• 한국식품영양학회지
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• 제3권2호
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• pp.123-132
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• 1990

Sweet potato $\beta$-amylase is a tetrameric enzyme consisting of four identical polypeptide chains with a molecular weight of 5.6$\times$104, though most of the other $\beta$-amylases are monomeric enzymes. But, the relationship between subunit structure and catalytic function of the enzyme is not known. This study was done to know what the function of the subunit structure of the enzyme is. We obtained the monomer from the enzyme by the treatment of SDS, alkali pH buffer and urea. But the monomer had not activity. We tried to prepare the active monomer from the enzyme by the modification with periodate-oxidized soluble starch , In the result, we succeeded in isolating an active monomer as an oxidized soluble starch-conjugated form The active monomer had 57% of the original activity, 13.2% of the sugar and the molecular weight was estimated to be 5.4$\times$104. This results suggest that the tetrameric form of the enzyme is a most stable one and exists in nature, and the subunit structure of the enzyme Plays an important role in stabilization but not catalytic function.

• 펄프종이기술
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• 제36권3호
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• pp.35-43
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• 2004

Reduction of fresh water consumption and effluent discharge provide diverse advantages in raw materials and energy savings. Papermaking system closure, however, reduces the efficiency of additives, decreases retention and dewatering, and causes many other Problems in papermaking. Accumulation of inorganic and organic substances in the process white water is the prime cause of these problems. Understanding of the accumulation phenomena of the detrimental substances in the papermaking process is of great importance for papermaking system closure. In this study a process simulation method was employed to analyze the accumulation phenomena of anionic starch in the process white water as the reuse rate of dry broke and pick up of surface sizing agent is increased. Steady state simulation studies were carried out based on the model developed in previous study. The variation of dissolved starch concentration in each process unit was monitored as a function of reuse rate of dry broke and surface sizing agent pick up rate. The result showed that dissolved starch concentration Increased as reuse rate of dry broke and surface sizing agent pick up rate was increased.

• 펄프종이기술
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• 제46권6호
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• pp.50-55
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• 2014

An oxidized starch was modified for surface sizing via etherification and esterification. Propylene oxide (PO), sodium monochloroacetate (SMCA), and acrylonitrile (AN) were used as etherification, and vinyl acetate monomer (VAM), maleic anhydride (MA), fumaric acid (FA), and itaconic acid (ITA) were used for esterification. Esterification and etherification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14 to 16%. Surface sizing performance of starches in tensile strength, stiffness and compressive strength was improved by esterification and etherification of the oxidized starch. Especially, SMCA etherification was found to be the most effective modification method.

• 펄프종이기술
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• 제36권1호
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• pp.16-23
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• 2004

Recently the increased concerns about the cost reduction and environmental protection make the paper industry increase the closure level of papermaking system, which results in the buildup of organic and inorganic materials in the papermaking process water. Increase of the system closure causes deterioration of additive performance and provokes diverse problems in papermaking process and product quality. To investigate the effects of process water quality on the physical properties of fine papers handsheets were prepared with process water containing various amounts of inorganic and organic contaminants including calcium or sodium ions and oxidized or cationic starches. Inorgainc and organic materials did not show any significant effect on the physical properties of handsheets. Recycled GCC showed the same trends as inorganic and organic materials. The performance of cationic starch was deteriorated, however, in the recycled white water, which resulted in the reduction of tensile index of handsheets.

• 한국포장학회지
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• 제4권2호
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• pp.3-11
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• 1998

산화전분을 골판지 구성원지인 표면라이너지와 이면라이너지에 각각 코팅하였으며 산화전분 코팅에 따른 골판지의 물성변화를 조사, 산화전분 코팅의 효과를 분석한 결과는 다음과 같았다. 산화전분의 코팅에 의해 골판지의 수직압축강도 뿐만아니라 파열강도도 동시에 개선될 수 있었다. 골판지의 파열강도는 구성 라이너지의 처리면에 관계없이 일정수준의 도공량에 도달할 때까지 크게 증가하다가 그 이상에서는 더 이상의 증가를 보이지 않았다. 표면라이너지에 처리한 골판지의 경우 도공하지 않은 골판지의 파열강도에 비해 도공량이 $2.32g/m^2$일 때 30.3%가 증가하였고 이면라이너지에 처리한 경우 도공량이 $4.84g/m^2$일 때 36.8%가 증가하였으며 표면라이너지와 이면라이너지 모두 처리한 경우 도공량이 $7.16g/m^2$일 때 39.9%가 증가하였다. 산화전분의 코팅은 골판지 원지의 섬유간 결합을 증가시키는데 기여하고 강직성을 개선시켜 골판지 수직압축강도의 개선을 가져왔다. 구성 라이너지의 처리면에 관계없이 골판지의 수직압축강도는 산화전분 도공에 의해 전반적으로 증가하였는데, 이면 라이너지에 처리한 경우 도공량이 $1.58g/m^2$일 때 11.3%가 증가하였고, 표면라이너지와 이면라이너지 모두 처리한 경우 도공량이 $2.99g/m^2$일 때 11.9%가 증가되어 소량의 산화전분 도공에 의해서도 수직압축강도가 크게 개선되었다.

