• 제목/요약/키워드: Acidic Properties

검색결과 588건 처리시간 0.03초

Simultaneous Determination of UV Absorbers Migrated from Polyethylene and Polypropylene Food Packaging Materials into Food Simulants by HPLC-UVD (HPLC-UVD를 이용한 폴리에틸렌, 폴리프로필렌 기구 및 용기·포장 유래 자외선흡수제 동시분석법)

  • Choi, Heeju;Choi, Jae Chun;Bae, In-Ae;Lee, Chanyong;Park, Se-Jong;Kim, MeeKyung
    • Journal of Food Hygiene and Safety
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    • 제32권5호
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    • pp.434-442
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    • 2017
  • The UV light in sunlight breaks down the chemical bonds in a polyolefin polymer through a process called photodegradation, ultimately causing cracking, chalking, colour changes, and loss of physical properties such as impact strength, tensile strength, elongation, and others. UV absorbers are used to prevent or terminate the oxidation of plastics by UV light. They are receptive to UV radiation and dissipate the energy harmlessly as heat. Benzotriazoles and benzophenones are used mainly in polyolefins such as polyethylene and polypropylene. In this study, we have developed a method for the analysis of 12 UV absorbers, which are Uvinul 3000, Cyasorb UV 24, Uvinul 3040, Tinuvin 312 and P, Seesorb 202, Chimassorb 81, Tinuvin 329, 234, 326, 328 and 327, migrated from the food packaging materials into four food simulants for aqueous, acidic, alcoholic and fatty foods. The UV absorbers in food simulants were determined by reversed-phase high performance liquid chromatograph-ultraviolet detector with 310 nm after solid-phase extraction with a hydrophilic-lipophilic balance (HLB) cartridge or dilution with isopropanol. The analytical method showed a good linearity of coefficient ($R^2{\geq}0.99$), limits of detection (0.049~0.370 mg/L), and limits of quantification (0.149~1.120 mg/L). The recoveries of UV absorbers spiked to four food simulants ranged from 70.05% to 110.13%. The developed method would be used as a reliable tool to determine concentrations of the migrated UV absorbers.

Properties of the Silkworm (Bombyx mori) Dongchunghacho, a Newly Developed Korean Medicinal Insect-borne Mushroom: Mass-production and Pharmacological Actions (한국에서 개발된 곤충유래 약용버섯인 누에동충하초의 생산기술개발 및 약리학적 특성)

  • Lee, Sang Mong;Kim, Yong Gyun;Park, Hyean Cheal;Kim, Keun Ki;Son, Hong Joo;Hong, Chang Oh;Park, Nam Sook
    • Journal of Life Science
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    • 제27권2호
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    • pp.247-266
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    • 2017
  • Cordyceps is a traditional Chinese medicinal herb well-known in China, Korea and Japan since B.C. 2,000. The original entomopathogenic fungus, Cordyceps sinensis belonging to the genus Cordyceps could not be found inside Korean peninsula due to the absence of the host insect for the corresponding entomogenous fungus. The development of artificial production methods of Korean type Cordyceps using the silkworm Bombyx mori as in vivo culture medium for the the entomopathogenic fungus Paecilomyces tenuipes is the first, and wonderful occasion in the research history of insect industry of this global world. The aim of this article is to review the historical research background, mass-production methods, and pharmacological effects of the silkworm-dongchunghacho (Paecilomyces tenuipes) which is a newly developed Korean medicinal insect-borne mushroom, and another non-insect-borne medicinal mushroom (Cordyceps militaris and Cordyceps pruinosa). Their biological actions include anti-tumor, immunostimulating, anti-fatigue, anti-stress, anti-oxidant, anti-aging, anti-diabetic, anti-inflammatory, anti-thrombosis, hypolipidaemic and insecticidal effects. The bioactive principles are protein-bound polysaccharides (hexose, hexosamin), cordycepin, D-manitol, acidic polysaccharide etc. Protein-bound polysaccharides and n-butanol fractions were demonstrated to show a significant anti-tumor activities but did not show a cytotoxicities. D-mannitol exhibited a significant prolongation of the life span in tumor bearing mice. Ergosterol did not show an efficient anti-tumor activity, but showed a significant phagocytosis enhancing activity. Anti-tumor activity of silkworm-dongchunghacho might be attributed to immuno-stimulating activities rather than cytotoxic effects [164]. Also this review comprises the breeding of Dongchunghacho varieties, optimization of culture conditions, improvement of learning and memory by Dongchunghacho, application of them as foods and chemical constituents.

