• Title/Summary/Keyword: natural colorants

Search Result 123, Processing Time 0.017 seconds

Analysis of Dyes and Mordants of 16~17th Century Textiles Excavated from Daejeon (16~17세기 출토염직품의 염료와 매염제 분석)

  • Baek, Young-Mee;Kwon, Young-Suk;Goto-Doshida, Sumiko;Saito, Masako
    • Journal of Conservation Science
    • /
    • v.28 no.2
    • /
    • pp.119-129
    • /
    • 2012
  • Excavated textiles provide very important research data on the costume culture of the Joseon dynasty. In particular, dyed textiles are indispensable for textile conservation research and for restoration of remains as well as for general costume culture research. Unfortunately, a prolonged burial environment causes the colors to change and gradually fade after excavation. Therefore, it is very difficult to identify the original color. In this study, natural dyed samples of red, yellow, purple and blue were prepared and analyzed using HPLC-PDA. Dyes of colorants extracted from excavated textile remains were analyzed by HPLC. In addition, mordants were analyzed using (SEM-EDX) in order to estimate the original color. The 16~17th Century's three samples were analyzed, sample 1, and 2 from Eunjin Song's Song Mun-Chang excavated at the Songchon-dong in Daejeon, and sample 3 from Yeosan Song's Song, Hee-Jong excavated at the Mokdal-dong in Daejeon. From the HPLC results, alizarin, purpurin, and indigo were detected on sample 1, alizarin and purpurin on sample 2, ellagic acid and indigo on sample 3. Therefore they were dyed with madder and indigo (sample 1), madder (sample2), pomagranted and indigo (sample 3). Al mordant was identified on three samples.

A study on the Red Painting of stone monuments (비석(碑石)에 칠해진 주사(朱砂)안료에 관한 연구)

  • Shin, Eun-Jung;Han, Min-Su;Kang, Dai-Il
    • Korean Journal of Heritage: History & Science
    • /
    • v.38
    • /
    • pp.359-385
    • /
    • 2005
  • Red ocher, red lead or cinnabar has been as red colorant for ages. Cinnabar of the red pigments has been highly regarded as a valuable ingredient because it represent a symbol of exorcising and a haute image. It was used as a pigment of painting and mural painting, bowl, clothes, rock writing, gravestone, etc. It is powder which dissolves in perilla oil or glue before using. Because it is high-priced, the use of cinnabar may be limited to the privileged class. Therefore, red ocher or red lead was used instead of cinnabar. "Gongsagyunmunrok" demonstrated that government official's gravestonea has been painted red by two colorants in the period of the Goryeo dynasty. However, cinnabar may be used to paint gravestones for the first time in the period of the Three States because it has been transmitted since the times. This study discuss the results obtained from an analysis of the pigments used on the red pigments of the Stone Monuments. The results can be briefly summarized as below; First, the microcrystalline structures seen on the surface section of analyzed pigments, samples of which were taken from various parts of red pigments show that different sizes and shapes of pigment particle. Second, a result of the analysis on the composition and structure of the pigments shows that the main components in their composition are : Red pigments - Red lead($Pb_3O_4$), Cinnabar(HgS) and Hematite($Fe_2O_3$) White pigments - Calcite($CaCO_3$) Especially, we knew that red Stone Monuments were found to be natural mineral pigments, which were used as a singular or a mixture.

Physicochemical Stability of Anthocyanins from a Korean Pigmented Rice Variety as Natural Food Colorants (천연색소로서 한국산 유색미 안토시아닌의 안정성 연구)

  • Yoon, Joo-Mi;Cho, Man-Ho;Hahn, Tae-Ryong;Paik, Young-Sook;Yoon, Hye-Hyun
    • Korean Journal of Food Science and Technology
    • /
    • v.29 no.2
    • /
    • pp.211-217
    • /
    • 1997
  • The physical and chemical stability of anthocyanins from a Korean pigmented rice variety was investigated at various conditions of pH, temperature, metal ion, sugar, organic acid and light. The anthocyanin pigments were relatively stable with half-lives of 36 days (pH 2.0) and 17 days (pH 3.0), while they were decomposed in a day at neutral and basic pH of 7.0 and 9.0 at $25^{\circ}C$. The anthocyanins also showed high thermal stability at pH 3.0; the half-lives were 7.4 hr, 23.6 hr and 96.3 hr at $95^{\circ}C,\;75^{\circ}C\;and\;50^{\circ}$, respectively. Addition of di- and tri-valent metal ions at pH 3.0 resulted in the increase of color intensity and stability throughout 21 days of storage periods at $25^{\circ}C$. Most sugars added accelerated the degradation of anthocyanin pigments, so that fructose showed the greatest degradation effect on the pigments. Addition of citric acid at pH 3.0 increased stability of anthocyanins, while tartaric acid decreased stability. The anthocyanins were very sensitive on light irradiation with a degradation half-life of 14 hr under 20,000 lux-light dosage at pH 3.0.

  • PDF