• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.29-38
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• 1997

In the w/o concentrated emulsion, the volume fraction of the dispersed is greater than 0.74 and the hydrophilic liquid is dispersed in the hydrophobic liquid of the continuous phase. The emulsion has the same appearance and behaviour as a gel. The polarity of the hydrophilic liquids and hydrophobic liquids, the pH and the ionic strength of the hydrophilic liquid are found to be important factors in the stability at the polymerization temperature such as $50^{\circ}C$. The lower the polarity of the hydrophobic liquid and the higher the polarity of the hydrophilic liquid, the more stable the emulsion. Electron microscopy studies of the hydrophilic-hydrophobic polymer composites show that the particles of polyacrylamide, the dispersed phase, are separated by he network of the thin film of polystyrene, the continuous phase. This hydrophilic-hydrophobic polymer composites show higher permselectivity to water in the mixture of water-ethanol. The pervaporation experiment shows that the selectivity of the membrane ranges between 4-40 and increases with increasing enthanol concentration in the feed. The rate of permeation decreases with increasing ethanol concentration in the feed.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.636-641
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• 2018

This study was conducted to compare the stability between branched-chain amino acid (BCAA)-encapsulated liposome and double emulsion (DE). Liposome was produced by high-speed homogenization and ultrasonication whereas DE was prepared by homogenizing with surfactants. All samples were fixed at pH 4 and 7 and stored at 4, 25, and $40^{\circ}C$ for 5 days. Encapsulation efficiency and cumulative release rate were measured under $4^{\circ}C$ and at $25^{\circ}C$. The results showed that the size of BCAA-coated liposome was greater at pH 7 than at pH 4. The zeta-potential value of BCAA-coated liposome was greater at pH 4 than at pH 7. It was supposed that the negatively charged liposomes attracted the positively charged BCAAs at pH 4 resulting in the formation of the vesicle with smaller size. Particle size of DE was smaller than $100{\mu}m$. Encapsulation efficiencies of BCAA in DE or liposome were over 97%, approximately, and the cumulative release rates of them were below 30% for 5 days.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.04a
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• pp.88-88
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• 2001

최근 들어 초지기의 고속화, 원료의 저급화, 가공작업의 온라인화에 따라 초지기 상에서 안 정된 조업성이 더욱 중요하게 부각되고 있다. 이러한 초지 시스랩의 변화에 따라 사이징 효과의 발현 속도에 대한 관심이 고조되고 있다. 중성 사이징 시스템으로 ASA를 적용할 경우에는 초지기상에서 사이즈도의 대부분이 발현되기 때문에 온라인 후가공 작업의 안정성이 향상되며 사이즈프레스에서 조업성 역시 개선될 수 있을 것으로 기대된다. 본 연구에서는 가격이 저렴하고 국내 수급이 용이한 옥수수 양성전분을 ASA 유화안정제로 이용하기 위해서 OSA (Octenyl Succinic Anhydride)를 이용한 에스테르화 및 산가수분해를 통하 여 ASA 에멀션의 안정성 및 사이징 효과를 개선시킨 전분을 개발하고 그 효과를 규명하고자 하였 다. 이를 위해 전분을 FT-IR을 이용하여 분석하고 호액의 pH, 전기전도도, 전하밀도, 점도 변화 등 을 측정하였을 뿐 아니라 ASA 유화액의 pH, 전기전도도, 시간에 따른 가수분해 안정성 등을 평가 하였다. 또한 ASA 에멀션의 입도 변화 섬유에 대한 흡착특성과 수초지의 사이즈도를 평가하였다. 그 결과는 다음과 같았다. 첫째,OSA 전분의 사용에 따라 전분 호화액의 pH와 전기전도도의 변화는 나타나지 않았 다. 전하밀도는 첨가량이 증가할수록 감소하였으며 호화액의 점도는 상숭하였다. 또 OSA 전분의 적 용이 수초지의 사이즈도에는 영향을 주지 않았다. 그러나 OSA 전분을 사용하여 제조된 ASA 유화 액의 가수분해 안정성은 향상되었다. 이것은 콜로이드 상의 ASA 입자를 캡슐화 하는데 있어 소수성 을 띠고 있는 OSA 전분이 보다 강하고 안정하게 흡착하기 때문인 것으로 판단되었다. 둘째, 전분의 호화 시 H2S04을 사용하여 전분의 산 가수분해를 유도할 수 있었다. 이를 통 하여 전분 호화액의 pH는 낮아지고 전기전도도는 증가하였으나 전하밀도의 변화는 없었다. 또한 겔 화 온도가 낮아지고 저온에서의 점도가 상승하는 변화를 나타냈다. IN-H2S04를 2.3%까지 첨가하였 을 때 ASA 에멀션의 입도가 더욱 감소하였고 섬유에 대한 흡착량이 증가하였으며 수초지의 사이즈 도가 향상되었다. 특히 기존에 사용되어 오던 감자 양성전분에 비해 최대 90%까지 사이즈도의 향상 이 있었다.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.623-630
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• 2017