Characterizations of Kefir Grains in Fermented Whey and Their Effects on Inflammatory Cytokine Modulation in Human Mast Cell-1 (HMC-1) (Kefir grain에 의한 유청발효액의 특성과 human mast cell-1 (HMC-1)에서 염증 cytokine 조절에 미치는 영향)

  • Son, Ji Yoon;Park, Young W.;Renchinkhand, Gereltuya;Han, Jung Pil;Bum, Jin Woo;Paik, Seung-Hee;Lee, Jo Yoon;Nam, Myoung Soo
    • Journal of Life Science
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    • 제26권6호
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    • pp.689-697
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    • 2016
  • Kefir is an acidic-alcoholic fermented milk product originating from the Caucasian mountains. Kefir has long been known for its probiotic health benefits, including its immunomodulatory effects. The objectives of this study were to investigate the properties of a fermented whey product and to examine the effects of kefir grains on the in vitro immune-modulation of human mast cell-1 (HMC-1). The results showed that the whey fermented by kefir grains contained the maximum lactic acid bacteria and yeast for 16 hr by 1.83×108 and 6.5×105 CFU/ml, respectively, and lactose and whey proteins were partially hydrolyzed. The experimental whey fermented by kefir grains exhibited an in vitro anti-inflammatory effect on the HMC-1 line for 8, 16, and 24 hr, and this effect induced the expression of interleukin (IL)-4 as a pro-inflammatory cytokine, but not for 48 hr by RT-PCR in HMC-1 cells. In addition, the same phenomenon was observed for the expression of IL-8 as a pro-inflammatory cytokine by the kefir-fermented whey during the same periods of 8-48 hr under the same conditions. These cytokines resulted in the production of IL-4 at 20-25 ng in HMC-1 cells for 8, 16, and 24 hr, whereas 5 ng was produced for 48 hr by the fermented whey. In contrast, IL-8 was produced at 15-20 ng in HMC-1 cells during 4, 8, 16, and 24 hr, while 7 ng was produced at 48 hr. It was concluded that the whey fermented by kefir grains possesses a potential anti-inflammatory function, which could be used for an industrial application as an ingredient of functional foods and pharmaceutical products.

Removal of Fluoride Using Thermally Treated Activated Alumina (고온 처리된 활성알루미나를 이용한 불소 제거)

  • Park, Seong-Jik;Kim, Jae-Hyeon;Lee, Chang-Gu;Park, Jeong-Ann;Choi, Nag-Choul;Kim, Song-Bae
    • Journal of Korean Society of Environmental Engineers
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    • 제32권10호
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    • pp.986-993
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    • 2010
  • In this study, sorption characteristics of thermally treated activated alumina (AA) for fluoride were investigated. Sorption experiments have been conducted in equilibrium and kinetic batch conditions. Also, effects of solution pH and anions on fluoride removal have been observed. The properties of thermally treated ( $700^{\circ}C$) activated alumina (AA700) and untreated activated alumina (UAA) were compared using field-emission scanning electron microscope, energy-dispersive spectrometry, X-ray diffractometer (XRD) analysis, and Brunauer-Emmett-Teller (BET) analysis. From the experiments using AA thermally treated at different temperatures (100, 300, 500, $700^{\circ}C$), it was found that at high fluoride concentrations (50, 100, 200 mg/L) the sorption capacity of thermally treated AA increased with increasing thermal treatment temperature. At an initial fluoride concentration of 200 mg/L, the sorption capacity of AA700 was 3.67 times greater than that of UAA. The BET analysis showed that the specific surface area of UAA was about 2 times larger than that of AA700. The XRD analysis indicated that UAA was composed of both boehmite (AlOOH) and bayerite ($Al(OH)_3$) while AA700 was $Al_2O_3$. The reason that fluoride sorption capacity of AA700 increased despite of decrease in specific surface area compared to UAA could be attributed to the change of crystal structure. The kinetic sorption test showed that fluoride sorption to AA700 arrived at equilibrium after 24 h. The equilibrium test demonstrated that the maximum sorption capacity of AA700 was 5.70 mg/g. Additional batch experiments indicated that fluoride sorption to AA700 was the highest at pH 7, decreasing at both acidic and basic solution pHs. Also, fluoride sorption to AA700 decreased in the presence of anions such as phosphate, nitrate, and carbonate. This study demonstrated that thermal treatment of AA at high temperature could increase its sorption capacity for fluoride.

