• Textile Coloration and Finishing
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• v.27 no.4
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• pp.229-244
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• 2015

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.73-80
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• 1998

This Study was performed to get the suitable oil dispersion agent by assessment of color strength of organic pigment in non-aqueous systems. Organic pigment is used as a color expression material with other body pigments in the make-up products. But occasionally aggregation or agglomeration occurs for the lack of affinity with medium, This function is the cause of disturbing homogeneous dispersion, and then bring about an instability of products. Our study, research of dispersion mechanism between the pigment and oil phase, has been executed to solve this problem, and find a oil dispersion agent having optimum dispersion condition. Generally dispersion is related to between the solid-liquid mutual properties and electrical phenomena associated with solid-liquid interface. This factor is determined to input energy, milling time, optical properties, particle size, rheological properties, etc. Ideal dispersion state is told that coloring primary solid particle is homogeneously dispersed in medium. Good dispersed colorants are strongly and clearly appeared. We are already known that the particle size of organic pigment, chemical properties and viscosity of medium, refractive index. Consequently We determine the affinity of medium and organic pigment by measuring of color strength in the same mechanical condition. UV-VISIBLE RECORDING SPECTRO PHOTOMETER is used for measuring apparatus. We can decided the dispersion level of oil dispersion agent by measuring absorbance of color strength in the visible range that diluted medium for colloid colorant particles.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.4
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• pp.355-362
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• 2004

Studies on extraction and color stability of carotenoids from astringent persimmon(Diospyros kaki) were performed to provide the basic information for the utilization of persimmon pigment as a new source of natural food colorant. The major carotenoids in astringent persimmon were beta-cryptoxanthin, lycopene and beta-carotene. Beta-cryptoxanthin was the first major pigment and lycopene the next. Total carotenoid content in persimmon calculated as beta-carotene equivalent was 107.4 $\mu\textrm{g}$/g. The data indicated that the astringent persimmon was a good source of carotenoid pigment. The physical and chemical stabilities of carotenoid from astringent persimmon were investigated at various conditions of temperature, pH and antioxidant. The effects of oxygen and light on the stability of carotenoid pigment has been investigated. The factors that cause the discoloration were visible light, temperature above 60, pH below 5 and oxygen. Especially, the carotenoid pigment was very sensitive to light and oxygen. Carotenoid stability was much improved with increasing nitrogen concentration in the atmosphere. Persimmon pigments have been found to be most stable at 5∼10. And tocopherol was the most effective inhibitor of the pigment discoloration.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.325-332
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• 2016

Purpose: The purpose of this study was to investigate the stability of anthocyanin pigment extract from Yangha (Zingiber mioga ROSC). Methods: Yangha extract was investigated for the effects of metal ion, temperature, light, heating time, sugars, and organic acids on the stability of anthocyanin pigments. Results: Yangha pigment was more stable than other anthocyanin pigments at unstable temperatures. The stability of anthocyanin pigment significantly decreased one day after exposure to light. All tested sugars decreased the abundance of Yangha pigments, with highest levels in the presence of sucrose, and progressive decrease in the presence of maltose, fructose, glucose and galactose, in order. Among the organic acids tested, citric acid and malic acid were the most effective in stabilizing the Yangha pigment, followed by acetic acid and formic acid. Most metal ions except $Fe^{2+}$ were effective in stabilizing the pigment. Conclusion: These results provide useful reference data for the use of pigments from Yangha in processed foods.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.348-355
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• 1999

Effects of pH, sugars, organic acids, metal ions, ascorbic acid and light on the stability of anthocyanin pigment extracted from purple-fleshed potato (Solanum tuberosum L.) were studied. The pH had marked influences on the color of the potato anthocyanin pigment: i.e., the lower the pH of the anthocyanin solution was, the more stable and intenser of the pigment was. It showed characteristic bathochromic shift as the pH of the solution increased. Generally, the addition of sugars into the purple-fleshed potato anthocyanin solution caused decrease in color stability of the pigment. Among the sugars tested, maltose was the most deleterious followed by sucrose, galactose, fructose and glucose. The addition of organic acids greatly increased the stability of the pigment. Malic acid was found to be the most effective in stabilizing the pigment followed by tartaric, citric and succinic acids, while malonic acid was found to be deteriorative to the stability of the pigment. Most metal ions except $Cu^{2+}$ increased stability of the pigment-especially, $Cd^{2+}\;and\;Al^{3+}$ were more effective than the others. Ascorbic acid degraded the pigment considerably, but the adverse effect was diminished by adding thiourea. Light gave an adverse effect to the stability of the purple-fleshed potato anthocyanin pigment, which could be minimized by shielding the light from the pigment.

