• Food Science and Biotechnology
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• 제14권6호
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• pp.836-840
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• 2005

Extraction characteristics of Bonus species of Brassica oleracea var. capita and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 44.07% was obtained at ratio of solvent to sample of 27.94 mL/g, ethanol concentration of 24.35%, and extraction temperature of $55.21^{\circ}C$. At ratio of solvent to sample, ethanol concentration, and extraction temperature of 21.11 mL/g, 58.53%, and $68.83^{\circ}C$, respectively, maximum electron-donating ability was 48.44%. Maximum inhibitory effect on tyrosinase was 68.94% at ratio of solvent to sample, ethanol concentration, and extraction temperature of 24.08 mL/g, 10.49%, and $78.71^{\circ}C$, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 24.78% at ratio of solvent to sample of 22.66 mL/g, ethanol concentration of 45.69%, and extraction temperature of $93.81^{\circ}C$. Based on superimposition of four-dimensional RSM with respect to extraction yield, electron-donating ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were ratio of solvent to sample of 20-30 mL/g, ethanol concentration of 35-65%, and extraction temperature of $50-80^{\circ}C$.

• KSBB Journal
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• 제26권5호
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• pp.459-464
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• 2011

In this study, the canadian peat moss extract was purified by a supercritical ₂ using three different conditions and assessed its biological activities. Peat moss was extracted by acid-alkaline extraction method (sample 1) and purified by a supercritical $CO_2$ at $40^{\circ}C$ under pressure of 100 bar (sample 2), 120 bar (sample 3) or 150 bar (sample 4). We evaluated the antioxidant activities of the samples by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging, $Fe^{2+}$/ascorbate (FTC) and 2-thiobarbituric acid (TBA) methods. The antioxidant activities were examined by comparing the results with that of ascorbic acid as a positive control. Sample 3 showed relatively higher DPPH radical-scavenging activities than other samples. The antioxidant activity by FIC method exhibited similar results as the DPPH radical-scavenging activities. On the other hand, sample 2 showed higher antioxidant activity measured by TBA method of all. The whitening effects of the samples were examined using mushroom tyrosinase and B16F10 melanoma cells. Sample 3 exhibited overall significant whitening effects, however, other samples showed relatively lower effects. These results suggest that the peat moss extract purified by a supercritical ₂ could be used as a cosmetic ingredient for the anti-aging and whitening effects.

• 한국식품과학회지
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• 제36권4호
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• pp.568-573
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• 2004

3%의 콩단백질을 첨가한 옥수수전분 용액을 건조가열 시켜 만든 시료의 호화특성, 겔의 조직감 및 노화특성에 대해 연구하였다. 건조가열로 만들어진 시료의 경우, 단순 혼합 시료보다 낮은 pasting 온도와 높은 RVA 점도들을 보였으며 유의적으로 낮은 호화엔탈피를 보였다. 높은 온도에서 건조가열한 시료(heated sample)의 경우, 낮은 온도에서 건조가열한 시료(unheated sample)보다 pasting 온도가 낮았으며 peak viscosity, breakdown viscosity가 유의적으로 높았다. 또한 pH가 증가할수록 보다 높은 점도 profile을 보였다. 가열 건조한 시료는 낮은 파괴강도 및 파괴 strain을 보였으며 pH가 높을수록 elastic modulus와 파괴강도는 감소하고 파괴 strain은 증가하였다. 콩단백질의 첨가와 더불어 건조가열은 전분의 노화방지에 도움을 주며 겔의 미세구조를 변화시켜 겔의 조직감을 변화시켰다. 전분의 호화 및 노화특성과 겔의 조직감을 콩단백질의 첨가와 더불어 건조가열과 pH 조절을 이용하여 변화시킬 수 있었으며, 이는 전분의 호화온도와 단백질의 변성온도 이하의 온도에서 건조 후 고온 건조가열을 통해 전분-단백질의 구조적 변성과 결합을 유도하여 새로운 기능성 전분을 만들 수 있는 가능성을 보여준다.

