• 한국의류산업학회지
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• 제13권5호
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• pp.778-789
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• 2011

The natural dyeing of silk fabrics with guava leaf extract was investigated. Mixed components of flavonoid and tannin seem to be the components of guava leaf extract. The temperature and time for dyeing of silk fabrics with guava leaf extract were $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. The dyeing equilibrium was shown at the fourth time of repeated dyeing. The highest K/S value was recorded at pH 3. Fe-mordanted fabrics showed the highest K/S value. High K/S values were shown in the post-mordanting of dyed fabrics at $40^{\circ}C$ and the pre-mordanting of dyed fabrics at $90^{\circ}C$. After repeated dyeing and mordanting, various color change occurred with mordant treatment. Surface colors were changed to YR color in alkaline water extract and to Y color in acidic water and ethanol extract, respectively. The washing fastness was level 3-4 for Sn-mordanted fabrics and level 4 for Fe-mordanted fabrics, and the dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was satisfactory with level 3-4. The light fastness was above level 4 only when Fe-mordanting was conducted, and the rest of dyed fabrics was not fast enough. In the antibacterial activity, the powder of guva leaf extract showed 99.9% of high antibacterial activity and Staphylococcus aureus showed 99.6% in dyed fabric. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

• 한국식품조리과학회지
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• 제26권2호
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• pp.171-179
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• 2010

The objectives of this study were to investigate the antioxidative activity of crackers made with a guava(Psidium guajava Linn.) leaf extract harvested in Korea. Guava leaf extraction using boiling water showed significantly higher antioxidative activities than extracting using 70% ethanol based on the higher total phenolic contents, FRAP, and ABTS assays(p<0.05). The crackers containing 1% guava leaf extract, and 0.075% BHT were stored at $63^{\circ}C$ for 7 days for the Schaal oven test, and the oxidative stability(AV, POV), antioxidative activity(DPPH, FRAP, ABTS assay), and sensory evaluation were compared. The crackers containing 1% guava leaf extract were found to have a higher oxidative stability than the control due to a lower acid value and peroxide value after 7 days of storage. The antioxidative activities of the crackers containing 1% guava leaf extract was the highest after 7 days as determined in the DPPH and ABTS assay, and was lower than crackers containing 0.075% BHT after 4 days as assessed by the FRAP assay. In the sensory evaluation, the crackers containing the 1% guava leaf extract had the highest scores in terms of taste, texture, and overall palatability than others at increasing storage time. As a result, the addition of 1% guava leaf extract harvested in Korea increased the antioxidative effect as well as the sensory acceptability of crackers.

• 한국식품영양과학회지
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• 제36권11호
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• pp.1377-1384
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• 2007

본 연구에서는 녹차(Camellia sinensis)잎 추출물, 구아바(Psidium guajava)잎 추출물 그리고 장미 (Rosa hybrida)꽃잎 추출물로 이루어진 식물추출 복합물(PEM381)이 실험동물상에서 제 I 형 알레르기 반응에 미치는 영향을 알아보고자 제 I 형 알레르기 반응을 유발시킨 생쥐를 모델로 류코트리엔류, 프로스타글란딘류 그리고 히스타민 농도 및 호산구의 비강내 침윤 정도를 측정하였다. 그 결과 PEM381은 류코트리엔류의 생합성을 억제할 뿐만 아니라 호산구의 비강내침윤도 억제하는 것으로 나타났다. 그리고 비록 통계학적으로 유의적인 차이는 없었으나 PEM381은 히스타민 방출을 억제하는 것으로 나타났다. 그러나 PEM381에 의한 프로스타글란딘류의 생합성에 미치는 영향은 신뢰할만한 결과를 얻어내지 못했다. 이상의 결과로 미루어 PEM381은 알레르기성 비염, 아토피 피부염 및 기관지 천식 같은 제 I 형 알레르기 질환에 대하여 예방 및 개선에 유용하게 사용될 수 있을 것으로 생각된다.

