Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

In a nuclear facility, the base metal can be radiologically contaminated during the operation. They must be decontaminated to reduce the radiation exposure to workers before decommissioning of the nuclear facility. In order to decontaminate the nuclear facility, it is possible to apply a perfluorocarbon (PFC) based emulsion consisted of surfactant and decontamination reagent. The PFC has high resistance for the radiation decomposition, and PFC based emulsion can be easily stabilized using the ultrasonication method. During decontamination process, a dispersion stability of the emulsion affects to the decontamination performance because the decontamination reagents dispersed in the emulsion contact contaminated surface. In this study, the dispersion stability the PFC based emulsion was evaluated following the composition of the emulsion and dispersion condition such as temperature, ultrasonication time. It was confirmed that the concentration of surfactant is highly related to the dispersion stability from the result of Turbiscan analysis using the multiple light scattering method. It was also verified that the droplet size of the decontamination reagent in the stable emulsion was smaller than that in the unstable emulsion. This phenomena can be explained by the relationship between the interfacial tension and droplet size. Finally, the recovering test of the PFC from the spent PFC-based decontamination emulsion was conducted using distillation method. The distillation test was performed using vacuum distillation unit, and the distillation temperature was 80°C. From the distillation test, about 95 % of PFC was recovered by distillation. From this result, it is considered that PFC-based decontamination emulsion reduces the volume of the secondary waste.

본 연구에서는 일반적으로 O/W 에멀젼에 비해 안정화가 어려운 W/O 에멀젼, 특히 유동성이 높은 저점도 W/O 에멀젼의 안정성 증진을 위하여 유화제, 전해질, 유화 안정화제, 겔화제 등을 적용한 다양한 실험을 수행하여 보았다. 그 결과 이번 실험에서는 Polyglyceryl-4 diisostearate/ polyhydroxystearate/sebacate를 주 유화제로 하면서 PEG-30 dipolyhydroxystearate와 Cetyl PEG/PPG-10/1 dimethicone을 보조 유화제로 하는 유화 체계에, 전해질로 Sodium chloride를 0.5 %, 유화 안정화제로 Distearyldimonium chloride를 1 %, 유상 겔화제로 Glyceryl behenate/eicosadioate를 0.5 % 적용한 유화 입자도 작고 조밀하며 점도도 2,000 cps 이하로 일정하게 유지되는 안정한 저점도 W/O 에멀젼을 제조할 수가 있었다. 또한 상기와 같은 에멀젼 베이스에 무기 자외선 차단성분의 적용 실험을 통하여 안정성이 우수한 저점도 플루이드형 자외선 차단제품의 개발 가능성도 긍정적으로 검토 할 수가 있었다.

This study was performed to analyze a saltiness enhancement at the same salt content through multiple emulsion. We compared the samples with different conditions to determine the optimum stability conditions of water-in-oil through layer separation rate, microscopic observation and size analysis. Four electrolytes such as NaCl, KCl, MgCl2, and CaCl2 were used and agar contents ranged from 0 to 1% were experimented at different volume ratios including 5:5, 4:6, 3:7, 2:8, and 1:9 of water and oil. As a result of this study, the droplet size according to the electrolyte type did not show significant differences (p<0.05). Therefore, KCl was used to facilitate in-body excretion of NaCl in the outer water phase, and corn oil containing 8%(w/w) polyglycerol polyricinoleate was used as oil phase. When the volume ratio of water and oil was 3:7, 2:8, and 1:9, the layer separation rate was relatively slow and droplet size was also small. It reveals that the particle size becomes smaller as the water volume ratio decreases. However, considering the amount of water to be stored and eluted on the inner water, appropriate volume ratio of water and oil should be adopted to 3: 7. At Microscopic observation depending on agar concentrations, small particle size appeared at 0.2% and 0.4% agars. When the water and oil ratio was fixed at 3:7, the particle size was measured at 0.2% and 0.4% agar using a zeta sizer. In conclusion, the droplet size of 0.2% agar was smaller than 0.4%. Therefore, the most stable water-in-oil emulsion was obtained with 0.2% agar, when water to oil ratio was 3:7.

