• Title/Summary/Keyword: 점도변화

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Rheological Properties of Sweet Potato Starch-sucrose Composite (고구마전분-sucrose 복합물의 레올로지 특성)

  • Cho, Sun-A;Yoo, Byoung-Seung
    • Korean Journal of Food Science and Technology
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    • v.40 no.2
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    • pp.184-189
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    • 2008
  • Effects of sucrose at different concentrations (0, 10, 20, and 30%, w/w) on steady and dynamic shear rheological properties of sweet potato starch (SPS) paste (5%, w/w) were investigated. The steady shear rheological properties of SPS-sucrose composites were determined from rheological parameters based on power law and Casson flow models. At 25$^{\circ}C$ all the samples showed pseudoplastic and thixoropic behavior with high yield stress. Consistence index (K), apparent viscosity (${\eta}_{a,100}$), and yield stress (${\sigma}_{oc}$) values of SPS-sucrose composites decreased with increasing sucrose concentration from 10% to 30%. The decrease of swelling power was observed at higher sucrose concentration (>20%) and the low swelling power yielded a lower K, ${\eta}_{a,100}$, and ${\sigma}_{oc}$ values. In temperature range of 25-70$^{\circ}C$, Arrhenius equation adequately assessed variation with temperature. Oscillatory test data showed weak gel-like behavior. Magnitudes of storage (G') and loss (G") moduli increased with an increase in sucrose concentration and frequency. The SPS-sucrose composite at 30% concentration closely followed the Cox-Merz superposition rule.

Effect of Wheat Flour Brew with Bifidobacterium bifidum on Rheological Properties of Wheat Flour Dough (Bifidobacterium bifidum을 이용한 밀가루 brew가 반죽의 이화학적 성질에 미치는 영향)

  • Cho, Nam-Ji;Lee, Si-Kyung;Kim, Sung-Kon;Joo, Hyun-Kyu
    • Korean Journal of Food Science and Technology
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    • v.30 no.4
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    • pp.832-841
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    • 1998
  • In order to economically utilize flour brew with Bifidobacterium bifidum as a bread improver, the effect of flour brew on the rheological properties of dough, growth curve and acid production, and symbiosis with yeast were investigated. Growth of bifidobacteria was not increased more than initial seed volume but was consistent during 24 hours of incubation. pH was decreased and T.T.A was increased up to 12 hours of incubation. Symbiosis between bifidobacteria and yeast was little. Bifidobacteria produced more lactic acid than acetic acid in flour brew and the opposite in skim milk broth. This result was inferred from Lactobacillus sp. inherent in flour. On rheological properties of dough, farinograms of flour showed progressively decreasing baking absorption, mixing time and stability as the amount of flour brew increased. The validation of extensograms showed that R/E ratio linearly increased with increment of flour brew, and nearly doubled in all treatments comparing to that of control, which suggest the reduction of actual fermentation time. On visco/amylograms, malt index increased with addition of flour brew, accordingly showing the decrease in viscosity. Break down and set back value decreased with increment of flour brew, suggesting that staling rate of bread can be delayed.

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Isolation, Identification, and Fermentation Characteristics of Bacillus sp. with High Protease Activity from Traditional Cheonggukjang (전통 청국장으로부터 protease 분비능이 우수한 Bacillus sp. 균주의 분리 동정 및 발효 특성)