• 한국식품영양과학회지
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• 제36권2호
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• pp.155-162
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• 2007

본 연구에서는 녹차(Camellia sinensis)잎 추출물, 구아바(Psidium guajava)잎 추출물 그리고 장미(Rosa hybrida)꽃잎 추출물로 이루어진 식물추출 복합물(PEM381)에 대하여 제I형 알레르기 반응 억제 효능 및 생화학적 기전을 밝히기 위하여 COX 억제 활성, LO 억제 활성, compound 48/80에 의한 랫드 복강 비만세포의 탈과립과 히스타민 유리에 미치는 영향 그리고 수동피부아나필락시스 반응 억제효능을 측정하였다. 그 결과 PEM381은 5-LO $IC_{50}$ 값이 $14.11{\pm}0.51ppm$으로 나타났고, COX-1에 비해 COX-2를 선택적으로 억제하는 것으로 나타났다. 또한 PEM381은 compound 48/80에 의한 비만세포의 탈과립과 히스타민 유리를 농도 의존적으로 억제할 뿐만 아니라 수동피부아나필락시스 반응도 억제하였다. 이상의 결과로 PEM381은 알레르기성 비염, 아토피 피부염 및 기관지천식 같은 제I형 알레르기 질환에 대하여 예방 및 치료에 유용하게 사용될 수 있을 것으로 생각된다.

• 한국식품영양학회지
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• 제25권2호
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• pp.317-323
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• 2012

We investigated the quality characteristics of cookies prepared after the addition of various concentration of used guava leaf powder(0%, 1%, 3%, 5%, all w/w) as a substitute for flour. In this study, as guava leaf powder concentration rose, there was a decrease in the water content level. In addition, color, spread factor, hardness and sensory evaluation of the cookies were examined. The results showed that with an increase in guava leaf powder concentration, the L value decreased significantly, while the values for a and b of cookies increased when more guava leaf power was added to cookies. The spread factor of cookies decreased, but the hardness of cookies increased significantly, as guava leaf powder concentration increased. Cookies containing 0% and 3% of guava leaf powder showed a similar sensory evaluation score in terms of color, taste and flavor of the cookies. In the case of texture and overall consumer acceptability, cookies with 3% of guava leaf powder showed the highest score.

• 한국식생활문화학회지
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• 제36권2호
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• pp.210-217
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• 2021

This study evaluated the biological activity and cytoprotective effect of guava (Psidium guajava L.) branch against oxidative stress. The contents of vitamin C, beta-carotene, total carotenoids, quercetin and catechin determined were 26.783, 43.676, 65.083, 58.245, and 8.309 mg/100 g, respectively. To measure antioxidant activity, the guava branch was extracted using various concentrations of ethanol (60, 80, or 100%) and water. The highest content of polyphenols (0.245 mg gallic acid equivalent/mg residue) and flavonoids (0.128 mg cathechin equivalent/mg residue) was found in the 100% ethanol extract of the branch (E100). Moreover, E100 also possessed the highest radical scavenging activities and showed the highest inhibition rate of α-glucosidase (77.692%). E100 was the most effective extract to impart cytoprotectant activity against oxidative stress in HepG2 cells. Taken together, our results determine the promising antioxidant activity of guava branch, and indicate the potential to be applied as a natural antioxidant.

• 한국의류산업학회지
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• 제14권5호
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• pp.866-877
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• 2012

The natural dyeing of hanji cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing were $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics in pre-mordanting. The dyeing equilibrium was shown at the fourth time of repeated dyeing. In the processing of hanji cotton fabrics, K/S value was high when hanji cotton fabric was treated with soybean milk at $90^{\circ}C$. Similar K/S value of dyeing was shown when fabrics were processed with chitosan, regardless of dyeing temperature. High K/S value of dyeing was seen when fabrics processed with gallnut tannin at 40. Fabrics dyed with acidic water extract showed yellowish color. Fabrics dyed with alkaline water extract showed reddish color, and fabrics dyed with ethanol extract showed greenish yellow color. In case of Sn-mordanted fabrics, the washing fastness level was between 3 to 4, and other dyed fabrics showed low fastness. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness of the fabrics was better in dry rubbing than in wet rubbing. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. Hanji cotton fabric maintained certain deodorization in the state of raw fabric. All dyed fabrics showed higher UV protection rate than control fabric.