Vitamin A, particularly all-trans retinol is excellent for anti-aging but is sensitive to oxygen, heat and light and has low solubility in water. In this study, retinol was encapsulated within oil-in-water (O/W) emulsion, protein-based particle and cycloamylose(CA). And then, it confirms that retinol contained in each delivery system is stable to UV, pH, and temperature and finally measures bioaccessibility. O/W emulsion was compared according to the type and concentration of emulsifier. UV stability of retinol increased with increasing oil concentration. More than 10 wt% of oil was required to maintain stable retinol (50% residual after 24 hours of irradiation). Using anionic emulsifier, retinol had unstable storage stability regardless of oil concentration and temperature. Protein based particle was compared according to the type of stabilizer and polysaccharide. UV stability of retinol was highest in pectin-coated particles. However, 20% retinol remains after 6 hours of irradiation and is vulnerable to UV compared to other delivery systems. In pH stability, pectin-coated particles also stably retained retinol. Inclusion complex of retinol and CA was compared according to the concentration of CA. When CA was used, the residual amount of retinol to UV was high (50% residual after 24 hours of irradiation) regardless of the concentration of the host molecule. In the case of storage stability, retinol remained significantly higher regardless of temperature when cycloamylose was used. It was finally confirmed bioaccessibility each of retinol delivery system. O/W emulsion was determined by emulsifier type, protein-based particle by coating agent, and inclusion complex by CA concentration. All O / W emulsions retained more than 50% retinol, protein based particles retained more than 80% retinol, and inclusion complex retained more than 70% retinol. The bioaccessibility of pure retinol is about 20%. This study provides important information for designing effective delivery systems for improving the stability of retinol.

Curcumin is an active polyphenolic compound with antioxidant, anti-inflammatory and antitumor properties. Curcumin, however, is highly unstable under physiological conditions due to its low stability in acidic and alkaline conditions. Therefore, the objective of this study was to investigate the effects of enzyme-treated rice starch as a wall material on the stability of curcumin in oil-in-water emulsion under different pH conditions. The rice starch was treated using 4-a-glucanotransferase for different time periods and their molecular weight distribution was measured by HPSEC. Curcumin was encapsulated within lipid droplets of O/W emulsion prepared with Tween 20 and the modified rice starch in the aqueous phase at different concentrations (0, 2.5, 7.5 and 10 wt%). The temperature and pH stability of the system were determined respectively by measuring particle size, zeta potential and retention of the curcumin loaded in the emulsion after one-week storage in the solutions with different pH and temperature conditions. The average molecular weight of the modified starch decreased with treatment time. The 96h treated rice starch had the lowest molecular weight while the 1h treated starch mainly consisted of high molecular weight components. The storage temperature did not significantly influence the stability of curcumin emulsion. However, the particle size of the emulsion with modified starch slightly increased when stored at acidic pH condition, which might be attributed to starch aggregation. The curcumin retention was higher for the samples with the modified starch than the control at all concentrations. The pH stability of the curcumin was also higher than the control at all pH conditions. Specifically, the 1h treated starch showed the best performance regarding curcumin protection in emulsion, which might be attributed to the high viscosity that retarded the curcumin release. Further research needs to be conducted on the mechanism.

Retinol is a type of vitamin A that helps the skin's epidermal cells maintain their original function and plays an important role in visual acuity. However, retinol cannot simply be incorporated into foods in its pure form because of limited solubility and chemical instability. In this study, retinol was encapsulated within lipid droplets of oil-in-water (O/W) emulsion and the photo stability of retinol loaded in O/W emulsion was examined. O/W emulsions containing retinol were prepared using Tween 20, Decaglycerine myristate and WPI, respectively, at different oil concentrations (0.1, 0.5, 1.0, 2.0, and 4.0 wt%). Photo stability of retinol was determined by measuring retention rate (%) of retinol loaded in O/W emulsions after exposure to UV light for 24 h and compared to that of retinol dissolved in ethanol. The retinol retention rate was higher for O/W emulsions than retinol in ethanol and the retention rate increased as the oil concentration of emulsions increased, which might be attributed to the opaqueness of emulsions. As the oil concentration of emulsions increased, the turbidity of emulsions also increased. In terms of the type of emulsifier, decaglycerine myristate-stabilized emulsion had the highest retinol retentions rate than other emulsifier-stabilized emulsions after exposure to UV light. This study provides important information for designing effective emulsion-based delivery systems for improving the stability of retinol.

Ginsenosides are sensitive to various factors such as pH, temperature, ionic strength, etc. However, powdery form of ginseng is good to preserve ginsenosides in it compared to the extracted form. In addition, the ginseng powder can provide pickering effect to control emulsion stability as a substitute of emulsifier forming wall on the surface of oil. A ginseng pickering emulsions was prepared by mixing, MCT oil, polysorbate 80 and ginseng. Thereafter, to homogenize the emulsions magnetic stirrer, homogenizer and ultra sonicator were used. The physicochemical properties, stability, and bioaccessibility of the ginseng pickering emulsion were investigated. Both particle size and polydisperse index of the ginseng pickering emulsion were constant as time elapsed. However, pH and zeta-potential of the ginseng pickering emulsion decreased over time. Moreover, to find out the proper amount of ginseng powder, different ginseng powder weights were added to sample respectively and the physiochemical characteristics were measured. The pH and zeta-potential value tended to decrease following increase of amount of ginseng powder. This result is impacted to food quality and it could be used as a preliminary result in the development of food product.

