• Food Science and Preservation
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• v.13 no.2
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• pp.211-215
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• 2006

Photostimulated luminescence (PSI) and thermoluminescence (TL) were analyzed for dried vegetables irradiated at 0, 1, 4 and 7 kGy, such as dried oak mushroom, spinach, radish leaves, water cress, radish, and pumpkin, to detect irradiation treatment. PSL results that photon counts for non-irradiated samples were lower than 700 that corresponds to negative, while those of irradiated samples over 1 kGy showed positive photon counts$(\geq5000)$, indicating irradiation treatment Meantime, TL ratio by normalization was lower than 0.021 in threshold value for non-irradiated samples and more than 0.653 for irradiated samples, and therefore it was possible to detect whether the 6 kinds of dried vegetables were irradiated or not by analyzing PSL and TL.

• Mycobiology
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• v.40 no.3
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• pp.164-167
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• 2012

The effects of aeration through lid filters on the hyphal growth of Lentinula edodes (oak mushroom) in sawdust cultivation bags were investigated. The aeration treatment levels were traditional 27 mm hole cotton plugs, cotton balls and combinations of seven hole sizes ${\times}$ two hole positions (up and under) in the lids covering plastic bags containing 1.4 kg sawdust medium at 63% moisture that had been autoclaved for one hour and inoculated with sawdust spawn of L. edodes strain 921. Aeration treatment effects were measured based on the $CO_2$ concentration at the 15th wk, as well as the hyphal growth rate and degree of weight loss of bags every 14 days for 15 wk. In bags with traditional cotton plugs, the $CO_2$ concentration was $3.8{\pm}1.3%$, daily mean hyphal growth was $2.3{\pm}0.6mm$ and daily mean weight loss was $0.84{\pm}0.26g$. In the bags with 15 mm diameter holes, the $CO_2$ concentration was $6.0{\pm}1.6%$, daily hyphal growth was $2.8{\pm}0.2mm$ and daily weight loss was $0.86{\pm}0.4g$. The bags with 15 mm holes had a higher $CO_2$ concentration and lower water loss than bags with other hole sizes, but the hyphal growth was not significantly different from that of other bags. The weight loss of bags increased proportionally relative to the lid hole sizes. Taken together, these results indicate that traditional cotton plugs are economically efficient, but 15 mm hole lids are the most efficient at maintaining hyphal growth and controlling water loss while allowing $CO_2$ emissions.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.319-331
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• 2015

The marketing system of non-timber forest products has been criticized as it mainly depends upon private local dealers, having too many steps between producers and consumers, we believe, which makes it less efficient. Meanwhile, there were only a few empirical studies of how they are delivered to consumers. In order to devise and implement targeted forest policies efficiently, it is quite necessary to understand the distribution channel of them. We analyzed the distribution channel of chestnut, bitter persimmon, oak mushroom, and wild greens by data analysis, field and phone survey, and then drew an implication for improving the marketing system. First of all, the number of middle step has to be reduced and the direct transaction has to be expended. In addition, we need to have more active involvement of Forest cooperative in production sites, adding values by processing, and the upgrade of current marketing centers of non-timber forest products, which have been launched since 2004 by Korea Forest Service.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.72-76
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• 1996

Hot air drying of Lentinus edodes was studied using the microcomputer drying system that can control the drying parameters such as air temperature, relative humidity and a weight-loss of water. The physico-chemical properties of dried products were measured in order to investigate the drying characteristics. The mechanism of water movement during air drying of Lentinus edodes closely followed the Page model. That was $M-M_c/M_0-M_c\;=\;\exp\;(-0.275t^{1.154})$ at $50^{\circ}C$ and 20% RH. The free amino acids increased with increased relative humidity. The color and browning degree increased with increased air temperature and relative humidity. The rehydration rate was low when the air temperature and relative humidity were high.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.65-75
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• 1996

