• Textile Coloration and Finishing
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• v.20 no.1
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• pp.1-7
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• 2008

The study has attempted to introduce a new coating than the conventional standardized method of spray, padding and roll coating. The study has focused on finding condition for separating water and organic layer in marble bath and surface effects according to kind of raw hide. It was found that dyestuff-free was to be used in water layer and the input amount of initial insoluble pigment to be added in marble bath should be adjusted following the change of surface area of the marble bath in order to get efficient marble effect while preventing coagulation of water and organic layers. Eventually, amorphous high value-added leather could be obtained treated in process other than the conventional standardized method. Even raw hides of low grades($C{\sim}E$ grades) could be processed into amorphous marble effect that could conceal or shield surface scratches by the colorant, which eventually eliminated necessity of using excessive amount of chemicals in the coating process leading to achieving high quality marble leather of natural look.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2012.05a
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• pp.124-125
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• 2012

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.281-287
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• 2015

The aim of this study was to investigate the possibility utilizing Metasequoia(Metasequoia glyptostroboides) cone as a new natural dye resource. In previous study, dyeing onto cotton fiber was carried out and Metasequoia cone colorant showed low affinity to cotton fiber and maximum dye uptake was obtained at pH 3.5 showing YR Munsell color. For further evaluation of its efficacy as a new natural dye resource, effects of dyeing conditions and mordanting on dye uptake, color change, and colorfastness were investigated for silk fiber. Metasequoia cone colorant showed good affinity toward silk fiber showing YR Munsell color and maximum dye uptake was shown at pH 3.5. Post-mordanting with Cu and Fe improved dye uptake, especially Fe($C_5H_{10}FeO_6$) mordant was effective as much as 2 times higher dye uptake comparing with un-mordanted sample. The color of dyed fabrics with mordanting showed YR Munsell color. Fe mordanted fabrics appeared dark gray~black color. Colorfastness to washing was relatively good, whereas lightfastness of the dyed fabrics showed grade 2. It was confirmed that Metasequoia cone colorant can be used as a new dye resource for silk fiber getting brownish yellow to dark gray/black color depending on mordant type. In addition, it showed antimicrobial functionality.

• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.631-639
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• 2018

The purpose of this study was to investigate the characteristics of macaroons prepared using natural color materials (Opuntia ficus-indica var. saboten (Re-N), mulberry leaf (Gr-N), pumpkin (Ye-N), and cocoa powder (Br-N)) and corresponding artificial food colorants (red (Re-A), yellow (Ye-A), green (Gr-A) and brown (Br-A)). The moisture content of macaroons prepared using natural color material was higher compared to the macaroons prepared using artificial food colorant. DPPH and ABTS radical scavenging activity was similar in both types of macaroons. Lightness and redness of Re-N, Gr-N, Ye-N, and Br-N macaroons were lower than Re-A, Gr-A, Ye-A and Br-A macaroons. Yellowness of Re-N was higher because of the browning reaction. The texture profile analysis revealed lower hardness when natural color powder was employed. In the sensory evaluation, overall acceptability was not significantly different between natural colored and artificial colored macaroons. As a result, macaroons with the natural color material were softer and showed higher antioxidative activity, however, organoleptic properties were not much different when compared with macaroons with artificial colors. Apparently, it is stated that more studies on the development of macaroons with more enhanced physical functionality and good taste using natural materials should be performed.

• The Korean Journal of Food And Nutrition
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• v.12 no.1
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• pp.85-90
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• 1999

The characcteristics of anthocyanin pigments from crab apple (Malus prunifolia Wild. Borkh. "red fruit") by ethanol extract were investigated at various condition of light temperature sugar, organic acid me-tal ion and pH. The pigments were stable(over the 60%) on the light irradiation throughout 20 days sto-rage period at room temperature and in the pesenc of Al-foil red blue green and yellow cover were rage period at room temperature and in the pesence of Al-foil red blue green and yellow cover were very stable. The pigments also showed high thermal stbility(over the 67% at 115$^{\circ}C$ 10min) at pH2.5 respectively. The pigments with added organic acid greatly increased thickness of red color. The pig-ments with added metal ions at pH 2.5 such as Na+ K+, Mg2+ Ca2+ and Mn2+ were stable throughout 20 days storage period at $25^{\circ}C$. But Cu2+ addition showed the rapidly degradation of the pigments and Al3+ addition induced the color conversion from red to redish violet. The thickness of the red color of anthocyanin pigments increased increased as the pH decreased. These results indicated that crab apple antho-cyanin pigments might be potental source of natural food colorant. colorant.

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.389-392
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• 1986

To evaluate a pigment of the flower of cockscomb, Cclosia critata. as a natural food colorant, jelly-po, candy and sherbet were chosen as model foods and colorized to red with the pigment of the flower. Color changes were evaluated by analyses with Hunter color difference colorimeter. Lovibond tintometer and UV-visible spectrophotometer. Also sensory evaluation was carried out. The results obtained indicated that the red pigment of the flower had a good potential as food colorant, when it is utilized under the certain limited conditions: low water activity such as candy or low temperature. Data obtained indicated good correlation between instrumental analyses and sensory evaluation as well.

