• Title/Summary/Keyword: 산분해

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STUDIES ON THE VARIATION OF MICROFLORA DURING THE FERMENTATION OF ANCHOVY, ENGRAULIS JAPONICA (멸치 젓갈 숙성에 따른 미생물상의 변화에 대하여)

  • LEE Jong-Gap;CHOE Wi-Kyune
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.3
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    • pp.105-114
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    • 1974
  • Identification and change of microflora during the fermentation of anchovy Engraulis japonica, under the halophilic circumstance were investigated. The change of salinity and pH in meat and juice which decide the environment for microorganism and decomposition of nitrogenous compound which functions as a nutrient source were also discussed by measuring the content of total-N, amino-N, nonprotein-N, TMA and VBN, The fresh anchovy was mixed with rock salt (20 percent w/w) and stocked for six months. Through the fermentation lag phase of viable cells extended for 20 days that was obviously larger compared with other circumstances, hereafter increased to reach the maximum value of $5\times10^4$ total count per gram at 35 day stock. The stationary phase proceeded for 25 days. 540 strains were isolated and among them 11 genus of bacteria, 3 genus of yeasts, were identified and other 2 yeast strains of unidentified. At the initial stage of fermentation, Pseudomonas, and Helobacterium prevalently grew, at the middle stage, they disappeared rapidly and Pediococcus and yeasts completely dominated, where they are assumed to get directly involved with fermentation of fish, The PH value tended to decrease in the progress of fermentation and at 100 day stock it showed the minimum value of 5.5 to 5.6 in both meat and juice. The highest salinity of meat decreased to 18 percent, while in juice it decreased to 28 percent since 50 days stock. The content of total-N in meat gradually decreased to 2.8 percent, while in juice it increased to 2.3 percent at 100 day stock, However nonprotein-N was 1.8 percent and amino-N was 1.1 Percent. Since 100 days stock, the increasing rate of amino-M is too low it could be judged to entered the final stage of fermentation, In the first 20 days stock, the increase of VBN and TMA can be explained by the growth of putrefactive bacteria such as pseudomonas on the meat before salts penetrate into the fish meat, while reincrement after 100 days stock, is explained by decomposition of free amino acid due to the reactions of bacteria and enzymes.

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Analysis of Evaluation Methods for the Efficacy of Protein Removal Agents for Soft Contact Lens (소프트콘택트렌즈 단백질제거제의 효능 평가법 분석)

  • Byuna, Hyun Young;Sung, Hyung Gyeong;Won, Hye Lim;Shim, Ji In;Park, Mijung;Kim, So Ra
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.51-57
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    • 2014
  • Purpose: The present study was conducted to establish the experimental condition for the proper evaluation of protein removal efficacy when developing protein removal agents. Its protein removal efficacy was further analyzed and compared with the result from protein removal efficacy against protein deposition on contact lens to suggest the evaluation method for efficacy of protein removal agents. Methods: Protein digestibility assay presented in the Korean pharmacopoeia was selected to establish the evaluation method for efficacy of papain, pancreatin, subtilisin A and protease itself as a ingredient and protein removal tablets or solution containing those enzymes and find a suitable test conditions. Furthermore, the cleaning efficacy of commercially available protein removal tablets and solution on balafilcon A lens deposited with protein artificially was measured and the correlation between two evaluation methods was further analyzed. Results: When pancreatin itself and the product containing pancreatin was evaluated by protein digestibility assay, both reached 28 IU/mg, the standard value of protein digestibility suggested by the Korean pharmacopoeia. In case of protease and subtilisin A tested with trichloroacetic acid B solution, both of them met the enzyme activity level proposed by the manufacturers when they were evaluated by protein digestibility assay however, papain and subtilisin A tested with trichloroacetic acid A solution were not reached the enzyme activity level. Among protein removal agents, three products except a product containing pancreatin did not meet the enzyme activity value specified by the manufacturer when they were evaluated by protein digestibility assay. However, actual protein removal efficacy of three products except a papain-containing product on the lens was greater than 90% protein removal. In the case of papain-containing protein removal product, its effect was not measured by protein digestibility assay however, its actual protein removal efficacy on the lens reached 73.72%. Conclusions: From the results, it was confirmed that the efficacy of protein removal agents for contact lens should be evaluated by different method according to the type of proteolytic enzyme contained. That is, the protein removal agents containing pancreatin, protease and subtilisin A can be evaluated by protein digestibility assay and protein removal efficiency evaluation and the products containing papain can be effectively evaluated by only the evaluation method for protein removal efficiency employing the lens.