Chemical and Spectroscopic Characterization of Peat Moss and Its Different Humic Fractions (Humin, Humic Acid and Fulvic Acid) (피트모스에서 추출한 휴믹물질(휴믹산, 풀빅산, 휴민)의 화학적 및 분광학적 물질특성 규명)

  • Lee Chang-Hoon;Shin Hyun-Sang;Kang Ki-Hoon
    • Journal of Soil and Groundwater Environment
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    • 제9권4호
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    • pp.42-51
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    • 2004
  • Peat humin(p-Humin), humic acid(p-HA) and fulvic acid(p-FA) were isolated from Canadian Sphagnum peat moss by dissolution in 0.1M NaOH followed by acid precipitation. After purification cycles, they are characterized for their elemental compositions and, acid/base properties. Functionalities and carbon structures of the humic fractions were also characterized using FT-IR and solid state $^{13}C$-NMR spectroscopy. Those results are compared with one another and with soil humic substances from literatures. Main purpose of this study was to present a chemical and spectroscopic characterization data of humic substance from peat moss needed to evaluate its environmental applicability. The relative proportions of the p-Humin, p-HA and p-FA in the peat moss was $76\%,\;18\%,\;and\;3\%$, respectively, based on the total organic matter content ($957{\pm}32\;g/kg$). Elemental composition of p-Humin were found to be $C_{1.00}H_{1.52}O_{0.79}N_{0.01}$ and had higher H/C and (N+O)/C ratio compared to those of p-HA($C_{1.00}H_{1.09}O_{0.51}N_{0.02}$) and p-FA($C_{1.00}H_{1.08}O_{0.65}N_{0.01}$). Based on the analysis of pH titration data, there are two different types of acidic functional groups in the peat moss and its humic fractions and their proton exchange capacities(PEC, meq/g) were in the order p-FA(4.91) >p-HA(4.09) >p-Humin(2.38). IR spectroscopic results showed that the functionalities of the peat moss humic molecules are similar to those of soil humic substances, and carboxylic acid(-COOH) is main function group providing metal binding sites for Cd(II) sorption. Spectral features obtained from $^{13}C$-NMR indicated that peat moss humic molecules have rather lower degree of humification, and that important structural differences exist between p-Humin and soluble humic fractions(p-HA and p-FA).

Magnetic Properties of Electroless Co-Mn-P Alloy Deposits (무전해 Co-Mn-P 합금 도금층의 자기적 특성)

  • Yun, Seong-Ryeol;Han, Seung-Hui;Kim, Chang-Uk
    • Korean Journal of Materials Research
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    • 제9권3호
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    • pp.274-281
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    • 1999
  • Usually sputtering and electroless plating methods were used for manufacturing metal-alloy thin film magnetic memory devices. Since electroless plating method has many merits in mass production and product variety com­pared to sputtering method, many researches about electroless plating have been performed in the United State of America and Japan. However, electroless plating method has not been studied frequently in Korea. In these respects the purpose of this research is manufacturing Co-Mn-P alloy thin film on the corning glass 2948 by electroless plating method using sodium hypophosphite as a reductant, and analyzing deposition rate, alloy composition, microstructure, and magnetic characteristics at various pH's and temperatures. For Co-P alloy thin film, the reductive deposition reaction 0$\alpha$urred only in basic condition, not in acidic condition. The deposition rate increased as the pH and temperature increased, and the optimum condition was found at the pH of 10 and the temperature of $80^{\circ}C$. Also magnetic charac­teristics was found to be most excellent at the pH of 9 and the temperature of $70^{\circ}C$, resulting in the coercive force of 8700e and the squareness of 0.78. At this condition, the contents of P was 2.54% and the thickness of the film was $0.216\mu\textrm{m}$. For crystal orientation, we could not observe fcc for $\beta$-Co. On the other hand,(1010), (0002), (1011) orientation of hcp for a-Co was observed. We could confirm the formation of longitudinal magnetization from dominant (1010) and (1011) orientation of Co-P alloy. For Co-Mn-P alloy deposition, coercive force was about 1000e more than that of Co P alloy, but squareness had no difference. For crystal orientation, (l01O) and (lOll) orientation of $\alpha$-Co was dominant as same as that of Co- P alloy. Likewise we could confirm the formation of longitudinal magnetization.