  • Ahn, Yong-Sun;Kim, Yong-Suk;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.38 no.1
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    • pp.82-87
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    • 2006
  • Twenty one strains strongly producing protease were isolated from Korean traditional Cheonggukjang. Eight strains selected by sensory evaluation on Cheonggukjang prepared with isolated strains were identified with based on biochemical properties a and 16S rDNA sequencing. Identified strains were Bacillus subtilis MB4, and Bacillus amyloliquefaciens A1, A2, B1, MC1, SB2, SC1, and SD1. Protease activities, important strain selection factor, were higher in Cheongjukjang prepared with B. subtilis MB4 (179.6 Unit) and B. amyloliquefaciens SB2 (201.9 Unit) than commercial traditional Cheonggukjang (97.9 Unit). Sensory evaluation revealed Cheonggukjang prepared with B. subtilis MB4 had flavor very similar to commercial traditional Cheonggukjang. Cheonggukjang prepared with B. suhtilis MB4 (0.0006 Pa s) and commercial traditional Cheonggukjang (0.0002 Pa s) revealed lower viscosities than those of Cheonggukjang prepared with B. amyloliquefaciens SB2, MC1, B1, A1, SD1, A2, and SC1 (0.006 to 0.008 Pa s at 1001/s. Results show Cheonggukjang could be prepared using single strain of B. subtilis MB4, maintaining high protease activity and very similar sensory and viscosity qualities with those of commercial traditional Cheonggukjang.

Study on the Evaluation of Ecological Health by using Fish Communities in the Wonju Stream, Korea (원주천의 어류군집을 이용한 생태적 건강성 평가 연구)

  • Park, Hyun Kyung;Choi, Jun Kil;Won, Kyung Ho;Lee, Hwang Goo
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.684-693
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    • 2017
  • The purpose of this study was to analyze fish communities in the Wonju stream located in Wonju-si in Gangwon-do, and to evaluate the health of the stream through past and present changes. We performed investigations four times from May 2015 to September 2016. In the survey, 5,201 individuals which belonged to 27 species and 9 families were collected. Zacco platypus was the dominant species and Pungtungia herziwas the subdominant species. Eight Korean endemic species (Acanthorhodeus gracilis, Zacco koreanus, Coreoleuciscus splendidus, Squalidus gracilis majimae, Microphysogobio yaluensis, Iksookimia koreensis, Koreocobitis rotundicaudata, Coreoperca herzi) were observed and showed a ratio of 16.54%. The fish community of dominance ($0.72{\pm}0.10$), diversity ($1.37{\pm}0.32$), evenness ($0.61{\pm}0.13$), and richness ($1.70{\pm}0.23$) were evaluated. According to our analysis of tolerance guilds, the total individual number of intermediate species was higher than the sensitive and tolerant species. As a result of the trophic guild analysis,the omnivore and insectivore species were relatively high. The value of the qualitative habitat evaluation index (QHEI) in the wonju stream was averaged 121.2 (${\pm}23.4$), indicating a suboptimal condition. Stream health showed that the fish assessment index (FAI) value was an A to C grade in the Wonju stream. A correlation coefficient analysis with FAI and various factors was analysed statistically, and had a high correlation in QHEI, with the omnivore species, insectivore species, intermediate species, sensitive species, dominance, diversity, evenness, and richness.

Survey and Analysis of Insect Species in the South Korea Habitat (Yeoncheon) of the Water Spider, Argyroneta aquatica (연천군 물거미 서식지의 곤충상 조사 및 군집분석)

  • Kang, Juwan;Park, Taechul;Park, Junyeong;Kim, Jihun;Jeong, Youngmoon;Park, Jung-Joon
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.476-491
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    • 2017
  • The water spider (Argyroneta aquatica), a rare member of its species, is one of the few insects known to live under water all over the world. In Korea, the water spider can be found only in the Eundae-ri, Yeoncheon, Gyeonggi province, where they are designated as a natural monument. However, loss of habitat is obvious, as the Eundae-ri wetland undergoes hydrarch succession. Loss of habitat has a direct impact on the water spider population. Thus protective measures for the water spider are needed to preserve the water spider habitat. In this study, a sweeping and visual survey of insect species was conducted in the water spider habitat from May to September 2015. The characteristics of each one of the different insect species and the community features were analyzed in this study. A total of 3,929 insects representing 276 species from 13 orders collected for the analysis. The most frequently collected insects from the Order Hemiptera represented 24.2% of total species and 82.3% of the total number of insects. Community analyses showed dominance, diversity, evenness, and richness indices of 0.23, 2.27, 0.41, and 31.2, respectively. Compared with the previous survey data, these results showed that reduction of the spider's wetland habitat caused the most commonly collected insects to adapt and spread to the surrounding terrestrial environment.

