• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.249-255
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• 2022

The study was conducted to establish a method for the proliferation of hybrid poplar (P. alba × P. glandulosa) clone Bongwha1, an excellent biomass species. It was found that to collect the cuttings of Bonghwa1, it was necessary to use the main stem rather than the axillary branch. Stem growth by green-wood cuttings showed a tendency to decrease as the length of the collected cuttings increased, but the survival rate was low. Therefore, modified leafy stem cutting was attempted to increase the survival rate of the cuttings. In the modified leafy stem cutting method, 4 leaves were included in the cuttings, and especially, cuttings were performed using cuttings containing 2-4 cm xylem parts. Leafy stem cutting increased root growth and the number of stems, as well as the survival rate of hybrid poplar clone Bongwha1 compared to green-wood cuttings. The root growth of the leafy stem cutting poplar was better as there was more xylem part. Using two-year-old nursery stocks, the leafy stem cutting was used to produce about 66 cuttings. This study is expected to contribute to the mass propagation of high-quality nursery stocks.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.2
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• pp.175-180
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• 1997

Beta-carotene and lutein contents in 7 different green leafy vegetables(perilla leaf, mugwort, chwi, lettuce, spinach, leek, and crown daisy) were analyzed by HPLC. The isocratic separation was performed on a ${\mu}-Bondapak$ $C_{18}$ column with a solvent system of acetonitrile : dichloromethane : methanol = 70:20:10. To check the reliability of the method applied, precision and recovery tests were performed. Perilla leaf showed the highest ${\beta}-carotene$ content(12,570 ${\mu}g$ / 100 g), followed by mugwort and chwi, all of those have ${\le}10,000\{\mu}g\{\beta}-carotene$ per 100 g vegetables. Green lettuce, spinach, leek, crown daisy and reddish brown lettuce contained 9,869, 6,689, 5,664, 3,601 and 3,299 ${\mu}g\{\beta}-carotene/100 g$, respectively, Lutein content was the highest in perilla leaf($13,718{\mu}g/100 g$) followed by chwi($11,989{\mu}g/100 g$), mugwort($11,522{\mu}g/100 g$), green lettuce($10,307{\mu}g/100 g$) and spinach($10,115{\mu}g/100 g$). ${\beta}-carotene$ contents in perilla leaf, mugwort, chwi and green lettuce were 47.8~49.6% of total carotenoids, and ${\beta}-carotene$ contents in the other green leafy vegetables analyzed were 37.7~41.4% Vitamin A contents of green leafy vegetables analyzed by HPLC were 2~6 times higher than the vitamin A values shown in food composition tables except crown daisy.

• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.216-222
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• 2017

Antioxidant rich green leafy vegetables including garden spinach leaf, water spinach leaf, Indian spinach leaf, and green leaved amaranth were selected to evaluate the effects of water boiling and oil frying on their total phenolic content (TPC), total flavonoid content (TFC), reducing power (RP), and antioxidant capacity. The results revealed that there was a significant increase in TPC, TFC, and RP in all the selected vegetables indicating the effectiveness of the cooking process on the antioxidant potential of leafy vegetables. Both cooking processes enhanced significantly (P<0.05) the radical scavenging ability, especially the oil fried samples showed the highest values. There is a significant reduction in the vitamin C content in all the vegetables due to boiling and frying except in the Indian spinach leaf. However, the present findings suggest that boiling and frying can be used to enhance the antioxidant ability, by increasing the bioaccessibility of health-promoting constituents from the four vegetables investigated in this study.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.31-36
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• 2023

