• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.307-316
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• 2007

Yellow poplar (Liriodendron tulipifera L.) has low germination rate relatively other species, so the seedling production of Yellow poplar is a hard task. Accordingly this study was conducted to determine the optimal germination conditions for healthy seedling production and to promote survival rate after afforestation. Gemination percentage was examined at different media and seed covering materials using planting flats in the greenhouse. The best germination percentage was observed in sand for media and compound soil for covering materials. But it was time to transplant, seedlings became a poor character (i.e. height, root length, number of root, dry weight) in sand for media. In order to produce healthy seedlings, each different medium was compounded with TKS-2 (this is a gardening bed soil.) in the ratio 1:1 (v/v.), and compared two conditions. Quality of seedling was better than not mixed TKS-2 into each medium. Transplanting seedlings from greenhouse to nursery grew up rapidly 2 months later (early in August~early in October). Growth amount during two months corresponded to 85.6% and 71.3% in total growth amount of height and diameter at root collar, respectively. In the case of the competition-density effect on yellow-poplar seedlings, direct seedling produced the maximum 35 standard seedlings above 8 mm of root collar diameter per $m^2$, while transplanting seedling produced the maximum 64 standard seedlings per $m^2$. And produced seedlings of two way were significantly different rootlet while axial root and lateral root was not significantly different.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.360-367
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• 2015

The present study investigated the habitats of Korean fir trees (Abies koreana E. H. Wilson) on Mt. Baekwun (Baekwun-san), determined the current distribution, quantified the contribution of biological and non-biological environmental factors affecting the distribution, derived actual and potential habitats, presented a plan for the establishment of protected areas, applied RCP 8.5 climate change scenario to analyze the effects of climate change on the future distribution of Korean fir trees, and predicted future potential habitats. According to the results of the study, 3,325 Korean fir trees (DBH >= 2.5 cm) inhabited Mt. Baekwun, and their distribution area was approximately 150 ha. Populations of Korean fir trees were confirmed to exist at an altitude of 900 m above sea level and were distributed up to 1,200 m. Based on potential distribution, areas appropriate for habitation by Korean fir trees were analyzed to be 450 ha, three times the current distribution area, with a focus on Sang Peak (Sang-bong), Eokbul Peak (Eokbul-bong), Ddari Peak (Ddari-bong), and Dosol Peak (Dosol-bong). The forest stands near Sang Peak, the main peak, were evaluated as those with the most appropriate potential for the habitation of Korean fir trees, and populations of the trees tended to prefer the northern slope rather than the southern slope. When climate change scenario RCP 8.5 was applied and future potential distribution was analyzed, the habitats were expected to decrease in area to 20 ha by 2050, with a focus on Sang Peak, and areas appropriate for habitation were predicted not to exist by 2080. Judging from such results, as global warming accelerates, the habitats of Korean fir trees are clearly expected to move from lowlands to highlands.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.390-396
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• 2015

This study was carried out in order to closely examine quality index by shading level of 2-year-old (1-1 seedling) container seedling of Daphniphyllum macropodum which is known as the species of having shade tolerance that is evergreen broad leaved tree in the warm temperate region. The shading treatment was regulated with the shading level of full sunlight, and 35%, 55%, 75%, 95% of full sunlight. As a result of surveying growth according to the shading level, both height and root collar diameter were surveyed to be the highest with 45.1 cm and 8.22 mm, respectively, under 75% of shading. The next was surveyed to be 43.2 cm & 8.05 mm and 42.5 cm & 7.98 mm, respectively, in order of 35% and 55% in shading. Leaf, shoot, root, and whole dry mass production were the highest under 75% of shading. The next was higher in leaf, stem, and whole dry mass production under 55% of shading. A root was higher under 35% of shading in the next. H/D ratio was the range of 5.29~5.35 under the 35~75% shading that showed the relatively high height and root collar diameter. T/R ratio was the lowest with 1.17 under 35% of shading. It was 0.41 under 95% of shading as for LWR, 0.24 under 75%-95% of shading as for SWR, and 0.46 under full sun and 35% shading as for RWR. QI was the highest with 3.74 under 75% of shading. As a result of surveying the whole experiment, it is concluded that the production of D. macropodum seedling is more effective under 75% shading

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.759-765
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• 2012

This study was performed to investigate improvements in diabetes mellitus by extracts of yacon in streptozotocin (STZ)-induced diabetic rats. Fifty rats were divided into a normal group and four experimental groups. STZ (45 mg/kg) was injected intraperitoneally to induce type I diabetes in the four experimental groups. Yacon extracts were administered for 5 weeks. Forty-five ICR mice were also divided into one positive control group and four experimental groups for the oral glucose tolerance test (OGTT) after fed yacon extract. The control group did not eat any yacon extracts, while Group 1 (GI) was fed 125 mg/kg of yacon extracts, Group 2 (GII) was fed 250 mg/kg of yacon extracts, and Group 3 (GIII) was fed 500 mg/kg of yacon extracts. After treatment for 5 weeks, blood glucose in GIII group showed decreased tendency at the 5 week. In OGTT by glucose, the glucose level of yacon treatment group in diabetic rats was significantly decreased compared to the glucose level of the control group, but there was no difference in OGTT by maltose. In ICR mice, the glucose level of the experimental group in OGTT by maltose was significantly decreased compared to the control group. The area of the islets of Langerhans was increased by yacon treatment in a dose-dependent manner on diabetic rats. Insulin concentration of the GIII group was also decreased compared to the control group, while the concentration of fructosamine, total cholesterol, and triglycerides in serum showed no difference. OGTT by glucose or maltose in ICR mice or diabetic rats, area of the Islets of Langerhans, and insulin concentration improved. Yacon treatment may be a useful therapeutic and preventive strategy for diabetes mellitus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.376-382
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• 2012

