• The Korean Journal of Food And Nutrition
• /
• v.11 no.4
• /
• pp.375-380
• /
• 1998

A study of characteristics of greenish pigments from silkwarm excrement by ethanol extraction. Through visible absorption scanning, it showed two absorption peaks at 415 and 657nm, and it was shown to be greenish color. In the presence of light, the stability of pigments rapidly degraded, but in the presence of Al-foil, green and blue cover were very stable. It was shown to be stabilized at the temperature of 7$0^{\circ}C$ until 20days and presence of metal ions, such as Na+, K+, Ca2+, Mg2+ and Zn2+. The pigments was shown to be stabilized in 5% acetic acid solution, but in the presence of lactic acid, citric acid and tartaric acid solution were unstable. On the result of TLC analysis, pigments were shown to be composed of eight color fractions, and main color fractions were F-1, F-2 and F-3. In F-1, F-2 fractions were revealed green color and F-3 fraction were revealed yellow color.

• Korean Journal of Food Science and Technology
• /
• v.26 no.1
• /
• pp.93-97
• /
• 1994

A study of physical and chemical characteristics of pigments from Rhodopseudomonas viridis DSM 133 was carried out for development of natural greenish colorant. Through visible absorption scanning, it showed three main absorption peaks at 378, 414 and 677 nm with three minor peaks at 510, 540 and 618nm, and it was shown to be greenish color. These pigments were more stabilized in alkaline solutions than in acid of between pH 6 and 9, and it was shown to be stabilized at the temperature below $40^{\circ}C$. In the presence of light and oxygen, the stability of pigments rapidly degraded, and it became unstable in the presence of metal ion such as $Fe^{3+}$ and $Al^{3+}$. But in the presence of $Cu^{2+}$ were very stable. On the result of TLC analysis, pigments were shown to be composed of four color fractions and main color fractions were F-4 and F-2.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.3
• /
• pp.460-469
• /
• 1996

This study was intended to observe the physicochemical and sensory characteristics of anchovy added kimchi during fermentation at 4$^{\circ}C$ for 4 weeks. Salting of Chinese cabbage for 10 hours at 10% brine solution was turned out to be appropriate organoleptically for kimchi preparation. Salt content of all kimchies prepared in this study was below 2%. The changes of pH and acidity during fermentation was slow in raw anchovy added kimchi compared to other kimchies. The content of vitamin C was not changed significantly through the fermentation period, whereas the content of reducing sugar was increased at the early stage of fermentation and subsequently decreased as fermentation proceeded. The number of lactic acid bacteria was the highest in raw anchovy added kimchi. The content of calcium and phosphorus were higher in anchovy powder added kimchi and raw anchovy added kimchi than control. In the early stage of fermentation, the major pigments of kimchi were the chlorophyll and carotenoid, but in the later stage of fermentation, the color of Chinese cabbage became greenish brown as chlorophyll was converted to pheophytin. In sensory evaluation test, raw anchovy added kimchi received high score at the early stage of fermentation and anchovy powder added kimchi at the late stage of fermentation, respectively.

• Journal of the Korean Society of Costume
• /
• v.39
• /
• pp.79-89
• /
• 1998

This study was carried out the effect of stability and color extract for it's condition in the curcuma L.. dyeing. The stability is to investigate the absorbance of the curcumin, one of the major yellow pigments and the stability regarding the effect of light, oxygen temperature and pH. The dyeing condition is compared the effect of mordanting condition and the best way to extract pigment and analysed through the color-fastness rating, color-difference value test. The main results obtained are summarized as follows ; 1.The best and proper solvent to extrect curcumin pigment was a ethanol and a distilled water. 2. The light effect indicated that the absorbances of solution in absence of ligh was more stable. 3. The oxygen(O2) effect to curcumin show-ed that the condition in the absence of O2 was more stable than that in presence of O2 4. The temperature showed that the absorbnace was best stable in4$^{\circ}C$ and less changed at $25^{\circ}C$ 5. The curcumin-etanol solution was stable in pH 2~4. 6. Generally color-fastness rating to silk, wool and cotton indicated that crocking C.F. and perspiration C.F. were more than 3rd grade and dry cleaning C.F. was more than 4th grade. But light color-fastness and washing color-fastness were very poor. 7. To make good color fastness, the mordan-ting treated group and the pre-mordant conditions were more effective than others 8. When compared with color-difference value test indicated that the silk was looks like more reddish and bluish color and than the wool and cotton were greenish and bluish. As a mordant, A(C2H4OH(COOH3) and D(K2Cr2O7)were more effective to make green-ish color in the silk and the reddish color was abtained by B(Al.K(SO4)2.12H2O) and C(FeSO4.7H2O).

