• 한국식품과학회지
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• 제34권6호
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• pp.977-983
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• 2002

식용색소 및 공업용 염료의 인공적 착색여부를 조사한 결과, 심황색소, 식용희석황색소, 마리골드색소, 식용황색 4호, 안나토색소, 카로틴색소는 유사한 색으로 착색되었으며 다른 색소는 착색되지 않았다. 물에 의한 추출시험에서는 참조기 색소와 식용색소황색 제4호는 물에서 용출되지 않았다. 착색 후 색소의 물성실험을 한 결과 물 젖은 가제수건이나 휴지로 색소부위 표피를 문지를 경우 참조기 색소는 표면에 전혀 묻어 나오지 않으나 인공적으로 착색된 색소의 경우에는 물에 의해 색이 뚜렷하게 묻어 나왔으며 참조기의 착색 부위 표피를 아세톤으로 추출할 경우 참조기 색소는 아세톤에 옅은 황색용액으로 추출되었다. 또한, 참조기의 색소처럼 물에 용출되지 않도록 염착이 가능한 공업적 합성염료인 반응성 염료와 분산염료의 착색거동에 대해 실험한 결과, 반응성 염료는 조기에 착색되지만 물 젖은 휴지로 착색부위를 문지를 경우 색소가 용출되었고, 아세톤에는 추출되지 않아 참조기 색소와는 쉽게 판별되었으며 분산염료는 염료가 고르게 착색되지 않고 염료가 입자를 형성하며, 물 적신 휴지로 색소부위를 문지를 경우 색소가 용출됨을 알 수 있었다. 카로틴색소(참조기 색소와 구조가 유사한 색소)와 azo염료의 산화 환원 반응에 따른 소색 반응에서는 산화반응에서 azo염료는 sodium percarbonate와 peracetic acid에서는 소색이 되지 않았으나, fenton시약에서는 1시간 후 소색되었고, sodium hypochlorite에서는 바로 소색되었다. 이에 비하여 카로틴색소는 sodium percarbonate 및 fenton시약에서는 소색되지 않았으나, sodium hypochlorite에서는 2시간 후 소색되었고, peracetic acid에서는 바로 소색되었다. 또한, sodium hydrosulfite, sodium carbonate를 사용한 환원반응시험에서는 azo염료는 소색되었으나, 카로틴색소는 소색되지 않았다. 이러한 결과를 통해 두 색소의 특징적 group을 제거할 때 나타나는 소색 결과를 토대로 진품참조기와 모조참조기의 판별에 이용할 수 있을 것으로 사료된다.

• Journal of Applied Biological Chemistry
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• 제60권3호
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• pp.249-256
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• 2017

The Monascus azaphilone (MAz) pigment is a well-known food colorant that has yellow, orange and red components. The structures of the yellow and orange MAz differ by two hydride reductions, with yellow MAz being the reduced form. Orange MAz can be non-enzymatically converted to red MAz in the presence of amine derivatives. It was previously demonstrated that mppE and mppG are involved in the biosynthesis of yellow and orange MAz, respectively. However, ${\Delta}mppE$ and ${\Delta}mppG$ knockout mutants maintained residual production of yellow and orange MAz, respectively. In this study, we deleted the region encompassing mppD, mppE and mppG in M. purpureus and compared the phenotype of the resulting mutant (${\Delta}mppDEG$) with that of an mppD knockout mutant (${\Delta}mppD$). It was previously reported that the ${\Delta}mppD$ strain retained the ability to produce MAz but at approximately 10% of the level observed in the wildtype strain. A chemical analysis demonstrated that the ${\Delta}mppDEG$ strain was still capable of producing both yellow and orange MAz, suggesting the presence of minor MAz route(s) not involving mppE or mppG. Unexpectedly, the ${\Delta}mppDEG$ strain was observed to accumulate fast-eluting pigments in a reverse phase high-performance liquid chromatography analysis. A LC-MS analysis identified these pigments as ethanolamine derivatives of red MAz, which had been previously identified in an mppE knockout mutant that produces high amounts of orange MAz. Although the underlying mechanism is largely unknown, this study has yielded an M. purpureus strain that selectively accumulates red MAz.

