• 센서학회지
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• 제4권4호
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• pp.81-87
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• 1995

A novel biomaterial capable of incorporating biotinylated biomolecule has been synthesized. Our strategy is to biotinylate one-dimensional electroactive polymers and use a bridging streptavidin protein on Langmuir-Blodgett (LB) organized films. These copolymers are derivatized with long alkyl chains and biotin moieties to bind, respectively, to the hydrophobic surface and the biotinylated species, through the biotin and streptavidin complexation. We utilize the polymer assembly approach to attach a signal transducing biomolecule biotinylated phycoerythrin (B-PE) into this novel biomaterial by binding the unoccupied biotin binding sites on the bound streptavidin (4 sites total). The pressure-area isotherm of the protein injected monolayer showed area expansion. A characteristic fluorescent emission peak at 576nm was detected from the monolayer transferred onto a solid substrate. These observations demonstrated the promise of the organized thin polymer assemblies for their application to the sensor system.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.112-116
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• 2003

An immunosensor based on surface plasmon resonance (SPR) onto a protein G layer by Self-assembly technique was developed for detection of Legionella pneumophila. The protein G layer by self-assembly technique was fabricated on a gold (Au) surface by adsorbing the 11-mercaptoundecanoic acid (MUA) and an activation process for the chemical binding of the free amino (-NH$_2$) of protein G and 11-(MUA) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDAC) in series. The formation of the protein G layer by self-assembly technique on the Au Substrate and the binding of the antibody and antigen in series were confirmed by SPR spectroscopy. The Surface topographies of the fabricated thin films on an Au substrate were also analyzed by using an atomic force microscope (AFM). Consequently, an immunosensor for the detection of L. pneumophila using SPR was developed with a detection limit of up to 10$^2$CFU per mL.

• 기술사
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• 제18권2호
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• pp.16-22
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• 1985

This study was carried out to evaluate the quality of soybean sprouts grown under three different sources of light. The soybean was germinated under light through blue (251 ux), red (751 ux) and white (50 to 200 lux) polyethylene films at 25$^{\circ}C$ for 10hr./day. Vitamin C, chlorophyll, cellulose and total protein contents were determined and texture was evaluated by tasting soybean sprouts soup. protein pattern in the soybean sprouts were investigated using polyacrylamide gel electrophoresis. Vitamin C, chlorophyll and cellulose contents were increased by white light intensity. The texture of the sprouts grown under white light (50 lux, 100 lux) was better than darkness, but fought under 200 lux. Vitamin C contents of soybean sprouts grown under various sources of light (in order of light : blue > white > red) were higher than theses of ones grown in the darkness. Biosynthesis of chlorophyll was not correlated to Vitamin C content. Total protein contents of cotyledon was not changed significantly under light irradiation. But the soybean sprouts grown under different quality of light, hypocotyl was higher than those grown darkness. (37% and 20% higher for blue light and white light) Densitometric tracing of disc polyacrylamide gel electrophoretic patterns showed that protein of hypocotyl under white light had more high molecular weight protein.

• 한국축산식품학회지
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• 제35권3호
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• pp.350-359
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• 2015

This review focuses on the enhanced functional characteristics of enzymatic hydrolysates of whey proteins (WPHs) in food applications compared to intact whey proteins (WPs). WPs are applied in foods as whey protein concentrates (WPCs), whey protein isolates (WPIs), and WPHs. WPs are byproducts of cheese production, used in a wide range of food applications due to their nutritional validity, functional activities, and cost effectiveness. Enzymatic hydrolysis yields improved functional and nutritional benefits in contrast to heat denaturation or native applications. WPHs improve solubility over a wide range of pH, create viscosity through water binding, and promote cohesion, adhesion, and elasticity. WPHs form stronger but more flexible edible films than WPC or WPI. WPHs enhance emulsification, bind fat, and facilitate whipping, compared to intact WPs. Extensive hydrolyzed WPHs with proper heat applications are the best emulsifiers and addition of polysaccharides improves the emulsification ability of WPHs. Also, WPHs improve the sensorial properties like color, flavor, and texture but impart a bitter taste in case where extensive hydrolysis (degree of hydrolysis greater than 8%). It is important to consider the type of enzyme, hydrolysis conditions, and WPHs production method based on the nature of food application.

