In this study, the antioxidative effects and inhibitory effects on tyrosinase and elastase of Sorbus commixta (S. commixta) twig extracts were investigated. The aglycone fraction of S. commixta twig extract showed the prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity(FSC50, 13μg/mL). Reactive oxygen species (ROS) scavenging activities of S. commixta twig extracts on ROS generated in Fe3+-EDTA/H2O2 system were investigated by the luminol-dependent chemiluminescence assay. The 50 % ethanol extract among extracts showed the most prominent ROS scavenging activity (OSC50, 0.189μg/mL). The cellular protective effects of extract/fractions of S. commixta twig on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The 50 % ethanol extract and ethyl acetate fraction showed the cellular protective effects against ROS in a concentration dependent manner (5~50μg/mL). The inhibitory effect of S. commixta twig extract on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate (IC50, 113.2μg/mL) and aglycone fraction(IC50, 105.3μg/mL) on tyrosinase showed more remarkable inhibitory effect than arbutin(IC50, 226.88μg/mL), known as the whitening agent. The inhibitory effect of aglycone fraction (IC50, 6.9μg/mL) on elastase was simillar to quercetin(IC50, 6.1μg/mL), flavonoid known as reference compound. These results indicate that extract/fractions of S. commixta twig can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging 1O2 and other ROS, and protect cellular membranes against ROS. S. commixta twig extracts can be applicable to new functional cosmetics for anti-aging products.

This study was performed to analyze the retarded degree of Garaetteok retrogradation added with different ratios 0-15% (w/w) of apple pomace dietary fiber powder (DFP). SEM (×500) showed that air cell size on the Garaetteok surface increased as DFP content increased, whereas control had a compact structure without air cells. The degrees of Garaetteok retrogradation after 3 days at 4 and 25℃ by α-amylase iodine method were 57.44 and 41.55% for control, respectively. On the other hand, those of 15% DFP Garaetteok were 28.38 and 15.05%, respectively. Enthalpy changes (δE) by DSC of control, 10 and 20% DFP Garaetteok after 3 days of storage at 4℃ were 4.41, 4.17, and 3.80 J/g, respectively, whereas those at 25℃ were 2.14, 1.04, and 0.72 J/g. Hardness of 15% DFP Garaetteok was around 48% compared to that of control after 3 days of storage at 25℃. Increasing DFP content from 0 to 15% decreased L color value from 86.2 to 55.1, whereas a and b values increased from -1.9 to 8.9 and from 5.3 to 20.8, respectively. In a sensory intensity test, hardnesses of 15% DEP Garaetteok were significantly different at 1 and 0.1% compared to those of control after production and followed by storage for 3 days at 4℃, respectively.

In this study, we evaluated the anti-oxidative, whitening and anti-wrinkle effect of Tetrapanax papyriferum extract. Tetrapanax papyriferum was extracted by two different solvents which were n-Hexane, ethyl acetate. The anti-oxidant activity was measured by free radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl radical). And the inhibitory activities of tyrosinase for whitening effect and collagenase, elastase for anti-wrinkle were investigated. For anti-oxidant activity, ethyl acetate fraction of Tetrapanax papyriferum extract showed more significant activity than n-Hexane fraction of Tetrapanax papyriferum extract. For whitening activity, n-Hexane fraction of Tetrapanax papyriferum extract exhibited strong inhibition effects compared with reference. Therefore, Tetrapanax papyriferum extract may be useful as a new antioxidant and whitening agent.

In this study, we evaluated the anti-oxidative, anti-wrinkle and whitening effect of Duchesnea indica (Andr.) Focke extract. Duchesnea indica (Andr.) Focke was extracted by two different solvents which were n-hexane and ethyl acetate. The anti-oxidant activity was measured by free radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl radical). And the inhibitory activities of tyrosinase for whitening effect and collagenase for anti-wrinkle were investigated. For anti-oxidant activity and whitening activity, ethyl acetate fraction of Duchesnea indica (Andr.) Focke extract showed more significant activity than n-hexane fraction of Duchesnea indica (Andr.) Focke extract. For anti-wrinkle activity, ethyl acetate fraction of Duchesnea indica (Andr.) Focke extract exhibited strong inhibition effects compared with reference. Therefore, Duchesnea indica (Andr.) Focke extract may be useful as a new antioxidant and anti-aging agent.

