• Korean Journal of Heritage: History & Science
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• v.38
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• pp.359-385
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• 2005

Red ocher, red lead or cinnabar has been as red colorant for ages. Cinnabar of the red pigments has been highly regarded as a valuable ingredient because it represent a symbol of exorcising and a haute image. It was used as a pigment of painting and mural painting, bowl, clothes, rock writing, gravestone, etc. It is powder which dissolves in perilla oil or glue before using. Because it is high-priced, the use of cinnabar may be limited to the privileged class. Therefore, red ocher or red lead was used instead of cinnabar. "Gongsagyunmunrok" demonstrated that government official's gravestonea has been painted red by two colorants in the period of the Goryeo dynasty. However, cinnabar may be used to paint gravestones for the first time in the period of the Three States because it has been transmitted since the times. This study discuss the results obtained from an analysis of the pigments used on the red pigments of the Stone Monuments. The results can be briefly summarized as below; First, the microcrystalline structures seen on the surface section of analyzed pigments, samples of which were taken from various parts of red pigments show that different sizes and shapes of pigment particle. Second, a result of the analysis on the composition and structure of the pigments shows that the main components in their composition are : Red pigments - Red lead($Pb_3O_4$), Cinnabar(HgS) and Hematite($Fe_2O_3$) White pigments - Calcite($CaCO_3$) Especially, we knew that red Stone Monuments were found to be natural mineral pigments, which were used as a singular or a mixture.

• Current Research on Agriculture and Life Sciences
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• v.30 no.2
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• pp.76-81
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• 2012

In this study the natural colorant was extracted from black bean seed coat in aqueous solution and used to dye silk and cotton fabrics. To obtain the optimal dyeing conditions it was examined at various dyeing condition (temperature, pH, time and liquor ratio). The dyeing behavior and the depths of shade which were evaluated in terms of K/S and CIELAB color difference values of the dyed and mordanted fabrics were also investigated. The dyeing fastness evaluated standard light and wash fastness tests. The obtained results were as follows ; The most K/S value of silk and cotton fabrics were obtained when the pH was 4.0 and 4.8, respectively and it increased slightly with dyeing time passes when the dyeing temperatures were at $40^{\circ}C$ and $60^{\circ}C$ but, it increased at $80^{\circ}C$. The color of silk fabrics changed from yellowish red to yellow at only Fe mordanting among various mordanting. Sn and Ti mordanting of silk fabric and only Ni mordanting of cotton fabric increased the $L^*$ values, but the others decreased. The light fastness of silk fabrics showed 4-6 grade without mordant, 4-5 grade with Al, 3-4 grade with Cu and Sn, and 2-3 grade with Fe as mordant, and that of cotton fabrics showed 1-2 grade without mordant, 2-3 grade with Fe, 2 grade with Cu, 1-2 grade with Al and Sn as mordants. All mordanting coluld not improve the light fastness of fabrics. Washing fastness(fade) of silk fabrics showed 2 grade without mordants and 2-3 grade with mordants and those of cotton fabrics showed 4 grade with Cu, 3 grade without mordant and with Al, Sn and Fe. All of the washing fastness(stain) of both fabrics showed 4-5 grade.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.211-217
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• 1997

The physical and chemical stability of anthocyanins from a Korean pigmented rice variety was investigated at various conditions of pH, temperature, metal ion, sugar, organic acid and light. The anthocyanin pigments were relatively stable with half-lives of 36 days (pH 2.0) and 17 days (pH 3.0), while they were decomposed in a day at neutral and basic pH of 7.0 and 9.0 at $25^{\circ}C$. The anthocyanins also showed high thermal stability at pH 3.0; the half-lives were 7.4 hr, 23.6 hr and 96.3 hr at $95^{\circ}C,\;75^{\circ}C\;and\;50^{\circ}$, respectively. Addition of di- and tri-valent metal ions at pH 3.0 resulted in the increase of color intensity and stability throughout 21 days of storage periods at $25^{\circ}C$. Most sugars added accelerated the degradation of anthocyanin pigments, so that fructose showed the greatest degradation effect on the pigments. Addition of citric acid at pH 3.0 increased stability of anthocyanins, while tartaric acid decreased stability. The anthocyanins were very sensitive on light irradiation with a degradation half-life of 14 hr under 20,000 lux-light dosage at pH 3.0.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.404-410
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• 2009

We investigated the physicochemical stabilities and biological activities of ethanol- extracted pigment from marine bacteria Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14. The bacterial pigment of strain Ju11-1 was very stable at pH 5.0 below $25^{\circ}C$. The stability of the pigment showed higher stability in the presence of metal ions such as $Cu^{2+}$ and $Mg^{2+}$. The pigment has activity of free-radical scavenging ($IC_{50}$ $95.2{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $82.3{\mu}g$/ml) against DNA damage in human lymphocytes. The bacterial pigment of strain Ju14 was very stable at pH range between 4.0 and 8.0 below $40^{\circ}C$. In the presence of light, the pigment was also very stable, showing more than 90 percent of remaining absorbance during 14 days at $25^{\circ}C$. The stability of the pigment, when metal ions were present, showed higher stability in all examined metal ions except for $Fe^{2+}$, $Al^{3+}$, and $Cu^{2+}$, especially in the presence of $Na^+$. The pigment has activity of freeradical scavenging ($IC_{50}$ $208.6{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $ 96.4{\mu}g$/m) against DNA damage in human lymphocytes. The result indicates that the bacterial pigments from marine bacteria, Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14 showed higher physicochemical stability and significant effects for reduction in oxidative DNA damage. Therefore, the results suggest that these bacterial pigments could be used as a natural colorant having the advantages of antioxidant.