• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.84-88
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• 1973

The antioxidant activity of some extracts from various stages of a Mailard type browning reaction mixture, a 0.2 M glucose + 0.2 M glycine solution heated at $100^{\circ}C$, was determined, using edible soybean oil as a substrate. The activity was compared with the length of reaction times, and also with the intensity of color of the reaction mixture at various stages. The absorbance, at $490\;m{\mu}$, of the reaction mixture appeared to increase almost in proportion to the length of the reaction times. All the extracts from the reaction mixture exhibited considerable antioxidant activity. However, unlike the Absorbance of the reaction mixture, the antioxidant activity of the extracts from the reaction mixture did not appear to increase in proportion to the length of the reaction times. The activity of the extract from the reaction mixture heated for 30 hours was indeed greater than that of the extract from the reaction mixture heated for 2 hours, but the difference of the activity was not so great as one might expect. The results appear to indicate that most of effective antioxidative compounds formed during the Mailard type browning reaction could not be brown-colored pigments formed during the reaction.

• Journal of environmental and Sanitary engineering
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• v.11 no.1
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• pp.1-8
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• 1996

In the present study the sesamin and sesamol contents of the sesame extracts prepared from nine provinces in Korea were determined HPLC method. A comparative test was also carried out using the Villavecchia-suarez test, the red colored reaction for the sesamol and sesamol derivatives. The contents of sesamin and sesamol of the sesame oils from each area by the HPLC method were 0.57-0.78% and 0.010-0.023%, respectively, and the paralled results were obtained by the Villavecchia-suarez test and the HPLC method. The average content of the sesamin was $0.68{\pm}0.074%$ by the HPLC method and the average absorbance of the Villavecchia-suarez test was $0.56{\pm}0.034$. The contents of sesamol from sesame oil by the HPLC method and the Villavecchia-suarez test were so low that it was not possible to correlate with the sesamin contents. The contents of sesamol from the sesame oil produced in Kyeong-gi and Jeon-nam provinces were $0.010{\pm}0.002%$ and $0.023{\pm}0.004%$, respectively.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.451-460
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• 2017

This study optimized the extraction of antioxidants from Gugija (Lycium chinensis Mill). To determine operational parameters, including ethanol concentration ($X_1$, 0~80%) and extraction time ($X_2$, 1~5 hr), response surface methodology was applied to monitor yield, anthocyanins, flavonoids and DPPH radical scavenging activity. Coefficients of determinations ($R^2$) of the models were range of 0.8645~0.9859 (p<0.01~0.1) in dependant parameters. Yield of Gugija extracts was maximized 23.12% in extraction conditions of 4.22 h at 8.25% ethanol. Anthocyanins was maximized 1.43 (OD in 530 nm) in extraction conditions of 3.06 h at 79.98% ethanol. Flavonoids was maximized $3,100{\mu}g/100g$ in extraction conditions of 3.37 h at 67.02% ethanol. DPPH radical scavenging activity was maximized 96.93% in extraction conditions of 1.67 h at 69.81% ethanol. Optimum extraction conditions (2.5 h extraction at 70% ethanol) were obtained by superimposing the contour maps with regard to anthocyanins, flavonoids and DPPH radical scavenging activity of Gugija. Maximum values of anthocyanins, flavonoids and DPPH radical scavenging activity in optimum extraction condition were 1.0080 (OD in 530 nm), $3,145{\mu}g/100g$, 96.96%, respectively. But values of anthocyanins, flavonoids and DPPH radical scavenging activity in water extraction condition (1 h at water) were 0.4652 (OD in 530 nm), $1,633{\mu}g/100g$, 86.98%, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.453-461
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• 2000