The purpose of this research was to investigate the effect of weighting agent (WA) and high pressure homogenization (HPH) on the stability of water-in-oil-in-water double emulsion (DE). To prepare oil phase (O), olive oil, glycerol ester of wood rosin (WA; variable 1), and polyglycerol polyricinoleate (lipophilic emulsifier), and for interior water phase (W1), deionized water, gelatin, sodium chloride, ascorbic acid, and green tea extract(core material) were mixed and heated. When temperature of O and W1 reached up to 60℃, W1 was dispersed into O dropwisely followed by magnetic stirring at 1500 rpm for 2 min (O:W1=3:1). By applying homogenization at 4000 rpm for 2 min followed by ultrasonication for 4 min, water-in-oil primary emulsion (PE) was produced. And resting PE at 4℃ for 30 min was followed. For exterior water phase (W2), deionized water, sodium chloride, ascorbic acid, and polysorbate 80 (hydrophilic emulsifier) were mixed. When temperature of PE reached at room temperature (24 ± 2℃), PE was dispersed into W2 dropwisely followed by magnetic stirring at 1500 rpm for 15 min (PE:W2=1:3). By applying ultrasonication for 2 min followed by HPH at 500 bar for 1 to 3 times (variable 2), DE was produced. When DE was freshly produced, phase separation occurred at different period of time depending on whether variable 1 and 2 were applied or not (from 5 min to more than a day). The structure of DE was observed through optical and transmission electron microscopy. And relationship between the mean size of oil droplets and the occurring time of phase separation was studied. DE can be used as an appropriate delivery system for co-loading both hydrophilic and lipophilic bioactive compounds simultaneously, and promoting industrialization as well by applying it to food products, for example, beverage.

나노에멀젼은 서브마이크론 크기의 에멀젼으로 치료 약물의 전달을 향상시키는 약물 전달체로서 많은 연구가 진행되고 있다. 본 연구의 목표는 폴리머를 함유한 나노에멀젼의 안정성에 대한 연구이다. 고농도의 Carbopol 941, Aristoflex AVC, Aronbis M, Permulen TR 2 및 Aculyn 44를 함유한 나노에멀젼의 안정성은 마크로에멀젼과는 다르게 불안정하였다. 폴리머를 유화 전에 첨가하여 제조한 에멀젼이 유화 후 폴리머를 첨가하여 제조한 에멀젼에 비해 초기 입자 크기가 더 크게 형성되었다. 저 농도의 폴리머를 함유한 경우에도 폴리머를 함유하지 않은 나노에멀젼에 비해 안정성이 감소하였으나 그 정도는 고농도에 비해 적었다. 점도가 유사한 경우 안정성에 미치는 순서는 Aristoflex AVC < Carbopol 941 < Permulen TR2 < Carbopol 941 + Aculyn 44 < Aronbis M의 순서로 불안정하였다.

폴리글리세롤에스터 유화제를 이용한 에멀젼의 입자상태 및 시간의 변화에 따른 안정성을 여러 가지 오일을 이용하여 실험을 실시하였다. 실험결과 오일의 종류에 따라 입자크기 및 안정성에 있어서 다소의 차이가 있는 것을 확인하였다. 폴리글리세롤 에스터로 유화된 가장 안정한 오일은 polar 오일인 실리콘계열과 지방산에스터 오일이고, 탄화수소계열의 nonpolar오일(Mineral oil, squalane, polydecene) 등이 유화에 있어서 가장 불안한 상태를 보였다. 식물성오일도 폴리글리세릴 에스터 유화제와는 안정한 형태의 입자형성을 보였다.

In this study, the characteristics of emulsified fuel were studied. The emulsified fuel which was composed of water and diesel was manufactured by using homogenizer and ultrasonic generator. The more the percentage of water contents increases, the more the density increases to the emulsified fuel. However, the viscosity increased in the 60% of water contents and decreased in the 70% of water contents because the O/W type was formed. The 3 minutes's ultrasonic waves during the irradiation time was appropriate of 16,000 rpm. And the energy density of ultrasonic waves was 87.5J/g. The emulsion stability has improved in the lower temperature, the lower percentage of water contents, and the most stable emulsion state was obtained from 20%(w/w) of water contents. Also, the emulsion stability was related to the HLB values of emulsifiers. Especially, the HLB values of emulsifier were appropriate from 4 to 7 values.

