• KSBB Journal
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• v.24 no.5
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• pp.458-462
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• 2009

Silk fibroin is a structural protein from Bombyx mori and can be sulfated to provide biofunctional polypeptides showing antiviral and anticoagulating activities. However, the sulfated fibroins have not been characterized enough to present their compositions and structures. In this report, sulfation reaction was investigated by varying the reaction temperature and sulfuric acid concentration and analysis of the resulting peptides were carried out. The degree of sulfation was proportion to sulfuric acid concentration but the maximum product yield was obtained at $60^{\circ}C$ and 5% of sulfuric acid concentration. FT-IR spectrum, UV absorption and NMR spectrum support that o-sulfate ester was formed at the hydroxyl group of serine and tyrosine residues. Size exclusion chromatography identified that sulfated fibroin was composed of a highly hydrolyzed polypeptide mixtures and peptides of relatively higher molecular weight.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.147-155
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• 2004

Freeze dried antler, heat dried antler, antler were extracted through processing step by water, protease and hydrochloric acid(HCl). Extraction rate of freeze dried antler at 50$^{\circ}C$ by water was 9.01％(8.82, absorbance at 280 nm), that of heat dried antler was 9.01％(4.45, absorbance at 280 nm), and that of antler was 1.10％(0.31, absorbance at 280 nm), respectively. Extraction rate of freeze dried antler by bacterial protease was 16.89％(4.50, absorbance at 280 nm), and that of heat dried antler was 17.29％(5.62, absorbance at 280 nm), and that of antler was 18.22％(0.64, absorbance at 280 nm), respectively. Extraction rate of freeze dried antler by 0.8N HCl was 72.25％(4.60, absorbance at 280 nm), that of heat dried antler was 71.14％(4.70 absorbance at 280 nm), and that of antler was 79.82％ (2.80, absorbance at 280 nm), respectively. Extraction rate of freeze dried antler through three processing steps was 98.15％, that of heat dried antler was 97.35％, that of antler was 99.14％, respectively. The result of analysis by HPLC shows that high molecular pe which appears in young antler and antler extraction was changed into a small molecular peak of about 1,000 by the reaction of protease, and protein of about MW 70,000 was extracted from their remaining residue by 0.8N HCl. The above result shows that water extraction and protease extraction in the freeze dried young antler, protease extraction and HCl extraction in dried young antler, and HCl extraction in antler are most effective.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.388-396
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• 2003

The freeze dried young antler residue was extracted by proteases and hydrochloric acid(HCl). The young antler was extracted by water at 50$^{\circ}C$ and the residue was reacted by proteases for 5 hours at 50$^{\circ}C$. The extraction rate of its residue was 32.8%(absorbance 3.61 at 280nm) of bacteria protease, 23.8%(absorbance 0.69) of papain, and 31.2% (absorbance 2.96) of pepsin. The young antler was extracted by boiling water and the residue was reacted by proteases for 5 hours at 50$^{\circ}C$. The extraction rate of its residue was 45.0%(absorbance 3.61) of bacteria protease, 30.4%(absorbance 0.33) of papain, and 51.2% (absorbance 2.77) of pepsin. The result of HPLC analysis reveals that in 50$^{\circ}C$ water extract and boiling water extract, all high molecular peak was reduced under MW 1,000 by proteases. The result from the extract of young antler residue reacted by HCl for 5 hours at 50$^{\circ}C$ shows that its extraction rate was 45% (absorbance 0.78) in concentration of 0.1N HCl, 61% (absorbance 1.82) in 0.2N, 81% (absorbance 2.29) in 0.4N, and 82.0% (absorbance 3.28) in 2.0N. The result of HPLC analysis also reveals that in the extract by 0.8N HCl, the peak of about MW 70,000 accounted for 78% in total. Protein content of the extract by 0.8N HCl was 8.2%, and content of amino acid was 81.6%, ash was 1.3%, and mineral contents were 0.1 % of Ca, 2.3% of P, 0.8 % of Mg, 3.4% of Na, 0.002% of F by dry base.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.563-566
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• 2003

This study was proposed to measure total polyphenols and antioxidant activities from leaves of Stachys sieboldii MIQ. Solvents such as acetone 60%, petroleum ether, ethylacetate, and water were used for this purpose The fraction by ethyl acetate fraction showed the strongest activity by DPPH method and contained much more polyphenols than those by other solvents.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.113.1-113.1
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• 2011

미세조류 내의 엽록소는 바이오디젤 전환 반응에서 산 촉매의 활성을 억제 할 뿐만 아니라, 짙은 색상을 띄게하여 바이오디젤 품질규격으로부터 벗어나게 한다. 미세조류의 엽록소 분석은 용매에 의해 엽록소를 추출한 후, 흡광도를 측정하여 그 함량을 계산하는 방법을 널리 사용하고 있다. 건조된 미세조류의 분석은 선택되는 용매에 따라 최대 추출량이 달라지는 것을 제외하고 큰 문제가 없지만 미세조류를 lipid 오일로 변환하면, 용매에 녹지 않아 추출이 되지않는 문제가 발생하여 흡광도 측정을 어렵게 한다. 따라서 미세조류의 형태가 powder일 때와 오일인 경우를 구분하여 용매를 선택해야 하며, 오일 또는 powder 형태 구분 없이 사용할 수 있는 분석법을 적용하여 서로 다른 엽록소 함량을 비교한 후 분석법 간의 상호 장단점을 파악해야한다. 본 연구에서는 메탄올을 용매로 사용하는 분석법(porra et al.)과 아세톤을 용매로 사용하는 분석법(Humphrey and Jeffrey)을 적용하여 엽록소 함량을 비교하였고, AAS(Atomic Absorption Spectrometer)를 통한 Mg 함량 측정을 통해 엽록소 함량을 계산하는 분석법간의 차이를 확인하였다.

