• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.375-381
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• 2006

In this sturdy, spherical activated carbon(SPAC) contained $TiO_2$ was made by ion-exchanged treatment and heat treatment for applying fluidizing bed system. The ion-exchange resin was treated by $TiCl_3$ aqueous solution. The treated resin and raw resin were heat-treated under nitrogen condition to convert into Ti-SPAC. During the heat-treatment, burn-off weight amounts and the element were measured by means of TGA and TGA/MS, individually. The physicochemical properties of Ti-SPAC was characterized by means of XRD, SEM, EDS, BET, EPMA, ESR, intensity and titanium content. The Ti-SPAC had spherical shape with diameter size about $350{\mu}m{\sim}400{\mu}m$ and $617m^2/g$ specific surface area. Structure of $TiO_2$ in Ti-SPAC was anatase and rutile form. Also, $TiO_2$ on SPAC were found that the $TiO_2$ were uniformly distributed through EPMA analysis. Moreover, the Ti-SPAC showed indirect photocatalyst activity estimation through ESR analysis, characteristics of photocatalyst potentially. Over all results, Ti-SPAC was used in fluidizing bed UV/photocatalyst system to remove HA(Humic Acid). That results were HA removal efficiency was about 70％ and Ti-SPAC intensity was preserved during reaction. Ti-SPAC showed practical possibility as photocatalyst in fluidizing bed system.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.559-567
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• 2008

SAPO-34 is a well-known catalyst for methanol to olefins (MTO) process, but is rapidly deactivated by coke formation. It is necessary to improve the catalyst lifetime of SAPO-34 for MTO process. In the present work, SAPO-34 catalysts were synthesized with a variety of structure directing agent, and the physicochemical properties of the catalysts were examined by $N_2$-isotherm, XRD, SEM, and $NH_3$-TPD. It was found that mixed structure directing agents, especially DEA and TEAOH, gave well developed SAPO-34 crystal structure and reduced the crystal size and moderated acidity of SAPO-34 under the same synthetic conditions as that of various structure directing agents. Also, we could find that SAPO-34 catalyst prepared by mixed templates of DEA and TEAOH had the superior catalytic activity and the longer lifetime in MTO reaction.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.203-209
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• 2007

Soybean milk cake (SMC) was used for the solid-state fermentation by Bacillus subtilis PUL-A isolated from soybean milk cake. In the presence of 5% glutamate the maximum production of biopolymer (59.9 g/kg) was performed by fermentation at $42^{\circ}C$ for 24 hr. The recovered biopolymer was consisted of 87% $\gamma$-polyglutamic acid with molecular weight of $1.3{\times}10^6$ dalton and other biopolymer. The biopolymer solution showed the great decrease in consistency below pH 6.0, regardless of the molecular weight of PGA. Biopolymer solution has a typical pseudoplastic flow behavior and yield stress. The consistency of biopolymer solution was greatly decreased by increasing heating time and temperature in acidic condition compared to the alkaline condition. In kaolin clay suspension, the flocculating activity of biopolymer was the highest value with 15 mg/L biopolymer and 4.5 mM $CaCl_2$, but decreased greatly with $FeCl_3$. The flocculating activity of biopolymer was maximum at pH5, but decreased drastically by heating at $60{\sim}100^{\circ}C$. In particular, biopolymer with native PGA showed the efficient flocculating activity compared to that of modified biopolymer containing low molecular weight of PGA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.210-216
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• 2008

Leuconostoc mesenteroides SM isolated from a raw carrot was used for the fermentation of carrot juice (CJ). Lactic acid fermentation of CJ was performed at $25^{\circ}C$ for 24 hr with $0{\sim}20%$ sucrose concentration, resulting in the production of mucilage. The fermented CJ showed the complete conversion of sugar into dextran after fermentation for 24 hr in the presence of sucrose below 15% concentration. With 15% sucrose, the fermented CJ had pH 3.8, 0.9% acidity, consistency index of $3.5\;Pa{\cdot}s^n$. After cold storage for 3 weeks, fermented CJ showed slight increase in acidity and relatively constant value in pH; however, the consistency index, red color value and viable cell counts were slightly decreased for 3 weeks. The ${\beta}-carotene$ content in CJ was drastically decreased by lactic acid fermentation for 24 hr, indicating $72\;{\mu}g/mL$ as compared to $142\;{\mu}g/mL$. The fermented CJ had improved body texture, red color and stability without sedimentation.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.83-91
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• 2018

Baekseolgi made with arrowroot flour (AF, 0 to 15% of rice flour) was steamed to examine the effect of heating on its antioxidant activity and physicochemical properties. Despite the presence of abundant dietary fiber and superior water-holding capacity of AF, moisture in baekseolgi was not significantly increased. This could partly be attributed to AF having 50% less moisture content than rice flour. Hence, hardness of baekseolgi was also not significantly altered. Total reducing capacity and flavonoid content of baekseolgi increased proportionally with the increase in AF addition. However, these values were lower than the predicted values calculated from the antioxidant activities of heated AF, which was more apparent in total reducing capacity. This indicated that the stability of non-phenolic reducing compounds in AF was lower than that of the phenolic compounds. Thermally processed baekseolgi made with 9% AF exhibited antioxidant activity without noticeable loss in the quality of the product.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.42-48
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• 2004