This study examined the effects of acorn (Quercus. acutissima CARR.) jelly powder (0%, 25%, 50%, and 75%) and acorn extract (0%, 0.1%, 0.5%, and 1.0%) addition on the quality characteristics of hardtack. In the sensory test, acorn jelly powder added group scored 50% higher than the other added group. Regarding hardtack color, L (lightness) and b (yellowness) values decreased with increasing acorn powder and acorn extract addition. Hardness of hardtack increased with added acorn jelly powder, but no significant difference was observed with acorn extract. The taste and texture of the hardtack 0.1% acorn extract added group significantly increased. Overall, preferences decreased with increasing acorn extract but not significantly. In conclusion, the results of this study suggest that addition of 50% acorn jelly powder in combination with addition of less than 0.1% acorn extract to hardtack was the most desirable.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.434-442
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• 2015

The process of cultivation and production of oak mushroom (Lentinula edodes (Berk.) Pegler) on sawdust surface beds were investigated. Sawdust surface bed cultivation is the method by which oak mushrooms are cultured and produced on sterilized sawdust surface bed without using bags. The bed was made by inoculating with 3 to 1 ratio of bed sawdust to oak mushroom mycelial inoculum. The sawdust bed medium with 65% water content was pasteurized at $65^{\circ}C$, inoculated with sawdust spawn and spread on the surface on vinyl film in cultivation shed. During 78 days of cultivation period, water content in the medium varied from 61 to 72%, its pH decreased from 5.6 to 3.9~4.6 and ergosterol concentration increased to $0.33{\sim}0.59{\mu}g/g$. $CO_2$ concentration in the medium rapidly increased to 8.06% in two weeks. In seven weeks the medium surface started browning and $CO_2$ concentration increased to about 5.63%. Until 11th week the $CO_2$ concentration was maintained at 6~7%. After removing the plastic cover on the bed for ventilation in 12 weeks, $CO_2$ within the bed reduced dramatically to 1.5%. In the cultivation shed the internal temperature was $7.1{\sim}29^{\circ}C$ and humidity was 27.3 to 100%, while bed temperature ranged $11.6{\sim}30^{\circ}C$. Oak mushroom fruiting started from late July, in 120 days after bed establishment in late March and continued for approximately 100 days until early December with eight cycles of irrigation treatment. The mushroom yield of the eight cycles were 288~352 kg during the 1st (7/29~8/4) to 3rd cycle (9/3~9/7), 800 kg at the 4th cycle (9/19~9/24), 1,296~1,853 kg during 5th (10/3~10/8) to 7th cycle (4.11~11/9) and 990 kg at 8th cycle (11/23~12/7). Total production was approximately 7.4 tons from 33.0 tons of oak sawdust medium, thus harvest efficiency of the mushroom production was approximately 22.4%.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.421-426
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• 2015

The objective of this paper is to look into the growth of Cryptomeria japonica stand in South Korea along with the evaluation on their yields, followed by their carbon stocks and removals. A total of 106 sample plots were selected from Jeonnam, Gyeongnam, and Jeju, where the groups of standard are grown. We only used 92 plots data except outlier. As part of the analysis, the Weibull diameter distribution was applied. In order to estimate the diameter distribution, the growth estimation equation for each of the growth factors including the height, the diameter at breast height, and the basal area was drafted out and the verification for each equation was examined. The site index for figuring out the forest productivity of Cryptomeria japonica stand for each district was also developed as a Schumacher model and 30yr was used as a reference age for the estimation of the site index. It was found that the site index for Cryptomeria japonica stand in South Korea ranges from 10 to 16 and this result was used as a standard for developing the stand yield table. According to the site 14 in the stand yield table, the mean annual increment (MAI) of the Cryptomeria japonica reaches $7.6m^3/ha$ on its 25yr and its growing stock is estimated to be at $190.1m^3/ha$. This volume is about $20m^3$ as high as that of the Chamaesyparis obtusa. Furthermore, the annual carbon absorptions for a Cryptomeria japonica stand reached the peak at 25yr, which is 2.14 tC/ha/yr, $7.83tCO_2/ha/yr$. When compared to the other conifers, this rate is slightly higher than that of a Chamaecyparis obtusa ($7.5tCO_2/ha/yr$) but lower than that of the Pinus koraiensis ($10.4tCO_2/ha/yr$) and Larix kaempferi ($11.2tCO_2/ha/yr$). With such research result as a base, it is necessary to come up with the ways to enhance the utilization of Cryptomeria japonica as timbers, besides making use of their growth data.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1171-1178
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• 2010

