• 한국가스학회:학술대회논문집
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• 2002.05a
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• pp.69-77
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• 2002

• Culinary science and hospitality research
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• v.18 no.2
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• pp.162-171
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• 2012

This study was conducted to investigate the changes of macerating properties from grape suspensions for which both were treated with protopectinase(PPase) and mechanical maceration stored at $4^{\circ}C$ for 28 days. Changes of macerating properties such as pH, total acidity, color, total polyphenol and antioxidant activity of suspensions after enzymatic hydrolysis were determined before and after heating, and microscopic observation made on suspensions containing single cells. With the PPase, grapes were enzymatically macerated to separate cells to primary cell wall without damage. Also, the changes of macerating properties in grape suspension treated with PPase and after heat treatment at $80^{\circ}C$ for 30 min were more stable than those of mechanical maceration, indicating the thermal stability. Thus, the PPase treatment for grapes could be a better choice for preparing highly valuable and functional processed food as well as for prolonging preservation periods.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.11-16
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• 2008

The extraction conditions for resveratrol production from grape fruit stem, which is a by-product of grape processing, were optimized to develop high-functional grape-based products. Additionally, the bioefficacy of grape fruit stem extract (GFSE) as an antioxidant agent was evaluated. Resveratrol was extracted using various experimental conditions such as extractant type, extractant concentration, raw material-extractant ratio, extraction time and temperature, and the results were analyzed using a statistical program (SPSS). The resveratrol yield was the highest when 80% ethanol with a raw-material-extractant ratio of 1:10 (w/v) was used. In addition, the optimal temperature and time were selected as $60^{\circ}C$ and 90 min, respectively. When the antioxidant activity was analyzed and expressed as DPPH radical scavenging activity and SOD-like activity, the antioxidant activity of GFSE was higher than that of BHT, BHA and L-ascorbic acid. Finally, it was found that GFSE could be used as a raw material for the production of high antioxidant agents.

• Polymer(Korea)
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• v.34 no.6
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• pp.547-552
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• 2010

Biodegradable polymers have gained enormous attentions in the pharmaceutical and biomedical applications, especially in drug delivery. In this work, we report the synthesis and characteristics of high molecular weight polyoxalate with ~75000 Da. Hydrolytic degradation kinetics and degradation products were characterized by nuclear magnetic resonance and gel permeation chromatography. Polyoxalate is a semicrystalline and thermally stable polymer with a glass transition temperature of ${\sim}35^{\circ}C$, which is suitable for drug delivery applications. The hydrophobic nature of polyoxalate allows it to be formulated into nanoparticles and encapsulate drugs using a conventional oil-in-water emulsion/solvent displacement method. Polyoxalate nanoparticles also exhibited excellent cytotoxicity profiles. It can be suggested that polyoxalate has great potential for numerous biomedical and pharmaceutical applications.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.879-887
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• 2021

This study was carried out for elucidating bioacive properties of three domestic tomato cultivars. Total polyphenol and flavonoid of Rafito, Momotaro and Medison were 10.44±1.84, 11.14±1.95, 12.26±1.82 and 3.62±0.57, 3.24±0.35, 3.87±0.60 mg/g(dry weight) respectively. Domestic tomatoes showed DPPH and ABTS radical scavenging activities. All of tomatoes had no cytotoxicity for normal liver cell, but showed remarkable growth inhibitory effect against cervical cancer cell and liver cancer cell. These results suggested that domestic tomatoes can be used as a bioactive food material.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.772-778
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• 2012

This study was conducted to investigate physiologically active components and antioxidant capacity of grapevine leaves at growth stages. The leaves from two strains of grapevine, 'Campbell Early' and 'Rosario Bianco', were collected at five different growth stages (leafing, blossom, fruiting, coloring, and maturity). Total flavonoid content was higher in leafing stage than the other stages and gradually decreased during growing. Total phenol content was higher in 'Campbell Early' than in 'Rosario Bianco'. Hydroxyl radical scavenging ability increased in the leafing stage and decreased during growing. The electron donating ability was higher in 'Campbell Early' then 'Rosario Bianco' until blossom stage. Leaves from 'Campbell Early' showed higher total antioxidant capacity than those from 'Rosario Bianco'. According to the above results, grapevine leaves until the blossom stage would possess strong antioxidant activity by physiologically active components such as polyphenol compounds. Therefore, these results suggest that young grapevine leaves can be used as materials for the development of functional foods.

