This study was carried out in order to provide useful data for planning fabrics of summer eco-friendly fashion products. The fabrics used in this study were four cellulose fibers: cotton, cotton/mulberry blended, flax, and flax/lyocell blended. Dyeing with natural indigo was carried out under three different reducing conditions (i.e., general, eclectic, and eco-friendly) that have different reducing agent and pH levels, and hydrosulfite and glucose were used as a reducing agent. The dye uptake (K/S value) of fabrics dyed with natural indigo by a reducing condition was the highest at 660nm. Regardless of the fabrics, dye uptake was the highest under the general reducing condition and the lowest under the eco-friendly reducing condition. Under different reducing conditions, the dye uptake of natural indigo fabrics with the maximum absorption wavelength indicated a difference. The colorfastness of cellulose fabrics that were dyed with natural indigo had a rate of 4 to 5 except for rubbing fastness, which indicated good colorfastness. Additionally, natural indigo-dyed cotton and flax fabrics had good antibiosis. When the color characteristics of fabrics dyed with natural indigo were measured, all of the three reducing conditions created purple blue (PB) colors, and the color characteristics of dyed fabrics by reducing condition and fabric showed significant differences.
Background : Rehmannia glutinosa root (R. root) has been used as traditional medicine, and is important resource for natural medicines and functional foods. However, R. root have catalpol which have bitterness, and undigested sugars, including stachyose, raffinose, and verbascose as main compounds, and these compounds can cause diarrhea and abdominal pain. Therefore, this study was performed to determine the changes in reducing sugar producted from undigested sugars and catalpol contents as a bitter taste compound in R. root with aging treatment conditions.
Methods and Results : R. root was treated at 10 - 70℃ for 0 - 48 h, and extracted with 50% ethanol solution. Their catalpol content was analyzed using HPLC-UVD, reducing sugar content generated from undigested sugars was measured by the Nelson-Somogyi methods, and these reaction rates were calculated from their variation according to aging time and temperature. During aging treatment, reducing sugar content increased and catalpol content decreased. Their formation and degradation rates were highest at 50℃ and 30 - 40℃, and their rates were 1.89 ㎎/g·h and 23.09 - 23.33%/h, respectively.
Conclusion : These results indicated that aging treatment can positively affect the sweetness and digestibility of R. root slurry. Therefore, aging treatment could be considered for improving the sensory qualities and digestibility of R. root.
산화/환원 반응에 매우 민감한 우라늄의 침철석 및 몬모릴로나이트에 대한 수착 특성을 알아보기 위해 산화우라늄(VI)과 환원우라늄(IV)를 준비하였다. 환원우라늄은 황산염환원박테리아에 의해 황산염이 환원되는 과정에서 같이 환원된 우라늄(IV)를 희석하여 사용하였다. 광물에 대한 우라늄의 수착량은 우라늄(IV)가 우라늄(VI)에 비해 상대적으로 낮았으며, 이러한 원인 중의 하나는 용액상의 우라늄(IV)가 미세한 콜로이드 형태로 존재하여 광물 표면에 대한 수착력이 약했기 때문이다. 투과전자현미경을 사용하여 우라늄(IV)가 나노 콜로이드의 특징을 가지고 있음을 확인하였고, 이러한 결과는 심부 자연계의 지하수를 따라 이동 가능한 우라늄종이 이온성 우라늄(VI)뿐만 아니라 콜로이드성 우라늄(IV)도 포함될 수 있음을 의미한다.