• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.309-315
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• 2009

Maintenance of adequate soil water content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement for precision irrigation would allow efficient supply of water to crops, thereby resulting in minimization of water drainage and contamination of ground water. This research reports on the characterization of spatial and temporal variations in water contents through three different textured soils, such as loam, sandy loam, and loamy sand, when water is applied on the soil surface using an one-line drip irrigation system and the soils are dried after the irrigation stops, respectively. Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30cm depths. Spatial variability in water content for each soil type was strongly influenced by soil textural class. There were big differences in wetting pattern and the rate of downward movement between loam and sandy loam soils, showing that the loam soil had a wider wetting pattern and a slower rate of downward movement than did the sandy loam soil. The wetting pattern in loamy sand soil was not apparent due to a low variability in water content (< 10%) by a lower-water holding capacity as compared to those measured in the loam and sandy loam soils, implying that the rate of water drainage below a depth of 30cm was high. When soils were dried, there were highly exponential relationships between water content and time elapsed after irrigation stops ($r^2$${\geq}$0.98). It was estimated that equilibrium moisture contents for loam, sandy loam, and loamy sand soils would be 17.6%, 6.2%, and 4.2%, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.144-150
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• 2014

Yams (Dioscorea spp), which are edible or medicinal tuber crops, are a important crop in South Korea. Yams require a high level of soil fertility. The various cultural practices such as fertilizing and plowing were tested for marketable tuber production in Chinese yam (Dioscorea opposita). Tuber yield was also affected by organic matters in soil. Application higher level of organic matters result in increased each tuber weight and tuber yield per unit area. The nutrient absorption quantity of the plant such as nitrogen, phosphoric acid, calcium and potassium was increased from 100~120 days after planting, which time to begin tuber enlargement. The tuber yield was increased when the fertilization increased in quantity. Total yield and marketable ratio were the highest in 31~32 kg/10a of nitrogen fertilizer. From above result, income become larger with increase of marketable yield and quality improvement at 63% (27 kg/10a) level of conventional N fertilization (43 kg/10a). The tuber yield was not significantly different between with in various application level of potash fertilizer. Tuber size and weight decreased accordingly to decreased fertilizing level, so the rates of small tubers increased greatly at cultivation without chemical fertilizer. In considering the accumulation rates of allantoin in Chinese yam tubers, the apt harvest season was after October. The allantoin quantity of it was not influenced with nitrogen fertilizing. Moreover it was advantageous with decrease of chemical fertilizer and appropriate fertilizing in soil environment protection. Commercial tuber's number and yield were increased in trenching before planting with trencher compared with rotavating with tractor.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.358-365
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• 2011

Lespedeza cuneata G. Don is a plant commonly grown in Asian countries, which has been widely used as an oriental medicinal herb to treat diabetes, diarrhea and various other inflammatory diseases. The phenolics of dry leaves of L. cuneata G. Don were extracted by using 80% (v/v) aqueous methanol in assistance with homogenization and sonification. The phenolic extract and its five different fractions (n-hexane, chloroform, ethyl acetate, n-butanol, and water) were used to evaluate the levels of total phenolics, total flavonoids, and antioxidant capacity as well as the inhibitory effect of tyrosinase activity. Ethyl acetate fraction (1 g) had the highest levels of total phenolics at 240.8 mg gallic acid equivalents (GAE), total flavonoids as 90.4 mg catechin equivalents (CE) as well as antioxidant capacity at 523.4 mg vitamin C equivalents (VCE) on ABTS assay and 329.5 mg VCE on DPPH assay among fractions. One g of water fraction contained total phenolics at 133.1 mg GAE, total flavonoids at 34.5 mg CE, and antioxidant capacity at 333.4 mg VCE for ABTS assay and 313.2 mg VCE for DPPH assay. Inhibition of tyrosinase activity of water fraction at 300 ${\mu}g{\cdot}mL^{-1}$ was at 47.2% and 21.1% for L-tyrosine and L-DOPA as its substrate, respectively. On the other hand, ethyl acetate fraction at 300 ${\mu}g{\cdot}mL^{-1}$ showed tyrosinase inhibition of 10.2% for L-tyrosine and 11.9% for L-DOPA. These results suggested that the phenolics from dry leaves of L. cuneata G. Don may be utilized as a potent source of antioxidants and skin whitening agents.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.181-188
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• 2014