This study was conducted to evaluate the efficacy of sodium hypochlorite in eliminating Escherichia coli strains from leafy green and stem vegetables, which are frequently sold at community service centers. A cocktail of non-pathogenic E. coli and enterohaemorrhagic E. coli (E. coli O157:H7) was used to artificially contaminate the vegetables (initial numbers of bacteria 7-8 log CFU/g). The contaminated vegetables were soaked in sodium hypochlorite for 5 min and then washed three times with running water. After the treatment, number of viable bacterial cells on the vegetables was estimated. Sodium hypochlorite treatment reduced the E. coli population by 1-2 log CFU/g on leafy green and stem vegetables, a significant reduction from the initial number. Further, sodium hypochlorite showed better antimicrobial efficacy for leaves with a larger surface area, less roughness, and softness. There was no significant difference in the antimicrobial effect between 100 and 200 mg/kg of sodium hypochlorite. Therefore, it is not necessary to increase sodium hypochlorite concentration than the level suggested in the school meal hygiene management guidelines. However, sodium hypochlorite treatment is not sufficient to achieve a safe level of microorganisms on leafy green and stem vegetables since they generally have a high abundance of microorganisms on their surface. Thus, an alternative cooking method for fresh leafy green and stem vegetables in summer should be developed to ensure they are safe for consumption.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.504-514
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• 2001

The contents of total flavonoids, total antioxidant status and superoxide scavenger activity of edible plants were measured. Among twenty one samples of leafy vegetables and teas, mugwort (Artemesia capillaris) and green teas gave high total flavonoids contents, 48.2 mg/g sample and 44.7 mg/g sample, respectively. The highest concentration of total flavonoids among eighty nine samples analyzed was 52.1 mg/g sample from propolis. When samples were tested for total antioxidant status, a kind of groundsel showed the highest Total Antioxidant Status(TAS) value, 13.4 mM among leafy vegetables and teas and green tea gave high TAS value, 11.84 mM. On the other hand, purslane gave the lowest TAS value, 0.01 mM. The superoxide scavenge activity was measured from the extracts of all edible plants. The superoxide scavenge activity of polygonatum(81.1%) and chrysantemum (78.5%) were the highest among leafy vegetables, teas and medicinalplants. On the other hand, ginseng, poria, cassiae semen and dioscoreae rhizoma showed no superoxide scavenge activities.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.2
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• pp.271-277
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• 2012

Ten green leafy vegetables were cultivated from medicinal plant seed. Their nutritional content, taste, appearance and texture were evaluated. Moisture content was $91.23{\pm}0.00%$ in $Saururus$ $chinensis$ (Sc), $90.39{\pm}0.05%$ in $Perilla$ $frutescens$ (Pa) and $66.78{\pm}0.05%$ in $Agastache$ $rugosa$ (Ar). The fat content was 8.89% in $Salvia$ $plebeia$ (Sp) and 0.13% in $Peucedanum$ $japonicum$ (Pj). The protein content was $11.1{\pm}0.00%$ in Ar and $0.54{\pm}0.03%$ in Pj. Total sugar content was $20.06{\pm}0.03%$ in $Geum$ $japonicum$ (Gj), $12.73{\pm}0.03%$ in $Coixlacry$ $majobi$ (Cm) and $1.04{\pm}0.03%$ in $Atractylodes$ $japonica$ (Aj). Medicinal leafy vegetables had higher glucose, sucrose and fructose, but lower maltose. Ascorbic acid content was $33.67{\pm}1.40$ mg% in Sc, $27.91{\pm}2.91$ mg% in Pa and $15.68{\pm}1.09$ mg% in At. Chlorophyll content was higher in $Perilla$ $frutescens$ var. $acuta$ Kudo than other leafy vegetables. The evaluation also showed that Cm, Pa and Aj tasted sweeter and had low acidity.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.289-294
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• 2004

The antioxidant activity of forty two kinds of salad vegetables grown in Korea was evaluated. Methanol extract of freeze-dried vegetable was assayed by radical scavenging activity using 1,2-diphenyl-2-picrylhydrazyl (DPPH) and Fe^{2+}$-catalyzed lipid peroxidation inhibition by TBA method. Total phenolics were determined colorimetrically using Folin-Ciocalteu reagent. The highest radical scavenging activity was expressed by perilla leaf, followed by dandelion leaf, red and green leafy lettuce, of which $IC_{50}$ was less than 0.10 mg/mL. Angelica leaf showed the highest inhibitory action for lipid peroxidation with $95\%$, and then dandelion leaf, water spinach, and perilla leaf inhibited over $80\%$. However, lettuce (Iceberg) and young Chinese cabbage exhibited the lowest antioxidant activity based on both assay methods. Highly positive correlations between antioxidative activities and total phenolics were observed (p < 0.001). The results suggested that salad vegetables, especially perilla leaf, leafy lettuce, dandelion or angelica, could be used for easily accessible sources of natural antioxidants.