• Textile Coloration and Finishing
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• v.17 no.2 s.81
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• pp.10-18
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• 2005

Silk fabrics mordanted with $Fe^{2+},\;Ni^{2+},\;and\;Cu^{2+}$ were dyed with the aqueous extract of Cassia tora L. seed which was known to include water soluble colorant kaempferol, one of flavonol compounds. Kaempferol can react with free radicals and chelate transition metal ions, which is thought to catalyze processes leading to the appearance of free radicals and have antioxidant activity. In relation to the coordinating and chelating mechanism of the ions with the silk protein and kaempferol, reasonable conclusions should be made on the colorant uptake and the water fastness of the fabric. The amount of the colorant on the fabric was in the order of $Fe^{2+}>Ni^{2+}>Cu^{2+}$. In case of dyeing through coordinaiton bonds between transition metal ions and silk protein and colorants, it was thought that the ions with the smaller secondary hydration shell, the higher preference to the atoms of the ligand coordinated, and the suitable bonding stability for the substitution of primarily hydrated water molecules for colorants led to the higher colorant uptake. The water fastnsess of the fabric was in the order of $Fe^{2+}>Cu^{2+}>Ni^{2+}$. It should be reasonable to choose transition metal ions with weak and strong tendency to the ionic and the coordination bond, respectively, to the carboxylate anion of the silk protein. Although further research needs to be done, the conclusions above may be generally applied to the natural dyeing through the coordination bond mechanism between transition metal ions and colorants and substrates.

• Journal of the Korean Home Economics Association
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• v.38 no.9
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• pp.119-130
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• 2000

The purpose of this study was to confirm the possibility of screen printing with Natural dyes. The coloring matter such as sappan wood was used in order to obtain the colorant powder through the processes of extraction, low pressure concentration and the spray dry. After the screen printing on silk and cotton fabrics with colorant, K/S value changes of color and color fastness were measured. The main resets were as follows : 1. The viscosity of printing thickeners of sappan wood powder was about 15,200 cps, and the highest K/S value of the fabrics printed with sappan wood was obtained at 90$\pm$2$\^{C}$ of steaming temperature and 80 minutes of steaming time. 2. For the fabrics printed with sampan wood, adding of urea was not effective, since the more the concentration of urea increased, the more K/S values decreased. 3. For the natural dyes printing, the more the concentration of colorants increased, the more K/S values increased. In general, the K/S values of the printed fabrics were higher when treated with mordants rather than without mordants. Specifically, the λmax sappan wood was 520∼570 nm, and the K/S value was highest when treated with Cu mordant and lowest when treated with Sn. 4. Generally, the color fastness was relatively fair.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.55-55
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• 2012

To improve the deodorizing and antibacterial performance of various fabrics (cotton, silk and wool) dyed with pomegranate(Punica granatum L.) extract without mordants, natural colorant solutions, which were extracted from pomegranate using water as an extractant at $90^{\circ}C$ for 90 min with a various liquor ratio (solid natural colorant material/solvent water, weight ratio) from 1:100 to 1:5 were used. To achieve the highest K/S and the deodorizing and antibacterial performance, the best liquor ratio, dyeing bath ratio, dyeing temperature and dyeing time were found to be 1:10, 1:50, $80^{\circ}C$ and 60 min, respectively. The deodorizing performance of dyed cotton, silk and wool fabrics against acetic acid vapor were found to be95,70,90%,respectively. However, all the dyed fabrics displayed outstanding deodorizing performance(99%) against ammonia gas and antibacterial performance(bacteriostatic reduction rate:99.9%) against Staphylococcu aureus and Klebsiella pneumonia(bacteriostatic reduction rate: 99.9%). It is worth noting that pomegranate (Punica granatum L.) colorants notably enhanced the deodorizing and antibacterial performance of cotton, silk and wool fabrics.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.756-762
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• 1996

In order to develop the method for mass production of natural food colorant from Monascus anka, optimum cultivation conditions for producing red and yellow pigments by cultiva- ting the mold in a jar fermenter and their color characteristics were investigated. The mold produced red and yellow pigments both intracellularly and extracellularly. These pigments showed unique light absorption characteristics with maximum absorption of 494, 380, 506, and 388 nm for extracellular red pigment (ERP), extracellular yellow pigment (EYP), intracellular red pigment (IRP), and intracellular yellow pigment (IYP), respectively. Optimum conditions for producing red pigments were found to be temperature 30$\circ$C, initial pH 6.0, rice powder 3-5%, peptone 0.05%, magnesium sulfate 0.25%, aeration rate 0.1 vvm. Optimum temperature for producing yellow pigments was around 35$\circ$C which is higher than that of producing red pigments. The initial pH and rice powder concentration for producing yellow pigments were the same as those of producing red pigments. The higher concentration of nitrogen source and inorganic salt, aeration rate, the more the yellow pigments were produced. The optimum agitation speed was 100 - 300 rpm for pigment production.