• 한국의류학회지
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• 제23권1호
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• pp.140-146
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• 1999

Colorants in green tea were extracted freeze-dried and analyzed to investigate the possibility of using as a natural dye. Fractionation of the colorants was carried out by column chromatograpy. Colorants in green tea were eluted into five fractions. All the fractions except fraction F2 showed absorption peakat 280nm. Fraction f2 showed absorption peak at 270nm and broad peak at 350nm, From the IR analysis it is speculated that fractions F2-F5 having similar stucture but different molecular weight are catechis. Silk fabrics dyes with fractions F1-F4 showed yellowish red color while sample dyed with fraction F5 showed red color. The colorants from green tea infusion was applied to silk wool nylon cotton and rayon fabrices. It showed relatively good affinity to protein and polyamide fibers bur low affinity to cellulose and regenerated cellulose fibers.

• 한국의류학회지
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• 제23권3호
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• pp.385-390
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• 1999

Dyeing properties of silk fabric with green tea colorants were studied by investigating the effect of dyeing conditions such as concentration pH dyeing temperature and time on dye uptakes and effect of mordants on color change and dye uptakes, And various colorfastnesses of dyed fabrics were evaluated for practical use. Green tea colorants showed relatively good affinity to silk fabric and produced yellowish red color. Langmuir adsoption isotherm was obtained. Therefore it is considered that ionic bondings between colorants and silk fibers are formed. Mordants did not improve dye uptakes and affect color of dyed fabrics significantly. But mordanting adversely affected lightfastness of dyed fabrics. Regardless of mordanting colorfastness to perspiration especially in alkaline condition of dyed fabrics showed low rating compared with other colorfastness. It is concluded that mordanting is not necessary for silk dyeing with green tea colorants.

• 한국의류학회지
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• 제23권4호
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• pp.510-516
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• 1999

Dyeing properties of cotton fabrics with green tea colorants were studied by investigating the effects of dyeing conditions such as colorants concentration. pH dyeing temperature and time on dye uptakes effects of mordats on dye uptakes and color change and effects of cationizing agent on dye uptakes. And various colorfastnesses of dyed fabrics were evaluated for practical use. Green tea colorants showed low affinity to cotton and produced yellowish red color. Freundlich adsorption isotherm was obtained thus it is considered that hydrogen bondings are formed between colorants and cotton. Dye uptake was maximum at pH 5 and decreased as pH increased. Mordants especially Cu and Sn were effective for increasing dye uptake. Dye uptakes were improved remarkably by cationizing. Cationized cotton showed Langumuir adsorption isotherm indicating that ionic bondings were formed between colorants and cationized cotton. While mordanting did not affect lightfastness cationizing affected adversely. Colorfastness of cationized sample was generally inferior to that of mordanted samples.

• 한국의류학회지
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• 제36권4호
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• pp.412-421
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• 2012

The yerba mate that grows in the subtropical forests of South America is an evergreen tree within the Aquifoliaceae family. The yerba mate (Ilex paraguariensis) tea is habitually used as a drink in Argentina, Paraguay, Uruguay, and Southern Brazil. A wild mate tree needs about 25 years to fully grow to 15 a height of meters; however, they only grow to a height of 3-5 meters when cultivated. The leaves are 7-11 cm long and 3-5cm wide with a serrated margin. Yerba mate tea-based beverages are made from the leaves and stems of the mate tree. It is known that they contain a rich content of antioxidants and polyphenol, vitamins, amino acids, minerals and colorants. Dyeing properties of a mate plant in the silk, wool, linen and cotton fabrics were investigated. Constituents of colorant of mate tea are chlorophyll and carotinoid; in addition, it has more minerals such as (Fe, Ca, Mn, Mg, Na, K, Zn, and Cu) than green tea. Mate tea colorants showed good affinity to silk and wool fabrics. It was found that the optimum condition for dyeing was 30 minutes for dyeing time, 7 for pH of dyebath, and at a dyeing temperature of $80^{\circ}C$. The maximum absorbance wavelength (${\lambda}_{max}$) of silk and wool fabrics dyed with mate tea were at 420-440nm; however, that of linen and cotton fabrics were at 400nm. K/S values of fabrics dyed under optimum conditions were 1.979 for silk fabrics, 1.541 for wool fabrics, 0.551 for linens and 0.465 for cotton fabrics. Munsell hue values of dyed fabrics measured 3.1Y-6.4GY for silk, 1.4Y-8.3Y for wool, 5.5Y-3.7GY for linen, and 5.3Y-1.3GY for cotton. All dyed fabrics showed hues in-between greenish yellow and greenyellow. Colorfastness to rubbing, perspiration and dry-cleaning of dyed fabrics with mate tea were very good; however, the grades of colorfastness to washing of dyed linen and cotton fabrics were poor, and colorfastness to light were poor.

• 한국식품영양학회지
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• 제32권4호
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• pp.335-341
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• 2019

Beta-carotene is the most prominent member of the group of carotenoids, natural colorants that occur in the human diet. Beta-carotene is also an effective source of vitamin A in both conventional foods and vitamin supplements, and it's generally safe. In this study, we explored the beta-carotene contents in agricultural products widely and specifically grown in Korea. The beta-carotene contents were ranging from 223 to $27,908{\mu}g/100g$ in leaves, and 0 to $7,588{\mu}g/100g$ in vegetables. In leaves and vegetables, the amount of beta-carotene was the highest in green tea powder ($27,908{\mu}g/100g$), followed by pepper ($7,588{\mu}g/100g$). In fruits, the beta-carotene content was found to range from $0{\mu}g/1,011g$ to maximum of $293.66{\mu}g/100g$(plumcot). However, there beta-carotene was not detected in strawberry. In the case of cereals and specialty crops, the beta-carotene contents were $326{\mu}g/100g$ for non-glutinous rice, $313{\mu}g/100g$ for glutinous rice, $57{\mu}g/100g$ for amaranth and $15{\mu}g/100g$ for pine nut, respectively. However, the beta-carotene content was not detected in other samples. This study revealed the presence of beta-carotene content in agricultural products specifically grown in Korea for nutritional information and food composition database.