• The Korean Journal of Food And Nutrition
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• v.3 no.2
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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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.3
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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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.1
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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.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.2
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• pp.3-11
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• 1998

Coating was carried out on liner components of B flute, single-wall corrugated board(SK180/S120/K200) to examine the effect of liner component coatings by oxidized starch on the properties of corrugated board. Both bursting strength and edgewise compression strength(ECS) of corrugated board were improved by coating of its liner components with oxidized starch. Bursting strength of corrugated board rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in bursting strength. The results showed 30.3% improvement for $2.32g/m^2$ coating on outside liner component, 36.8% improvement for $4.84g/m^2$ coating on inside liner component and 39.9% improvement for $7.16g/m^2$ coating on both liner components in bursting strength of corrugated board. Regardless of treated liner components, ECS of corrugated board was improved by coating of oxidized starch, and especially greater improvement was accomplished when corrugated board was coated on inside liner component or both liner components at low level of coating weight - 11.3% improvement for $1.58g/m^2$ coating on Inside liner component and 11.9% improvement for $2.99g/m^2$ coating on both liner components.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.2 s.110
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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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.2
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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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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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.

• Food Engineering Progress
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• v.15 no.1
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• pp.70-74
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• 2011

The effects of high pressure homogenization (microfluidization) on physicochemical properties of normal maize and oxidized maize starch film were studied. The molecular dispersibility of amlyose and amylopectin and the disintegration of granular structure had a marked effect on the physicochemical properties of starch films. The high pressure homogenized starch films showed increased solubility and transmittance due to the absence of gelatinized starch granules. The tensile strength of starch film increased significantly with decreasing oxygen permeability after high pressure homogenization, indicating that starch molecules were more uniformly and fully dispersed during the film formation. As a result, a clear starch film with improved mechanical properties was obtained after high pressure homogenization due to the increased interactions between the uniformly dispersed starch molecules.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.342-347
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• 2000

The stabilization of barley $\beta$-amylase(Biozyme ML, Amano) was attained by modification with periodate-oxidized soluble starch. The specific activities of modified enzyme at pH 9.7 and pH 8.0 were 42% and 92%, respectively, compared with that of native enzyme. The pH stability of modified enzyme was increased at pH 2~5 and 7~12 in the presence of $\alpha$-cyclodextrin( $\alpha$ -CD) compared wish that of native enzyme. Thermal stability of the modified enzyme was increased. After treatment at 6$0^{\circ}C$ for 10min. the activity remained 8% for the enzyme modified at pH 8.0 in the presence of $\alpha$-CD, 4.5% for the native enzyme. The native enzyme and modified enzyme showed two peak in HPLC. The molecular weight of the modified enzyme was slightly increased in HPLC analysis.