Sulfate reduction and the precipitation of metal sulfides may have great potential to improve water quality of mine effluents in wetland treatment systems. Laboratory experiments using sulfate reducing bacteria (SRB) and limestone to treat effluents from the abandoned Dalsung tungsten-copper mine show that encouraging results, that have been attributed to sulfate reduction. Fe, Al, Cd, Cu and Zn are reduced to below detection limits with $99{\sim}100%$ metal removal rates, Mn is reduced by at least 90% to below 8.0 mg/l, and the pH is raised from 5.12 to 7.60 after 53 days of experiments. In the staged design, laboratory experiments are initiated to determine what would be reasonable substrate materials for remediation of the mine effluents. A substrate mixture containing 70% oak compost and 30% mushroom compost maintains $0.03{\sim}0.04mM$ of lactate, which provides good condition for the SRB granule. A downflow SRB wetland system is proposed as follows : 1) The lower part of the treatment system consists with a 25 cm thick layer of high quality (above 95% of $CaCO_3$) of limestone; 2) The geotextile (geonet) is recommended to be spread on the limestone bed to prevent clogging the limestones with the substrates; 3) The mixture of substrates with 70% oak and 30% spent mushroom composts, and SRB granules overlain on top of the geonet with 25 cm height. The sizes of the passive treatment systems are calculated according to metal loading and permeability criteria : 1) $220m^3$ ($15{\times}15{\times}1m$) for -1 level effluents; 2) $28m^3$ ($5.3{\times}5.3{\times}1m$) for -2 level; and 3) $2700m^3$ ($52{\times}52{\times}1m$) for the -3 level. The -3 level system needs to be broken down into 5 to 15 cells.

• Food Science and Preservation
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• v.24 no.8
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• pp.1103-1112
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• 2017

This study was performed to investigate the effects of different cooking methods (boiling, roasting, stir-frying, and deep-frying) on folate retention in 6 kinds of mushrooms (Beech-, button-, Juda's ear-, oak-, oyster-, and winter-mushrooms) frequently consumed in Korea. In order to assure reliability of analytical data, trienzyme extraction-L casei method was verified and analytical quality control was also evaluated. Folate contents of mushrooms varied by 6.04-64.82 g/100 g depending on the type of mushrooms. and were significantly affected by cooking methods. Depending on cooking methods, folate contents of mushrooms decreased by 22-48%, 2-31%, and 17-56% for Juda's ear-, oak- and oyster-mushrooms, respectively, while 17-90% of folate was increased in Beech mushroom. Overall, the largest weight loss was found in boiled mushrooms, but the lowest one in deep-fried samples. True folate retention rates considering processing factor were less than 100% for all cooked mushrooms except for Beech samples. Overall, folate loss was the largest by boiling with water but the smallest by deep-frying. Both accuracy and precision of trienzyme extraction-L-casei method were excellent based on a recovery close to 100% and coefficient variations less than 3%. Quality control chart of folate analysis (n=26) obtained during the entire study and an international proficiency test (z-score=-0.5) showed that trienzyme extraction-L casei method is reliable enough for production of national folate database.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.370-376
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• 2005

Sarcodon aspratus is well known as a natural edible mushroom and a symbiotic mycorrhizal fungus with oaks. This study was conducted to clarify the effects of environmental conditions on the fruiting of S. aspratus on the hillslope of Wolak Mt., Jecheon city, Chungbuk, South Korea. Soil moisture and soil temperature in S. aspratus colony were measured hourly and compared with those in the non-colony soil. The mean soil moisture during the mushroom development was 14.3% in the colony soil and 16.4% in the non-colony soil. The S. aspratus colony soils showed 2.1% less soil moisture. The mean soil temperature was $16.8^{\circ}C$ in the colony soil and $16.5^{\circ}C$ in the non-colony soil. The S. asprauts colony soils showed slightly higher temperature. It is considered that more soil water was consumed and more energy was emitted during the mycelial elongation and the mushroom development. The development of S. aspratus seems similar to that of T. matsutake which is known to be considerably affected by soil moisture, daily maximum air temperature, daily minimum air temperature and daily minimum soil temperature. The season of S. aspratus development ranges from the end of August to the beginning of October. And Ellino phenomenon and its unusual change in the weather seems to affect primodia and fruiting body development. Especially if daily minimum soil temperature continues to become higher than $20^{\circ}C$, the damage of primodia and its fruiting body was frequently observed in the field plots during the last few years recently.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.55-64
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• 2000

