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        검색결과 88

        1.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To improve the quality of jujube (Zizyphus jujuba Miller var. hoonensis), which is a fruit of health functional, the effect of polyphenol preparation treatment on the fruit characteristics of two cultivars (cv. Bokjo and cv. Sangwang) of jujube was investigated. There was no difference in the height and breast diameter of jujubes tested between the polyphenol treatments and non treatment. Jujube trees treated with polyphenol preparation produced significantly more fruit than untreated in both cultivars. In cvultivar of Bokjo, the polyphenol preparation treatment increased the fruit's fresh weight and dry weight more than two times, respectively, compared to the untreated treatment. Polyphenol preparation tr eatments also changed the leaf characteristics of jujube trees. In the polyphenol-treated trees, leaf thickness tended to be thickest at the top and thinnest at the bottom. Polyphenol preparation treated jujube trees showed no difference in chlorophyll content. Moisture content was slightly higher in the untreatment than in the treatments. Visually, the polyphenol preparation treatment had a dark green color. Jujubes treated with polyphenol preparations showed differences in polyphenol content in fruits. The polyphenol content in both peel and flesh of the treatments were much higher than that of the untreatment. Reducing sugar was contained more in the peel than in the flesh and was higher in the untreatment than in the polyphenol preparation treatments. Treatment with polyphenol preparation showed differences in fruit appearance. As described above, it was found that the treatment of polyphenol preparation changed the leaves, fruit shapes and components of jujube trees. In particular, jujubes treated with polyphenol preparations are expected to contribute significantly to eco-friendly and highly functional jujube cultivation, as they appear to produce many fruits and increase the content of polyphenols and sugars.
        4,200원
        3.
        2022.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of manufacturing temperature on curcuminoid contents and the antioxidant activity of turmeric (Curcuma aromatica Salab.) powder-enhanced nurungji. Two different processes employed turmeric powder (2%): AR (added after rice cooked) and BR (added before rice cooked). AR and BR nurungji samples were prepared by heating cooked rice at 180oC, 200oC, and 220oC for 3 minutes. As a result of the HPLC analysis, the contents of curcumin, demethoxycurcumin, and bisdemethoxycurcumin decreased as the heating temperature increased. Moreover, AR samples showed higher curcuminoids than BR samples. The total polyphenol contents, DPPH, and ABTS radical scavenging ability proportionally increased with the increase of the manufacturing temperature. On the other hand, flavonoid contents were decreased with increasing temperature. These results suggest that the preparation of turmeric powder-enhanced nurungji by AR process at 200oC is preferable to preserving curcuminoid contents and antioxidative activity.
        4,000원
        9.
        2020.12 구독 인증기관 무료, 개인회원 유료
        Green tea polyphenol (–)-epigallocatechin-3-gallate (EGCG) is a potent antioxidant with protective effects against neurotoxicity. However, it is currently unclear whether EGCG protects neuronal cells against radiation-induced damage. Therefore, the objective of this study was to investigate the effects of EGCG on ultraviolet (UV)-induced oxidative stress and apoptosis in PC12 cells. The effects of UV irradiation included apoptotic cell death, which was associated with DNA fragmentation, reactive oxygen species (ROS) production, enhanced caspase-3 and caspase-9 activity, and poly (ADP-ribose) polymerase cleavage. UV irradiation also increased the Bax/Bcl-2 ratio and mitochondrial pathway-associated cytochrome c expression. However, pretreatment with EGCG before UV exposure markedly decreased UV-induced DNA fragmentation and ROS production. Furthermore, the UV irradiationinduced increase in Bax/Bcl-2 ratio, cytochrome c upregulation, and caspase-3 and caspase-9 activation were each ameliorated by EGCG pretreatment. Additionally, EGCG suppressed UV-induced phosphorylation of p38 and rescued UV-downregulated phosphorylation of ERK. Taken together, these results suggest that EGCG prevents UV irradiationinduced apoptosis in PC12 cells by scavenging ROS and inhibiting the mitochondrial pathways known to play a crucial role in apoptosis. In addition, EGCG inhibits UV-induced apoptosis via JNK inactivation and ERK activation in PC12 cells. Thus, EGCG represents a potential neuroprotective agent that could be applied to prevent neuronal cell death induced by UV irradiation.
