• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1994.06a
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• pp.17-22
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• 1994

Food additives are minor components which are used to enhance nutritive or sensory values, and to improve shelf life of foods. In foods, natural additives are preferred over artificial or synthetic materials because of concern on food safety. Many biotechnological techniques have been applied to the production of food additives since the biotechnology has been utilized to prodyce many flavor components such as glutamate, 5'-nucleotides, esters, 2,3-bytadione, pyrazines, terpenes, and lactones. Natural flavors, fragrances, sweetners, and colorants can be produced by plant cell culture. Many lactic acid bacteria produce bacteriocins such as nisin or diplococcin. These bacteriocins are used as safe preservatives in foods and many researches on the improvenment of bacteriocin productivity by genetic engineering are in progress.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1994.06a
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• pp.41-49
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• 1994

The meanings, classification, and regulatory status of 'natural food colorants' are discussed. Nowadays the technological advances for processing Cochineal color is flourishing here and aboard, makes highly concentrated products (e.g., 95% Carminic acid) is comercially available. Application of carminic acid for a food system needs target-specific formulation, mixing with alumn, tartaric acid, and other salts to stabilize the color hue in food system. On the other hand, carmine, the aluminium-lake of carminic acid, is more convenient product to be used and would give more strong color. Of these reasons Carmine is much popular product than Cochineal extract in Western and European countries. We insist that carmine should be also certified as natural colorant together with Cochineal extract in Korea. Authors expect that several kinds of anthraquinone colorant (Lac and Kermes) would be introduced in Korean market in near furture.

• Fashion & Textile Research Journal
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• v.15 no.4
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• pp.635-641
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• 2013

This study examined the dye-properties of natural fabrics dyed with Coptis chinensis and Curcuma longa root fermented with fungi. The optimum culture conditions for the fermentation of microorganisms, the relationship between natural dye color and fermentation conditions were investigated. Two different medical herbs (ground to 80-100 mesh in size) were used as a natural dyeing source. Phellinus linteus (P. linteus), which can grow in different media, such as Agarmedium (only agar containing medium), maltose extract agar (MA) and potato dextrose extract agar (PDA) culture media, were isolated from the medium. P. linteus was confirmed to be the optimum microorganism for the fermentation of Coptis chinensis and Curcuma longa, and the MA medium was confirmed to be the best for culturing. When using the microorganism as the fermenting agent, $32^{\circ}C$ was found to be the optimum fermenting temperature for both natural colorants. Regarding the dyeing property of the fermented natural dye, silk was dyed quite darkly in an appearance by naked eye estimation and the K/S value in the color strength of silk reached a high level of 16 after the fermenting process. The washing fastness of dyed silk after treatment washing was reduced from 4 to under4 and indicates that dyed silk with fermented plant was not unsubstantial. The light fastness was 1 to 2, showing intended to maintain due to the fermentation process.

• Fashion & Textile Research Journal
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• v.10 no.2
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• pp.260-266
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• 2008

Recently there has been a growing interest in the use of natural dyes in textile applications. Natural dyes can exhibit better biodegradability and generally have a higher compatibility with the environment. In this study, the colorants of clove were extracted with boiling water. Chitosan crosslinked cotton fabrics have been dyed with aqueous extract of clove and their dyeabilities on the fabrics were studied. Additionally the fastness to washing and light, and the effects on antimicrobial properties were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(clove) by the chemical linking of chitosan to the cellulose structure. This process was applied by means of the conventional mercerizing process. The chitosan finishing and durable press finishing of the cotton fabrics occurred simultaneously in the mercerization bath. The dyeability(K/S), which was obtained by CCM observation, remarkablely became increased when the crosslinked chitosan concentration was higher. The hue value indicated reddish yellow with increasing the crosslinked chitosan concentration. And the color fastness to washing and light was the almost the same. The chitosan treated cotton fabrics showed very high activities with almost 100% reduction.

• Journal of the Korean Home Economics Association
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• v.41 no.7
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• pp.13-24
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• 2003

Recently there has been interested in the use of natural dyes in textile applications. Generally natural dyes can exhibit better biodegradability and have a higher compatibility with the environment. In this study, cotton, wool and silk fabrics were dyed with alkali extract of Arecae semen using various mordants, and their dyeabilities were discussed. Additionally the fastness to washing, perspiration, light, rubbing, and drycleaning and UV-B protection rate were also investigated. Cotton, silk and wool fabrics dyed with alkali extract of Arecae semen were colored in reddish yellow tint. The optimum dyeing condition of the colorants extracted from the Alecae semen was three repeated dyeing at $95^{\circ}C$ for 1.5 hrs. The dyed fabrics by using mordanting methods improved the fastness to washing, perspiration and drycleaning, but the fastness to light and rubbing were not increased. The UV-B protection rate of the wool fabrics were increased by dyeing with extract of Arecae semen.