• 한국약용작물학회지
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• 제28권5호
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• pp.331-338
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• 2020

Background: The aim of this study was to analyze the total phenol and total flavonoid contents and antioxidant activity of steam-treated leaves and rhizomes of Polygonatum sibiricum Redoute. In addition, we aimed to confirm their potential use as cosmetic materials by investigating their anti-aging and skin-whitening activity. Methods and Results: The leaves and rhizomes of P. sibiricum were treated with steam at different temperatures for different durations, and the antioxidant activity (DPPH and ABTS radical scavenging activity) and total phenol and total flavonoid contents of each sample were tested. The steam temperature and treatment duration siginificantly affected the antioxidant activity and, total phenol and total flavonoid content of the leaves and rhizome of P. sibiricum. Treating the P. sibiricum samples with steam at 120℃ for 12 h, yielded higher total phenol and total flavonoid contents. Comparatively, the samples treated with steam at 120℃ for 12 to 24 h showed significantly higher antioxidant activity. Further, the steamed samples of P. sibiricum demonstrated collagenase and tyrosinase inhibition activity, which indicated their anti-aging and skin-whitening properties. The samples steamed at 120℃ for 12 h, exhibited higher collagenase and tyrosinase inhibition activity. Conclusions: Leaves and rhizomes of P. sibiricum steamed at 120℃ for 12 h, showed highest antioxidant activity and, total phenol and total flavonoid contents than all other samples. Our results indicate the potential of using P. sibiricum as a cosmetic material by confirming its excellent anti-aging and whitening activity.

• 대한기계학회논문집A
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• 제34권5호
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• pp.535-539
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• 2010

본 논문에서는 시료의 희석비를 조절할 수 있는 $2{\times}6$ well 어레이 디지털 희석소자를 제안한다. 본 소자는 정해진 체적을 가지는 Well 의 경계면에 경계밸브(Inter-well Valve)를 설치하고, 이를 선택적으로 개폐하여 구조적 변경 없이 희석비를 조절할 수 있다. 제안된 희석소자는 희석비를 선형 또는 지수적으로 희석 오차 17% 이내에서 조절 할 수 있을 뿐만 아니라, 희석된 시료의 체적을 정확하게 제어하여 이종시료와 17.7% 오차 이내에서 희석된 시료를 반응시킬 수 있다.

• Journal of Biosystems Engineering
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• 제34권5호
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• pp.377-381
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• 2009

Excessive presence of heavy metals in environment may contaminate plants and fruits grown in that area. Rapid on-site monitoring of heavy metals can provide useful information to efficiently characterize heavy metal-contaminated sites and minimize the exposure of the contaminated food crops to humans. This study reports on the evaluation of a bismuth-coated glassy carbon electrode for simultaneous determination of cadmium (Cd) and lead (Pb) in a NIST-SRM 1568a rice flour by anodic stripping voltammetry (ASV). The use of a supporting electrolyte 0.1 M $HNO_3$ at a dilution ratio (sample pretreated with acid digestion in a microwave oven: supporting electrolyte) of 1:1 provided well-defined, sharp and separate peaks for Cd and Pb ions, thereby resulting in strongly linear relationships between Cd and Pb concentrations and peak currents measured with the electrode ($R^2\;=\;0.97$, 0.99 for Cd and Pb, respectively). The validation test results for spiked standard solutions with different concentrations of Cd and Pb gave acceptable predictability for both spiked Cd and Pb ions with mean prediction errors of 6 to 30%. However, the applicability of the electrode to the real rice flour sample was limited by the fact that Cd concentrations spiked in the rice flour sample were overly estimated with relatively high variations even though Pb ion could be quantitatively measured with the electrode.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.260-268
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• 2008

Optical diffuse reflectance sensing has potential for rapid and reliable on-site estimation of soil properties. For good results, proper calibration to measured soil properties is required. One issue is whether it is necessary to develop calibrations using samples from the specific area or areas (e.g., field, soil series) in which the sensor will be applied, or whether a general "factory" calibration is sufficient. A further question is if specific calibration is required, how many sample points are needed. In this study, these issues were addressed using data from 42 paddy fields representing 14 distinct soil series accounting for 74% of the total Korean paddy field area. Partial least squares (PLS) regression was used to develop calibrations between soil properties and reflectance spectra. Model evaluation was based on coefficient of determination ($R^2$) root mean square error of prediction (RMSEP), and RPD, the ratio of standard deviation to RMSEP. When sample data from a soil series were included in the calibration stage (full information calibration), RPD values of prediction models were increased by 0.03 to 3.32, compared with results from calibration models not including data from the test soil series (calibration without site-specific information). Higher $R^2$ values were also obtained in most cases. Including some samples from the test soil series (hybrid calibration) generally increased RPD rapidly up to a certain number of sample points. A large portion of the potential improvement could be obtained by adding about 8 to 22 points, depending on the soil properties to be estimated, where the numbers were 10 to 18 for pH, 18-22 for EC, and 8 to 22 for total C. These results provide guidance on sampling and calibration requirements for NIR soil property estimation.