        4,200원
        10.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A liquid-phase exfoliation of few-layer graphene in tea is considered as one of the alternative approaches for the preparation of environment-friendly graphene. However, the removal of chemically adsorbed tea-polyphenols from graphene is known to be difficult and the application of centrifugation or filtration alone for the purification of graphene against tea-polyphenols is regarded to be almost technically impossible. Notably, a strategy for facile deoxygenation of tea-graphene must be established for a green and economical production of graphene to be realized. In this work, a simple purification method of graphene through the application of merely a household bleach ( Clorox®) after the pre-exfoliation in black tea has been proposed. It has been found that the carbon–oxygen (C/O) value for graphene increases from 2.7 to 8.1 while the values of C–OH, C–O–C and C=O region in the C1s spectrum of graphene decrease significantly after being purified in bleach for 5 h. The stretching and shift of C–OH, C=O and C–O–C at 3468 cm−1, 1637 cm−1 and 1008 cm−1 from IR spectrum of purified graphene seems to be in agreement with the produced data from the XPS and Raman spectroscopy. Despite the enhanced ID/IG of Raman from the hybridization of sp2 by hydroxylation, the deoxygenation of tea-graphene does not negatively affect the electrical performance since the sheet resistance was impressively reduced to 193 Ω from 2.1 kΩ. It is believed that this photo-Fenton-inspired purification strategy would assist in the washing issue of polyphenol-stabilized graphene for various future electronic applications.
        4,000원
        11.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 꽃송이버섯을 4종의 유산균(Lactobacillus plantarum subsp. plantarum, L. acidophilus, L. helveticus, L. delbrueckii subsp. bulgaricus)을 사용해 발효를 하였다. 발효된 꽃송이버섯 발효물을 항산화 활성(DPPH free radical scavenging activity, ABTS radical scavenging activity, Hydroxy radical scavenging activity), SOD activity, 총 폴리페놀 함량(TPC), HPLC 분석, protease 활성을 동해 발효 전 후 생리활성 변화를 확인하였다. 꽃송이버섯 발효물의 항산화 활성은 IC50 28.09-64.46 μg/ mL, SOD 활성은 IC50 15.75-39.42 μg/mL, TPC 는 57.66-100.43 GAE μg/mL 와 85.25-110.68 μg/mL 로 확인되었다. 꽃송이버섯 추출물의 항산화 활성보다 약 8배 이상 증가된 결과로 확인되었다. 또한 꽃송이버섯 발효물의 HPLC 분석 결과는 ascorbic acid, gallic acid, chlorogenic acid의 함량이 높게 확인되었으며, protease 활성 또한 발효물의 활성이 높은 것으로 확인되었다. Lactobacillus 균주들의 작용에 의하여 꽃송이버섯이 발효 되면서 폴리페놀류가 증가하여 생리활성이 꽃송이버섯 추출물에 비해 증가한 것으로 추측된다. Lactobacillus 균 중에서 L. helveticus 균주로 발효된 꽃송이버섯 발효물은 가장 높은 활성을 나타냈으며, 꽃송이버섯을 발효하는데 있어 L. helveticus 균주가 가장 적합한 균주로 확인되었다.
        4,000원
        13.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dipalmitoyl phosphatidyl choline(DPPC), Polyphenol 유도체, 그리고 Hematoxylin-Eosin은 5분 동안 산성 상태에서 직접 초음파 처리하여 명확한 표준용액을 제공했다. 25 ℃에서 DPPC 계의 레시틴소포에서 폴리페놀유도체의 흡수특성은 흡수분광학에 의해 분석하였다. 레시틴소포에서 단량체와 이량체 사이의 폴리페놀유도체의 평형은 폴리페놀유도체의 저농도에서 존재했지만 올리고머는 레시틴소포 의 고농도에서 소포안에 형성되었다. 폴리페놀유도체의 일정한 농도에 Bacteriorhodopsin(BR)을 첨가함으로써 DPPC의 상전이동안 폴리페놀유도체의 흡수비율(α/β)이 감소되었다. 기둥이 있는 곳에 라멜라 소포와 uni- and multilamella 응집체의 혼합물이 존재한다. 용출된 기둥과 혼합물사이의 속도 차이가 관찰되었으므로 기둥 용출된 라멜라반응 보다 촉매 효과를 나타냈다. DPPC 및 폴리페놀유도체에 대한 가수분해의 상전이 온도는 DPPC 및 폴리페놀유도체 보다 높게 측정되었다.
        4,000원
        14.