Effects of Dietary Barley on the Growth Performance and Carcass Characteristics in Hanwoo Steers (보리의 사료가치평가와 한우 거세우 급여에 의한 발육 및 육질개선효과 구명)

  • Chang, S.S.;Oh, Y.K.;Kim, K.H.;Hong, S.K.;Kwon, E.G.;Cho, Y.M.;Cho, W.M.;Eun, J.S.;Lee, S.C.;Choi, S.H.;Song, M.K.
    • Journal of Animal Science and Technology
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    • v.49 no.6
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    • pp.801-818
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    • 2007
  • This study was carried out to determine the effects of processing methods of barley as a proper source of grain in diets of Hanwoo on fermentation pattern in the rumen fluid and digestibility of the diets, the growth performance and carcass characteristics of Hanwoo. The degree of ruminal pH change in the cows fed diets of the Corn(corn basis) and GDRB(ground and dry-rolled barley) tended to be greater than those in the cows fed other two diets (ground barley, GB and dry-rolled barley, DRB). The diet of GDRB showed the lowest ruminal pH(5.5), indicating the rapid degradation of the diet in the rumen. Although ammonia concentration was not affected by diet, the GR and DBR diets maintained the low concentrations of ruminal ammonia compared with other two treatments. And the effects of feeding processed barley grain on body weight gain and meat quality of Hanwoo steers were as follows. Steers fed DRB diet had the highest body weight, 683.0kg at 28 months old, while those fed the GDRB showed the lowest body weight, 653.3kg. The average daily gain(ADG) was similar between the steers fed Corn and GR throughout the whole period, but the GDRB showed the lowest ADG. The steers fed the DRB showed the significant increase in ADG(0.89kg/d from 19 to 23 months old and 0.43kg/d from 24 to 28 months old) compared with those fed other diets. Feeding diets containing corn and/or barley did not influence live body weight, cold carcass weight, carcass yield, back-fat thickness and carcass grade of Hanwoo steers.

Influences of Roasted or Non-roasted Brown Rice Addition on the Nutritional and Sensory Properties and Oxidative Stability of Sunsik, Korean Heated Cereal Powder (현미의 볶음 처리 유무와 첨가량이 선식의 영양적 관능적 특성 및 산화안정성에 미치는 영향)

  • Lee, Byung-Yong;O, Jin-Hwan;Kim, Mi-Hyun;Jang, Ki-Hyo;Lee, Jae-Cheol;Surh, Jeong-Hee
    • Korean journal of food and cookery science
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    • v.26 no.6
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    • pp.872-886
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    • 2010
  • Six kinds of sunsik containing different contents of brown rice(BR; 20, 30, and 50%) were prepared and subjected to various processing conditions(with or without roasting at $200^{\circ}C$ for 20 min e.g., designated as RBR50 or BR50) to assess their functionality as ready-to-eat foods. They were also assessed for their nutritional and sensory properties and oxidative stability. Dietary fiber contents were proportionate to the levels of added BR. Protein was highest in RBR50 (p<0.001), which also had the highest amounts of free and structural amino acids. The amount of free amino acids tended to increase with roasting, although most amino acids were present in structural form. Oleic acid and linoleic acid were the predominant fatty acids in all prepared sunsik, and RBR50 presented noticeably higher peroxidability index due to its higher amount of linoleic acid(p<0.05). Nevertheless, RBR50 showed good oxidative stability; this phenomenon was observed in all sunsik with roasted BR but not in those with non-roasted BR. It is implied that potential antioxidants might have been newly formed or converted from their precursors while BR was roasted. Roasting process also had an impact on the sensory properties of sunsik, e.g., sunsik with added roasted BR showed lower dissolution and darker color intensity compared to its counterpart sunsik.