The purpose of this study was to investigate the possibility of applying cosmetic material about extracted from Lycii Fructus seed supercritical fluid. This study was conducted to evaluate the anti-melanogenesis effect and antimicrobial activity about the extracts from Lycii Fructus seed. These researches studied for emulsion physical stability of pH, viscosity, particle size from emulsion containing Lycii Fructus seed extract. As a result, the supercritical fluid extract from Lycii Fructus seed significantly inhibited melanin synthesis by 81.86 % at the concentration $750{\mu}g/mL$. Antimicrobial effects of extract was determined against Staphylococcus aureus, Candida albicans, Escherichia coli. except by Staphylococcus epidermidis. The physical stability of viscosity and pH on the emulsion containing Lycii Fructus seed extract were stable for 28 days. Emulsion containing Lycii Fructus seed extract did not change particles at observation into optical microscope. These results suggest that extracts from Lycii Fructus seed may have value as the potential cosmetic formulation.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.365-374
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• 2021

In this study, the effect of enzyme-modified starch used in the preparation of filled hydrogel powder loaded with curcumin (FHP) on redispersibility, thermal and UV stability, and curcumin retention during in vitro digestion was investigated. FHP maintained stability without layer separation when redispersed and showed more stability against UVB than the emulsion powder (EMP). There was no significant difference in the chemical stability of curcumin between rice starch-based filled hydrogel powder (RS-FHP) and enzyme-modified starch-based filled hydrogel powder (GS-FHP). However, the gel matrix of GS-FHP maintained greater stability of lipid droplets in the stomach compared to RS-FHP, thereby improving the retention rate of curcumin after in vitro digestion. GS-FHP could be used as a novel material for developing premixes that require stable formulation and maintenance of functional substances, as it can increase the dispersion stability and retention rate of functional substances after digestion.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.324-330
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• 2018

In this study, we examined the effects of carrier oil type (MCT oil: MO, corn oil: CO, palm oil: PO), pH of dispersion solution, and antioxidants on the chemical degradation of ${\beta}$-carotene in oil-in-water nanoemulsions. The pH of the emulsion had a significant influence on the stability of ${\beta}$-carotene, which showed rapid degradation in emulsions at low pH value and relatively higher stability at high pH values. The influence of the carrier oil type on ${\beta}$-carotene stability was assessed. The rate of ${\beta}$-carotene degradation increased in the following order: CO > PO > MO. The effect of antioxidants on ${\beta}$-carotene degradation was monitored during storage at $25^{\circ}C$ for 4 weeks. The rate of ${\beta}$-carotene degradation decreased upon addition of water-soluble (ascorbic acid) or oil-soluble (tocopherol) antioxidants. In general, tocopherol was more effective than ascorbic acid in reducing ${\beta}$-carotene degradation. To utilize this nanoemulsion for producing acidic beverages, adding a higher concentration of antioxidants is required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.534-544
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• 2017