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The Comparative Understanding between Red Ginseng and White Ginsengs, Processed Ginsengs (Panax ginseng C. A. Meyer) (홍삼과 백삼의 비교 고찰)

  • Nam, Ki-Yeul
    • Journal of Ginseng Research
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    • 제29권1호
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    • pp.1-18
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    • 2005
  • Ginseng Radix, the root of Panax ginseng C. A. Meyer has been used in Eastern Asia for 2000 years as a tonic and restorative, promoting health and longevity. Two varieties are commercially available: white ginseng(Ginseng Radix Alba) is produced by air-drying the root, while red ginseng(Ginseng Radix Rubra) is produced by steaming the root followed by drying. These two varieties of different processing have somewhat differences by heat processing between them. During the heat processing for preparing red ginseng, it has been found to exhibit inactivation of catabolic enzymes, thereby preventing deterioration of ginseng quality and the increased antioxidant-like substances which inhibit lipid peroxide formation, and also good gastro-intestinal absorption by gelatinization of starch. Moreover, studies of changes in ginsenosides composition due to different processing of ginseng roots have been undertaken. The results obtained showed that red ginseng differ from white ginseng due to the lack of acidic malonyl-ginsenosides. The heating procedure in red ginseng was proved to degrade the thermally unstable malonyl-ginsenoside into corresponding netural ginsenosides. Also the steaming process of red ginseng causes degradation or transformation of neutral ginsenosides. Ginsenosides $Rh_2,\;Rh_4,\;Rs_3,\;Rs_4\;and\;Rg_5$, found only in red ginseng, have been known to be hydrolyzed products derived from original saponin by heat processing, responsible for inhibitory effects on the growth of cancer cells through the induction of apoptosis. 20(S)-ginsenoside $Rg_3$ was also formed in red ginseng and was shown to exhibit vasorelaxation properties, antimetastatic activities, and anti-platelet aggregation activity. Recently, steamed red ginseng at high temperature was shown to provide enhance the yield of ginsenosides $Rg_3\;and\;Rg_5$ characteristic of red ginseng Additionally, one of non-saponin constituents, panaxytriol, was found to be structually transformed from polyacetylenic alcohol(panaxydol) showing cytotoxicity during the preparation of red ginseng and also maltol, antioxidant maillard product, from maltose and arginyl-fructosyl-glucose, amino acid derivative, from arginine and maltose. In regard to the in vitro and in vivo comparative biological activities, red ginseng was reported to show more potent activities on the antioxidant effect, anticarcinogenic effect and ameliorative effect on blood circulation than those of white ginseng. In oriental medicine, the ability of red ginseng to supplement the vacancy(허) was known to be relatively stronger than that of white ginseng, but very few are known on its comparative clinical studies. Further investigation on the preclinical and clinical experiments are needed to show the differences of indications and efficacies between red and white ginsengs on the basis of oriental medicines.

Study on the Lubricity Characteristics of Bio-heavy Oil for Power Generation by Various feedstocks (다양한 원료에 따른 발전용 바이오중유의 윤활 특성 연구)

  • Kim, Jae-Kon;Jang, Eun-Jung;Jeon, Cheol-Hwan;Hwang, In-Ha;Na, Byung-Ki
    • Journal of the Korean Applied Science and Technology
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    • 제35권4호
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    • pp.985-994
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    • 2018
  • Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.