The objective of this study was to analyze the microbiological hazards of Astragalus membranaceus Bunge on the post-harvest processing. Samples from processing equipments (cleaner, water, cart, table, tray and packaging machine), personal hygiene (hand) and harvested crops (before washing, after washing, after sorting, and after drying) were collected from four farms (A, B, C, and D) located in Chungchengbuk-do, Korea. The samples were analyzed for sanitary indication bacteria and pathogenic bacteria. First, total aerobic bacteria and coliform in processing facilities were detected at the levels of 0.93~4.86 and 0.33~2.28 log CFU/$100cm^2$ and/mL respectively. In particular, microbial contamination in hand (5.43~6.11 and 2.52~4.12 log CFU/Hand) showed higher than processing equipments. Among the pathogenic bacteria, Bacillus cereus was detected at the levels of 0.33~2.41 log CFU/$100cm^2$, 1.48~3.27 log CFU/Hand and 0.67~3.65 log CFU/g in equipments, hands, and plants and Staphylococcus aureus were detected in cleaner, table, hand and harvested crops (before washing and after sorting) by qualitative test. Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. were not detected. These results indicated that personal hygiene and processing equipments should be managed to reduce the microbial contamination of A. membranaceus Bunge. Therefore, management system such as good agricultural practices (GAP) criteria is needed for hygienic agricultural products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1761-1768
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• 2010

Hypoglycemic effect through activity inhibition of $\alpha$-glucosidase and $\alpha$-amylase was evaluated using leaves of Eleutherococcus senticosu, Eleutherococcus gracilistylus, Eleutherococcus sieboldianus and Eleutherococcus sessiliflorus which belong to Acanthopanax sessiliflorus genus. As a result of measuring $\alpha$-glucosidase activity inhibition, extract of Eleutherococcus gracilistylus showed around 43.38% of activity inhibition compared with acarbose and extract of Eleutherococcus senticosu showed 41.24% inhibitory effect. As a result of measuring $\alpha$-amylase activity inhibition, acarbose showed 73.25% of activity inhibition in 10 mg/mL concentration, and the extract of Eleutherococcus senticosu leaves showed 91.90% higher activity inhibition compared with acarbose. Also, after subjects in a model were induced diabetes with streptozotocin (STZ) intake plant extract from Acanthopanax sessiliflorus for 2 weeks, effect of improving blood glucose level and fat was examined. In all groups with specimen, Eleutherococcus senticosu (T1), Eleutherococcus gracilistylus (T2), Eleutherococcus sieboldianus (T3) and Eleutherococcus sessiliflorus (T4), blood glucose level was significantly decreased compared with that in control group (C). In an experiment of examining changes in fat concentration in blood, total cholesterol content increased in a control group compared with a normal, while in T1, T3 and T4, it decreased significantly compared with the control group. As for HDL-cholesterol, it significantly increased in all diabetes induced groups compared with the normal group, and in T3, it increased the most significantly by 55.61% compared with the control group. In case of LDL-cholesterol, specific difference between the normal group and the control group was not found; however, significant increase was detected in T2 and T3, whereas in T1 and T4, it decreased significantly compared with the control group. As for triglyceride, its concentration increased in the control group like total cholesterol. It decreased 60.16% in T3, 60.80% in T4 and 50.16% in T1 compared with the control group. As a result of measuring the concentration of triglyceride in extracted liver, the control group showed significant increase compared with the normal group, whereas T1 and T2 showed significant decrease compared with the normal group. The above results show that extracts from Acanthopanax sessiliflorus genus are effective for hypoglycemic and improving fat metabolism due to diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1397-1403
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• 2011

Epimedium koreanum Nakai is a wild medicinal plant commonly consumed in South Korea due to its health beneficial effects. In the present study, the antioxidative, antimutagenic and immunological activities of E. koreanum Nakai extracts were investigated for their use in food. The yields of icariin compounds from the ethanol extract as well as the ethyl acetate, butanol, hexane, water, and chloroform fractions of E. koreanum were 27.9, 2.5, 1.7, 1.4, and 1.3 ${\mu}g/g$, respectively. The icariin components (295.5 ${\mu}g/g$) were collected from the ethyl acetate fraction by thin layer chromatography (TLC) and analyzed via high performance liquid chromatography (HPLC). The antioxidant activities of each fraction were as follows: ethyl acetate (49.0 ${\mu}g/mL$), butanol (59.2 ${\mu}g/mL$), hexane (119.8 ${\mu}g/mL$), water (122.0 ${\mu}g/mL$), and chloroform (138.5 ${\mu}g/mL$), based on $RC_{50}$ ${\mu}g/mL$. Icariin, isolated and identified as the main component, showed strong antioxidant activity with a $RC_{50}$ value of 15.3 ${\mu}g/mL$, which was higher than those of ascorbic acid (19.5 ${\mu}g/mL$) and ${\alpha}$-tocopherol (18.2 ${\mu}g/mL$). In an Ames test, none of the fractions produced mutagenic effects on Salmonella Typhimurium TA98 and TA100. In an immunomodulating activity test, the effects of E. koreanum Nakai on B cells (Rhamos) and T cells (Jurkat) were investigated. These results show that the growth and viability of B and T cells were increased by isolated icariin components for 1.27 and 1.28 fold, respectively. These results also provide preliminary data for the development of E. koreanum Nakai as an edible food material.