Liquid crystal (LC) system was introduced into W/O emulsion in order to enhance the stability and moisturizing effect. The LC system, composed of beeswax, surfactant, and water was formed on the surface of emulsion droplet, which was investigated through a polarized microscope. The phenomenon that the viscosity in W/O emulsion system is decreased with time, was reduced by the formation of LC with the addition of beeswax. Centrifugal separation test showed that the stability of emulsion system was increased with the addition of beeswax to 3%. The color change of vitamin C was delayed in LC emulsion systems, which indicates stabilization effect against the oxidation of vitamin C. Evaporation rate in W/O emulsion was retarded by LC, so that high moisturizing effect is expected in W/O LC system.

Cosmetic industries have recently developed sun-block products, which are composed of W/O or O/W emulsion system. It was very difficult for waterproofing product to show the stability in W/O emulsion with TiO2. To enhance the stability of W/O emulsion, it needs to be combined with the water and oil soluble components as the gelling agents. The emulsifiers used in W/O were 3.0% of cetyl dimethicone copolyol, 2.0% of sorbitan sesquioleate as the basic emulsifiers, and 0.6% of quaternium-18 bentonite and 1.5% of dextrin palmitate as stabilizer were used. The content of titanium dioxide was optimized up to 8.0%. Titanium dioxide was used as the UV scattering powder coated with Al2O3(UV-sperse T40/TN). The sunscreen cream prepared with W/O emulsion system by using QB and DP showed higher stability than that of W/O emulsion system by using each QB and DP. W/O emulsion from Formula 3 for passing one year was very durable more than F1 and F2. Within W/O emulsion by observing F1, F2 and F3 for one year, F3 was more excellent than F2 and F3 when they were observed at RT, 4℃, 40℃, because F3 used the mixed QB and DP in W/O emulsion. The zeta potential for F1, F2, and F3 after one year were 21, 30 and 43, respectively. From these result F3 was found best stable emulsion. The in-vitro SPF value for F3 was 35 for the initial product at room temperature and also, the in-vitro SPF values of F3 was 32 for after one year. Finally, the mean in-vivo SPF value of 10 volunteers for F3 was 27.3 by the Korea cosmetic association made the rules of SPF.

The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was 600nm~612nm. But it was identified that only methanol can be used to photographic emulsion.

Rapeseed cake was extracted with 80% ethanol and then fractionated with H2O (fraction I) as well as with 30% (II), 50% (III), 70% (IV), and 100% ethanol (V). Total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric-reducing antioxidant potential, and Trolox equivalent antioxidant capacity were in the order of fractions II > III > I > IV > V. The three fractions with high antioxidant activities and TPC (I, II, and III) were pooled and hydrolyzed by NaOH solution, resulting in 18.97 mg sinapic acid/g hydrolyzed extract and 21- and 2.2-fold increases in TPC and DPPH radical scavenging activity, respectively. Hydrolyzed rapeseed cake extracts (200, 500, and 1,000 ppm) and catechin (200 ppm) as a comparison were added to 10% fish oil-in-water emulsion, and their effects on oxidative stability were investigated by measuring hydroperoxide values (PV) during refrigerated storage. PVs were significantly lower in the emulsions with added hydrolyzed extract as compared to the control (p<0.05) and significantly decreased with increasing extract concentration (p<0.05) over a period of 29 days. The emulsion added with hydrolyzed extract showed higher PV than that added catechin at the same concentration (200 ppm) during 13-22 days (p<0.05), but after then, the PV was not significantly different (p>0.05). This study indicates that hydrolyzed rapeseed cake extract rich in sinapic acid may inhibit oxidation in a fish oil-in-water emulsion in a concentration-dependent manner.

본 연구에서는 친수성 계면활성제와 친유성 계면활성제가 조합된 다양한 HLB (Hydrophilic Lipophilic Balance) 값을 갖는 유화 시스템의 조건에서, required HLB 값이 각기 다른 오일들을 적용하여 제조한 O/W 및 W/S 에멀젼들의 특성 및 유화 안정성을 조사해 보았다. 그 결과 O/W 에멀젼은 유화제의 HLB 값이 낮을수록 점도가 높고, 유화입자는 작고 조밀한 경향을 나타내었으며, 원심분리에서도 더 안정한 경향을 나타내었다. W/S 에멀젼은 유화제의 HLB 값이 높을수록 유화입자는 작고 조밀해지는 경향을 나타내었으며, 원심분리에서도 더 안정한 경향을 나타내었다. 그러나 W/S 에멀젼은 시간이 경과할수록 모든 유화제의 HLB 조건에서 점도가 낮아지는 경향이 나타나 장기 안정도에서는 불안정한 특성을 나타내었다. 이번 연구의 결과는 O/W 에멀젼은 HLB 값이 높은 비이온 계면활성제의 적용이 적합하며 W/S 에멀젼은 HLB 값이 낮은 비이온 계면활성제의 적용이 적합하다는 기본 이론과 상반되는 결과로서 앞으로의 화장품 연구 개발 시 유용한 연구 자료가 될 것으로 사료된다.