• Polymer(Korea)
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• v.32 no.2
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• pp.131-137
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• 2008

We have fabricated polystyrene (PS) nanofibrous scaffold for hepatocyte culture by electrospinning method and subsequently coated with specific ligand of Poly[N-p-vinylbenzyl-O-$\beta$-D-galactopyranocyl-($1{\rightarrow}4$)-D-gluconamide](PVLA) to enhance hepatocytes attachment. Rat hepatocytes behavior on the PVLA-coated and non-coated PS nanofibrous matrices have been investigated. Electrospun PS nanofiber structures revealed randomly aligned fibers with average diameter of 500 nm. It is observed that PS nanofibrous matrix could incorporate many cells into the interior of the matrix probably due to the suitable pore size. Cell viabilities cultured on PVLA-coated PS nanofibrous mats were maintained for 3 weeks, while it was decreased rapidly on PVLA-coated PS dishes. High hepatic functions especially for albumin secretion and ammonia removal were maintained at least for 2 weeks on nanofibrous mats but rapidly decreased on flat PS dishes. These results indicate that nanofibrous structure enabled 3-D culture with high level of cell-cell contact results in providing cell-cell communications and subsequent long-term maintenance of specific cell functions.

• Clean Technology
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• v.21 no.4
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• pp.224-228
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• 2015

Phospholipase D (PLD) was immobilized on a submicro-porous membrane through covalent immobilization. The immobilization was conducted on the porous membrane surface with the treatment of polyethyleneimine, glutaraldehyde, and the anhydrase, in sequence. The immobilization was confirmed using X-ray photon spectrometer. The pH values of phosphatidylcholine (PC) dispersion solution with buffer were monitored with respect to time to calculate the catalytic activities of PC for free and immobilized PLD. The catalytic rate constant values for free PLD, immobilized PLD on polystyrene nanoparticles, and immobilized PLD on a porous cellulose acetate membrane were 0.75, 0.64, and 0.52 s^-1, respectively. Reusability was studied up to 10 cycles of PC hydrolysis. The activity for the PLD immobilized on the membrane was kept to 95% after 10 cycles, and comparable to the PLD on the nanoparticles. The stabilities for heat and storage were also investigated for the three cases. The results suggested that the PLD immobilized on the membrane had the least loss rate of the activity compared to the others. From these studies, the porous membrane was feasible as a carrier for the PLD immobilization in the production of phosphatidic acid.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.7
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• pp.549-555
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• 2006

In the present study, sterilizing and antibacterial performance tests of Polybutylene pipe with nano-silver were carried out in the testing bench of water supply facilities. Experimental results show that the average sterilizing and antibacterial rate of two micro-biological samples such as E. coli and S. aureus is about 90% in case of stillness experimental condition and 99% in case of flowing experimental condition, when elapsed time is 120 hours and 3 hours, respectively. Experimental results also show that the supply water velocity in nano-silver Polybutylene pipe varies from 1 m/s to 1.5 m/s, the elapsed time needed sterilizing rate reach to 100% decreases.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.567-575
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• 2022

This study was carried out to elucidate bioacive effects of three domestic cherry tomato cultivars. Total polyphenol and flavonoid of Summerking, Qutiquti, and Minichal cultivar were 12.56±1.88, 12.50±1.92, 11.65±1.85 mg/g and 4.58±1.03, 4.19±0.40, 4.30±0.49 mg/g(dry weight) respectively. Domestic cherry tomatoes showed antioxidative activity(DPPH and ABTS radical scavenging activities). All of the cherry tomatoes had no cytotoxicity for normal liver cell, but showed strong inhibitory effect against cervical cancer cell(HeLa) growth. These results revealed that domestic cherry tomatoes can be used as a bioactive food material.