• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.147-153
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• 2018

PLGA microcapsule particles encapsulating BSA aqueous solutions were prepared using a water-in-oil-in-water emulsion method. The morphology, particle size, BSA encapsulating efficiency, and in-vitro release test were also studied using the microcapsule particles. In the outer aqueous phase, an emulsifier, e.g., PVA, was replaced with metal salts for surface solidification. Scanning electron microscopy (SEM) showed that the microcapsule particles had smooth surfaces and were between $1{\mu}m$ and $7{\mu}m$ in size. The microcapsule particle morphology was affected directly by the ratio between the polymer solution and inner aqueous solution, and composition of the outer aqueous solution. The factors also partially affected the BSA encapsulation efficiencies and in-vitro release rates. All the microcapsule particles showed an initial burst release through the in-vitro release test. On the other hand, the particles also showed a relatively long release period. Metal salts could be good choices to replace the emulsifier to solidify the microcapsule particle surfaces.

• Korean Journal of Environmental Agriculture
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• v.11 no.2
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• pp.146-154
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• 1992

DDVP, malathion and diazinon ECs which differ in chemical compositions and moisture contents were formulated with nine emulsifiers, three solvents(xylene, cyclohexanone and DMF) and epichlorohydrin. For the studies of decomposition characteristics, these technicals and ECs were subjected to the test under elevated temperature at $54^{\circ}C$ for 15 days and $38^{\circ}C$ for 90 days respectively. DDVP technical was rapidly decomposed in early stage of thermoaccelerated test at $54^{\circ}C$, but the decomposition rate slowed down with time. As for malathion and diazinon technicals, the longer they were incubated, the more decomposed. The decomposed AI in ECs increased with solvent polarity. The increment of moisture content in ECs accelerated the decomposition of AI, and that was remarkable especially in diazinon ECs. Addition of emulsifiers increased the moisture content to be accelerated the decomposition of AI, but the decomposition of AI was more affected by the kind of emulsifier than by the moisture content of emulsifier, Stabilizing effect by epichlorohydrin was distingished in malathion and diazinon ECs, but there was no effect in other solvent-based formulation except xylene.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.196-203
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• 1993

Emulsions were prepared with the inversion emulsification method which adopted the agent-in-oil method-dissolving the mixed surfactants composed of the glycerin monostearate, polyoxyethylene(100) monostearate, and polyoxyethylene(20) sorbitan monostearate into mixtures of liquid paraffin and beeswax, and adding the aqueous solution of propylene glycol, gradually-and then their phases and viscosities behaviors in the emulsifying process were investigated. The fine and homogeneous o/w emulsions were formed in the HLB region (HLB 10.1~12.3), showing liquid crystalline phase and white gel phase in the emulsifying process. The phase inversion steps in the emulsifying process appeared as follows, i.e., oil continuous phase${\rightarrow}$liquid crystalline phase${\rightarrow}$white gel phase${\rightarrow}$o/w emulsion. Shear rate-shear stress curves of the prepared emulsions had the yield values which pointed out the existence of inner structure between emulsion particles, and the hysteresis loop which showed that the inner structure wasbroken irreversibly by the shear. The area of hystersis loop, an index of breakdown of inner structure, was increased with the decreasing of the HLB value of emulsifier, Shear time-shear stress curves showed the time dependence of plastic viscosity, and the relaxation time in time thinning behavior(${\lambda}$) indicated that the stability of emulsions prepared with the inversion emulsification method was decreased with the increasing of HLB values of emulsifier and was higher than that of emulsions prepared by homomixer.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.532-538
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• 2020

In this study, emulsification process were conducted to manufacture the natural sunscreen from raw materials such as shea butter, olive emulsifier wax, and green tea extract. The emulsification was optimized by using the central composite design model-response surface methodology (CCD-RSM) where the response values were established as the mean droplet size (MDS) and emulsion stability index (ESI) after 7 days in addition to UV absorbance at 300nm. The amount of emulsifier and additives and emulsification time were established as operating variables and the optimal conditions of sunscreen emulsification were accepted as 3.70, 2.47 wt.%, and 15.42 min, respectively according to the result of CCD-RSM. On the other hand, the response values were estimated as 1173.80 nm and 99.56% for MDS and ESI, respectively, after 7 days, in addition to UV absorbance at 300 nm (2.47). The average error from actual experiments was a low level as about 3.0 ± 1.5%, which is mainly due to the fact that the optimization using CCD-RSM applied in this study was in the relatively high significant level.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.87-97
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• 2017