• Rapid Communication in Photoscience
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• v.3 no.1
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• pp.25-27
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• 2014

The relative importance of radiation dose, storage time, and temperature in radiation processing of spinach (Spinacia oleracea L.), was evaluated in terms of the postharvest quality through a model study using leaf disks. Physiological activity and chlorophyll and carotenoid contents were measured to represent the postharvest quality (in terms of external appearance) of spinach, a leafy green vegetable. At $22^{\circ}C$ and $30^{\circ}C$, the higher gamma-radiation dose caused a greater decrease in the physiological activity, depending on the storage time of 4 d. However, this decrease was not significant at $4^{\circ}C$ and $15^{\circ}C$. Total chlorophyll and carotenoid contents were substantially decreased by 3 kGy at $15^{\circ}C$, and dose-dependently by 0.5-3 kGy at $22^{\circ}C$. In contrast, the proportion of lutein in total carotenoid was significantly increased in the 2-3-kGy samples only at $22^{\circ}C$, while that of ${\beta}$-carotene was slightly decreased, indicating progression of leaf aging. These data suggest that the unfavorable effect of gamma irradiation on the postharvest quality of spinach could be avoided or controlled by the storage time or temperature rather than the radiation dose. The current study could be available to improve radiation processing of other leafy green vegetables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.492-500
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• 1999

The aim of this study was to assess the association between total vitamin A, retinol and carotene intakes and serum concentration of total carotenoids in Korean male smokers and nonsmokers. Food frequency and nutrient intakes of 64 healthy college students were estimated by the 24 hour recall method and food frequency questionnaire and analyzed by smoking status. Serum total cartenoids and lipid profiles were measured in 28 smokers and 36 nonsmokers. The mean total vitamin A, retinol and carotene intakes of smokers were not significantly different from nonsmokers. However, carotene intakes of the smokers who have smoked more than 5 packyears were significantly lower than those of nonsmokers. Smokers consumed green yellow leafy vegetables more often(P=0.005) and fresh fruits less often(P=0.017) than nonsmokers. The serum total carotenoids of smokers consuming the same amount of retinol and carotene as nonsmokers, 1.79 g/ml, were 17% lower than nonsmokers, 2.15 g/ml(P<0.05). The lipid profiles including total cholesterol, LDL cholesterol, VLDL cholesterol and triglycerides of smokers were not significantly different from nonsmokers, however, the concentration of HDL cholesterol of smokers were significantly higher than that of nonsmokers. The serum carotenoids concentration was positively associated with fruit consumption frequency in smokers, and also was positively associated with green yellow leafy vegetable consumption frequency in non smokers. There were no correlations between dietary and serum carotenoids for smokers as well as nonsmokers. It was concluded that smoking could be inversely related to the serum concentration of carotenoids at constant carotene intakes and smokers might require more carotene to reach the same concentration comparable to nonsmokers.

• Journal of Environmental Science International
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• v.31 no.5
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• pp.405-411
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• 2022

Production of lettuce under indoor cultivation is highly affected by light intensity. In this study, we used shade cloth (commercial black net) to examine the effect of these condition on growth without an associated yield penalty of container-grown lettuce. Four levels of shading treatments (0%, 35%, 55%, and 75% referred to as Cont., S₃₅, S₅₅, and S₇₅ with respect to Cont.) and two lettuce varieties (red and blue) were evaluated. Variety-specific growth responses were observed with respect to different levels of shading treatments. High growth of red lettuce was occurred in Cont. treatment despite plant height and leaf length being higher than Cont. However, under 35% shading treatment blue lettuce was higher than in control plants. The highest root length was observed 0% shading (Cont.) of both varieties. These results reinforce the idea that blue lettuce is the better leafy vegetable rather than red lettuce for indoor cultivation related to lower light intensity environment conditions.