• 한국세라믹학회지
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• 제46권4호
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• pp.397-404
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• 2009

Using rice husk ash as silica, the influence of the firing temperature and holding time on the color intensity of Pr-$ZrSiO_4$ pigments were investigated. The Pr-yellow pigments were calcined at 500, 700, 800, 900, 950, 1000, $1100^{\circ}C$ in a ceramic method. The synthesized pigments were characterized by DT-TG thermal analysis, X-ray diffraction, UV-Vis spectroscopy, and SEMEDAX analysis. The relationship between the zircon phase-formation growth and Pr-yellow color development was evaluated and the optimum firing conditions were determined. The color of the pigment samples was characterized on the grounds of the Commission Internationale de l'Eclairage (CIE) standard procedure (CIE $L^*a^*b^*$ measurement) after an application on the bisque ceramic tile.

• Natural Product Sciences
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• 제21권4호
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• pp.255-260
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• 2015

Two new thiodiketopiperazines (TDKPs), designated graphiumins I (1) and J (2), were isolated from the culture broth of the marine-derived fungus Graphium sp. OPMF00224 by solvent extraction, silica gel column chromatography, and HPLC. Their absolute structures were elucidated by spectroscopic analyses (1D and 2D NMR data, ROESY correlations, and CD data) and chemical methods. They were found to be structurally rare TDKPs with a phenylalanine-derived indolin substructure. Compounds 1 and 2 inhibited yellow pigment production by methicillin-resistant Staphylococcus aureus (MRSA) with $IC_{50}$ values of 63.5 and $76.5{\mu}g/ml$, respectively, without inhibiting its growth, even at $250{\mu}g/ml$.

• 한국세라믹학회지
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• 제56권3호
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• pp.298-301
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• 2019

This paper details the synthesis of α-FeOOH (goethite) rods through the reaction of iron (III) nitrate with KOH as a strong base, and shape control of the particles for use as a yellow inorganic pigment. The crystal phase of the α-FeOOH crystal with OH content according to the addition of KOH and the change in morphology were investigated. The optical properties varied with the aspect ratios, and the yellowness increased with increasing aspect ratio. However, the enhanced chromaticity characteristics reversed beyond a certain critical aspect ratio. Thus, the relative optimal aspect ratio of the α-FeOOH rods as a vivid yellow inorganic pigment was derived. The morphology and coloration of the prepared rods were investigated in detail using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy, and CIE Lab color parameter measurements.

• 대한화학회지
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• 제4권1호
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• pp.27-37
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• 1957

High-fire stain is influenced by the conditions of glaze, firing atmosphere, etc. On the contrary, low fire stain is not influenced by those conditions but obtainable in arbitrary colors and it is indispensable for pottery decoration. It is difficult for us to study into the color in the sphere of result publication method and expression of color. Looking over the literature on this subject, I have been confronted with much difficulties, accordingly, I made a basic and systematic experiment as to six low-firing stains (blue, green, blue-green, brown black and yellow) and made it proper to be applied in these studies. On pigment, I confirmed the influence of the assistant coloring matter by mixing up the coloring matter and the assistant coloring matter in various proportions. On flux, I measured the melting point by making PbO-$SiO_2$ system and PbO-$B_2O_3-SiO_2$ system and decided the range of usage. Also I checked the coloring by making the pigment on laze with pigment and flux manufactured, and concluded the pigment and flux adaptation to it.

• 한국식품위생안전성학회지
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• 제11권2호
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• pp.123-127
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• 1996

The isolation and chemical characterization of yellow food pigments from Monascus purpureus were studied according to the compositions of media. Monacus yellow pigments were isolated and purified by solvent fractionation, silicagel column chromatography, TLC and HPLC. The retention time of Monascus yellow pigments isolated by HPLC was respectively 5 min(I) and 9 min(II) as the yeast malt extract agar(YMA) media and was respectively 4.6 min(III), 5 min(I) 5.7 min(IV), 8.3 min(V), 9 min(II) and 10.7 min(Ⅵ) at the malt extract agar(MEA) media. The structure of monascin(I), ankaflavin(II), 6,11-dihydrorubropunctatin(III), 6,11-dihydromonascorubrin(V) and unknown compounds(IV,Ⅵ) was elucidated by EI-Mass, H and C NMR, UV-visible spectrometer. Therefore, it was suggested that 6,11-dihydrorubropunctatin(III) and 6,11-dihydromonascorubrin(V) are new intermediates of Monascus yellow pigments.

