• 제목/요약/키워드: Partial hydrolysis

검색결과 91건 처리시간 0.02초

전분을 이용한 itaconic acid의 생산

  • 정상윤;나영;이종일
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2002년도 생물공학의 동향 (X)
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    • pp.228-231
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    • 2002
  • Itaconic acid has been produced during the cutivation of Aspergillus terreus DSMZ 5770 by using several starchs as carbon sources. The starchs were pretreated by partial hydrolysis with some acids at various pH conditions. The highest yield for the production of itaconic acid has been found when rice starch was pretreated by sulfonic acid at pH 2.5 and utilized for the cultivation. Using the results from shaker fermentation A. terreus has been cultivated in 2.5 L bioreactor for the production of itaconic acid and its on-line monitoring.

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TEOS의 부분가수분해에 의한 실리카 졸의 합성과 유리섬유 제조 (Preparation of Silica Sol by Partial Hydrolysis of TEOS and High Purity Silica Glass Fiber)

  • 양현수;권오현;이재도;노재성;김영호
    • 공업화학
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    • 제7권5호
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    • pp.823-831
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    • 1996
  • 본 연구는 [$H_2O$]/[TEOS]=1.7에서 산촉매를 첨가한 부분가수분해를 행하여 졸을 합성하였다. 최적의 방사성을 갖는 졸을 결정하기 위하여 부분가수분해에 의하여 합성된 졸을 trimethylsilylation하여 안정화시킨 후에 반응시간에 따르는 분자량과 점도의 변화를 관찰하였다. 최적조건하에서 제조된 졸용액에서 용매를 제거한 후 겔섬유를 제조하였고 이를 $1,000^{\circ}C$에서 열처리하여 실리카섬유를 제조하였다. 제조된 섬유는 단면적이 원형이며 인장강도는 $83{\pm}20kg/mm^2$이었고, 순도는 약 99.997%이었다.

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Leucocyte lysosomal proteinase에 의한 닭의 근섬유(筋纖維) 단백질(蛋白質) 분해(分解)에 미치는 NaCl과 pH의 영향(影響) (Influence of NaCl and pH on Hydrolysis of Chicken Myofibrillar Proteins by Leukocyte Lysosomal Proteinases)

  • 신승이;이종욱
    • 한국식품과학회지
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    • 제22권5호
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    • pp.569-574
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    • 1990
  • 닭의 근섬유(筋纖維) 단백질(蛋白質) 돼지의 백혈구(白血球)에서 추출(抽出)한 lysosomal proteinase에 의해서 분해(分解)될 때 미치는 NaCl과 pH의 영향(影響)에 대해서 연구(硏究)하였다. Leucocyte lysosomal proteinase에 의한 근섬유(筋纖維) 단백질(蛋白質)의 분해(分解)는 다른 pH를 갖는 Tris-maleate buffer에서 partial hydrolysis로 진행(進行)하였다. 분해(分解)는 높은 pH에서 더욱 심화(深化)되었으며, 여기에 NaCl이 첨가(添加)되었을 때 proteinase의 activity는 pH의 고저(高低)에 관계(關係)없이 더욱 증가(增加)함을 보여주었다.

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Renal Artery Embolization Using a New Liquid Embolic Material Obtained by Partial Hydrolysis of Polyvinyl Acetate (Embol): Initial Experience in Six Patients

  • Sung Il Park;Do Yun Lee;Jong Yoon Won;Sangsoo Park
    • Korean Journal of Radiology
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    • 제1권3호
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    • pp.121-126
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    • 2000
  • Objective: To evaluate the therapeutic efficacy of a new liquid embolic material, Embol, in embolization of the renal artery. Materials and Methods: Embol is a new embolic material obtained by partial hydrolysis of polyvinyl acetate mixed in absolute ethanol and Iopromide 370 and manufactured by Schering Korea, Kyonggido, Korea. Six patients who underwent embolization of the renal artery using Embol were evaluated. Four were male and two were female and their ages ranged from 11 to 70 (mean, 53) years. Clinical and radiologic diagnoses referred for renal artery embolization were renal cell carcinoma (n = 3), renal angiomyolipoma (n = 2) and pseudoaneurysm of the renal artery (n = 1). After selective renal angiography, Embol was injected through various catheters, either with or without a balloon occlusion catheter. Changes in symptoms and blood chemistry which may have been related to renal artery embolization with Embol were analyzed. Results: The six patients showed immediate total occlusion of their renal vascular lesions. One of the three in whom renal cell carcinoma was embolized with Embol underwent radical nephrectomy, and the specimen thus obtained revealed 40% tumor necrosis. In the two patients with angiomyolipomas, the tumors decreased in size and abdominal pain subsided. Bleeding from pseudoaneurysm of the renal artery was successfully controlled. Four patients showed symptoms of post-embolization syndrome, and one of these also showed increased levels of blood urea nitrogen and creatinine. One patient experienced transient hypertension. Conclusion: Embol is easy to use, its radiopacity is adequate and it is a safe and effective embolic material which provides immediate and total occlusion of renal vascular lesions.