• 한국의류산업학회지
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• 제14권2호
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• pp.320-330
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• 2012

The natural dyeing of cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing are $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics were dyed in pre-mordanting. The K/S value of dyeing fabrics could be increased with repetitive dyeing and mordanting. Compared to untreated dyed fabrics, the K/ S values of fabrics which had been treated with soybean milk, chitosan and gall nut tannin were increased. The changed surface colors of fabrics that were treated with soybean milk, chitosan and gall nut tannin were Y, YR and achromatic colors. Fabrics dyed with alkaline water extract showed reddish color. Sn-mordanted fabrics dyed with acidic water extract showed vivid yellowish color, and Cu-mordanted fabrics dyed with ethanol extract showed yellowish green color. In case of Sn-mordanted fabrics, the washing fastness was level 4. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was better in dry rubbing than in wet rubbing of the fabrics. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the powder of guava leaf extract and the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.215-220
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• 2007

One of the important functions of skin is protection from harmful environments. Many studies have explored how to prevent skin from wrinkling and the occurrence of pigmentation changes. Skin wrinkling and pigmentation changes could be caused by unusual disruption of connective tissue, the formation of free radicals and ultraviolet radiation. In this study, extracts obtained from 254 different kinds of Jeju medicinal plants were screened for inhibitory effects on tyrosinase and elastase, and for free radical scavenging effects. Four herbs, Phormium tenax, Morus bombycis, Morus alba, and Cudrania tricuspidata, were potent inhibitors of tyrosinase ($IC_{50}$ values 4.62, 5.46, 8.17, and 64.17 ${\mu}g$/mL, respectively). Aleurites fordii [$IC_{50}$: 5.29 ${\mu}g$/mL, 1,1-diphenyl-2-picrylhydrazyl (DPPH)], Distylium racemosum ($IC_{50}$: 6.14 ${\mu}g$/mL), Acer palmatum ($IC_{50}$: 5.44 ${\mu}g$/mL), and Spiraea salicifolia ($IC_{50}$: 5.25 ${\mu}g$/mL) showed good antioxidative effects. Furthermore, Distylium racemosum ($IC_{50}$: 7.51 ${\mu}g$/mL), Diospyros kaki ($IC_{50}$: 15.1 ${\mu}g$/mL), Cornus macrophylla ($IC_{50}:$ 16.59 ${\mu}g$/mL), and Psidium guajava ($IC_{50}$: 40.25 ${\mu}g$/mL) exhibited potent inhibitory effects on elastase. These results suggest that medicinal plants possessing several biological activities may be potent inhibitors of the processes involved in pigmentation increases and aging. Further investigations will focus on in vivo assays and on the chemical identification of the major active components responsible for whitening and anti-aging activity in the screened efficacious extracts.

• The Plant Pathology Journal
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• 제29권3호
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• pp.242-248
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• 2013

In the Northeast of Brazil, expansion of guava crops has been impaired by Meloidogyne enterolobii that causes root galls, leaf fall and plant death. Considering the fact that arbuscular mycorrhizal Fungi (AMF) improve plant growth giving protection against damages by plant pathogens, this work was carried out to select AMF efficient to increase production of guava seedlings and their tolerance to M. enterolobii. Seedlings of guava were inoculated with 200 spores of Gigaspora albida, Glomus etunicatum or Acaulospora longula and 55 days later with 4,000 eggs of M. enterolobii. The interactions between the AMF and M. enterolobii were assessed by measuring leaf number, aerial dry biomass, $CO_2$ evolution and arbuscular and total mycorrhizal colonization. In general, plant growth was improved by the treatments with A. longula or with G. albida. The presence of the nematode decreased arbuscular colonization and increased general enzymatic activity. Higher dehydrogenase activity occurred with the A. longula treatment and $CO_2$ evolution was higher in the control with the nematode. More spores and higher production of glomalin-related soil proteins were observed in the treatment with G. albida. The numbers of galls, egg masses and eggs were reduced in the presence of A. longula. Inoculation with this fungus benefitted plant growth and decreased nematode reproduction.