• Title/Summary/Keyword: solubility test

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Effects of Functional Properties of Soy Protein Isolate and Qualities of Soybean Curd upon Proteolytic Hydrolysis (효소처리가 대두단백질의 기능특성과 두부의 품질에 미치는 영향)

  • Han, Jin-Suk;Hwang, In-Kyeong
    • Korean Journal of Food Science and Technology
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    • v.24 no.3
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    • pp.294-299
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    • 1992
  • This study was to examine the effect of functional properties of soy protein isolate(SPI) and qualities of soybean curd upon proteolytic hydrolysis. SPI was hydrolyzed using proteolytic enzyme, bromelain. The protein content of SPI by microkjeldahl method was 84% and the degree of hydrolysis in modified soy protein isolate(MSPI) was 2.7%. The solubility of MSPI was higher than that of control at various pH tested and proteolytic hydrolysis was increased emulsion formation and foam expansion while decreased emulsion stability, foam stability and calcium precipitation. Modified soybean curdI, standard soybean milk: Modified soybean milk=3:1, was soft and springy soybean curd when the texture properties of soybean curd were tested by texture profile analysis using Instron and sensory evaluation. The rheological model of soybean curds was investigated by stress relaxation test. The analysis of relaxation curve revealed that the rheological behavior of soybean curds could be expressed by 7-element generalized Maxwell model. The equilibrium modulus and modulus of elasticity decreased as the ratio of modified soybean milk was increased.

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Study on Stabilization of Arsenic in Soil through in situ Formation of Amorphous Fe Oxides and use of X-ray Absorption Spectroscopy (비결정질철산화물 원위치 형성을 통한 비소오염토양 안정화 및 X선 분광분석법의 활용에 대한 연구)

  • Park, Jinhee;Chung, Hyeonyong;Kim, Sang Hyun;An, Jinsung;Nam, Kyoungphile
    • Journal of Soil and Groundwater Environment
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    • v.25 no.2
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    • pp.9-15
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    • 2020
  • This study was conducted to investigate the in situ formation of amorphous Fe oxides as a stabilization technology in As-contaminated soil. After addition of ferric nitrate and the neutralizing agent, most of extractable fractions of As in soil (i.e., SO42- and PO43--extractable As) was converted into As bound to amorphous Fe oxides. In addition, results of solubility bioavailability research consortium (SBRC) test indicated that a significant amount of As in untreated soil changed to a non-bioaccessible form after stabilization. The reason was attributed to the newly formed amorphous Fe oxides in the stabilized soil, which was confirmed by linear combination of fitting (LCF) using X-ray absorption spectroscopy (XAS) analysis. Interestingly, after five months of aging of the stabilized soil, ferrihydrite and schwertmannite newly formed in the soil were transformed to crystalline Fe oxides such as goethite, and further decrease in SBRC extractable fraction of As was observed. The results suggest that co-precipitated As with amorphous Fe oxides can be further immobilized with time, due to the crystallization of amorphous Fe oxides.

A Development on Assessment Method of PVC Gloves Used in Pest Control Program (해충제어프로그램에서 사용되는 PVC장갑의 평가방법 개발)

  • Lee, Su-Gil;Lee, Nae-Woo
    • Journal of the Korean Society of Safety
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    • v.21 no.3 s.75
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    • pp.53-58
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    • 2006
  • Following a Mediterranean fruit fly outbreak in South Australia, a bait spray program involving the pesticides like malathion(MAL) was carried out. During the application, dermal exposure was considered for the pest controllers wearing PVC gloves. However there is a lack of information about PVC glove performance like break through times and permeation rates with MAL, therefore, a new analytical method for HPLC-UV was developed. A standard permeation test cell was used in this study. From the results of this study, more than 96% solubility of MAL was provided at 30% isopropyl alcohol in distilled water as a collecting media. However, there was significant decomposition of MAL when the solutions were kept at over $50^{\circ}C$ for 2-3 hours. As a mobile phase, 50% acetonitrile water solution (pH 6.0) gave the greater sensitivity compared with other compositions of acetonitrile solution. The arm section of the gloves had shorter breakthrough times and higher permeation rates compared with the palm. There was no malathion solution breakthrough up to 24 hours using the 1% MAL working strength solution. When the temperature was changed from $22{\pm}1^{\circ}C\;to\;37{\pm}1^{\circ}C$, the breakthrough times were decreased by 14.5% on palm and 37.5% on arm, and permeation rates were increased significantly. The findings of this study indicate that further investigations on used gloves, periods of use and varying working conditions like tasks and seasons should be carried out to assess potential worst case scenarios.