• Journal of the Korea Fashion and Costume Design Association
• /
• v.11 no.3
• /
• pp.135-141
• /
• 2009

In this paper, Tagetes extracts were extracted from leave, root, stem and flower at $100^{\circ}C$ for 20 minutes. Silk fabrics were dyed with Tatetes Patula L. to investigate the dyeing properties in accordance with dye concentration, pH, temperature, time of pre-, simul- and post-treatment of mordants using the three types of mordants. As a result, the surface color of the silk fabrics was yellowish regardless of the types of mordants. However, the a values were decreased and b values were increased in the order of the dyeing using Al>Cu>Fe: Al mordanted silk fabrics were appeared in greenish yellow and Fe mordanted silk fabrics were done in redish yellow. K/S values of the silk fabrics treated with Fe mordant were 3 times higher than those of Al and Cu mordants according to the increase in dye concentration. This behaviour was shown even in the increase of mordant concentration due to the interaction of mordant and pigments of Tatetes Patula L. But, the types of mordants did not affect because the equilibrium was obtained in 20 minutes in a similar way. And it showed that the highest K/S value of the silk fabrics studied was pH 4 and $80^{\circ}C$ regardless of the types of mordants.

• Journal of Conservation Science
• /
• v.35 no.6
• /
• pp.573-587
• /
• 2019

In this study, reproducing specimens were made from mixing domestically produced magnetite, clay and non-plastic raw materials to reproduce the pigments used in the manufacture of traditional cheolhwa buncheong stoneware. In order to reveal the color fomation of glaze, 30 specimens with good color development were analyzed scientifically. Magnetite, which is the main raw material of the pigment, is a pigment capable of creating a dark black color in a reducing environment at 1,200℃. However, it reacts with the additionally added lime component and discolors to greenish yellow color in oxidizing environment at 1,230℃. Hematite is not significantly affected by the firing temperature and environment, but develops a dark black color when mixed with clay with iron content of more than 10%. The fluidity of the pigment is determined by R₂O₃/RO₂ value, which also affects the color development. In the microtexture observation, the color formation of the glaze layer and the iron oxide crystals identified some differences depending on the particle size of the pigment and the firing environment. Reproduced specimens made of magnetite are present in the form of aggregates of iron oxide in the interface between glaze layer and slip layer in the oxidizing environment at 1,200℃. However, in the reducing environment, aggregates of iron oxides do not exist in the reproduced specimens, and they are homogeneously distributed in the glaze layer and formed a dark black color. In contrast, hematite-based specimens form dendritic structures in the glaze layer in an oxidizing environment and develop black.

• Korean Journal of Materials Research
• /
• v.23 no.4
• /
• pp.233-239
• /
• 2013

We collected Seokganju minerals (regions in Gyeryong Mountain, Sangsin-ri, Banpo-myeon, Gongju Chungcheongnam-province), which were used as natural color pigments for grayish-blue during the 15th~16th centuries of the Joseon era, and investigated their crystallographic features to develop a black pigment having a spinel structure. By a Raman analysis, the color of Seokganju under transparent glaze as a pigment for painting was black because hematite ($Fe_2O_3$) in Seokganju was converted to magnetite ($Fe_3O_4$) However, Seokganju into the transparent glaze as a pigment was brown because of hematite ($Fe_2O_3$) and small amounts of maghemite (${\gamma}-Fe_2O_3$) in Seokganju minerals. Only Seokganju mineral is used, it is not suitable for black pigment into the transparent glaze. This study tried to develop a spinel crystal black pigment stabilized by Seokganju with CoO, $Cr_2O_3$, NiO, and $MnO_2$ at $1280^{\circ}C$. A Raman spectroscopy analysis was performed to verify the presence of Mn The results showed that it existed as spinel, and two crystal phases $CoFe_2O_4$ and $MnFe_2O_4$ were mixed. $CoFe_2O_4$ spinel has a dark grayish black color and $MnFe_2O_4$ spinel has a greenish black color, and these two appeared as black. The color of a specimen calcined by adding 6 wt% of pigment mixed with 5 wt% of $MnO_2$ added to lime glaze was analyzed with a UV spectrophotometer. When applying the color pigment, it appeared black stabilized with $L^*$24.23, $a^*$ 0.12, $b^*$ -2.29 at $1260^{\circ}C$ oxidative calcination, With $1240^{\circ}C$ reduction firing, it is appeared black stabilized with low brightness of $L^*$ 23.13, $a^*$ -1.12, $b^*$ 0.54.