• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.383-389
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• 2000

Stabilities to heat, pH, light were investigated about isolated red color pigment from the Korean Lithospermum erythrorhizon. The extracted pigment, acetylshikonin was stable heating at 40∼80$\^{C}$ for 1∼2 hours, hut it was specially unstable on the storage above 55$\^{C}$. The extracted pigment, acetylshikonin was stable on the sunlight under the red and green filters but unstable under the yellow and blue filters. The extracted pigment, acetylshikonin was stable under the pH of 4∼8 but unstable under the pH above 10. The extracted pigment, acetylshikonin was stable under the KCl and NaCl at concentration of 10$\^$-1/Mole. The pigment was very unstable under the CaCl$_2$, FeCl$_3$, CoCl$_2$, AlCl$_3$ and MnCl$_2$ at concentration of 10$\^$-1/Mole. The red pigment, acetylshikonin was stable under citric acid and acetic acid at concentration of 1 Mole. Especially, acetic acid was effective for the stability of the pigment.

• Journal of Food Hygiene and Safety
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• v.14 no.2
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• pp.160-166
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• 1999

Microbial populations of total aerobic bacteria and coliforming bacteria, TBA, Hunter's color value, heme pigments, muscle protein solubility, cooking loss and shear force were investigated fro evaluating the shelf life of chicken legs gamma-irradiated at doses of 1, 3, 5 and 10 kGy with air-contained and vacuum-packaged methods. The initial microbial populations decreased with gamma irradiation depending upon the dose, and microorganisms in the vacuum-packaged samples were inhibited more than those in the air-contained samples. Hunter's L and a values of the surface and inside of the legs increased by gamma irradiation, showing a bright red color and the red color was maintained during the storage of both samples. The concentrations of oxymyoglobin among the heme pigments increased by gamma irradiation. Muscle protein solubility slightly increased by increasing the applied dose. There were no significant differences in the cooking loss and shear force values. In conclusion, the combination of gamma irradiation and vacuum-packaging could extend the shelf life of chilled chicken without deterioration of the quality.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.5
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• pp.753-767
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• 2019

Dyeing behavior of indigo leaf powder was examined in regards to the effect of the amount of pigments on color and dye adsorption for silk dyed by reduction and nonreduction dyeing. The amount of indigotin and indirubin pigments adsorbed in dyed silk was examined by HPLC-DAD analysis. The color of dyed silk showed 7.7BG - 2.7B hue when silk was dyed at $50^{\circ}C$, and 3.5G - 4.9BG when dyed at $70^{\circ}C$. Blue ($b^*$) and green ($a^*$) color decreased as the pH of dyebath increased. When silk was dyed using nonreduction, R (red) and RP (red purple) hue and R hue was more apparent in samples dyed at $90^{\circ}C$. In reduction dyeing, amount of indigotin detected from silk exceeded the amount that was initially contained in the input dye. The amount of indirubin was lower than indirubin that was initially in the powder. In nonreduction dyeing, silk showed a higher amount of indirubin adsorption compared to silk dyed by reduction. The amount of indigotin adsorbed in silk was lower than the amount initially contained in the input dye. The amount of indigotin and indirubin adsorption was primarily dependent upon the dyeing method-reduction or nonreduction along with dyeing temperature and the pH of dyebath.

• 보존과학연구
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• s.21
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• pp.119-143
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• 2000

The pigments composition and structure of the mural painting at Pongjongsa Kuknakjon is discussed. The structure of inner wall is consisited of Paint layer, Ground divided two layers of yellow and white pigments, Support. In case of outer wall, it is consisted of Paint layer, Ground divided three layers of yellow and green pigments, a layer mixed green pigments and paint layer, Support. As a result of compositon analysis of mural painting pigments at Pongjongsa Kuknakjon using Micro-area X-ray diffraction system, the red pigment on inner wall is consisted of Heamatite($Fe_2O_3$), Magnetite($Fe_3O_4$)of deep black pigment, and Chalcocite($Cu_2S$) of light black pigment. The white pigment on outer wall is consisted of Anglesite($PbSO_4$) and Atacamite($Cu_2CI(OH)_3$) of green pigment. We found out that natural pigments painted in the mural painting at Pongjongsa Kuknakjon has kept up its own color for a long time due to using the natural pigment not to artificial synthetic pigment.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.187-192
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• 2007