This study was carried out to compare the physicochemical characteristics of vinegars fermented from cereal crops with Incalgyun. The crude protein, mineral and $P_2O_5$ contents of vinegars fermented from cereal crops with Incalgyun were higher than the circulated brown rice vinegar (CBRV). Brix degree, turbidity and pH of vinegar fermented from cereal crops with Incalgyun were higher, and total acidity was lower than the CBRV. The glucose content of the CBRV was 4.89 mg/mL, and vinegars fermented from glutinous foxtail millet without and with Incalgyun were 5.62 and 5.58 mg/mL. The major organic acids were acetic acid and succinic acid. The total organic acid content of the CBRV was 41.92 mg/mL, and vinegars fermented from cereal crops without and with Incalgyun were 12.14~42.31 and 13.07~41.80 mg/mL. Total amino acid content of the CBRV was $63.75\;{\mu}g/mL$, and vinegars fermented from cereal crops without and with Incalgyun were 1,125.24~1,976.37 and $1,045.36{\sim}2,057.34\;{\mu}g/mL$. The total polyphenol content of CBRV was 2.31 mg/100 mL, and vinegars fermented from cereal crops without and with Incalgyun were 28.59~41.26 and 26.57~39.62 mg/100 mL. The ABTS and DPPH radical scavenging activities of the CBRV were 1.45 and 2.85 mg TEAC/100 mL. The highest ABTS and DPPH radical scavenging activities were 37.10 and 20.26 mg TEAC/100 mL at the vinegars fermented from nonglutinous foxtail millet and glutinous foxtail millet with Incalgyun, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1087-1096
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• 2010

This study was conducted to investigate the physiological activity of extracts of fresh mushrooms. The components were extracted by hot water; subsequently, the hot-water extract was subjected to 60% ethanol precipitation to yield high-molecular-weight (HMW) and low-molecular-weight (LMW) fractions. Total polyphenol contents, $\beta$-glucan contents, electron-donating ability (EDA), superoxide dismutase (SOD)-like activity, nitrite-scavenging activity, fibrinolytic activity, nitric oxide (NO) production, and inhibition of NO production of the mushroom extracts were measured using lipopolysaccharide (LPS)-stimulated murine macrophages, RAW 264.7 cells. The extracts of Lentinus edodes (Berk.) Singer and Pleurotus ostreatus (Fr.) Kummer contained the highest levels of $\beta$-glucan (33.5% and 25.57%, respectively). Further, the LMW fractions of the Phellinus linteus contained the highest levels of polyphenols (233.23 mg/g). The EDA of LMW fractions (10 mg/mL) of the Phellinus linteus and Agaricus bisporus were 80.74% and 51.35%, respectively. Further, SOD-like activities of the LMW fractions were high as compared to those of the HMW fractions. Nitrite-scavenging activities of the LMW fractions (pH 1.2; concentration, 10 mg/mL) of the Phellinus linteus and Pleurotus ostreatus (Fr.) Kummer were 75.95% and 41.05%, respectively. The fibrinolytic activity of the LMW fractions of all mushrooms showed no enzyme activity by fibrin plate assay. The fibrinolytic activity of the extracts of Tricholoma matsutake was the greatest inhibitory activity at 60.4%. Further study revealed that the mushroom extracts exhibited anti-inflammatory effects on RAW 264.7 cells. The LMW fraction ($500\;{\mu}g/mL$) of the Phellinus linteus considerably inhibited NO production (100%).

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1179-1186
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• 2010

The antiradical property of hot water extract from dried radish (DR) or dried radish roasted with pressure (DRRP) was investigated in vitro and in LLC-PK1 cell system. The contents of total free amino acid and reducing sugar in DR were decreased by 72.86% and 3.17%, respectively, after pressurized roasting. In vitro test, $IC_{50}$ for DR and DRRP for DPPH radical scavenging activity were 646.70 and $135.45\;{\mu}g/mL$, 896.10 and $566.98\;{\mu}g/mL$ for superoxide anion radical, and 722.26 and $531.84\;{\mu}g/mL$ for hydroxy radical, respectively. The radical scavenging effects of DRRP was significantly greater than those for DR (p<0.001). These radical scavenging effects of DR and DRRP were confirmed in LLC-$PK_1$ at which oxidative stresses were induced by superoxide, nitric oxide and peroxynitrite generated in the treatment of pyrogallol, SNP, and SIN-1, respectively. Cell viability was increased in the presence of DR or DRRP, dose dependently (p<0.05), and TBARS formation was decreased. The protective effects of DRRP against oxidative damage in LLC-$PK_1$ were greater than those of DR at the same concentration tested (p<0.05). This superior antiradical activity of DRRP might be due to the products produced during the pressurized roasting in addition to the antioxidative compounds originally present in the radish. 5-hydroxyl methyl furfural (5-HMF) known as an intermediate product of the maillard reaction was detected in DRRP (0.57 mg/g), but not from DR. In conclusion, daily consumption of DRRP may prevent oxidative damage by retarding oxidative stress.