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.283-290
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• 2008

The Siberian ginseng and Eucommia are a kind of medicinal plant with powerful anti-oxidant activity. An experiment was conducted to investigate the effect of Siberian ginseng leaf and Eucommia leaf at level of 0.5% and 1% per feed in Ross commercial broiler for 4 to 35 days of age on performance, organ weight, blood biochemical profiles and telomere quantity. Chickens consuming diets containing 1% Siberian ginseng had higher feed conversion ratio than the other treated chicken during experimental period whereas no significant differences were detected in body weight, weight gain and feed intake. The weight of bursa of fabricius was significantly increased in chickens with dietary supplementation compared with chickens fed control but this was not seen in liver, spleen and thymus. In blood biochemical profiles, chickens with dietary supplementation had higher concentration than chickens fed control in triglyceride, cholesterol and glucose. The concentration of aspartate aminotransferase, alanine aminotransferase, albumin and total protein, however, was not significantly different between dietary supplemented chickens and control chickens. The relative amount of telomeric DNA of lymphocytes in chickens with dietary supplementation was significantly higher than that of control chickens but the difference was not found in liver, heart and testis tissues. In conclusion, dietary supplementation of Siberian ginseng and Eucommia in broiler improved immune activity and telomere length without decreasing chicken growth performance.

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.267-274
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• 2008

There are many kinds of anti-oxidant materials in natural plant resources. The Siberian ginseng and Eucommia are well known as anti-oxidant and medicinal plants. To investigate the effect of their anti-oxidant-like activity on telomere quantity and egg quality, diets containing Siberian ginseng leaf and Eucommia leaf at 0.5% and 1% were given Hyline Brown commercial laying hens during two periods of age: 20 to 30 wks and 60 to 70 wks. The amount of telomere in lymphocyte, liver, ovary, heart and lung was analyzed by quantitative fluorescence in situ hybridization using telomeric DNA probe. Egg weight, albumin height, Haugh unit, egg yolk color, egg shell color, egg shell thickness, egg shell weight and egg shell density were measured to analyze egg quality. The chickens consuming diets Siberian ginseng and Eucommia had higher telomeric DNA in lymphocytes than control chickens in younger layers whereas no significant differences were detected in all target cells analyzed from older layers. Egg quality was increased in younger hens with dietary supplementation as determined by egg weight, albumin height and Haugh unit but there were no effects in older hens. These results imply that dietary supplementation of Siberian ginseng and Eucommia in layers improves bio-activity and egg quality at early laying stage.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.93-100
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• 2011

Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.51-57
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• 2018

The objective of this study was to identify beauty food activity of Polygala japonica Houtt., which were widely used as a folk medicinal plant to treat inflammatory diseases. Both hot water and 50% ethanol extract of P. japonica Houtt. were evaluated for their anti-oxidant, whitening, anti-wrinkle and anti-inflammatory effect based on their phenolic concentration. To measure anti-oxidant activity, four experiments were carried out. 1,1-diphenyl-3-picrylhydrazyl, 2,2-azinobis (3-ethylbenzothia-zoline-6-sulfonic acid) and thiobarbituric acid reactive substances all showed more than 80% efficacy in both hot water and 50% ethanol extract of P. japonica Houtt. and likewise antioxidant protection factor value more than 2. To investigate the whitening effect of P. japonica Houtt., the inhibition effect of tyrosinase on hot water and 50% ethanol extract was inhibited by 12.46 and 22.10%, respectively. To examine the anti-wrinkle effect, the inhibition effect of elastase and collagenase on hot water and 50% ethanol extract were inhibited by 28.28, 58.36% and 59.73, 78.90% respectively. To investigate the anti-inflammatory effect and moisturizing effect by hyaluronidase inhibitory effect, hot water and 50% ethanol extract were 35.65 and 86.80%, respectively. The result of all the above experiments show values at a concentration of $200{\mu}g/mL$, and based on these experimental results, P. japonica Houtt. can be expected as a functional material in beauty foods.