Application of Solid Phase Microextraction to the Analysis of Pesticides in Vegetables

  • Cho Tae-Hee;Kang Hee-Gon;Kim Tae-Rang;Chang Min-Su
    • Proceedings of the Korean Society of Food Hygiene and Safety Conference
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    • 2001.10a
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    • pp.171-174
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    • 2001
  • Solid phase micro-extraction (SPME), a solvent-free, rapid and inexpensive method for the extraction of organic compounds from aqueous sample matrices, was evaluated for determination of the 120 pesticides in vegetables such as crown daisy, perilla leaf, leafy lettuce and to mato. The analysis conditions were chosen for the SPME method: 15 min of immersion of the PDMS fiber in 10 ml of the solution with stirring at 1,000 rpm. The recovery tests were carried out in triplicate. The range of recoveries was 0-142% for organochlorine pesticides and $4.9\sim200\%$ for organophosphorus pesticides. The recoveries were very low in the pesticide groups with low solubility in water. The recoveries became lower in proportion to the interference materials in vegetables. The recovery in tomato was relatively higher than that in perilla Ie af and crown daisy. The recovery values obtained by SPE and SPME were compared. In leaf y lettuce, recovery obtained by SPE method ranged from $58.1\%\;to\;136.1\%$ and recovery by SPME ranged from $9.6\%\;to\;176.3\%$ In organophosphorus pesticides. The recovery in SPME method was satisfactory with $136\%$ for ethoprophos, $119\%$ for methidathion and $113\%$ for diazinon. Meanwhile, recovery of EPN, phenthoate and 2,4-DDT revealed relatively low value of $38\%,\;41\%\;and\;3.4\%,$ respectively. However, most of pesticides applied to SPME method sho wed constant recovery and precision. From these results, it can be concluded that solid phase micro-extraction might be an appropriate method for the screening test of pesticides in vegetables.

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The research regarding an information system risk management process characteristics (정보시스템 위험관리 프로세스 특성에 관한 연구)

  • Kim, Tai-Dal;Lee, Hyung-Won
    • The KIPS Transactions:PartD
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    • v.14D no.3 s.113
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    • pp.303-310
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    • 2007
  • Information system failure is various such as program test unpreparedness, physical facilities for damage prevention unpreparedness from simple software error. Although cross is trifling the result causes vast damage. Recently, became difficult by simple outside security system to solve this problem. Now, synthetic countermove establishment and suitable confrontation connected with danger came in necessary visual point about general Information Technology of enterprise. In connection with, in this paper, various informations and system and control about data that can happen information inside and outside considering integrity for IT resource, solubility, confidentiality within organization studied about special quality to model synthetic Risk Management System that can of course and cope in danger.

Effect of Photoinitiators on Adhesion Properties of 2-EHA/AA PSA (광개시제의 종류에 따른 2-EHA/AA 점착제의 접착특성)

  • Yoon, Hong-Beom;Kim, Ho-Gyum;Min, Kyung-Eun
    • Polymer(Korea)
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    • v.38 no.4
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    • pp.491-495
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    • 2014
  • Pressure sensitive adhesive (PSA) based on 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) copolymer was synthesized using different photoinitiators. Results showed that PSA with Irgacure$^{(R)}$651 (benzyldimethylketal) and Irgacure$^{(R)}$184(1-hydroxy-cyclohexylphenyl ketone) proved to be good for adhesion properties. This may be attributed to strong absorption near 350 nm wavelength and also high solubility in monomer mixtures. The addition of Irgacure$^{(R)}$819, bisacylphosphine oxides as a photoinitiator caused cohesive failure with high loading in a peel test owing to the additional radical formation. It is assumed that the insoluble photoinitiator reacts with oxygene, which may act as a hydrogen donor.

Comparative Effects of Gamma Irradiation and Methyl Bromide Fumigation on Disinfestation and Physicochemical Properties of Mung Bean (감마선과 Methyl Bromide 처리가 녹두의 살충 및 이화학적 특성에 미치는 영향)

  • 노미정;권중호;권용정;허은엽;권용순;변명우
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.3
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    • pp.444-449
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    • 2001
  • Comparative effects of gamma irradiation and methyl bromide (MeBr) fumigation on disinfestation and physicochemical attributes of mung bean were investigated. Insects in domestic mung bean were identified to be Collosobruchus chinensis Linne. Ina disinfestation test, MeBr showed 100% disinfestation effect on Larva and adult at 5th day after treatments, while irradiation dose above 3 kGy was effective for disinfesting all larva at that time. Adults were more sensitive to radiation than larva. Around 1 kGy was enough to control larva and adult in mung bean following 10 to 15 days of irradiation. In physicochemical properties of treated sampels, nitrogen solubility, TBA value, amino acid and fatty acid compositions were not different among the control, 2.5 kGy-irradiated and MeBr-fumigated samples. MeBr fumigation caused the decrease in lightness (Hunter's L value) and the increase in redness (a value) and yellowness (b value), thereby resulting in overall color difference (${\Delta}E$) in a noticeable level (NBS 2.61~2.94).