The effect of xylitol on the Dongchimi fermentation was investigated by measuring the sensory, physicochemical and microbiological properties during fermentation of up to 30 days. Dongchimi with 0, 1, 2, 3 and 4％ w/v xylitol was fermented at 10$^{\circ}C$. The addition of 1％ xylitol gave the highest scores in terms of the overall acceptability, texture, ripeness, sweet taste and smell. During the fermentation, the total acidity increased, while the pH gradually decreased. The reducing sugars showed the highest content with the addition of 1％ xylitol. The vitamin C was increased in the early stage of fermentation, but reduced gradually after 5 days. The vitamin C content of the Dongchimi with 2％ xylitol addition was shown to be the highest. The total viable cells and lactic acid bacteria increased between 2 and 5 days of fermentation, but were gradually reduced thereafter. The numbers of lactic acid bacteria with 1％ xylitol addition were more numerous than with the other percentage additions. The current study showed that the application of 1％ xylitol to the fermentation of Dongchimi enhanced the sensory values of the fermented product.

• Polymer(Korea)
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• v.34 no.4
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• pp.333-340
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• 2010

Zaltoprofen, a propionic acid derivative non-steroidal anti-inflammatory drug (NSAID), is known to have powerful inhibitory effects on acute, subacute and chronic inflammation. We developed poly(lactide-co-glycolide)(PLGA) microspheres loaded with zaltoprofen for sustained controlled delivery using an oil-water solvent evaporation methods by varying PLGA molecular weight and cosurfactant contents. Physicochemical properties and morphology of zaltoprofen-loaded PLGA microspheres were investigated by scanning electron microscope, X-ray diffraction and differential scanning calorimeter. The size of microspheres increased with the molecular weight of PLGA and the content of cosurfactants. The increase of PLGA molecular weight and cosurfactant content decreased the porosity of microspheres, subsequently resulting in the slow drug release. The results demonstrated that the adjustment of PLGA molecular weight and the cosurfactant content allowed us to control the drug release profiles of drug-loaded microspheres.

• Polymer(Korea)
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• v.38 no.1
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• pp.69-73
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• 2014

In this study, polysaccharide-poly(vinyl alcohol) (PVA) hydrogels were prepared by using ${\gamma}$-ray and evaluated for potential application as an anti-inflammation patch. Ulmus davidiana var. japonica (UD), one of polysaccharides has been particularly used as an oriental remedy for the treatment of inflammation and ulcers. PVA as a biocompatible polymer and glycerin as a moisturizer were blended with the UD, and its hydrogels were prepared by radiation crosslinking. Characterizations for UD hydrogels were performed by using cytotoxicity assay, antioxidant activity test, and physicochemical test such as gel fraction ratio, and swelling behavior. The results showed that these UD hydrogels had excellent physical properties, anti-inflammation activity, and non-cytotoxicity on the cells. Therefore, these polysaccharide based-UD hydrogels can be effectively used as an inflammation patch.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.445-454
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• 2019

Layered double hydroxides (LDHs) nanoparticles have emerged as novel nanomaterials for bio-imaging applications due to its unique layered structure, physicochemical properties, and good biocompatibility. Bio-imaging is one of the most important fields for medical applications in clinical diagnostics and therapeutics of various diseases. Enhanced diagnostic techniques are needed to realize new paradigm for next-generation personalized medicine through nanoscale materials. When nanotechnology is introduced into bio-imaging system, nanoparticle probes can endow imaging techniques with enhanced ability to obtain information about biological system at the molecular level. In this review, we summarize structural features of LDH nanoparticles with current issues of bio-imaging system. LDH nanoparticle probes are also discussed through in vitro as well as in vivo studies in various bio-imaging techniques including fluorescence imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), and computed X-ray tomography (CT), which will have the potential in the development of the advanced nanoparticles with high sensitivity and selectivity.

• Journal of the Korean Society of Food Culture
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• v.35 no.6
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• pp.613-618
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• 2020

This study evaluated the effects of acidulant treatment on the quality and storage period of Topokkidduck. Two samples of Topokkidduck were prepared, one soaked in 10% acidulant (10SAT) and the other without soaking in the acidulant (NSAT). During the storage period, the two samples were tested for presence of microorganisms (aerobic bacteria, E.coli, and mold) and physicochemical properties (color value, texture profile analysis (TPA)). The 10SAT could be stored for 49 days without detection of E.coli and a mold level of 1.0 log CFU/g. NSAT could be stored for only 21 days. NSAT had an aerobic count of 2.27 log CFU/g as early as 7 days, and E.coli was detected at 21 days at a level of 4.15 log CFU/g. The presence of E.coli is not permitted according to the Ministry of Food and Drug Safety (MFDS). The hardness of the 10SAT increased during the storage period but to a much lesser extent compared to the NSAT. Thus the preparation of Topokkidduck by soaking in the acidulant controlled microbial growth for up to 49 days which is a much longer period compared to the control. Also, Topokkidduck soaked in the acidulant had a softer texture than the control during the storage period.