In order to use the sea flowering plant, Zostera marina, as a cosmetic ingredient, this study was conducted to evaluate its antioxidant effect. We confirmed the formulation stability of the emulsion containing Zostera marina extracts. We studied the antioxidant activity of the dissolved Zostera marina extracts through the DPPH (1,1-Diphenyl-2-picrylhydrazy) radical scavenging activity assay and SOD (superoxide dismutase)-like activity assay. Also, the pH, viscosity and particle dispersion of the emulsion containing Zostera marina extracts were measured using a Turbiscan LAB. The emulsions were measured at one-week intervals in a thermostat chamber ($25^{\circ}C{\pm}1^{\circ}C$, $40^{\circ}C{\pm}1^{\circ}C$) for 28 days. The extracts of Zostera marina showed a DPPH radical scavenging rate of 86.21% and SOD-like activity of 99.24% at 5.00 mg/ml and exhibited a dose-dependent increase in their antioxidant activity. We measured the stability of the pH, viscosity and emulsion particles using the Turbiscan LAB in a thermostat chamber for 28 days. The formulations to which the Zostera marina extracts were added were considered to be stable, due to their negligible physical property changes over time during storage. The results suggest that the Zostera marina extracts with 70% ethanol (v/v) could be used in cosmetics as an antioxidant for the anti-aging of skin.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.731-739
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• 2015

We conducted this study to investigate possibilities of applying cosmetic material about extrats from Sparassis crispa. The extracts of Sparassis crispa conducted a antibacterial activity against Straphylococcus epidermidis, Straphylococcus aureus, Escheri chia coli, Candida albicans by the paper disc method and antioxidative effect and Nitric oxide production inhibitory activity were performed in Raw 264.7 cells. Also, we evaluated of pH, viscosity, particle observation stability of emulsion that are applied of extracts from Sparassis crispa. The antimicrobial activity showed by the paper disc method against Straphylococcus aureus, Candida albicans. The physical stability were stable of pH, viscosity in emulsion included extracts from Sparassis crispa. Emulsion containing Sparassis crispa extracts did not change particles into optical microscope. These results suggest that extracts from Sparassis crispa may have value as the potential cosmetic formulations.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.174-188
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• 2019

The present study was carried out to investigate the emulsifying properties of heat-treated octenyl succinic anhydride(OSA) starch and the interfacial structure at oil droplet surface in emulsions stabilized by heat-treated OSA starch. First, the aqueous suspensions of OSA starch were heated at $80^{\circ}C$ for 30 min. Oil-in-water emulsions were then prepared with the heat-treated OSA starch suspension as sole emulsifier and their physicochemical properties such as fat globule size, surface load, zeta-potential, dispersion stability, confocal laser scanning microscopic image(CLSM) were determined. It was found that fat globule size decreased as the concentration of OSA starch in emulsions increased, showing a lower limit value ($d_{32}:0.31{\mu}m$) at ${\geq}0.2wt%$. Surface load increased steadily with increasing OSA starch concentration in emulsions, possibly forming multiple layers. In addition, fat globule sizes were also influenced by pH: they were increased in acidic conditions and these results were interpreted in view of the change in zeta potentials. The dispersion stability by Turbiscan showed that it was more unstable in emulsions at acidic condition. Heat-treated OSA starch found to adsorb at the oil droplet surface as some forms of membrane (not starch granules), which might be indicative of stabilizing mechanism of OSA starch emulsions to be steric forces.

• Polymer(Korea)
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• v.27 no.6
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• pp.596-602
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• 2003

A Polymeric emulsifier was synthesized by solution polymerization with 2-ethylhexyl acrylate, n-butyl acrylate, and acrylic acid. A series of polymeric emulsifier have been used in the emulsion copolymerization of 2-ethylhexyl actryacrylate and n-butyl acrylate. The size of the synthesized latex particles was around 145 nm and its distribution was very narrow. Emulsion with polymeric emusifier showed no coagulum after 7 cycles of freeze-thaw test, while the emulsion with traditional emulsifier exhibited coagulum after 2 cycles. The adhesion tests showed that the initial tackiness and peel strength decreased as the molecular weight and acrylic acid content of polymeric emulsifier increased, whereas the holding power increased.