The objectives of this study were to examine changes in the color and antioxidant compounds of paprika powder under various conditions, as well as to establish the suitable conditions for drying and storage. Paprika was dried using the following methods: freeze-drying, vacuum drying, far infrared-ray drying, and hot-air drying. Measurements of the moisture content, color pigments, and antioxidant compounds (total carotenoids, capsanthin, ascorbic acid, and total polyphenols) were completed during 120 days of storage at 4 and $30^{\circ}C$. We found that drying methods, storage temperatures, and packaging materials affected the American Spice Trade Association (ASTA) and Hunter color values, as well as the antioxidant content of paprika powder. There was a high correlation (r=0.87, p<0.01) between the ASTA color and the $a^*/b^*$ value. The loss of red color was closely related to the reduction of moisture content (r=0.81, p<0.01) during storage. Drying paprika with a low temperature in the absence of air resulted in better retention of the carotenoids and ascorbic acid. Also, as the retention of the carotenoids and ascorbic acid increased, the stability of the red pigment increased. Freeze-drying was found to be the most suitable drying method for the stability of the antioxidant compounds and red pigment.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.357-362
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• 2014

To prepare diketopyrrolopyrrole (DPP) red 254 pigment with high shield and bright color, DPP red 254 crude previously synthesized was treated at various thermal-treat temperature, addition derivative and ball-milling. The properties of samples were measured by the means of FT-IR, UV-Vis spectroscopy, TEM, PSA, BET surface area analyzer, viscometer and spectrophotometer. It was found that solvent thermal-treatment of the sample prepared after ball-milling as nano-scale was very effective method in pigmentation process.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.343-357
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• 1999

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600 hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smalt or color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order of non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light absorber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.

• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.183-186
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• 2004

Various myoglobin derivatives were manufactured in pork and beef ribeye in the laboratory and their colorimetric values were measured with a chromameter. The average values of L＊ and a＊ of pork pigments were higher and b＊ values were lower than those of beef pigments. Oxymyoglobin (bright red) is considered to be a desirable fresh red meat pigment for consumer acceptance. The means of L＊, a＊ and b＊ values of oxymyoglobin were 36.41, 27.32 and 4.71 for pork and 30.54, 25.58 and 9.81 for beef, respectively. Nitrosyl hemochrome, the pigment of processed meat products like sausages and hams had L＊, a＊ and b＊ values of 47.93, 26.85 and 6.63 for pork and 41.82, 23.19 and 11.82 for beef. It was found that as a discoloration developed in meat and the meat color turned to brown, the L＊, b＊ values increased and the a＊ value decreased.

• Journal of the Korean Society of Food Culture
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• v.7 no.1
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• pp.19-23
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• 1992

Jindo Hongju is a traditional liquor in Jindo island of Korea. The characteristics of Hongju are its unique flavour by fermetation and red color of gromwell(Lithospermum erythrorhizon) root. However, the evaluation of red pigment is different from one manufactures to other manufactures and from place to place, also the standard method is not established. An attempt has made to compare the quality of gromwell root from different places and to standardize the extracting method. The results obtained from this study are summerized as follow, The chemical properties and composition of gromwell root from Jindo and other areas were compared. There were no difference among the samples in moisture content, content of naphtoquinone derivatives and absoption spectra. These results indicate that the pigments from Jindo and other region products seems to be the same quality. For efficient extraction of gromwell pigment, more than 40% ethanol as solvent and at least 10 hours extraction time was required. According to the visual test for Hongju pigment, the most preferable color was that it shows absorbance of 1.0 (contents of shikonin was 3.90 mg/45% EtOH 20 ml). From this visual test it can be proposed that the may be applied absorbance at 1.0 for the quality control of pigment.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.428-432
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• 2013

This research presents a flexible reflective thermochromic display (TCD) comprised of thermochromic pigments and a patterned indium tin oxide (ITO) film coated on a polyethylene naphthalate (PEN) substrate, and the display's thermo-optical characteristics. The display showed maximum red, green, and blue reflectances of 30%, 38%, and 29%, respectively. Furthermore, the display exhibited a continuous grey color when the temperature was changed continuously. As a flexible display, the display showed reliable thermo-optical performance without image damage even when highly bent. We expect the proposed TCD will be used in outdoor information display applications where low cost is a key factor.