Improvement of Rheological and Functional Properties of Salmon FPC by Enzymatic Partial Hydrolysis 1. Production of Salmon FPC Hydrolysates and Their General Properties (효소적 부분 가수분해에 의한 연어 FPC(Fish Protein Concentrates)의 물성 및 기능성 개선 1. 연어 FPC의 가수분해물 제조와 일반적인 성상)

  • LEE Jong-Ho;LEE Keun-Tai;PARK Seong-Min;PARK Chan-kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.1
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    • pp.132-138
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    • 1998
  • To improve functional properties and enhance application of FPC in food industry, modified salmon FPC with enzyme treatment was produced and its general properties were investigated. Salmon FPC has over $84\%$ of protein and less than $0.18\%$ of lipid. Solubilities of FPC extracted with IPA and ethanol were very poor as less than $3\%$ in every pH range. In case of enzyme : substrate ratio of 1 : 100, degree of hydrolysis significantly increased until 4 hours and then slightly increased. No considerable differences were observed in general components of hydrolysates. Results of SDS-PAGE showed one unique band in each case and their molecular weight was less than 6,500. The flow properties of hydrolysates showed newtonian flow. Whiteness of hydrolysates were higher than that of salmon FPC as $5\~7$. There was no significant differences in the amount of peptide, but that of free amino acid slightly increased from 0.17 to 0.21 mg/ml.

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Characteristics on the Permeation of Protein Through Membrane of Ultrafiltration Reactor (한외여과막 반응기에서 단백질의 막 투과특성)

  • 변희국;전유진;김세권
    • Membrane Journal
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    • v.8 no.1
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    • pp.42-49
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    • 1998
  • Effects of operating time, pH, temperature, concentration and addition of proteolytic enzyme on permeate flux for the ultrafiltration of gelatin and bovine serum albumin(BSA) solutions were studied. The results showed that permeate flux of gelatin solution was maintained almost constant during the operating time, and that of BSA solution was decreased to 66% of the initial value after 40 min operation. The permeate flux of gelatin solution was increased by increasing temperature. The permeate flux of BSA solution was constant in the temperature range of 30~$50{\circ}C$, but increased at $60{\circ}C.$. The permeate fluxes of gelatin and BSA solution showed minimum values near the isoelectric point of pH 5.0. The permeate fluxes of 1%(w/v) and 6% gelatin solution were $43.0l/m^2\cdot hr$ and $13.5l/m^2\cdot hr$, respectively. Those of 1% and 4% BSA solution were $33.0l/m^2\cdot hr$ and $14.0l/m^2\cdot hr$, respectively. The permeate fluxes of gelatin and BSA solutions were decreased to 68.6% and 57.6% of their initial values by increasing their concentration, respectively. The permeate fluxes of gelatin and BSA solutions were enhanced by 30% with the addition of proteolytic enzyme.

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De l'image dans la philosophie cinémathographique chez G. Deleuze (들뢰즈 영화철학에서의 이미지론)