Culture maturity assessment can be used to control fruiting body flush timing. Culture maturity of sawdust-based substrate was evaluated by using oak mushroom, (Lentinula edodes (Berk.) Pegler). The influence of substrate water potential (${\psi}$) on the growth and fruiting of three genotypes of L. edodes was also investigated. Glucosamine content revealed a peak at the fruiting body senescent stage. Glucosamine increased steadily to the sporophore senescent stage, and sharply declined at crop treatment. Lipid phosphate and ergosterol contents peaked at pinning and button break stages, respectively. Therefore lipid phosphate and ergosterol contents would be considered as the convenient measurement for judging culture maturity and fruiting potentials. The substrate pH values before inoculation and on the fruiting stage were varied from 6.3 to 4.0. This pH changes were detected as changes in color from bluish purple to yellow by direct bromphenol blue(BPB) spraying, and shown a good correlation with fruit body yield of the 1 st flush. Concerning water potential of the cultures, a slight reduction of water potential, -0.5MPa, stimulated mycelial and colony growths on liquid, agar and sawdust-based substrates. The water potential of well-colonized matured substrate was -0.7MPa and -4.0MPa, before and after the fruiting, respectively. Excellent water providing capacity (higher ${\psi}$) is expected to well-matured cultures with a high density of mycelial colonization. Also, the substrate water potential significantly affected by the interaction between genotypes and spawn run time.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.192-202
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• 2010

Pesticide residues were investigated in 16 commodities (rice, foxtail millet, buckwheat, kidney bean, peanut, sesame, orange, grapefruit, kiwifruit, spinach, perilla leaves, leek, garlic stem, garlic, ginger and oak mushroom) collected from 22 provinces (Seoul, Busan, Incheon, Daegu, Daejeon, Gwangju, Ulsan, Suwon, Seongnam, Goyang, Bucheon, Yongin, Cheongju, Jeonju, Jeju, Cheonan, Changwon, Pohang, Gumi, Jinju, Wonju and Yeosu) in 2009. Pesticides (172 kinds) were analyzed using multiresidue method by GC/MS/MS from 510 samples, and phenthoate in kiwifruit was violated by exceeding MRL. The intake assessment for 24 kinds of pesticide residues including the detected pesticides at multi pesticide residue monitoring (bifenthrin etc.) were carried out. The result showed that the ratio of EDI (estimated daily intake) to ADI (acceptable daily intake) was 0.000007~0.458% which means that the detected pesticide residues were in a safe range so that residual pesticides in the agricultural products in Korea.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.664-675
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• 2010

This survey was carried out to estimate pesticide residue levels in commercial agricultural products in the year 2009. Residues were examined in 16 commodities (rice, foxtail millet, buckwheat, kidney beans, peanuts, sesame, oranges, grapefruit, kiwifruit, spinach, perilla leaves, leeks, garlic stem, garlic, ginger, and oak mushroom) collected from 22 provinces in Korea. Analyses were performed by multi-methods capable of detecting up to 60 pesticides by LC/MS/MS. A total of 510 samples were collected and analyzed. Of the samples, 96.1% contained no detectable pesticide residues. Detectable residues at or below the MRLs were found in 3.5% of the samples. However, in 0.4% of the samples (spinach and leeks), residue (ethaboxam and fluquinconazole) levels exceeded the MRLs. Furthermore, intake assessments of 7 kinds of pesticide residues were carried out, excluding those exceeding the MRLs. The results showed that the ratios of EDI (estimated daily intake) to ADI (acceptable daily intake) were 0.0001-0.0006%, which indicates that the detected pesticide residues were in a safe range. It is concluded that residual pesticides in agricultural products are properly controlled in Korea.