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Stimulation of an Esterase Activity of Thrombin by Dequalinium and Its Relationship with Blood Coagulation

  • Paik, Seung-R.;Kim, Do-Hyung;Chang, Chung-Soon
    • BMB Reports
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    • 제29권3호
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    • pp.225-229
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    • 1996
  • Effects on thrombin by an amphipathic cation, dequalinium, which has been recognized as an anticarcinoma agent were investigated with small chromogenic substrates such as Na-benzoyl-DL-argininep-nitroanilide (BApNA), H-D-phenylalanyl-L-pipecoyl-L-arginine-p-nitroanilide (S-2238), and Na-p-tosyl-L-arginine methyl ester (TAME). Among them, only TAME hydrolysis due to an esterase activity of the enzyme was significantly activated to 81% at 20 ${\mu}M$ dequalinium in the absence of NaCl. This stimulation became even higher in the presence of 0.2 M NaCl to 3.5-fold at 60 ${\mu}M$ dequalinium. This specific activation of thrombin was well correlated with the results of in vitro coagulation tests measuring the activated partial thromboplastin time (APTT) and the prothrombin time (PT) It is pertinent. therefore, to suggest that the esterase activity should be examined in addition to the effects on 5-2238 hydrolysis when especially any regulators not directed to an active site of thrombin need to be studied. We also expect that dequalinium could be a useful tool for studying structure-function relationship of thrombin and blood coagulation.

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반고형 이유식의 개발을 위한 변형 쌀가루 제조 및 이화학적 특성 I - 열-효소 처리한 쌀가루 (Physicochemical Properties of Modified Rice Powder for Rice-Based Infant Foods - Thermal-enzymatic Treatment on Rice Powder)

  • 최정선;손경희
    • 한국식생활문화학회지
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    • 제12권4호
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    • pp.375-382
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    • 1997
  • The establishment of optimal producing condition for rice-based infant foods using modified rice powder was attempted. The modification of rice powder was prepared by microwave heating as well as partial enzymatic hydrolysis. Not only thermal treatment but also enzymatic hydrolysis on rice powder increased D.E. value from 1.25 to 3.81. The water binding capacity, swelling power, solubility, digestibility by ${\alpha}-amylase$, light transparency, and paste clarity of the modified rice powder compared to unmodified rice powder were increased from 107% to 249%, from 7.80 to 42.52, from 0.04% to 0.89ft, from 9.19% to 23.01, from 33% to 42%, and from 2.2% to 3.9%, respectively. On the other hand, gelatinization temperature, apparent viscosity, and degree of retrogradation of modified rice powder showed negative correlation with D.E. value. The 「results suggested that the thermal and enzymatic treatment on rice powder improved the physicochemical properties of rice based infant food by enhancing carbohydrate absorptionability and lowering the viscosity and opacity.

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Improvement of Rheological and Functional Properties of Salmon FPC by Enzymatic Partial Hydrolysis 2. Rheological and functional properties of salmon FPC hydrolysates

  • LEE Jong-Ho;LEE Keun-Tai;PARK Seong-Min;PARK Chan-kyu
    • 한국수산과학회지
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    • 제30권6호
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    • pp.956-963
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    • 1997
  • To enhance application of FPC in food industry, salmon FPC hydrolysates were produced and their functional properties were investigated. Hydrolysates of salmon FPC showed high solubilities ranged from approximately $80\~95\%$. Emulsifying activity index (EAI) values of hydrolysates were higher than that of egg white, however sugar ester showed the highest EAI value of 32.5. Though sugar ester had the best emulsifying stability value $({\Delta}EAI)$ of 9.65, hydrolysates showed better ${\Delta}EAI$ value than that of egg white. Foam Activity of hydrolysates was predominantly better than those of controls and also foam stability value showed similiar trend. Osmolality of hydrolysates was increased with the increase of degree of hydrolysis (DH) and concentration of protein, but it showed very lower osmolality than that of NaCl. Flow property of hydrolysates showed different upward-downward curves, and hysteresis loop increased with the increase of DH. ACE inhibitory activity showed similiar value ranged from $21.1\~24\%$ at all DH values.