Aquatic humic substance (AHS) was extracted from Soyang lake water using XAD-8 resin. and its concentration distribution in the lake from May to October. 1997 was determined. Ozonation characteristics of the AHS were studied as factors of pH, carbonate ion concentration. and the biodegradability and structural changes of the AHS were also investigated after ozonaticn. DOC distribution in Soyang Lake water was 1~3 mg/L. and the concentrations of AHS ranged between 0.2~0.8 mg/L. which was corresponding to 20~30% of DOC. AHS was composed of around 20% of HA and 80% of FA. The optimum pH value for AHS ozonation was in range of pH 7~9. When carbonate ions were added for AHS ozonation as a ladical scavenger. it was found that DOC removals were decreased. and the absorbance decreases were increased slightly. Biodegradability of the ozonized AHS was 50% higher than that of unozonated AHS. $^{13}C-NMR$ analysis showed that the aromatic compounds of AHS, after ozonation, were decreased from 49% to 17%. and the aliphatic and carboxylic compounds were increased from 34% to 51% and from 17% to 32%. respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.420-424
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• 2016

In this study, we developed photocatalytic technology to address the emerging serious problem of air pollution through indoor air cleaning. A single layer of $WO_3$ was prepared by using the dry process of general RF magnetron sputtering. At a base vacuum of $1.8{\times}10^{-6}$[Torr], the optical and electrical properties of the resulting thin films were examined for use as a transparent electrode as well as a photocatalyst. The single layer of $WO_3$ prepared at an RF power of 100 [W], a pressure of 7 [mTorr] and Ar and $O_2$ gas flow rates of 70 and 2 sccm, respectively, showed uniform and good optical transmittance of over 80% in the visible wavelength range from 380 [nm] to 780 [nm]. The optical catalyst characteristics of the $WO_3$ thin film were examined by investigating the optical absorbance and concentration variance in methylene blue, where the $WO_3$ thin film was immersed in the methylene blue. The catalytic characteristics improved with time. The concentration of methylene blue decreased to 80% after 5 hours, which confirms that the $WO_3$ thin film shows the characteristics of an optical catalyst. Using the reflector of a CCFL (cold cathode fluorescent lamp) and the lens of an LED (lighting emitting diode), it is possible to enhance the air cleaning effect of next-generation light sources.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.19-32
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• 2013

In this study, outstanding white rot fungi for biodegradation of organosolv lignin were selected on the basis of their ligninolytic enzyme system. Fifteen white rot fungi were evaluated for their ability to decolorize Remazol Brilliant Blue R (RBBR) in SSC and MEB medium, respectively. Six white rot fungi (Ceriporiopsis subvermispora, Ceriporia lacerate, Fomitopsis insularis, Phanerochaete chrysosporium, Polyporus brumalis, and Stereum hirsutum) decolorized RBBR rapidly in SSC medium within 3 days. The protein contents as well as the activities of manganese peroxidase (MnP) and laccase for 6 selected fungi were determined on the SSC medium with and without organosolv lignin. Interestingly, extracellular protein concentrations were determined to relative higher for S. hirsutum and P. chrysosporium in the presence of organosolv lignin than others. On the other hands, each fungus showed a different ligninolytic enzyme pattern. Among them, F. insularis resulted the highest ligninolytic enzyme activities on incubation day 6, indicating of 1,545 U/mg of MnP activity and 1,259 U/mg of laccase activity. In conclusion, $STH^*$ and FOI were considered as outstanding fungi for biodegradation of organosolv lignin, because $STH^*$ showed high extracellular protein contents and ligninolytic enzyme activities over all, and ligninolytic enzyme activities of FOI were the highest among white rot fungi used in this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.653-659
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• 2008

In this study, the optimum pre-heating condition was investigated to improve water extraction yield of Phelinus linteus tea. Pre-heating was carried out using drying oven or hot plate at different temperatures and times, and extraction yield was estimated by measuring optical density at 370 nm and soluble solid content. The highest optical density and soluble solid content of Phelinus linteus tea were observed when pre-heated at $70{\sim}80^{\circ}C$ for 30 minutes in drying oven. Pre-heating in drying oven resulted in also faster color changes of Phelinus linteus tea at lower temperature. According to the organoleptic evaluation, pre-heated Phelinus linteus tea in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was preferred compared to the non-treated. In conclusion, pre-heating in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was found to be the most efficient conditions to increase extraction yield of Phelinus linteus tea.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.33-40
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• 2003

