• Food Science and Preservation
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• v.9 no.3
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• pp.345-350
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• 2002

This study was carried out to determine the effect of gamma irradiated Puerariae radix extract on color removal, antioxidative, DPPH radical scavenging and antimicrobial efftcts. Puerariae radix were extracted with methanol and acetone and irrdiated 10, 20 and 30 kGy with gamma ray. Hunter color L-value increased by irrdiation in a dose dependent manner, resulting in brighter color. But a and b values decreased by irradiation in a dose dependent manner. Antioxidant activities of the Puerariae radix extract in soybean oil emulsion were higher in methanol extract than acetone extract. Scavenging effect of Puerariae radix extracts on DPPH radical with methanol was not changed by irradiation but acetone decreased Acetone extract from Puerariae radix showed antimicrobial activities in B. subtilis, B, natto, B, megaterium S, aureus, Sal, typhymurium and E. coli methanol extract also had the antimicrobial activities but weaker for Sal. typhymurium and E. coli. Results suggested that Puerariae radix extracts have a potential as a natural food preservatives and cosmetic raw material.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.296-308
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• 2010

The peroxone process overcomes many of the limitations associated with conventional and advanced water treatment systems using chlorine disinfection and ozone oxidation processes. Ozone and hydrogen peroxide generate highly reactive hydroxyl free radical which oxidize various organic compounds and has highly removal efficiency. The key issue to operate peroxone process is developing the method to achieve high process effectiveness when scavengers that inhibit generation of OH radicals or consume OH radicals are co-existing in the process. Also many studies, to minimize inorganic oxidative by-products such as bromate and to reduce disinfection by-products after chlorination behind peroxone process, are needed. And we should consider the excess residual hydrogen peroxide in the water. On-line instruments and control strategies need to be developed to ensure effective and robust operation under conditions of varying load. If problems above mentioned are solved, peroxone process will be applied diversely for water treatment.

• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.184-191
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• 2013

This study performed physicochemical characteristics and sensory tests on brown sauce with different Salicornia herbacea L. (saltwort) content to find the best brown sauce recipe with saltwort. Moisture content increased with greater saltwort extract content. There was significant (p<0.001) pH difference with saltwort content. There was also significant (p<0.001) sweetness difference in the samples and sweetness increased with greater saltwort content. Viscosity measured at $20^{\circ}C$ and $60^{\circ}C$ was significantly (p<0.001) lower with greater saltwort content. The brightness of brown sauce containing saltwort extracts significantly (p<0.001) increased with greater saltwort content and its redness and yellowness usually decreased. SPS4 with the greatest saltwort content showed the highest value of 4.25% and DPPH radical removal increased significantly (p<0.001) with greater saltwort content. In the sensory test, the color value was lowest at 4.82 with BSL1 and the flavor value was lowest at 5.00 with BSL0, the control group. The taste and the flavor values were highest with BSL2 with 2% saltwort content. Overall acceptance was highest with BSL3, the brown sauce with 3% saltwort content, at 6.09. As a result, it was concluded that the brown sauce with 3% saltwort content was most suitable. Therefore, this study concluded that saltwort with various functions could be used for food and may be used to replace salt and have other functions in brown sauce, a popular sauce consumed in Korea.

• The Korean Journal of Food And Nutrition
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• v.31 no.4
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• pp.543-548
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• 2018

This study was conducted to investigated the antioxidant activities of extract for Megmoondong fruit. Liriope platyphylla L. was extracted with 70% methanol at room temperature for 48 hr and concentrated under reduced pressure to measure its total polyphenol contents and electron donating ability. The total polyphenol contents were $7,253.50{\pm}335.43{\mu}g\;GAE/mL$ in 70% methanol extract, $1,239.77{\pm}9.30{\mu}g\;GAE/mL$ in methylene chloride fraction, $919.30{\pm}50.83{\mu}g\;GAE/mL$ in methanol fraction, $105.44{\pm}2.04{\mu}g\;GAE/mL$ in ethyl acetate fraction. The total polyphenol contents showed significant differences (p<0.05) between the solvents. The electron donating ability was $69.17{\pm}12.61%$ for 70% methanol extract, $33.11{\pm}1.77%$ for methylene chloride fraction, $5.19{\pm}2.59%$ for ethyl acetate fraction, and $20.16{\pm}1.04%$ for methanol fraction. The electron donating abilities were significantly different (p<0.05) between the solvents. The removal ability of superoxide radical was $0.0174{\pm}0.0007$ for 70% methanol extract, $0.0164{\pm}0.0007$ for methylene chloride fraction, $0.0172{\pm}0.0007$ for ethyl acetate fraction, and nothing for methanol fraction. The measurement of hydrogen peroxide decomposition was $0.0985{\pm}0.1021$ for 70% methanol extract, $0.0896{\pm}0.0893$ for methylene chloride fraction, $0.0115{\pm}0.0085$ for ethyl acetate fraction, and $0.0170{\pm}0.0180$ for methanol fraction. The Liriope platyphylla L. extracts obtained from methylene chloride showed significantly relevant results in the total polyphenol contents and electron donating ability, which was higher than the original extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.137-142
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• 2003

This study was carried out to examine the effects of gamma irradiation on the color removal, antioxidation, DPPH radical scavenger, and antimicrobial activity of Schizandra fructus extracts by different solvents. Schizandra fructus was extracted by hot water, ethanol, acetone and methanol, and the extracts were irradiated 10, 20 and 30 kGy with gamma rays. Hunter color L-value was increased by irradiation in a dose-dependent manner, resulting in brighter color for all solvents used. The a and b values were decreased by irradiation in a dose-dependent manner. Antioxidant activity of the ethanol extract of Schizandra fructus against soybean oil was the highest. The free radical scavenging activity was the strongest in hot water extract. All solvent extracts from Schizandra fructus had the strongest antimicrobial activities to B. subtilis, B. natto, B megaterium, S. aureus, Sal. typhymurium and E. coli. These results suggested that Schizandra fructus extracts have a strong potential as natural food preservatives and cosmetic raw materials. Furthermore, irradiation may not influence adversely on biological activites of the extracts when irradiated up to 30 kGy.

