• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.518-527
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• 2013

5,6-dihydroxyindole was easily oxidation with air and light Conditions. Availability of 5,6-dihydroxyindole was studied for hair dye as a precursor of melanin. This study used wet and dry coating process to stabilize 5,6-dihydroxyindole. In wet process used dimethicone and cyclometicone, the 5,6-dihydroxyindole had darkened through the drying process at $58^{\circ}C$. Wet coating process was inappropriate to stabilize the coating. In dry coating process, shea butter coating was stable until 3 days. Dextrin palmitate was most efficient ingredient to prevent oxidation by sun light and air until 7days. Oxidation test with 1.0% and 1.5% of dextrin palmitate was not different under conditions of sun light and air and was not dependent on contents. Vitamin E acetate under conditions of sun light and air, there were no significant effect in preventing oxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1083-1089
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• 2000

본 연구는 에탄올의 급여수준과 금주 후 회복이 체내항산화비타민 상태에 미치는 영향을 조사하고자 평균 체중이 200g인 Dprague-dawley 종 숫쥐 50마리를 사용하여 혈장 및 간조직의 비타민 A 및 E 의 함량을 비교.분석하였다. 실험식이라는 에탄올 액체식이형태로 만들어 공급하였으며, 이때 식이는 mL당 1 kacal의 열량을 공급할 수 있도록 조제하였다. 각 실험군의 식이구성은 에탄올을 첨가하는 대신 dextrin-maltose를 급여한 C군, 전체 칼로리의 10%를 에탄올로 첨가하는 LE 군 , 20%를 첨가하는 ME 군, 30%를 첨가하는 HE군 , 30%의 에탄올을 5주간 공급한 후 다시 2주간 정상식이를 급여한 회복군(HR)으로 설정하여 실험식이를 공급하였다. 혈자에서의 retinol 함량은 에탄올 급여수준에 따른 유의적인 차이는 나타나지 않았다. 간조직 중의 retinol 함량은 20% 이상의 에탄올 군에서 대조군에 비해 유의적으로 감소되었고, 30% 에탄올군인 HE 군에서는 현저하게 저하되었다. 30% 에탄올 급여후 2주간 정상식이를 회복시킨 군에서도 간조직의 retinol의 함량은 그대로 저하된 상태를 유지하였다. 간조직의 retinyl palmitate 함량은 에탄올 급여수준이 높을수록 감소되는 경향이었으며, 30% 에탄올군에서는 대조군에 비해 유의적으로 감소되었다. 회복군의 경우에도 이러한 저하현상은 더욱 심화되었다. 혈장의 $\alpha$-tocopherol 함량은 에탄올 급여량에 따라 별다른 차이를 나타내지 않았다. 간조직에서 10% 에탄올군에서도 대조군에 비해 유의적으로 감소되었으며, 에탄올 급여수준이 증가될수록 현저하게 저하되었다. 그러나 회복군에서는 $\alpha$-tocopherol의 함량이 10% 에탄올군의 수준까지 회복되었다. 이상의 결과에서와 같이 만성적인 에탄올의 섭취는 대체로 열량의 20% 이상을 에탄올로 급여하였을대 섭취수준이 증가함에 따라 흰쥐의 간조직에서 비타민 A와 $\alpha$-tocopherol으 lgkafid이 저하되었다. 이는 에탄올의 섭취를 중단하고 정상식이를 일정기간 급여하여도 특히 비타민 A 함량은 회복되지 않는 경향을 보여 만성적인 에탄올 섭취자들에게 비타민 A영양상태의 문제를 예방할 수 있는 방안이 강구되어야 함을 나타낸다.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.67-75
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• 2000

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 $TiO_{2}$. 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 $Al_{2}O_{3}$(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, $4^{\circ}C$, $40^{\circ}C$, 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.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.3
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• pp.247-258
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• 2023

This study aims to investigate the enhancement of water resistance and improvement in adhesion to the skin by combining dextrin palmitate and isopropyl titanium triisostearate coating materials with titanium dioxide. Due to the recent increase in consumers who enjoy outdoor activities, the demand for sunscreen with excellent water resistance is increasing. Prior research was conducted with O/W, Pickering, and W/O/W multiple formulations, but there was a limit to water resistance. The purpose of this study is to develop a complex inorganic powder that can improve water resistance and increase adhesion to the skin to solve this problem. First, we combined dextrin palmitate and isopropyl titanium triisostearate coating materials to form a composite with titanium dioxide. The coating of the inorganic powder was confirmed using FE-SEM and FT-IR analysis. The composite exhibited significantly higher in vitro water resistance compared to other formulations. The hydrophobicity of the coated inorganic powder was compared by measuring the contact angles. When the coated inorganic powder was applied to the W/O sunscreen formulation and the non-coated inorganic powder was applied to the W/O sunscreen formulation as a control, the SPF of the sunscreen containing the coated inorganic powder was higher. These results were the same when observed with a UV camera. Finally the adhesion of the coated inorganic powder to the skin was assessed by applying it to a foundation product. In vivo study, it was observed that the product formulated with the coated powder exhibited less smudging compared to the foundation product formulated with the non-coated powder. The developed inorganic powder in this study demonstrated excellent adhesion to the skin, providing a superior sensory experience, as well as enhanced hydrophobicity and remarkable water resistance effects. In the future, the result of this study is expected to help develop various sunscreen products to improve water resistance.