  • Jin, Gi-haeng
    • Journal of Korean Philosophical Society
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    • v.117
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    • pp.355-372
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    • 2011
  • G. Deleuze a $exerc{\acute{e}}$ sa philosophie $cin{\acute{e}}mathographique$ dans ses œuvres essentielles $Cin{\acute{e}}ma$ 1: l'Image-Mouvement(Minuit:1983) et $Cin{\acute{e}}ma$ 2: l'Image-Temps(Minuit:1985) qui n'indiquent pas l'histoire $cin{\acute{e}}mathographique$ mais la taxinomie, et par $cons{\acute{e}}quent$, de l'image et du code. Cette ${\acute{e}}tude$ consiste donc $\grave{a}$ rendre compte la de l'image que G. Deleuze touche dans cette $d{\acute{e}}finition$ et $\grave{a}$ $v{\acute{e}}rifier$ quelles images peuvent ${\hat{e}}tre$ $cat{\acute{e}}goris{\acute{e}}es$: comment. Nous distinguons l'image-mouvement et l'image-temps qui sont les $cat{\acute{e}}gories$ essentielles chez $Cin{\acute{e}}ma$. C'est surtout sur ce point que nous insistons. Dans ce cas, nous discutons aussi de la question des spectateurs du film qui conduit. Cette question permet susciter de la $mani{\grave{e}}re$ $d^{\prime}{\hat{e}}tre$ des spectateurs entre le film qui est $compos{\acute{e}}$ de l'image-mouvement dont G. Deleuze decrit comme 'classique' et le film qui est $trait{\acute{e}}$ de l'lmage-temps dont il $d{\acute{e}}finit$ comme 'moderne': quelle variation. Dans ce point $d^{\prime}{\acute{e}}tude$, G. Deuleuze ecrit cette question $mentionn{\acute{e}}e$ $\grave{a}$ travers son oeuvre $Cin{\acute{e}}ma$($\grave{a}$ voir ch.7, Volume2).

A Study of Marine Response system for the tar type waste oil (타르성 기름찌꺼기 해상방제 방안에 관한 연구)

  • Jang, Duck-Jong;Kim, Tae-Ho;Yang, Kyung-Uk;Na, Sun-Cheol;Nam, Kwang-Hee
    • Proceedings of KOSOMES biannual meeting
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    • 2008.05a
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    • pp.117-120
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    • 2008
  • As we can see at the oil spill occident on the coast of Taean, the viscosity of the spilled oil becomes thicker as time goes by. It becomes waste oil with the form of tar. It moves to other areas following a tide. When the temperature of the water goes up, the viscosity becomes lighter and forms oil film. It repeats the process spreading to and polluting extensive areas where the tide reaches. People have used hand nets to collect waste oil of tar at the sea. But it is very difficult for them to collect the tar type waste oil spread on large areas before it reaches to the beach. This paper tried to find a way to collect the tar type waste oil efficiently. It used absorption mat of boom type that uses the attachment characteristics of the tar type waste oil and floating waste recovery device of net type. It tested the possibility of using the devices at the oil spill accident on the beach of Taean. The result showed that net type recovery device was much more efficient in collecting the waste oil in short time than the hand net system of people. It confirmed that the net type recovery device could be used to collect tar type waste oil.

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A Study on the Rheological Properties of Branched Polypropylene/silicate Composites (분지형 폴리프로필렌/실리케이트 복합체의 유변학적 특성 연구)

  • Dahal, Prashanta;Yoon, Kyung Hwa;Kim, Youn Cheol
    • Applied Chemistry for Engineering
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    • v.22 no.6
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    • pp.679-684
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    • 2011
  • Branched polypropylenes (LCB-PP) with a long chain branch were prepared by the solid-state and molt-state reaction. Divinylbenzene (DVB), 1,4-benzenediol (RES), and furfuryl sulphide (FS) were used as branching agents of fabricate LCB-PP/silicate composites. Chemical structures, thermal properties, and rheological properties of the LCB-PP were determined by FT-IR, DSC, TGA, and dynamic rheometer (ARES). The chemical structure of the LCB-PP was confirmed by the existence of =C-H stretching peak of the branching agent at $3100cm^{-1}$. From DSC and TGA results, the melting reaction was more effective than the solid state reaction in the manufacture of LCB-PP, which was additionally certified by rheological properties. Based on rheological properties, FS was the best for branching efficiency of PP. Compared to PP, LCB-PPs indicated an increase of complex viscosity in the low frequency and shear thinning tendency, and G'-G" plot represented an increase in elasticity and the heterogeneousness in a melt state. Rheological properties of LCB-PP/silicate composites were observed with the silicate content. When 5 wt% silicate was added in LCB-PP, distinct changes in the shear thinning and the slope of G'-G" plots were observed.