This study aimed at optimizing the manufacturing conditions of a milk beverage supplemented with coffee, and monitoring its physicochemical and sensory properties during storage. Raw milk, skim milk powder, coffee extract, and emulsifiers were used to manufacture the beverage. Two sucrose fatty acid esters, F110 and F160, were identified as suitable emulsifiers. The optimum conditions for the beverage manufacture, which can satisfy two conditions at the same time, determined by response surface methodology (RSM), were 5,000 rpm primary homogenization speed and 0.207% sucrose fatty acid emulsifier addition. The particle size and zeta-potential of the beverage under the optimum condition were 190.1 nm and $-25.94{\pm}0.06mV$, respectively. In comparison study between F110 added group (GF110) and F160 added group (GF160) during storage, all samples maintained its pH around 6.6 to 6.7, and there was no significant difference (p<0.05). In addition, GF110 showed significantly higher zeta-potential than GF160 (p<0.05). The particle size of GF110 and GF160 were approximately 190.1 and 223.1 nm, respectively at initial. However, size distribution of the GF160 tended to increase during storage. Moreover, increase of the particle size in GF160 was observed in microphotographs of it during storage. The $L^*$ values gradually decreased within all groups, whereas the $a^*$ and $b^*$ values did not show significant variations (p<0.05). Compared with GF160, bitterness, floating cream, and rancid flavor were more pronounced in the GF110. Based on the result obtained from the present study, it appears that the sucrose fatty acid ester F110 is more suitable emulsifier when it comes to manufacturing this beverage than the F160, and also contributes to extending product shelf-life.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.646-653
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• 2000

Using agar and waxy com starch as the wall material, we could encapsulate the purified fish oil. Firstly, we have developed a simple and sensitive method for the quantitative analysis of the microencapsulation yield using 5% cupric acetate pyridine solution. Then, the optimum conditions such as the ratio of [core material] to [wall material]$(X_1)$, the temperature of dispersion fluid$(X_2)$, and the emulsifier concentration$(X_3)$ for the microencapsulation process were determined by using response surface methodology(RSM). The regression model equation for the yield of microencapsulation(Y, %) of purified fish oil upon three kinds of independent variables could be predicted as follows; Y = 100.138621-0.735000$(X_1)$+0.840000$(X_1)(X_2)$+0.817500$(X_1)(X_3)$-0.852500$(X_2)(X_3)$. And the optimum conditions for the microencapsulation of the purified fish oil were the ratio of [core material] to [wall material] of 4.9 : 5.1(w/w), the emulsifier concentration of 0.48%, and dispersion fluid temperature of $19.4^{\circ}C$. The microcapsules containing the purified fish oil showed the highest storage stability at pH 7.0 and $20{\sim}25^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.345-355
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• 1991

In order to effectively utilize the by-products of sea-food, the utilization of enzyme-modified flounder(Limanda aspera) skin gelatin as an emulsifier was investigated. In the experiment, the gelatin was extracted from the flounder skin with the heat-treatment at $60^{\circ}C$ and in pH 5.0 for 3 hrs with four volumes of distilled water and emulsifiers were enzymatically modified L-leucine alkyl esters$(L-leucine-OC_n$ : n= 2, 4, 6, 8 and 10) to the gelatin$(EMFSG-C_2,\;EMFSG-C_4,\;EMFSG-C_6,\;EMFSG-C_8,\;EMFSG-C_{10})$ for improving the functional properties such as emulsifying activity, emulsifying viscosity, whippability, electric conductivity, critical micelle concentration and interface tension, etc. Also, the functional properties of the L-leucine alkyl ester modified gelatins were compared with those of Tween-60 as reference. Molecular weights of the enzymatically modified flounder skin gelatin(EMFSG) were 20.5kDa. in $EMFSG-C_2.\;19.5 kDa.\;in\;EMFSG-C_4\;and\;16.5kDa.\;in\;EMFSG-C_6,\;EMFSG-C_8$ and $EMFSG-C_{10}$. respectively. Emulsifying activity and emulsifying viscosity in the modified gelatins were risen with increase of carbon number of the introduced L-leucine alkyl esters. Among the modified gelatins, $EMFSG-C_6$ exhibited the highest emulsifying stability and foaming stability, whereas $EMFSG-C_8$ showed the highest whippability. The electric conductivities of the all $EMFSG-C_n$ were linearly risen to critical micelle concentration(CMC) , therefore $EMFSG-C_{10}$ exhibited the lowest CMC value and interface tension, and dense particles in the microscopic observation. In conclusion, the best quality in functional properties was assured on $EMFSG-C_{10}$.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.361-367
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• 1996

