\_$Cr/ was mainly removed by Fenton coagulation, where the ferric ions are formed in the initial step of Fenton reaction. On the other hand color was removed by Fenton oxidation rather than Fenton coagulation. The removal mechanism of COD$\_$Cr/ and color was mainly coagulation by ferrous ion, ferric ion and Fenton oxidation. The removal efficiencies were dependent on the ferric ion amount at the beginning of the reaction. However, the final removal efficiency of COD$\_$Cr/ and color was in the order of Fenton oxidation, ferric ion coagulation and ferrous ion coagulation. The reason of the highest removal efficiency by Fenton oxidation can be explained by the chain reactions with ferrous solution, ferric ion and hydrogen peroxide.

• Korean journal of food and cookery science
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• v.11 no.4
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• pp.396-400
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• 1995

The antioxidant effects in soybean oil was investigated by browning reaction mixtures formed by sugar and reaction temperatures above 110$^{\circ}C$. 0.1 M solution of xylose, glucose and sucrose were heated at 110, 120, 130, 140 and 150$^{\circ}C$ for 24 hrs respectively. A reaction rate constant(k), activation energy (Ea) and Q$\sub$10/ value were determined by color intensity that was measured absorbance at 490 nm in each temperature. Soybean oil containing the ethanol extracts taken from the browning reaction mixtures that were heated at 110, 130 and 150$^{\circ}C$ was stored in an incubator kept at 45.0${\pm}$1.0$^{\circ}C$ for 24 days. The results are as follows: 1. When 0.1 M solution of xylose, glucose and sucrose were heated at 110$^{\circ}C$ and 120$^{\circ}C$, the intensity of glucose browning mixtures was the highest, but heated at 150$^{\circ}C$, the color intensity increased in order of xylose > glucose > sucrose after 24 hrs. 2. The reaction rate constant (k) was increased rapidly above 140$^{\circ}C$ and appeared maximum at 150$^{\circ}C$, esp. xylose was the highest. The activation onergy (Ea) of xylose was the highest as 93.28 Joule/mole and the Q$\sub$10/ value of xylose was appeared 1.28. Q$\sub$10/ value was also the highest in xylose. 3. The browning reaction mixtures that were heated at 110$^{\circ}C$ appeared little antioxidant effects. But, in heated at 130$^{\circ}C$ and 150$^{\circ}C$, the antioxidant effects appeared in sucrose browning reaction mixtures. Therefore, in browning reaction mixtures that heated above 110$^{\circ}C$, only sucrose browning reaction mixtures appeared antioxidant effects and xylose, glucose appeared little antioxidant effects. On the contrary xylose and glucose increased peroxide values of soybean oil.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.123-128
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• 2006

The purpose of the research is to estimate the amount of a color image reaction variation by changing areas in order to design the method to reduce an error about the color sample when it is applied in the real situation. The summary of the results acquired in this research is as followed. (1) With fixed observing distance of 1m, we observed that the value and chroma of each color object became higher as sight angle was increased as $2^{\circ},\;10^{\circ},\;and\;30^{\circ}$, even though the variation ratio was different. (2) With fixed sight angle of 10, we observed that the value and chroma of each color object becane higher as observing distance was changed from 1m to 3.3m, even though the variation ratio was different. (3) With same area, we observed that the values and chromas of each color object in the conditions of $1m-30^{\circ}\;and\;3.3m-10^{\circ}$ were almost same. (4) When the area became larger, the subjects tended to feel that colors were bright and clear with the increase of tone. In all the colors, the variation of a color reaction in chroma is higher than those in value. In future, we can observe the limit in applying to colors in the architecture by identifying the tendency of the color change according to the area change qualitatively.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.8-23
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• 1981