• Journal of Life Science
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• v.19 no.8
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• pp.1132-1138
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• 2009

We investigated the physicochemical stabilities and biological activities of ethanol- extracted pigment from marine bacterium Pseudoalteromonas psicida TA20. This bacterial pigment was very stable at a pH range of between 4.0 and 8.0 at a temperature below $40^{\circ}C$. In the presence of light, the pigment was also very stable, showing more than 90 percent 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 $Al^{3+}$ and $Cu^{2+}$, especially in the presence of $Fe^{2+}$. This pigment showed higher stability than other pigment extracts reported. The pigment has free-radical scavenging (3,495 ${\mu}g/ml$) activity and 44% antioxidant protective effect against DNA damage of human lymphocyte cells at a concentration of 10 ${\mu}g/ml$. The results indicate that the bacterial pigment produced a significant reduction in oxidative DNA damage. The pigment also showed antimicrobial activity against major food poisoning bacteria. Therefore, these results suggest that this bacterial pigment could be used as a natural colorant in the food industry, having the advantages of antioxidant and antimicrobial activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1405-1407
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• 1999

A carotenoid pigment, which was a determinant for food quality, was extracted from a marine halophilic bacteria. The stability of the pigment extract was investigated for a food additive. The optimum temperature for stability was 20oC. The pigment degradation was significantly affected by solvent polarity, however, stable in salvent methanol and ethanol. The pigment degradation was highly sensitive to light and UV exposure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1544-1551
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• 2004

Effects of pH, sugar, ascorbic acid, organic acids and light sources on the stability of anthocyanin pigment extracted from Korean purple-fleshed potatoes (PL-6, PL-28, PL-31 and Jasim) were studied. The pH had remarkable influence on the color stability of anthocyanin pigment. With increasing pH, the color gradually fades as colorless pseudobases are formed. In acidic pH, anthocyanin was stable, but with increasing pH the color gradually changed to colorless. The addition of sugar decrease in color stability of the pigment during storage period. The most of organic acids, such as a tartaric, citric and succinic acids, were found to improve the stability of the pigment, while malic and malonic acid reduced the stability of the pigment. The addition of ascorbic acid considerable decreased in anthocyanin pigment stability, but the effect was not decreased by adding thiourea. The effect of light sources such as a darkroom, a fluorescent light, and sunlight, reduced gradually the stability of anthocyanin pigment. Therefore the pigment degradation could be minimized by shielding the light from the pigment.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1605-1610
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• 2012

Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3). In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of $300{\mu}m$, 0.8% red pepper powder processed as a super fine powder with a vibrational mill ($44{\mu}m$) and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% $Na_2CO_3$ either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3). In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (p<0.05) for birds fed 1.2, 2.4 or 9.6 ppm red pepper pigment than for birds fed the diet containing 0.3 ppm red pepper pigment. On d 14, egg color scores increased linearly as the level of red pepper pigment in the diet increased. In Exp. 2, feeding red pepper powder did not affect egg-laying performance, feed consumption or feed conversion ratio (p>0.05). However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (p<0.05). All the red pepper powder treatments also increased (p<0.05) the yolk color score compared with the control. The results of the present study suggest that both red pepper powder and pigment are effective feed additives for improving egg yolk color for laying hens.

• Applied Microscopy
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• v.27 no.4
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• pp.357-372
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• 1997

To study the age-related morphological differences of the retinal pigment cells and Bruch's membrane of mouse, retinae of one week-old, five weeks-old, eight weeks-old, six months-old, twelve months-old, eighteen months-old, twenty-four months-old and thirty months-old ICR mice were dissected out under anesthesia. Pieces of the tissue taken from the posterior region of the retina were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde (0.1 M Millonig's phosphate buffer, pH 7.3), and 1% osmium tetroxide (0.1 M Millonig's phosphate buffer, pH 7.3), and embedded in araldite mixture. The ultrathin sections were stained with uranyl acetate and lead citrate, and were observed under a JEM 100 CX-II electron microscope. Observed results were as follows: 1. Retinae of one week old mouse exhibit that some parts of the pigment cell provided with basal foldings, whereas other parts of the one contain without basal foldings. After (ive weeks-old, all retinal pigment cells have the basal infoldings. 2. In the one week-old, stage 1 and stage 2 melanosomes were observed in the retinal pigments cells, but after five weeks-old, most of the retinal pigment cells contain some matured stage melanosomes (stage III and stage IV). 3. The phagosomes in the retinal pigment cells were increased during aging. 4. After eighteen months-old, electron dense materials are observed within the basal infoldings. 5. After eighteen months-old, the thickness of the Bruch's membrane is prominently increased. The thickness of the basal laminae of the pigment cell and the choriocapillary endothelium is more prominently increased as compared with that of the other components of the Bruch's membrane. 6. The thickness of the basal lamina of the pigment cell is more prominently increased as compared with that of the choriocapillary endothelium on aging. From the above results, it was suggested that the pigment cell and Bruch's membrane matures structurally In five weeks, and the function of the pigment cell is prominently suppressed around eighteen months-old, and thereafter the functional suppression is continued on aging.