• 펄프종이기술
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• 제37권2호
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• pp.64-69
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• 2005

Suitability of corrugating medium for microflute shape formation was analyzed in terms of fiber bonding strength and paper stiffness. Cationic starch and oxidized starch were applied to corrugating medium's surface by bar coater in order to compare the relative importance of stiffness and fiber bonding on microflute formation. It was found that cationic starch was beneficial for better stiffness and oxidized starch was beneficial for better fiber bonding. The results of the decreasing ratio of length by flute formation, the calculated conditioning effect, and the flute height before and after conditioning treatment were obtained. For better microflute shape formation and its preservation it was found that fiber bonding strength should be increased, proper stiffness was required, and resistance to water absorption from surroundings should be increased.

• 펄프종이기술
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• 제41권2호
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• pp.20-25
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• 2009

Many researches are carried out for developing the technology to substitute the surface sizing, although this process improves physical properties and water resistance of paper. This is because surface sizing has fundamental limitation to increase drying energy consumption and to restrict speed of paper machine. However, practical and effective technologies were not developed yet. In this study, we investigated the possibility of the substitution of surface sizing using internal starches, such as cationic starch and oxidized starch. To identify effects of internal starches on physical and optical properties, papers were not only made by adding internal starches into pulp slurry but papers surface sized with oxidized starch were also prepared to compare physical and optical properties. Consequently, tensile strength and internal bond of paper containing internal starches were higher than those of surface sized paper by controlling the type and addition level of cationic starch.

• 펄프종이기술
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• 제34권2호
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• pp.22-31
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• 2002

In this paper, PVA(polyvinylalcohol), oxidized starch and SBR latex were used as binders for ink-jet printing papers, and their effects of the type and blending ratio of binders on ink-jet printing properties were compared. In case of coating color using PVA mainly used for a binder in ink-jet printing, spreading of printed letters decreased and excellent images were manifested resulting from strong hydrophilic of PVA. However, increasing solids content of coating color was somewhat limited because of the interaction of PVA and functional groups in silica as well as high molecular weight of PVA. When oxidized starch and SBR latex were mixed with PVA at desirable ratio to solve these problems, runnability in coating process was improved and good printing properties were shown. Gloss was improved when latex was used along with PVA as a binder because of the thermoplastic property of the latex. From this result, possibilities of high solids content and high gloss ink-jet printing papers were investigated.

• 산업식품공학
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• 제15권1호
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• pp.70-74
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• 2011

전분필름의 물성에 미치는 고압균질 처리의 영향을 검토한 결과, 고압균질처리 옥수수전분필름은 산화전분필름과 유사한 투명도를 가지며, 용해도와 산소투과억제력의 증가와 함께 인장강도가 다소 높아지는 것을 확인하였다. 이러한 고압균질처리 옥수수전분필름의 물성변화는 고압균질기의 고압과 전단력에 의해 호화전분입자가 완전히 소실되고 전분의 용해도 증가와 보다 균일한 분산상이 형성되기 때문으로 판단되었다. 일반적인 호화과정을 통해 형성되는 전분필름의 구조는 연속상의 아밀로오스에 팽윤된 접분입자가 분산되어 있는 network 형태에서 형성된다. 반면 고압균질처리의 경우, 호화전분입자의 붕괴로 아밀로펙틴이 연속상을 이루고 여기에 아밀로오스가 분산상으로 존재하는 새로운 분산계(dispersed system)가 형성되어, 기존 호화 방법으로 제조한 필름과 다른 물성을 나타내는 것으로 판단되었다.

• 한국식품영양학회지
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• 제13권4호
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• pp.342-347
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• 2000

과요오드산-산화전분으로 보리 $\beta$-amylase(Bio-zyme ML, 일본 아마노제약)를 변형시켜서 인공당단백질을 만들었다. pH 8.0에서 변형한 효소는 비변형효소의 92%, pH 9.7에서 변형한 효소는 42%의 활성이 남았다. 6$0^{\circ}C$에서의 열안정성은 $\alpha$-cyclodextrin ( $\alpha$-CD) 존재 시에 변형하여 $\alpha$-CD존재시 분석한 효소는 10분 뒤에 비활성의 8%가 남은 반면 변형하지 않은 효소는 4.5%밖에 남지 않았다. pH안정성은 변형 시켜서 $\alpha$-CD존재 하에 분석한 효소가 가장 높아서 pH 2~5와 7~12에서 안정성이 매우 증가하였다. HPLC분석 결과 효소는 두 개의 피크를 나타냈으며 변형시킨 것은 당결합으로 분자량이 커져서 유출시간이 약간 빨라졌다.