        2018.04 구독 인증기관·개인회원 무료
        감자를 마이크로웨이브 콜드 플라스마(microwave-powered cold plasma, MW-CP)로 처리한 후, 처리된 감자 내 polyphenol oxidase (PPO) 저해에 있어 표면적 대 부피 비의 영향을 관찰하였고, 형광 측정을 통해 단백질 구조의 변화를 관찰하였으며, 처리의 pH 및 저장 중 색도와 갈변도의 변화를 연구하였다. 또한, 감자에서 추출한 PPO 시료를 MW-CP 처리하여 Weibull model을 이용한 처리 시간에 따른 효소 활성을 예측하였다. MW-CP 형성 가스로 공기(O221%/N2)를 사용하였고, 667 Pa 압력에서 처리 전력 900 W로 40분 동안 감자를 MW-CP 처리하였다. 감자에서 추출한 PPO 시료는 처리 전력(500, 600, 800, 그리고 900 W)과 처리 시간(0, 10, 20, 30, 그리고 40분)을 다르게 하여 MW-CP 처리하였다. 감자의 표면적 대 부피 비가 7.13과 9.00일 때, PPO의 잔존 활성도는 각각 72.4와 58.9%로 표면적대 부피 비가 클수록 높은 저해 정도를 보였다(p<0.05). MW-CP 처리한 감자는 무처리군보다 유의적으로 낮은 형광강도를 보여(p<0.05), 단백질 구조의 변화로 인해 PPO의 활성이 저해되었음을 알 수 있었다. MW-CP 처리 전후 시료의 pH는 각각 6.5 ± 0.1과 6.5 ± 0.0으로 유의적인 차이를 보이지 않았으며(p>0.05), 감자의 명도는 처리 전보다 후가 더 높았고(p<0.05), 저장 시간이 지날수록 낮아졌다(p<0.05). 적색도와 황색도는 MW-CP 처리 전후의 변화가 없었으며, 황색도는 저장 시간이 지나도 유의적인 차이를 나타내지 않았다(p>0.05). MW-CP 처리된 감자의 갈변도는 처리되지 않은 감자보다 더 낮은 값을 보여(p<0.05), 색 관찰을 통해 MW-CP 처리가 감자의 갈변을 지연시킴을 알 수 있었다. Weibull model의 R2값은 처리 전력이 500, 600, 그리고 800 W일 때 각각 0.84, 0.76, 그리고 0.80으로 PPO 저해 예측에 적합함을 알 수 있었다. 본 연구를 통해 MW-CP 처리가 감자의 PPO를 저해시킬 수 있는 기술로서의 가능성을 확인하였다.
        15.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        피카오프레토 등 복합물의 개별인정 시험법인 총 폴리 페놀 시험법에서 Folin-phenol 시약 선정, 발색시약인 35% 탄산나트륨의 반응시간 및 온도, 시료량 등을 비교 실험 하여 총 폴리페놀에 대한 표준화된 시험법을 확립하였다. 총 폴리페놀의 표준화된 시험법의 밸리데이션을 수행한 결과 회수율은 102.3~112.4%, 정밀도의 표준편차는 0.81~ 3.18%였으며 검량선의 직선성은 결정계수(r2)가 0.999이상 을 나타냈고 검출한계는 5 μg/mL, 정량한계는 15 μg/mL 이었다. 유통제품에 대해 표준화된 총 폴리페놀 시험법의 적용성 검토를 위해 1건의 검체를 수거하여 분석한 결과, 총 폴리페놀 표시 함량 대비 105.6%로 적합하였다.
        4,000원
        17.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 인터넷 쇼핑몰에서 유통되는 컬러푸드 중 블랙푸드 76건을 대상으로 폴리페놀 17종 및 안토시아닌 5종을 동일한 전처리 방법으로 HPLC, HPLC-MS/MS 분석하여 정량 및 정성시험을 실시하였다. 분석대상 폴리페 놀은 gallic acid, protocatechuic acid, chlorogenic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, t-ferulic acid, t-cinnamic acid 등 9종의 phenolic acid와 (+)catechin, syringic aldehyde, rutin, epicatechin gallate, naringin, luteolin, naringenin, kaempferol 등 8종의 flavonoid 로 총 17종의 폴리페놀을 동시분석 하였고, 안토시아닌은 delphinidin-3-glucoside, delphinidin-3-rutinoside, cyanidin- 3-galactoside, cyanidin-3-glucoside, cyanidin-3-arabinoside 등 5종을 동시분석 하였다. 폴리페놀 17종의 총 함량은 서 리태 255.1 ± 7.5 μg/g, 서목태 275.8 ± 5.3 μg/g, 흑미 78.5 ± 4.6 μg/g, 흑임자 75.8 ± 3.2 μg/g, 블루베리 143.3 ± 5.5 μg/ g, 아로니아 195.2 ± 4.9 μg/g, 블랙커런트 131.6 ± 3.2 μg/g 로 나타나 서목태 > 서리태 > 아로니아 > 블루베리 > 블랙 커런트 > 흑미 > 흑임자 순으로 높은 함량을 나타냈다. 안 토시아닌 5종의 총 함량은 서리태 82.4 ± 17.2 μg/g, 서목 태 95.2 ± 6.1 μg/g, 흑미 74.1 ± 9.7 μg/g, 흑임자 불검출, 블 루베리 110.8 ± 1.9 μg/g, 아로니아 218.9 ± 6.1 μg/g, 블랙커 런트 209.7 ± 4.0 μg/g로 나타나 아로니아 > 블랙커런트 >블 루베리 > 서목태 > 서리태 > 흑미 순으로 높은 함량을 나타 났다. 본 실험결과 폴리페놀은 서목태, 안토시아닌은 아로니아가 가장 높은 함량을 나타내었으며 향후 유색 농산물 을 활용한 기능식품 개발이 필요한 것으로 판단된다.