• Food Science and Preservation
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• v.22 no.1
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• pp.129-133
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• 2015

The antioxidant potentials of ten kinds of medicinal plants used as natural dyeing agents were tested. Among the plant extracts and floral waters that were examined in this study, the antioxidant activities of the DPPH and ABTS radical scavengers increased with increasing amounts of the extracts. The hot-water extracts from Aphis chinensis, Caesalpinia sappan L., Rumex crispus L., and Areca catechu effectively inhibited the DPPH and ABTS radicals at concentration below 0.1 mg/mL. The floral water obtained through steam distillation from Areca catechu, Rubia akane Nakai, Coptis chinensis, and Phellodendron amurense showed relatively valid antioxidant activities. In particular, the natural colorants extracted from Rumex crispus L., Areca catechu, and Aphis chinensis effectively suppressed the photogenerated singlet oxygen induced by a photosensitizer in in-vitro assay systems. The concentrations ($IC_{50}$) of the hot-water Aphis chinensis extract required to exert a 50% reduction effect on DPPH, ABTS, and singlet oxygen were found to be 8.5, 8.0, and $210{\mu}g/mL$, respectively. The study results suggest that extracts derived from naturally occurring colorants as well as floral waters could be used as natural antioxidants in the food and health-care industries.

• Textile Coloration and Finishing
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• v.23 no.2
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• pp.90-99
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• 2011

The aim of this study is to develope eco-printing method using natural pigments and chitosan as a natural binder. Three chitosans with different molecular weights were employed to find appropriate conditions including chitosan concentration and pigment/binder ratio. Dye uptake, color and fastnesses of the printed fabrics were evaluated to find optimum conditions within the range of experiments carried out in this study. The effectiveness of chitosan as a printing binder was examined in comparison with color, dye uptake, and fastnesses of conventional synthetic binder and guar gum. It was found that chitosans with low or medium molecular weight were appropriate. Using low molecular weight chitosan, optimum concentrations were 1.7% for charcoal, madder and chlorophyll, whereas 2.2% for ocher, yellow soil, indigo and cochineal. Regardless of molecular weight and concentration of chitosan, the color fastnesess of fabrics printed with mineral pigments were superior to those of the fabrics printed with plant and animal pigments. As pigment/chitosan ratio became higher, rubbing fastness was decreased by 1-3 grade. The colorfastness of printed fabric with chitosan binder was similar to that with synthetic binder, which was higher than that with guar gum.

• Textile Coloration and Finishing
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• v.20 no.3
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• pp.8-17
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• 2008

For the purpose of standardization and practicability of natural dyeing, the mordanting and dyeing properties of turmeric was studied. In this study, the colorants of turmeric were extracted with boiling water. Chitosan-crosslinked cotton fabrics was dyed with aqueous extract of turmeric and their dyeabilities on the fabrics were studied. Additionally the fastness to washing and light were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(turmeric) by the chemical linking of chitosan to the cellulose structure. The chitosan finishing and durable press finishing of the cotton fabrics occurred simultaneously in the mercerization bath. The dyeability(K/S), which was obtained by CCM observation, remarkably became increased when the crosslinked chitosan concentration was higher. Dyeability of turmeric was improved on chitosan-crosslinked cotton fabric rather than only cotton fabric, while the saturated dyeing time was 20minutes at $60^{\circ}C$. The hue value indicated greenish yellow with increasing the crosslinked chitosan concentration. And the color fastness to washing and light was almost the same.

• Textile Coloration and Finishing
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• v.27 no.2
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• pp.142-148
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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. Dyeing onto cotton fiber was carried out to study the effect of dyeing conditions and mordanting effect on dye uptake, color change, and colorfastness. FT-IR analysis supported that hydrolyzable tannins were contained in the extracted colorant. Metasequoia cone colorant showed low affinity to cotton fiber and maximum dye uptake was obtained at pH 3.5 showing YR Munsell color. Mordanting improved dye uptake regardless of mordant type, 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 fabric with mordanting showed YR Munsell color except of the Fe($FeSO_4{\cdot}7H_2O$) mordanted sample showing Y Munsell color. Colorfastness to rubbing and washing was relatively good, whereas lightfastness of the dyed fabrics was above grade 3/4 except that the dyed samples with Fe mordanting showed grade 2. It is necessary to apply Metasequoia cone colorant onto other fibers, especially protein fibers, for evaluating its efficacy as a new natural dye resource.

• Fashion & Textile Research Journal
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• v.10 no.3
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• pp.377-384
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• 2008

For the purpose of standardization and practicability of natural dyeing, the mordanting and dyeing properties of gallnut was studied. In this study, the colorants of gallnut were extracted with boiling water. Chitosan crosslinked cotton fabrics were been dyed with aqueous extract of gallnut and their dyeabilities on the fabrics were studied. Additionally, the fastness to washing and light were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(gallnut) by the chemical linking of chitosan to the cellulose structure. The chitosan finishing and durable press finishing of the cotton fabrics carried out simultaneously in the mercerization bath. The dyeability(K/S), which was obtained by CCM observation, remarkably increased as the concentration of chitosan was high. Dye ability of gallnut showed higher toward chitosan treated cotton than controlled cotton fabric under condition at $60^{\circ}C$, for 20 min. The hue value indicated reddish yellow with increasing the crosslinked chitosan concentration. And the color fastness to washing and light was the almost the same.