Fusobacterium nucleatum, one of the bacteria causing halitosis, produces the volatile sulfur compounds (VSC) such as $H_2S$ in the media containing sulfur components, and forms FeS by binding with iron component. The various factors of oral cavity affect the concentration of sulfur compounds produced by Fusobacterium nucleatum. In this study, the effect of nutrients and pH on the production of sulfur compounds by Fusobacterium nucleatum was studied with the following results. 1. The optical density of broth was increased to $0.817{\pm}0.032$ and $1.297{\pm}0.024$ by adding 1.0% sodium thiosulfate and 0.05% L-cysteine hydrochloride in the media, respectively. 2. Though the optical density of broth was $0.799{\pm}0.032$ by adding volatile sulfur compounds (VSC) only in the media, it was increased to $1.775{\pm}0.003$ and $1.648{\pm}0.022$ by adding xylitol combined with glucose and fructose, respectively. 3. The concentration of VSC was above 20,000 ppb in the media above pH 5.5. The optical density of broth was still high in the media with L-cysteine hydrochloride of higher concentration, being low in the media of lower pH. 4. The concentration of VSC was high when there was distilled water or saline solution on the media, and their amount was small. These results suggest that the production of sulfur compounds by Fusobacterium nucleatum was inhibited by xylitol and acid.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.80-91
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• 2003

Mutans streptococci, especially S. mutans and S. sobrinus strongly implicated in pathogenesis of dental caries, the major cause of tooth loss in children. Use of an antibacterial agent controlling dental caries has been rationalized. The present study was performed to observe the antibacterial effect of inorganic polyphosphates (polyP) on S. mutans and S. sobrinus. S. mutans GS5 and S. sobrinus 6715 were grown in brain-heart infusion broth with or without polyP. Minimal inhibitory concentration (MIC) of polyP for S. mutans GS5 was determined to be 0.08% and that for S. sobrius 6715 was 0.17%. PolyP 15 added to the growing culture of S. mutans GS5 and S. sobrinus 6715 at their exponential phase was as effective in inhibiting the growth of S. mutans GS5 and S. sobrinus 6715 as polyP added at the very beginning of the culture. More than 85% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. mutans GS5 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. And more than 99.9% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. sobrinus 6715 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. Intracellular nucleotide release from S. mutans CS5 and S. sobrinus 6715 was increased in the presence of polyP 15 for 5h but was not really reversed by the addition of divalent cations like $Ca^{++}\;and\;Mg^{++}$. The majority of the cells appeared to be atypical in their shape, demonstrating accumulation of highly electron-dense granules and ghost cells. The overall results suggest that polyP have a strong bactericidal activity against S. mutans and S. sobrinus in which lysis in relation to chelation may not play the major role but unknown mechanism that possibly affects the viability of the bacterium may be involved. PolyP may be used as an agent for prevention of dental caries.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1298-1305
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• 2020

Objective: The study aimed to understand the degree of improvement in damaged hair by applying mink oil. Methods: The agent used to improve hair texture is mink oil, which was applied in varying dosages (0, 1, 2, and 3 g). Hair characteristics were measured before and after applying mink oil to bleached hair for comparative analysis. To understand the effects of mink oil on hair texture, tensile strength, absorbance, and gloss were measured. Results: The results indicate a decrease in the tensile strength of damaged hair compared with healthy hair. Tensile strength at level 7 was achieved with high dosages of mink oil. Furthermore, the experimental group demonstrated an increase in absorbance compared with control. Compared to 0g for the control group, the absorbance values for the experimental group with mink oil dosages of 1, 2, and 3 g at level 7 decreased with the increased in mink oil dose. In terms of gloss, an increase was observed for bleached hair compared with healthy hair. At level 7, gloss decreased with the increase in mink oil dose. Conclusions: The results verified the improvement in hair texture after the application of mink oil to damaged hair. Future research should explore the effects of various oil ingredients on hair texture.