Effects of Supplementation of Fat Sources, Ca and Mg on In Vitro Fermentation and the Performance of Finishing Hanwoo Bulls (지방의 공급형태와 Ca 및 Mg의 첨가가 In Vitro 발효 및 비육후기 한우의 성장성적에 미치는 영향)

  • Lee, H.G.;Lee, D.H.;Choi, N.J.;Lee, S.R.;Choi, Y.J.;Maeng, W.J.
    • Journal of Animal Science and Technology
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    • v.46 no.4
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    • pp.613-624
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    • 2004
  • This study was aimed at investigating the effect of fat supplementation with divalent ions such as MgO and $CaCl_2$ on 1) in vitro ruminal fermentation characteristics and insoluble fatty acid formation, and on 2) animal performance in finishing Hanwoo bulls. In in vitro trial, five different types of diets based on supplementation sources of fat and divalent ions, i.e. T=basal diet+4% tallow, T-Ca=T+0.5% $CaCl_2$, T-Mg=TA+0.5% MgO, T-MgCa = T +0.5% $CaCl_2$+0.5% MgO, T-caS =4% Ca salt tallow, were tested. Higher pH values were observed at 6 hr incubation(P<0.01) while higher amount of VFA were produced in diets 4 and 5 at 12 hr incubation(P<0.05). Nutrients(DM, OM, Crude protein and NDF) degradation tended to increase in divalent ions or Ca-salts treated tallow treatments compared with tallow treatment after 12 h. The amount of insoluble fatty acid increased by adding MgO or $CaCl_2$ to tallow or Ca soap tallow during incubation(P<0.05). In in vivo trial, thirty finishing Hanwoo(average BW 460kg) were divided into three groups based on fat sources and divalent ions, i.e. Control(EE 2.40), T-MgCa = control + tallow + $CaCl_2$ + MgO, T-CaS = control + Ca soap tallow (EE 5.30%). After feeding each diet for 80 days, average daily weight gain showed 0.89, 1.02, 1.17kg in diets 1, 2 and 3, respectively. The highest feed efficiency was observed(0.12) in diet 2 group, followed by diet 3 (0.10) and 1 groups(0.08; P < 0.05). In conclusion, the present results could be sununarized that the performance of Hanwoo bulls was improved by tallow with divalent ions without any negative effect on rumen fermentation.

THE EFFECT OF PRIMING ETCHED DENTIN WITH SOLVENT ON THE MICROTENSILE BOND STRENGTH OF HYDROPHOBIC DENTIN ADHESIVE (산 부식된 상아질에 대한 용매를 이용한 프라이밍이 소수성 상아질 접착제의 미세인장접착강도에 미치는 영향)

  • Park, Eun-Sook;Bae, Ji-Hyun;Kim, Jong-Soon;Kim, Jae-Hoon;Lee, In-Bog;Kim, Chang-Keun;Son, Ho-Hyun;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.34 no.1
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    • pp.42-50
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    • 2009
  • Deterioration of long-term dentin adhesion durability is thought to occur by hydrolytic degradation within hydrophilic domains of the adhesive and hybrid layers. This study investigated the hypothesis that priming the collagen network with an organic solvent displace water without collapse and thereby obtain good bond strength with an adhesive made of hydrophobic monomers and organic solvents. Three experimental adhesives were prepared by dissolving two hydrophobic monomers, bisphenol-A-glycidylmethacrylate (Bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA), into acetone, ethanol or methanol. After an etching and rinsing procedure, the adhesives were applied onto either wet dentin surfaces (wet bonding) or dentin surfaces primed with the same solvent (solvent-primed bonding). Microtensile bond strength (MTBS) was measured at 48 hrs, 1 month and after 10,000 times of thermocycles. The bonded interfaces were evaluated using a scanning electron microscope (SEM). Regardless of bonding protocols, well-developed hybrid layers were observed at the bonded interface in most specimens. The highest mean MTBS was observed in the adhesive containing ethanol at 48 hrs. With solvent-primed bonding, increased MTBS tendencies were seen with thermo cycling in the adhesives containing ethanol or methanol. However, in the case of wet bonding, no increase in MTBS was observed with aging.