• Analytical Science and Technology
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• v.8 no.1
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• pp.69-77
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• 1995

The instrumentation and operating characteristics of a gas-jet assisted radio frequency glow discharge atomic absorption spectrometry(RF-GDAAS) are studied. The roles of discharge power, pressure as well as gas flow rate on the sample loss rate and absorbance are described in this paper. Results show that the optimum discharge conditions depend on pressure and discharge power as well as on the gas flow rate. The gas flow rate plays as an important parameter in RF-GDAAS. Absorbance increases as the gas flow rate increase up to 600ml/min., and the optimum absorbance is obtained at the pressure of 3 mbar. The absorbance increases when the discharge power increases as expected, however, the instability of the system due to the heat might be the trade off factor. The linear calibration curves of Ni and Cr in stainless steel(BAS 461-468) and brass (KSS 1121-1126) are obtained with RF-GDAAS.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.416-421
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• 2008

A scheme for predicting the concentration of a glucose solution based on its relative optical absorbance at multiple probe wavelengths was proposed and verified. The relative absorbance at each of the probe wavelength was obtained with respect to the absorbance at a reference wavelength. The single reference wavelength (1310 nm) and a group of four different probe wavelengths (1064, 1550, 1685, 1798 nm) were selected to exhibit the glucose absorbance with opposite signs, thereby enhancing the accuracy of the prediction. The final glucose concentration was estimated by taking the average of the predicted values provided by the four probe wavelengths. The absorbance of the glucose solution for the path length of 5 mm was $-1.42{\times}10^{-6}\;AU$/(mg/dL) at the reference wavelength of 1310 nm and peaked at $+8.12{\times}10^{-6}\;AU$/(mg/dL) at 1685 nm. The concentration of the glucose solution was decently predicted by means of the proposed scheme with the standard error of prediction of ${\sim}28\;mg/dL$. In addition, the influence of the ambient temperature and the fat thickness upon the prediction of the glucose concentration was examined. The absorption change with the temperature was $-9.1{\times}10^{-5}\;AU/^{\circ}C$ in the temperature range of $26{\sim}40^{\circ}C$ at the reference wavelength, and $-2.08{\times}10^{-2}\;AU/^{\circ}C$ at 1550 nm. And the absorption change with respect to the fat thickness was +1.093 AU/mm at the probe wavelength of 1685 nm.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.723-728
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• 2016

This study is analyzed the optical property of red tide pixel by using Landsat-7 ETM+, Landsat-8 OLI and COMS/GOCI image. In order to sample red tide pixel, Landsat-7, 8 true color image were used and obtained coordinate of red tide pixel in the true color image. Normalized water leaving radiance(nLw) and absorption coefficient were obtained from GOCI image in the same coordinate of the true color image. When red tide was not occurred the main absorption range was 412nm and 660nm but when red tide occurred it was 660nm and absorption coefficient in 412nm are drastically reduced. It made no difference of nLw spectrum between red tide pixel and non red tide pixel in nLw, but the absolute value of nLw was low than non red tide pixel, especially 660nm and 680nm wavelength sharply decrease.

• Applied Biological Chemistry
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• v.24 no.3
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• pp.200-205
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• 1981

Some chemical components, absorbance at 450nm and color of traditional and improved soysauce during fermentation were investigated. The traditional soysauce was made from soybean Meju and the improved soysauces were prepared from Kojis of various mixtures of soybean and wheat. The contents of reducing sugar were higher in the improved soysauces than in the traditional soysauce and it increased with proportion to the mixing amount of wheat. The contents of total nitrogen and amino nitrogen were increased gradually during fermentation and, in the improved soysauce, it increased with the amount of soybean. The changes of the absorbance and the chromaticity were greaser in the traditional soysauce than in the improved soysauce during fermentation. The increase of absorbance and the chromaticity was greater in the improved soysauce than that of the traditional soysauce during heating process. In the improved soysauce, the greater the amounts of wheat in Koji, the greater the increase of color.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.937-942
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• 1995

Cutting force, degree of cooking, cooking loss and absorbances of cooking solution of three cultivars of Korean kidney beans, Pink(PKB), Red(RKD) and White(WKB) were compared. The cutting force of raw kidney bean was 23,500~27,000g. The optimum soaking conditions to give the same cutting force of beans were 10hr at $10^{\circ}C,\;8hr\;at\;20^{\circ}C,\;6hr\;at\;30^{\circ}C\;and\;3hr\;at\;40^{\circ}C$. At optimum soaking conditions, the degree of cooking was determined by measuring the maximum cutting force of cotyledon. The terminal points of cooking at $98^{\circ}C$ were 23min for PKB, 25min for RKB and 27min for WKB. Cooking loss of kidney beans during cooking were 3.4~5.4%. Absorbances of cooking solution showed a similar pattern in all samples, except PKB soaked at $10^{\circ}C$ for 10hr.