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The Characteristics of a Fine O/W Emulsion by Nonaqeous Emulsification (비수유화법에 의한 미세 O/W에멀젼의 특성)

  • Lee, S.J.;Ro, Y.C.;Gang, Yun-Seok;Nam, K.D.
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.145-152
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    • 1996
  • A fine oil-in-water (O/W) emulsion using nonaqueous emulsification technique was developed and the behaviors of POE(25)octyldodecyl ether in nonaqueous solvent/oil systems were studied by observing the surface tension, interfacial tension, turbidity and transition temperature. It was found that POE(25)octyldodecyl ether existed soluble in nonaqueous solvent while, in aqueous system, it formed micelles. So, when a solvent, like glycerine in which POE(25)octyldodecyl ether has poor solubility, was added, POE(25)octyldodecyl ether moved to the surface. After saturated at surface, POE(25) octyldodecyl ether began to precitate. The mean particle size of the final emulsion was 230nm. Also, the emulsion system was stable at 0, 25, 40, $50^{\circ}C$ and cycling test for a month, while the conventional emulsion system showed unstability. It is concluded that, by pertinent combination of solvents, the adsorption efficiency of surfactant could be improved.

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A Comparison Study on Physicochemical Properties of Two Small Red Bean ( Black and Red ) Starches and Gels (거두와 적두전분의 이화학적 특성 및 Gel 특성에 관한 연구)

  • Chae, Seon-Hee;Sohn, Kyung-Hee
    • Korean journal of food and cookery science
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    • v.6 no.2
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    • pp.7-14
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    • 1990
  • This study has been carried out in order to investigate the physicochemical properties of two small red bean starches. Some of rheological properties of the starch gels were also studied by experiments of various starch concentrations. Water binding capacity of black bean starch was 172.3% and that of red bean starch was 199.0%. Black bean starch had lower swelling power than red bean starch, but the solubility of the black bean starch was higher. When the temperature increased from 60$^{\circ}C$ to 70$^{\circ}C$, the transmittance of two starches rapidly increased. The gelatinized temperature in DSC for black bean was 66.2$^{\circ}C$ and that for red bean was 66.0$^{\circ}C$. Black bean and red bean starches had the blue vlaues of 0.55 and 0.56 and the alkali numbers of 4.40 and 4.13. The molecular weight of amylose was 40,000 and 33,611. The amylose contents of two starches were same at 52%. Brabender Amylographs of two small red bean starch pastes showed C pattern, which is stable. The results of compression test pointed out that TPA parameters varied with the change of storage time, and black bean starch gels had the higher TPA value. The retrogradation study by glucoamylase digestion method revealed that red bean starch gels were more easily retrogradated than black bean. X-ray diffraction patterns of two small red bean starches were A pattern, and diffraction peaks disappeared with gelatinization of starches.

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Synthesis and In Vitro Properties of Prednisolone 21-Sulfate Sodium as a Colon-Specific Prodrug of Prednisolone

  • Doh, Min-Ju;Jung, Yun-Jin;Kim, In-ho;Kong, Hye-Sik;Kim, Young-Mi
    • Archives of Pharmacal Research
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    • v.26 no.4
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    • pp.258-263
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    • 2003
  • Colon-specific delivery of glucocorticoids is highly desirable for the efficient treatment of inflammatory bowel disease. We synthesized prednisolone 21-sulfate sodium (PDS) as a colon-specific prodrug of prednisolone (PD) and investigated its properties using rats as test animals. We expected that introduction of sulfate ester as a sodium salt might increase the hydrophilicity and restrict the absorption in the GI tract. If PDS is stable and nonabsorbable in the upper intestine, it will be delivered to the colon as an intact form, where it hydrolyze by the sulfatase to release PD. Compared with PD, the solubility of PDS increased and the apparent partition coefficient decreased greatly. PDS was stable on incubation with pH 1.2 and 6.8 buffer solutions and with the contents of the stomach and small intestine. On incubation with the cecal contents, PDS decreased to 9.6% of the dose in 10 h producing PD. The amount of PD increased to give a maximum 54% of the dose and decreased. As a control, when PD was incubated with the cecal contents, it decreased to 29% of the dose in 8 h, which implied that reduction of PD proceeded under such conditions. These results suggested that hydrolysis of PDS took place to produce and accumulate PD, which decreased by reduction as the incubation period extended. Our results suggested that PDS can be a promising colon-specific prodrug of PD, and sulfate ester group might serve as a potential colon-specific promoiety, especially for the drugs which are resistant to reduction in the colon.