As a part of investigation for quality improvement of surimi gel from fish with a red muscle by addition of emulsion curd, we investigated the processing conditions of emulsion curd contained succinylated gelatin from conger eel skin as an emulsifier and emulsion curd-added surimi gel. Activity and stability of emulsion curd on standing at room temperature, chilled temperature and vibration were remarkably improved by the addition of 15 tunes of soybean oil and 5 times of water to succinylated gelatin from conger eel skin. The proximate composition of the emulsion curd was moisture 18%, protein 5%, lipid 76% and ash 0.5% and its appearance was white. Peroxide value and fatty acid composition of emulsion curd contained succinylated gelatin as an emulsifier were similar to these of soybean oil. By the addition of 6% of emulsion curd to mackerel surimi, gel strength, appearance and texture of the resulting surimi gel were improved, while its peroxide value and brown pigment revealed minor change. From the results of volatile basic nitrogen, viable cell counts and histamine content, the emulsion curd-added mackerel surimi gel can be safe In the sense of food sanitation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.654-659
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• 2002

To investigate the effects of preparation conditions of encapsulating ester compounds on retention rate of core material in microcapsules prepared with sea tangle alginate, the amounts of ester compounds migrated gelling solution (1 M $CaCl_2$) and washing water from microcapsules that were prepared by adding kinds of ester compound, by controlling ratios of emulsifier to ester compounds and by differing ratios of alginates (wall material) to ester compounds (core material) were measured. Also the amount of ester compounds retained in microcapsules was measured. The higher weight molecular of ester compounds were, the lower amounts of ester compounds migrated gelling solution and washing water from microcapsules were, But its amounts retained in microcapsules were increased, The changes of ethyl caprylate amount migrated gelling solution and washing water from microcapsules prepared by increasing ratios of emulsifier to ethyl caprylate were little, but its half-lives in microcapsules during storage at 25$^{\circ}C$ were steeply increased. Increasing ratios of wall material to core material, ethyl caprylate amount migrated gelling solution and washing water from microcapsules showed 1.8$\~$$2.0\%$ and 2.9$\~$$3.5\%$ respectively but half-lives of ethyl caprylate retained in alginate microcapsules were increased.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.530-535
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• 2019

In this study, an optimization for the emulsification process with coconut oil and sugar ester was performed in conjunction with the central composite design (CCD) model of response surface methodology (RSM). Response values for the CCD model were the viscosity of the emulsion, mean droplet size, and emulsion stability index (ESI) after 7days from the reaction. On the other hand, the emulsification time, emulsification rate, and amount of emulsifier were selected as quantitative factors. According to the result of CCD, optimum conditions for the emulsification were as follows; the emulsification time of 22.63 min, emulsification speed of 6,627.41 rpm, and amount of emulsifier of 2.29 wt.%. Under these conditions, the viscosity, mean droplet size, and emulsion stability index (ESI) after 7 days from reaction were estimated as 1,707.56 cP, 1877.05 nm, and 93.23%, respectively. The comprehensive satisfaction of the CCD was indicated as 0.8848 with an average error of $1.2{\pm}0.1%$ from the experiment compared to that of the theoretical one. Overall, a very low error rate could be obtained when the central composite model was applied to the optimized coconut oil to water emulsification.