• Polymer(Korea)
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• v.35 no.6
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• pp.615-618
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• 2011

Carbon nanotubes (CNTs) draw attention as promising materials due to their excellent electrical and mechanical properties. However, the intrinsic strong interaction between CNTs presents a challenge to their use in various applications. Here, we present a facile method to disperse single-walled carbon nanotubes (SWCNTs) in a polar solution using a graft copolymer, poly(vinyl chloride)-graft-poly(oxyethylene methacrylate), PVC-g-POEM. The graft copolymer was synthesized via atom transfer radical polymerization (ATRP), as confirmed by gel permeation chromatography (GPC) and $^1H$ NMR spectroscopy. The SWCNTs were uniformly dispersed in a polar solvent such as dimethylsiloxane (DMSO) using PVC-g-POEM as a dispersant, due to interaction between CNT and the graft copolymer, as revealed by transmission electron microscopy (TEM) analysis. Upon removal of the solvent, free standing nanocomposite films with good homogeneity were obtained.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.253-258
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• 2011

Acetylsalicylic acid (ASA) has been issued recently in contaminated water environments because of potential impacts on ecosystem and public health. This study was aimed at investigating the possibility of ASA degradation using gamma ray irradiation. In addition, the use of sodium persulfate, hydrogen peroxide, ferrous sulfate were tested in order to examine a synergistic effect with gamma ray. The absorbed dose was ranged from 0.2 to 10 kGy and the concentration of oxidants were from 0.1 to 10 mM in this study. The concentration of ASA was gradually decreased corresponding to the increase of the absorbed dose. When soudium persulfate was simultaneously applied, most of the parent compound was completely degraded even at a low dose of 0.8 kGy. The removal efficiency of total organic carbon was 90% even at the highest dose of 10 kGy without sodium persulfate. However, the efficiency was dramatically enhanced up to 98% at the same dose by adding 10 mM of oxidants. It was suggested that hydroxyl radical ($OH{\cdot}$) and sulfate radical ($SO{_4}^-{\cdot}$) were formed in the system and made roles in degrading ASA at the same time.

• Journal of the Korean GEO-environmental Society
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• v.12 no.2
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• pp.63-68
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• 2011

The aim of this study was 1,4-dioxane's degradation efficiency and toxicity test applying E-beam. The experiments were shows that the degradation efficiency in the initial concentration of 1,4-dioxane and the irradiation capacity of E-beam and the degree of mineralization based on a change of scavenger gas. The biological toxicity test by using on of green algae, Pseudokirchneriella Subcapitata was conducted to lead the reducing toxicity. Degradation efficiency of 1,4-dioxane was improved when E-beam irradiation intensity was higher and the efficiency of TOC removal using Radical scavenger gas was increased by $N_2O$, $O_2$ and $N_2$ in order. In 4 days(96hrs), toxicity test results indicated that toxicity effect was decreased by increase of E-beam irradiation intensity.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.2
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• pp.147-154
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• 2023

Mulberry exhibits unique characteristics and functionalities across various components, including the roots, branches, leaves, and fruits. However, despite numerous studies on mulberry, research on this plant at the seedling stage is insufficient. Therefore, this study aimed to compare the suitability for seedling cultivation and antioxidant effects of four Korean mulberry cultivars, namely, Daesim, Suhong, Simgang, and Cheongsu. In terms of seed weight, germination rate, and growth rate, Daesim was the most suitable cultivar for seedling production. Polyphenol and flavonoid content analysis showed that all cultivars, except for Cheongsu, showed the highest phenolic content at the 2-week seedling stage. Similarly, antioxidant assays using 2,2'-azino-di-3-ethylbenzthiazoline sulfonic acid (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals revealed that the antioxidant effect of all cultivars, except for Cheongsu, increased with cultivation at 2- 4- and 6-week. However, mulberry seedlings had a slower reaction rate against DPPH radical removal than mulberry leaves. In addition, ABTS radical scavenging activity showed a different correlation with polyphenol content. This phenomenon may be due to the different polyphenol compositions between mulberry leaves and seedlings. The results of this study suggest that mulberry seedlings exhibit different bioactivities from mulberry leaves, and component analysis is required in further research.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.43-51
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• 2012

Rreactivity of persulfate (PS) for oxidation of TCE under various conditions such as heat, $Fe^{2+}$, and UV was investigated. It was found that degradation rate of TCE increased with increasing temperature from 15 to $35^{\circ}C$. At pH 7.0, the rate constants (k) at 15, 25, 30, and $35^{\circ}C$ were 0.07, 0.30, 0.74, and $1.30h^{-1}$, respectively. For activation by $Fe^{2+}$, removal efficiency of TCE increased with increasing $Fe^{2+}$ concentration from 1.9 mM to 11 mM. The maximum removal efficiency of TCE was approximately 85% when pH of the solution dropped from 7.0 to 2.5. Degradation of TCE by UV-activated PS was the most effective, showing that the degradation rate of TCE increased with inreasing PS dosage; the rate constants (k) at 0.5, 2.5, and 10 mM were 34.2, 40.5, and $55.9h^{-1}$, respectively. Our results suggest that PS activation by UV/PS process could be the most effective in activation processes tested for TCE degradation. For oxidation process by PS, however, pH should be observed and adjusted to neutral conditions (i.e., 5.8-8.5) if necessary.