Survey of Heavy Metal Contents and Intake Rates After Decoction in Herbal Medicines Classified by Parts (한약재의 약용부위별 중금속 함량 및 탕 액에서의 이행률 조사)

  • Jung, Sam-Ju;Kang, Sung-Tae;Han, Chang-Ho;Kim, Su-Jin;Ko, Suk-Kyung;Kim, Yun-Hee;Kim, Yoo-Kyung;Kim, Bog-Soon;Choi, Byung-Hyun
    • Journal of Food Hygiene and Safety
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    • v.25 no.4
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    • pp.402-409
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    • 2010
  • The study was conducted to estimate the contents of heavy metal in commercial herbal medicines (1047 samples of 132 species) which were collected from markets in Seoul and to analyze the contents of heavy metals of herbal medicines by classifying them by parts. The samples were digested using microwave method. The contents of heavy metal (Pb, Cd, and As) and Hg were determined using Inductively coupled plasma-Mass spectrometer (ICP/MS). And the contents of Hg were obtained by Mercury analyzer. The average values of heavy metal in herbal medicines were as follows [mean (minimum-maximum), mg/kg]; Pb 0.870 (ND-69.200), As 0.148 (ND-2.965), Cd 0.092 (ND-2.010), and Hg 0.007 (ND-0.B7). And the average values of heavy metal by parts in herbal medicines were as follows [mean (minimum-maximum), mg/kg]; Ramulus 2.046 (0.065-4.474), Herba 1.886 (0.048-10.404), Flos 1.874 (0.052-5.393), Cortex 1.377 (0.011-4.837), Radix 1.165 (0.012-70.111), Rhizoma 1.116 (0.016-5.490, Fructus 0.838 (0.017-4.527), Perithecium 0.729 (0.013-4.953), Semen 0.646 (0.006-4.416). The average values of heavy metal of imported herbal medicines except Radix were higher than domestic ones. By decoction of herbal medicines exceeding the tolerances, average intake rates of Pb, As, Cd and Hg were obtained as 6.1%, 40.3%, 4.7%, and 2.2%, respectively.

Enhancement of the Thermostability of a Fibrinolytic Enzyme from Bacillus amyloliquefaciens CH51 (Bacillus amyloliquefaciens CH51이 생산하는 혈전용해효소의 열안정성 개선)

  • Kim, Jieun;Choi, Kyoung-Hwa;Kim, Jeong Hwan;Song, Young-Sun;Cha, Jaeho
    • Journal of Life Science
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    • v.23 no.1
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    • pp.15-23
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    • 2013
  • AprE51 from Bacillus amyloliquefaciens CH51 is a 27 kDa subtilisin-like protease with fibrinolytic activity. AprE51-6 showing increased catalytic activity was produced previously. To enhance the thermostability of AprE51-6, 2 residues, Gly-166 and Asn-218 based on B. subtilis subtilisin E were mutated by site-directed mutagenesis. The results of the mutational analysis showed that substitution of arginine for Gly-166 (AprE51-7) increased the fibrinolytic activity 1.8-fold. An N218S mutant (AprE51-8) also increased the fibrinolytic activity up to 4.5-fold in a fibrin plate assay. Purified AprE51-7 and AprE51-8 mutants had a 1.9- and a 2.5-fold higher $k_{cat}$, respectively, and a 2.1-1.9-fold lower $K_m$, respectively. This resulted in a 3.8- and a 4.7-fold increase in catalytic efficiency ($k_{cat}/K_m$), respectively, relative to that of wild-type AprE51. AprE51-8 had a broader pH range than AprE51-6 and nattokinase, especially at an alkaline pH value. In addition, AprE51-8 showed higher thermostability than AprE51-6 at $60^{\circ}C$. The half-lives of AprE51-7 and AprE51-8 at $50^{\circ}C$ were 21.5 and 27.3 min, respectively, which are 2.0 and 2.6 times longer, respectively, than that of the wild-type AprE51.