• Biomaterials and Biomechanics in Bioengineering
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• 제3권1호
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• pp.59-69
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• 2016

A surface resisting protein adsorption and cell adhesion is highly desirable for many biomedical applications such as diagnostic devices, biosensors and blood-contacting devices. In this study, a surface conjugated with sulfobetaine molecules was fabricated via the click reaction for the anti-fouling purpose. An alkyne-containing substrate (Alkyne-PPX) was generated by chemical vapor deposition of 4-ethynyl-[2,2]paracyclophane. Azide-ended mono-sulfobetaine molecules were synthesized and then conjugated on Alkyne-PPX via the click reaction. The protein adsorption from 10% serum was reduced by 57%, while the attachment of L929 cells was reduced by 83% onto the sulfobetaine-PPX surface compared to the protein adsorption and cell adhesion on Alkyne-PPX. In conclusion, we demonstrate that conjugation of mono-sulfobetaine molecules via the click chemistry is an effective way for reduction of non-specific protein adsorption and cell attachment.

• 한국축산식품학회지
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• 제35권2호
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• pp.216-224
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• 2015

The objective of present study was to evaluate the effects of the application of chitosan and chitosan/whey protein on the chemical, microbial and organoleptic properties of Göbek Kashar cheese during ripening time (on 3^rd, 30^th, 60^th and 90^th d). Difference in microbiological and chemical changes between samples was found to be significant (p<0.05) during ripening period. Cheese samples with edible coating had statistically lower mould counts compared to the uncoated samples. Furthermore the highest and lowest mould counts were determined in control (4.20 Log CFU/g) and other samples (<1 Log CFU/g) at 60^th and 90^th d of storage. All samples exhibited higher levels of water soluble nitrogen and ripening index at the end of storage process. At the end of 90 day storage period, no signicant dierences in salt and fat values were observed among the cheeses studied. The edible coatings had a beneficial effect on the sensory quality of cheese samples. In the result of sensory analysis, while cheese C and the chitosan coated cheese samples were more preferred by the panellists, the chitosan/whey protein film-coated cheese samples received the lowest scores. This study shows coating suggests could be used to improve the quality of cheese during ripening time.

• 한국축산식품학회지
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• 제43권6호
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• pp.1128-1149
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• 2023

In order to extend the shelf life of refrigerating raw lamb by inhibiting the growth of microorganisms, preventing the oxidation of fat and protein, and absorbing the juice outflow of lamb during storage, an active packaging system based on plastic/gelatin bilayer film with essential oil was developed in this study. Three kinds of petroleum-derived plastic films, oriented polypropylene (OPP), polyethylene terephthalate, and polyethylene, were coated with gelatin to make bilayer films for lamb preservation. The results showed significant improvement in the mechanical properties, oxygen, moisture, and light barriers of the bilayer films compared to the gelatin film. The OPP/gelatin bilayer film was selected for further experiments because of its highest acceptance by panelists. If the amount of juice outflow was less than 350% of the mass of the gelatin layer, it was difficult for the gelatin film to separate from lamb. With the increase in essential oil concentration, the water absorption capacity decreased. The OPP/gelatin bilayer films with 20% mustard or 10% oregano essential oils inhibited the growth of bacteria in lamb and displayed better mechanical properties. Essential oil decreased the brightness and light transmittance of the bilayer films and made the film yellow. In conclusion, our results suggested that the active packaging system based on OPP/gelatin bilayer film was more suitable for raw lamb preservation than single-layer gelatin film or petroleum-derived plastic film, but need further study, including minimizing the amount of essential oil, enhancing the mechanical strength of the gelatin film after water absorption.

• BMB Reports
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• 제34권5호
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• pp.457-462
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• 2001

Using the monomolecular film technique, we compared the interfacial properties of Staphylococcus simulans lipase (SSL) and Staphylococcus aureus lipase (SAL). These two enzymes act specifically on glycerides without any detectable phospholipase activity when using various phospholipids. Our results show that the maximum rate of racemic dicaprin (rac-dicaprin) hydrolysis was displayed at pH 8.5, or 6.5 with Staphylococcus simulans lipase or Staphylococcus aureus lipase, respectively The two enzymes interact strongly with egg-phosphatidyl choline (egg-PC) monomolecular films, evidenced by a critical surface pressure value of around $23\;mN{\cdot}m^{-1}$. In contrast to pancreatic lipases, $\beta$-lactoglobulin, a tensioactive protein, failed to inhibit Staphylococcus simulans lipase and Staphylococcus aureus lipase. A kinetic study on the surface pressure dependency, stereoselectivity, and regioselectivity of Staphylococcus simulans lipase and Staphylococcus aureus lipase was performed using optically pure stereoisomers of diglycerides (1,2-sn-dicaprin and 2,3-sn-dicaprin) and a prochiral isomer (1,3-sn-dicaprin) that were spread as monomolecular films at the air-water interface. Both staphylococcal lipases acted preferentially on distal carboxylic ester groups of the diglyceride isomer (1,3-sn-dicaprin). Furthermore, Staphylococcus simulans lipase was found to be markedly stereoselective for the sn-3 position of the 2,3-sn-dicaprin isomer.