Retarding retrogradation of Korean rice cakes(Karedduk) with a mixture of trehalose and Sun-Tender added, after 0, 24, and 48 hr of storage at 5℃, was analyzed by Avrami kinetics. A central composite design was used for arrangement of treatment. The two independent variables selected for retarding retrogradation analysis were amounts of trehalose(x) and Sun-Tender(y). Trehalose was added at 0, 3, 6, 9, and 12% levels, and Sun-Tender added at 0, 0.3, 0.6, 0.9, and 1.2% levels, to dry rice flour. The Avrami exponent(n) for the mixtures of 9% trehalose and 0.3% Sun-Tender, and 9% trehalose and 0.9% Sun-Tender were lower than in the control. The time constant(1/k) for the mixture of trehalose and Sun-Tender was higher than in the control. The effect of retarding retrogradation of Korean rice cakes with added mixtures of trehalose and Sun-Tender showed an increasing trend as the amount of trehalose increased. These results suggest that adding a mixture of 9% trehalose and 0.3% Sun-Tender, or 9% trehalose and 0.9% Sun-Tender to Korean rice cakes(Karedduk) is effective for retarding retrogradation.

Low-density polyethylene (LDPE)와 Styrene-butadiene-styrene (SBS)를 넣은 개질 아스팔트 혼합물은 바인더에 중량 비로 3~6% 첨가하여 여러 가지 특성을 획기적으로 향상시킨 아스팔트 재료이다. 아스팔트 재료의 개질목적은 일반 혼합물의 균 열저항과 소성 변형과 같은 전형적인 약점을 향상시키기 위해서이다. 이 재료들은 많은 장점들을 가지고 있으며 플랜트 적용이 간편하고 현장적용성이 우수한 특정을 가지고 있다. 여러 해 동안의 경험을 통해 습식 개질 아스팔트와 건식 아스팔트 혼합물이 현장에서 실용화할 수 있게 발전되었다. 본 연구에서는 이를 종합적으로 평가하여 그 장단점을 일반 아스팔트 혼합물과 비교 평가하여 LDPE, SBS 개질 아스팔트 혼합물의 특성을 체계적으로 밝히는 것을 본 연구의 목적으로 한다.

목적 : 노인과 청년의 암묵기억과제 수행의 연령차와 의미, 지각처리에 따른 기억과제 수행 정도의 차이를 알아보기 위해 실시되었다. 연구방법 : 본 연구는 청년집단과 노인집단에게 단어어간완성검사(암묵기억과제)와 단어회상검사(외현기억과제)를 실시하여 분산 분석하였다. 의미처리 과제와 지각처리 과제는 각각 학습 단계와 검사 단계로 나누어 실시되었다. 과제 수행 순서는 암묵기억, 외현기억 순으로 이루어졌다. 결과 : 첫째, 청년과 노인 간의 기억수행에 유의한 차이가 있다. 둘째, 청년의 기억검사 수행은 통계학적으로 유의한 차이를 보였으며 노인의 기억과제 수행에서는 통계학적으로 유의한 차이는 없었다.셋째, 기억과제와 처리수준간의 상호작용이 통계학적으로 유의하였다.

본 연구는 국내 현장실정에 적절한 아스팔트 혼합물의 실내노화방법을 개발하기 위한 연구이다. 강제공기순환식 오븐에서 154℃ 2시간의 단기노화를 거친 혼합물로 제작한 공시체를 110℃에서 24, 48, 72, 96시간 동안 장기노화를 시켰다. 또한 노화시간의 증가에 따라 아스팔트 바인더의 노화정도를 측정하기 위하여 GPC 분석을 수행하였다. 본 연구를 통해 노화시간이 길어짐에 따라 대형분자양이 증가하는 것을 확인하였고, 이에 대한 분석으로부터 적절한 인공노화시간의 추정이 가능함을 알 수 있었다. 본 연구에서 수행된 단기노화방법은 다소 과다하나 이를 RTFO와 유사한 수준으로 처리한다면 110℃로 약 48시간 이상 노화를 시키면 PAV 처리와 유사한 수준의 혼합물 노화가능성이 있음을 확인하였다.

본 연구는 154℃로 2시간의 단기노화를 거친 혼합물로 제작한 공시체를 110℃에서 24, 48, 72, 96시간 동안 장기노화를 시켜 아스팔트 혼합물의 노화와 소성변형 저항성을 평가하였다. 혼합물의 노화 시간이 증가함에 따라 강성의 증가로 인한 소성변형 저항성이 증가할 것을 고려하여 변형강도를 이용해 단기노화와 장기노화를 거친 공시체에 대해 소성변형특성을 측정하였다. 또한 노화 시간의 증가에 따른 바인더의 노화 정도를 측정하기 위하여 GPC (Gel-permeation chromatograph) 분석을 통하여 대형분자비율(LMS(%))을 측정하였다. 노화 시간이 길어짐에 따라 LMS(%)가 증가하고 혼합물의 변형강도 값이 커지는 것을 확인하였다. 또한 상관성 분석으로부터 LMS(%)와 변형강도가 상관성이 높은 것으로 나타나 이를 통해 혼합물이 노화되면 소성변형 저항성이 증가됨을 확인하였다. 따라서 LMS(%)의 측정으로 아스팔트 혼합물의 바인더 추출 없이도 소성변형특성을 추정 가능함을 확인하였다.