• 전기학회논문지
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• 제63권12호
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• pp.1671-1674
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• 2014

This paper presents a frequency-dependent cell impedance analysis chip for use in cancer and normal cell discrimination. The previous cell impedance analysis chips for flowing cells cannot allow enough time for cell-to-electrode contact to monitor frequency-dependent impedance response. Another type of the previous cell impedance analysis chips for the cells clamped by membranes need complex sample control for making stable cell-to-electrode contact. We present a new impedance analysis chip using the microchamber array, on which a PDMS cover is placed to make stable cell-to-electrode contact for the individual cell trapped in each microchamber; thus achieving frequency-dependent single-cell impedance analysis without complex sample control. Compared to the normal cells, the magnitude of NHBE cells is $60.07{\sim}97.41k{\Omega}$ higher than A549 cells in the frequency range of 95.6 kHz~2MHz and the phase of NHBE is $3.96^{\circ}{\sim}20.8^{\circ}$ higher than A549 cells in the frequency range of 4.37 kHz~2MHz, respectively. It is demonstrated experimentally that the impedance analysis chip performs frequency-dependent cell impedance analysis by making stable cell-to-electrode contact with simple sample control; thereby applicable to the normal cell and cancer cell discrimination.

• 대한기계학회논문집A
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• 제36권5호
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• pp.475-479
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• 2012

본 논문은 고차가지구조 폴리머인 AEO3000 를 이용한 UV 광경화 성형 공정을 제안하고자 한다. 이는 기존의 바이오칩 제작에 사용되는 PDMS 보다 경도가 높아 금속 전극 형성이 용이하고 제작 공정이 빠르다는 장점을 갖는다. AEO3000 을 이용하여 본 연구에서는 4 개의 소자를 전기적 유체적으로 연결할 수 있는 전기유체 통합벤치를 제작하고 미소유체 혼합소자와 세포분리소자를 연결, 본 소재와 공정이 바이오칩에 적용될 수 있음을 검증하였다. 전기 유체적 특성 분석 결과 전기적 접촉 저항은 $0.75{\pm}0.44{\Omega}$으로 충분히 작은 값을 보였으며, 유체 접속의 압력 저하는 8.3kPa로 기존의 튜브 연결 방법 대비 39.3% 개선된 값을 보였다. 통합벤치에 접속된 소자에 활성 및 비활성 효모를 주입하여 순차적인 혼합 및 재분리를 성공적으로 구현함으로써 본 소자에 적용된 AEO3000 및 UV 광경화 공정이 생체시료의 처리에 적용될 수 있음을 실험적으로 검증하였다. 이는 바이오 의료 분야에 적용 가능한 생체 친화적 소재의 고속 생산에 응용될 수 있다.

• 한국식품저장유통학회지
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• 제15권1호
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• pp.66-73
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• 2008

무화과를 이용한 기능성 음료의 제조를 위하여 반응표면 분석법에 의하여 무화과의 추출조건에 따른 무화과 유용성분의 추출특성을 모니터링하였다. 수율의 최대값은 66.46%이었으며, 이때의 추출조건은 시료에 대한 용매비 22.08 mL/g, 추출온도 $90.59^{\circ}C$ 및 추출시간 148.04 min이었다. 총페놀성 화합물 함량은 시료에 대한 용매비 17.87 mL/g, 추출온도 $98.82^{\circ}C$ 및 추출시간 130.80 min에서 최대 값 $121.31{\mu}g/mL$을 나타내었으며, 전자공여능은 시료에 대한 용매비 18.13 mL/g, 추출온도 $98.81^{\circ}C$ 및 추출시간 127.95 min일때 최대값을 나타내었다. 무화과 추출물의 단백분해효소의 활성은 시료에 대한 용매비 17.45mL/g, 추출온도 $99.01^{\circ}C$ 및 추출시간 131.43 min일 대 최대값을 나타내었으며, 환원당 함량은 시료에 대한 용매비 22.66 mL/g, 추출온도 $86.30^{\circ}C$ 및 추출시간 153.59 min에서 최대값이 19.14 mg/mL이었다. 무화과 유용성분의 추출을 극대화할 수 있는 최적 추출조건의 범위는 시료에 대한 용매비 $17{\sim}25$ mL/g, 추출온도 $80{\sim}100^{\circ}C$ 및 추출시간 $100{\sim}170$ min으로 예측되었으며, 실제 실험을 통하여 그 신뢰성을 검증하였다.