• 한국미생물·생명공학회지
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• 제8권2호
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• pp.119-123
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• 1980

누룩으로부터 사상균을 분리하여 우수한 색소 생산균주를 선별하였고 이를 형태학적으로 분지 동정하였다. 배양조건으로 pH, 탄소원, 질소원, 무기염류, 통기효과 및 배양기간 등이 황색 색소 생산에 미치는 영향을 조사하여 다음과 같은 결론을 얻었다. 1. 선별된 색소 생산 균주를 형태학적으로 균사에 격벽과 균사체 끝에 피자기를 가지고 자낭포자와 분생포자를 형성하며 후막포자가 있는 Monascus 속으로 동정 되었다. 2. 색소생산의 최적 PH는 4.5 부근이었으며 질소원으로 yeast extract 0.2%, 탄소원으로 sucrose 3 % 첨가가 양호하였다. 무기염류에 대한 영향으로 KH$_2$PO$_4$및 MgSO$_4$.7$H_2O$ 0.1% 첨가가 좋았으며 통기효과는 75/500m1 (v/v) 배양기간은 3일이 적합하였다.

• 한국식품영양학회지
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• 제26권1호
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• pp.78-84
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• 2013

To reproduce the brewing process of Hongkuk-ju and to identify the functional properties of it, Hongkuk-ju was brewed using different additions of Hongkuk (100%, 90%, 70%, 50%) and Nuruk (0%, 10%, 30%, 50%). The quality elements, including pH, total acidity, reducing sugar content, alcohol content and pigments (yellow, red, monacolin K and citrinin), were measured. The pH values of Hongkuk-ju showed a slight difference (pH 4.08~4.58) right after the $1^{st}$ stage mash; further, the pH on all groups (H1, H2, H3 and H4) in the terminal of the $2^{nd}$ stage mash (9 days in fermentation) were similar, ranging approximately at pH 3.70. The total acidity change did not show a difference directly the $1^{st}$ stage mash (nearby 0.2 %); however, it began to show a slight difference at the terminal of the $2^{nd}$ stage mash between the range of 0.69~0.76%. The residual reducing sugar of the content was decreased with the increased Nuruk content. The alcohol concentrations of the treatment brew with Nuruk ranging from 12.3% to 13.7% were higher than Hongkuk on its own. The yellow and red pigment contents of Hongkuk-ju ranged from 7.2~8.8 O.D. units (yellow pigment) and from 4.4~5.1 O.D. units (red pigment). The production of monacolin K and citrinin was the highest (9.48 mg/kg and 10.14 mg/kg) when the treatment solely brewed Hongkuk. The concentration of Nuruk and the preparation of the seed mash from it were critical factors compared to the treatment of rice in brewing Hongkuk-ju.

• 한국분말재료학회지
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• 제25권5호
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• pp.379-383
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• 2018

Silica is used in shell materials to minimize oxidation and aggregation of nanoparticles. Particularly, porous silica has gained attention because of its performance in adsorption, catalysis, and medical applications. In this study, to investigate the effect of the density of the silica coating layer on the color of the pigment, we arbitrarily change the structure of a silica layer using an etchant. We use NaOH or $NH_4OH$ to etch the silica coating layer. First, we synthesize ${\alpha}-FeOOH$ for a length of 400 nm and coat it with TEOS to fabricate particles with a 50 nm coating layer. The coating thickness is then adjusted to 30-40 nm by etching the silica layer for 5 h. Four different shapes of ${\alpha}-FeOOH$ with different colors are measured using UV-vis light. From the color changes of the four different shapes of ${\alpha}-FeOOH$ features during coating or etching, the $L^*$ value is observed to increase and brighten the overall color, and the $b^*$ value increases to impart a clear yellow color to the pigment. The brightest yellow color was that coated with silica; if the sample is etched with NaOH or $NH_4OH$, the $b^*$ value can be controlled to study the yellow colors.