        4,000원
        18.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted in an effort to investigate the effect of Maillard reaction products (MRPs) on enzymatic browning of burdock and their anti-oxidant activity. The MRPs were prepared by heating glucose and amino acids at 90°C, which served to produce a strong inhibitory effect on burdock polyphenol oxidase. As the reaction time of the solution containing glucose and amino acid increased at 90°C, the production of MRPs increased and intensity of the brown color deepened. When MRPs were prepared by heating at 90°C for five hours, the absorbance of MRPs from glucose and lysine was 6.44, while those of glucose and glycine was 1.95. The MRPs synthesized from the glucose and lysine also reduced the pH of MRPs from 5.60 to 4.51, but those from glucose and glycine decreased slightly from 5.57 to 5.33. The Michealis-Menten constant value (Km) of burdock PPO with pyrocatechol as a substrate was 16.0 mM, and MRPs were a non-competitive inhibitor against burdock PPO. The anti-oxidant activity of MRPs was measured by evaluating its radical scavenging activities of DPPH radicals, ABTS radicals and reducing power. The color intensity of MRPs produced by lysine and glucose were deeper than that produced by glucose and glycine. It was also found that MRPs produced from glucose and lysine exhibited stronger anti-oxidant properties than those produced by glucose and glycine.
        4,000원
        19.
        2017.10 구독 인증기관·개인회원 무료
        Honey production from approximately 1.7 million colonies owned by around 21 thousand beekeepers was almost 36 thousand M/T in Korea. Pollen has used as a food and medicine from before the Joseon Dynasty period in Korea. Pollen grains such as acorn (Quercus acutissima), actinidia (Actinidia arguta) and green tea (Camellia sinensis) are popular in the markets in Korea. But stiff pollen wall hindered dissolution of polysaccharides and lowered extraction efficiency. In the present study, we measured the antioxidant activity and the total polyphenol content from the pulverized and lyophilized green tea pollen grains inoculated with 6 kinds of fungi to confirm the husk removal effect. The total polyphenol content of green tea pollens was highest in lyophilized pollen medium inoculated with Armillaria mellea, and was lowest in pollen inoculated with Lentinula edodes. Total polyphenol content of the lyophilized pollen was higher than that of the refined pollen and the pulverized pollen in green tea pollen germinated with A. mellea. The total polyphenol content of the lyophilized green tea pollens germinated with A. mellea was 1.4-fold higher than that extracted with water. Measurement of antioxidant activity using the DPPH free radical scavenging method showed that the lyophilized green tea pollen grains germinated with A. mellea had the highest and that germinated with L. edodes was lowest in antioxidant activities. The lyophilized green tea pollen grains germinated with A. mellea was 2 to 4 times higher than that extracted with water in the antioxidant activity of DPPH free radical scavenging. Many germinated cells were formed around pore of green tea pollen inoculated with L. edodes, while those were formed at the end of hyphae derived from green tea pollen grains inoculated with A. mellea.
        20.
        2017.10 구독 인증기관·개인회원 무료
        In the present study, four edible mushrooms, Lentinula edodes, Agaricus bisporus, Pleurotus ostreatus, and Pleurotus eryngii, were air-dried or freeze-dried for a certain period of time. After finely ground the materials, their beta-glucan contents were measured. Beta-glucan is a polysaccharide of plant and fungal cell wall and also a dietary fiber. It has an effect on stimulating immune cells and decreasing cholesterol. In the mushroom materials used in this study, beta-glucan contents were measured as 11-16%. Among them, P. ostreatus represented the highest contents, 16%. The authors also examined the contents of polyphenol, which is a phenolic compound known to have antioxidant activity. The polyphenol concentrations of the selected mushrooms were measured in 1 mg/ml of each sample prepared by hot-air drying and freeze-drying, respectively. As a result, 28-32 mg/ml of polyphenol was measured in hot air dried samples of P. ostreatus. In P. eryngii, air-dried samples had 6 mg/ml more polyphenols than freeze-dried ones, while in P. ostreatus, the former had 10 mg/ml more than the latter, indicating that the polyphenol contents in mushrooms can be changed by the different drying treatments. In other words, for P. eryngii and P. ostreatus, hot-air drying is more suitable processing method than freeze-drying in the light of physiological activity.
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