• 한국식품영양과학회지
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• 제35권1호
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• pp.121-125
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• 2006

견 피브로인 용액 에 PEG를 농도 별로 처리하거나 PEG와 Gly를 혼합하여 사용하여 필름을 제조한 뒤 그 물성을 측정하였다. PEG의 농도가 $1\%$인 견 피브로인 필름에서 32.54 Mpa로 가장 높은 인장강도를 나타냈고, PEG의 농도가 높아 질수록 인장강도는 감소하였다. 인장강도와는 반대로 PEG의 농도가 증가할수록 신장률은 증가하는 경향을 보였는데 PEG의 농도가 $3\%$서 $4.5\%$로 증가할 때 $350\%$ 이상의 높은 증가율을 보였고 또한 투습도의 경우 $66\%$ 증가하였다. PEG와 Gly의 비율을 다르게 한 경우 인장강도는 PEG:Gly의 비가 100:0일 때 13.72 Mpa로 가장 높았고, 0:100일 때 4.58 Mpa로 가장 낮았다. 이에 반하여 신장률은 PEG:Gly의 비가 75:25일 때 $130.95\%$로 가장 높게 나타났다. 투습도의 경우 Gly만을 넣어 만든 경우 $5.13\;ng{\cdot}m/m^2s$ Pa로 투습도가 가장 높게 나타났고 Gly의 비가 높아질수록 투습도가 증가하는 경향을 보였다. 전체적인 Hunter L, a, b와 ${\Delta}E$ 값은 PEG 농도와 PEG:Gly의 혼합하여 만든 필름 사이에 뚜렷한 차이가 없었다. 본 실험 결과 견 피브로인 필름의 가소제로써 PEG와 Gly를 혼합하여 사용할 경우 PEG만을 사용하여 만든 필름보다 신장률이 크게 증가하며, 또한 PEG와 Gly을 75:25의 비로 흔용하여 사용한 경우가 Gly의 첨가로 투습도가 조금 증가하기는 하였으나 인장강도는 상업용 LDPE (low density polyethylene)와 유사한 수치를 나타내면서도 높은 신장률을 가지고 있기 때문에 식품포장재로 활용이 가장 적합하다고 판단된다.

• 한국식품과학회지
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• 제29권3호
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• pp.452-459
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• 1997

본 연구는 추출 pH가 분리 대두 단백질 필름의 인장 강도, 신장률 및 수증기 투과도에 미치는 영향에 대하여 조사하였다. 산성(pH 2.0, pH 3.0), 중성(pH 7.0) 및 알칼리성(pH 10.0, pH 12.0)에서 분리 대두 단백질을 추출하고 이로부터 가식성필름을 제조하였을 때, 산성에서 추출한 단백질로 제조한 $SPI_2$와 $SPI_3$ 필름의 인장 강도가 각각 2.881 MPa, 2.804 MPa로서 중성이나 알칼리성 영역에서 추출하여 제조한 가식성 필름보다 높게 나타났으며, $SPI_3$ 필름의 수증기 투과도는 필름의 두께가 $55\;{\mu}m$에서 $72\;{\mu}m$로 증가함에 따라 $3.349\;{\times}\;10^{-10}{\sim}3.871\;{\times}\;10^{-10}\;g{\cdot}m/m^2{\cdot}s{\cdot}Pa$로 증가하여 다른 중성이나 알칼리성에서 추출한 분리 대두 단백질 필름에 비해 낮은 수증기 투과도를 보여, 산성에서 추출한 분리단백질로 제조한 가실성 필름이 다른 pH영역에서 추출한 SPI로 제조한 필름보다 강한 인장강도와 우수한 수분차단력을 보였다. 가소제의 농도가 증가함에 따라 $SPI_2$로 제조한 가식성 필름의 인장 강도는 가소제의 농도가 0.2 g plasticizer/g $SPI_2$에서 0.8 g plasticizer/g $SPI_2$로 증가함에 따라 가소제가 glycerol인 경우 12.297 MPa에서 1.356 MPa로, propylene glycol인 경우 7.408 MPa에서 2.147 MPa로, polyethylene glycol인 경우 10.579 MPa에서 2.987 MPa로 감소하여 가소제의 종류 및 농도를 달리함으로써 필름의 기계적물성을 조절하는 것이 가능하였다. 산성 영역에서 추출한 분리 대두 단백질($SPI_2$, $SPI_3$)이 다른 것들에 비해 단백질 함량과 11S/7S의 함량비가 높게 나타났으며, 이는 가식성 필름의 물리적 성질의 변화의 주요한 인자로 생각되고 있다.