Studies on the Processings of Sterilized Salt-Fermented Anchovy Sauces (멸치액젓의 레토르트 식품화에 관한 연구)

  • Oh, Kwang-Soo
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1038-1044
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    • 1996
  • The salt-fermented anchovy sauce (AS) was packed in round No. 307-1 can, and thermally processed at $121.1^{\circ}C$ to obtain Fo values of 3, 5 and 10. The changes of food components and qualifies by thermal processing of sterilized AS (RAS) were examined. The compositions of AS were as followed; pH 6.81, VBN 394.7 mg/100g, total nitrogen 2,195.5 mg%, amino-nitrogen 1,010.5 mg%, and acidity 10.5 ml. Viable cell counts of AS on 0%, 5%, 20% NaCl-medium were $2.9{\times}10^3,\;9.1{\times}10^3$ and not detected, respectively. And viable cell counts of RAS were not detected. Acidity, total nitrogen and amino nitrogen contents of AS decreased slightly with the severeness of heat treatments, whereas pH and VBN content were increased. Total free amino acid contents of raw AS and RAS were 12,802.5 mg% and $11,212.6{\sim}12,105.4\;mg%$, and major amino acids were alanine, glutamic acid, leucine, isoleucine, valine and lysine. Also contents of IMP, hypoxanthine, TMAO and TMA in AS and RAS were 42.1 mg% and $35.5{\sim}40.9\;mg%$, 103.7 mg% and $103.1{\sim}105.5\;mg%$, 78.8 mg% and $58.2{\sim}71.6\;mg%$, 55.8 mg% and $58.9{\sim}68.5\;mg%$ respectively. And a little changes were observed in whole volatile components of AS with severeness of heat treatments by GC chromatogram patterns. Judging from the chemical and sensory evaluations, the Fo 3 heat treatment sample was not inferior to raw AS, and maintained good quality for 1 year storage.

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Biochemical Characterization of a Novel Thermostable Esterase from the Metagenome of Dokdo Islets Marine Sediment (독도 심해토 메타게놈 유래 신규 내열성 에스테라아제의 생화학적 특성규명)

  • Lee, Chang-Muk;Seo, Sohyeon;Kim, Su-Yeon;Song, Jaeeun;Sim, Joon-Soo;Hahn, Bum-Soo;Kim, Dong-Hern;Yoon, Sang-Hong
    • Microbiology and Biotechnology Letters
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    • v.45 no.1
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    • pp.63-70
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    • 2017
  • A functional screen of 60,672 fosmid metagenomic clones amplified from marine sediment obtained from the Dokdo islets in Korea identified the gene EstES1, whose product, EstES1, displayed lipolytic properties on tributyrin-supplemented media. EstES1 is a 576 amino acid protein with a predicted molecular weight of 59.4 kDa including 37 N-terminal leader amino acids. EstES1 exhibited the highest sequence similarity (44%) to a carboxylesterase found in Haliangium ochraceum DSM14365. Phylogenetic analysis indicated that EstES1 belongs to a currently uncharacterized family of lipases. Within the conserved domain, EstES1 retains the catalytic triad that consists of the consensus penta-peptide motif, GESAG. EstES1 demonstrated a broad substrate specificity toward the long acyl group of ethyl esters (C2-C12), and its optimal activity was recorded toward p-Nitrophenyl butyrate (C4) at pH 9.0 and $40^{\circ}C$ (specific activity of 255.4 U/mg). The enzyme remained stable in the ranges of $60-65^{\circ}C$ and pH 9.0-10.5 and in the presence of methanol, ethanol, isopropanol, and dimethyl sulfoxide. Therefore, EstES1 has potential for use in industrial applications involving high temperature, organic solvents, and/or alkaline conditions.