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금속 알콕사이드로부터 Mullite 초미분체의 제조 (Preparation of Ultrafine Mullite Powder from Metal Alkoxides)

  • 임굉;임재석;김영호
    • 한국재료학회지
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    • 제16권12호
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    • pp.719-724
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    • 2006
  • Ultrafine mullite powder was prepared from aluminium-secbutoxide and tetraethyl orthosilicate(TEOS) in the molar $Al_2O_3/SiO_2$=3/2. Sol-gel method by partial hydrolysis technique, as it were, first, TEOS was partially hydrolysized and then mixed with Al-secbutoxide for complete hydrolysis was used. X-ray diffraction, infrared spectroscopy and transmission electron microscopy, etc. confirmed that the mullite powder prepared by this method is in the stoichiometric $Al_2O_3/SiO_2$ ratio. Al-Si spinel was formed at $980^{\circ}C$ and ultrafine mullite powder with about 20 nm particle size was obtained above $1,200^{\circ}C$. Also mullite powders calcined at $1,600^{\circ}C$ had a stoichiometric composition, $3Al_2O_3{\cdot}2SiO_2$ and the lattice constants of the mullite powders calcined above $1,200^{\circ}C$ were almost coincided with theoretical values.

효소를 이용한 아스트라갈린 합성 반응의 최적화 (Reaction Optimization for Enzymatic Synthesis of Astragalin)

  • 이슬비;정대원
    • 공업화학
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    • 제23권4호
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    • pp.394-398
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    • 2012
  • 아스트라갈린(AS)은 폴리페놀의 일종인 캠페롤(KR)에 글루코스가 하나 결합해있는 배당체로서, 천연에는 미량만이 존재하고 있다. 최근 tea seed extract (TSE)에 포함되어 있는 camelliaside A (CamA) 및 camelliaside B (CamB)로부터 복합효소인 Mash에 의한 부분가수분해에 의해 AS를 합성할 수 있다는 것이 알려졌다. 본 논문에서는, Mash에 의한 TSE의 선택적 가수분해에 의해 AS를 제조하는 공정에서 반응 온도, 효소량 및 반응물의 농도 등의 변수에 따른 반응성을 검토하였다. 반응 온도, 효소량 등이 증가할수록 AS의 생성 반응은 빨랐으나, 일단 생성된 AS가 급격하게 KR로 변환되는 문제점이 나타났다. 결론적으로, 반응 속도 및 AS의 선택성 측면을 고려하면, $50^{\circ}C$에서 TSE 대비 2배의 Mash를 사용하여 15%의 기질 농도에서 반응을 수행하는 것이 최적인 것으로 나타났다.

Characteristics of a Black Soybean (Glycine max L. Merrill) Protein Isolate Partially Hydrolyzed by Alcalase

  • Yoon, Ji-Ho;Jung, Dong-Chae;Lee, Eun-Hye;Kang, Yoon-Seok;Lee, Sung-Yong;Park, Sae-Rom;Yeom, Hye-Jung;Ha, Mi-Sun;Park, Sang-Kyu;Lee, Yu-Si;Ha, Sang-Do;Kim, Gun-Hee;Bae, Dong-Ho
    • Food Science and Biotechnology
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    • 제18권2호
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    • pp.488-493
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    • 2009
  • A protein isolate was prepared from black soybean (Glycine max L. Merrill) that possessed higher antioxidant activity than ordinary white soy protein isolates. The isolate was partially hydrolyzed by alcalase to reduce the allergenicity of black soybean. Alcalase remarkably reduced the molecular mass of the major soybean allergens that have molecular weights of 53, 38, and 24 kDa. Hydrolytic breakdown occurred more effectively in Gly m Bd 30K than in Gly m Bd 60K or Gly m Bd 28K. Alcalase hydrolysis increased the solubility and hydrophobicity of the black soybean protein isolate. The foaming activity and stability of black soybean proteins were highly increased by the partial hydrolysis.