Color is one of the most important quality factors of red ginseng (Hong-sam) which is processed from fresh ginseng (Panax ginseng C. A. Meyer). Therefore, a study of characteristics of browning mixtures of aqueous fresh ginseng extracts, factors which accelerate the browning of the aqueous extracts, and the antioxidant activity of the browning mixtures may contribute to the improvement of the color and other quality of red ginseng and other ginseng products such as ginseng extracts. In the present study, factors which affect the Maillard-type browning reaction of aqueous extracts of fresh ginseng roots were investigated firstly by adding various concentrations (0.001-0.5M) of arginine or glucose solutions, by varying the browning reaction temperatures and durations. Secondly, some characteristics such as brown color intensity, amounts of water-soluble and ether-soluble extracts, amounts of non-dialyzable materials, pH, viscosity, and reactivity with 2,2'- diphenyl -1 - picrylhydrazyl and antioxidant activity of the browning mixtures of the aqueous fresh ginseng extracts with small amounts of 0.1 M arginine, 0.1 M glucose, and distilled water at various browning temperatures and reaction time were studied. The results of the present study are as follows. 1. Color intensity (absorbance at 470 nm) of the browning mixtures was increased by adding various concentrations of arginine solution to the fresh ginseng extract, but the addition of the same amount of glucose solution did not increase the color intensity. 2 The amounts of water- or ether-soluble extracts, amounts of non-dialyzable materials were slightly greater in case of the browning mixtures of the fresh ginseng extract with 0.1M arginine solution than in case of the browning mixtures of the fresh ginseng extract with the same amount of 0.1 M glucose solution. In the process of the browning reaction, the pH of the browning mixtures of the fresh ginseng extract with 0.1 M arginine solution decreased slightly, while that of the browning mixtures with 0. 1 M glucose solution was almost constant. 3. The color intensity (absorbance at 470 nm) of the browning mixtures of the fresh ginseng extract with 0.1 M arginine or 0.1 M glucose solutions did not correlate well with the reducing power or the antioxidant power of the browning mixtures. The antioxidant activity of 90% ethanol extracts from the earlier stages of the browning mixtures of the fresh ginseng extract with the arginine solution was almost comparable to that of the 90% ethanol extracts from the later stages of the corresponding browning mixtures. The browning mixtures of only the fresh ginseng extract or of the fresh ginseng extract with the glucose solution showed considerable antioxidant activity, although both showed less brown color intensity than the fresh ginseng extract with he arginine solution.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.10
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• pp.651-655
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• 2017

This work reports the surface morphology and transmittance of copper oxide thin films for semitransparent solar cell applications. We prepared the oxide specimens by subjecting copper thin films to an oxidation reaction at annealing temperatures ranging between $100^{\circ}C$ and $300^{\circ}C$. The color of the as-deposited specimen was red, but changed to purple at the annealing temperature of $300^{\circ}C$. The surface morphology and transmittance of the specimens were significantly dependent on the annealing temperature and thickness of the copper films. Copper oxide nanoparticles prepared from a 20-nm-thick copper film at an annealing temperature of $300^{\circ}C$ provided a maximum transmittance of 93%. The obtained optical characteristics and surface morphology suggest that copper oxide thin films prepared by an oxidation reaction can be potentially employed as color- and transmittance-adjusting layer in semitransparent thin solar cells.

• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.535-541
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• 2012

ALC was fabricated using cement, lime, quartzite and a foaming agent via a hydrothermal reaction. ALC has various hydrothermal reaction products and many pores. The properties and colors of ALC surfaces were changed by various factors during ALC fabrication process. This study tested various staying times to analyze these phenomena. It was found that the staying time of green body influenced the properties of hydrothermal products and color of ALC surface. The longer staying time of green body, the lower tobermorite content and cumulative loss weight. An increase in holding time changed color and decreased whiteness of ALC surface. The relationship between whiteness and cumulative loss weight was very high (Coefficient, r = 0.95). It was surmised that tobermorite content was an important factor for enhancement of whiteness However, ettringite and quartzite did not contribute to whiteness.