• Journal of Food Hygiene and Safety
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• v.39 no.1
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• pp.9-15
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• 2024

This study was performed to survey the distribution of Listeria spp. in fresh agricultural products in the Busan area, the Republic of Korea, from January to November 2022. We investigated the pathogenicity and epidemiological relationships by tracing isolated strains using polymerase chain reaction and pulsed-field gel electro-phoresis (PFGE) methods. Forty cases of Listeria spp. were detected in the 210 samples of fresh agricultural products analyzed. Four species, Listeria rocourtiae, L. innocua, L. grayi, and L. monocytogenes were detected only in green vegetables (lettuce, perilla leaps) and the others (L. innocua, L. monocytogenes, and L. grayi) were detected in enoki and oyster mushrooms. L. innocua was detected in 22 samples and L. grayi in six samples. L. monocytogenes, which causes foodborne diseases, was only detected in enoki mushrooms and the strains that were isolated had genes responsible for the pathogenicity of listeriosis (iap, prfA, inlA, inlC, inlJ, and hly). To investigate the genetic similarity and contamination route of L. monocytogenes, serotyping and PFGE were conducted for 12 strains isolated from fresh agricultural (10 strains) and poultry (2 strains) products distributed at a market in the Busan area. Two serotypes (1/2a, 1/2b) were detected in strains isolated from the agricultural and poultry products, but serotype 1/2b was only detected in strains isolated from agricultural products. PFGE analysis showed index of similarity values of 45.7 to 100% and the same patterns were represented in isolates from some enoki mushrooms. These isolates had the same serotypes and showed significant epidemiological relationships.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.402-408
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• 2016

Master packaging system consists of an inner individual package and secondary outer package. During the stages of chilled transport and distribution, the combination of primary individual package and secondary package was used to maintain a modified atmosphere for shiitake mushrooms. During the retail stage at higher temperature ($25^{\circ}C$), the primary individual package was exposed to display conditions after dismantling of the secondary packaging. The master packaging system was constructed to contain eight individual $30-{\mu}m$ thick polypropylene film bags of 500 g shiitake mushrooms inside a $40-{\mu}m$ low-density polyethylene bag. Carbon dioxide absorbent material [$Ca(OH)_2$] and/or moisture absorbent (superabsorbent polymer) were designed in their required amounts based on respiration characteristics and then applied to the outer secondary packaging in sachet form. Gas concentration of the packaging, temperature, and humidity were monitored throughout transport and storage. The quality of shiitake mushrooms was measured at the retail stage to determine the packaging effect. During the distribution stage of 108 h, $O_2$ and $CO_2$ concentrations in the master packaging system were maintained at 9~11% and 1~4% in the inner packaging, respectively, which are good for quality preservation. Compared to the control, the master packaging with $CO_2$ and/or moisture absorbents improved mushroom preservation and particularly reduced decay.

• Mycobiology
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• v.32 no.2
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• pp.68-73
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• 2004

Fresh mushrooms were collected during survey field trips to the southern areas of Songnisan National Park for 24 days from April to November in 2002. Through this investigation, a total of 682 fungal collections were obtained and taxonomically amounted to 5 classes, 14 orders, 44 families and 202 species. Among them, six genera Diplomitoporus, Heterochaete, Hydnochaete, Loweporus, Scytinostroma and Tomentellina, and twelve species, Asterostroma cervicolor, Diplomitoporus crustulinus, Fomitopsts cajanderi, Heterochaete delicate, Hydnochaete tabacinoides, Hyphodontia sambuci, Hypoxylon deustum, Lopharia cinerascens, Loweporus roseoalbus, Phanerochaete chrysosporium, Scytinostroma odoratum and Tomentellina fibrosa were confirmed as new to Korea and registered here with descriptions.

• Journal of Environmental Science International
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• v.29 no.12
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• pp.1199-1204
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• 2020

Lentinula edodes mushrooms cultivated under different relative humidities were wrapped at 4℃ and the results of storage characteristics were investigated. Changes in water content of fruiting bodies during the storage period showed the highest water content in fruit bodies harvested from the treatment with the highest relative humidity. The luminosity of the fresh fruiting bodies showed no significant change during the storage period, and the redness was higher in the relative humidity 95% treatment than in the other treatments. According to this study, the relative humidity of the pileus was 65%, and the content of Ergosterol was 0.67 ± 15 g / L at relative humidity of 65%, 80% and 95%. In addition, amino acid analysis and Principal Component Analysis (PCA) confirmed that methionine was the main cause of changes in storage time and relative humidity.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.245-251
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• 2001

This research was conducted to study the changes in physical characteristics of mushrooms (Agaricus bisporus) as influenced by drying methods. Samples were dried using either hot air drying, vacuum drying, or freeze drying and changes in the color, browning index, hardness and rehydration rate were evaluated by response surface methodology. Hot air drying resulted in the fastest drying of sample as compared to other methods. The rate of drying was most affected by the environmental temperature rather than air velocity or vacuum pressure. The overall color difference increased as the temperature and air velocity increased. The overall color changes of the freeze dried samples were minimal as compared to those of fresh mushrooms. The hot air dried samples showed the greatest changes in the overall color, browning index as well as hardness. The freeze dried samples showed the best rehydration characteristic and maintained the best overall quality after drying.

• The Korean Journal of Mycology
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• v.3 no.2
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• pp.19-23
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• 1975

A study on the variation of the air temperature in the pine mushroom box containing dry ice for the preservation of the freshness of the pine mushroom, Tricholoma matsutake (Ito et Imai) Sing. produced in Korea was made in Seoul, Korea during the period of August 1 to 30, 1975. A safe shipment of 5 kg (net weight) of fresh mushrooms with freshness preserved for 24 hours in August required the placement of 4.5 kg of dry ice-a half in the upper portion and the other half in the middle portion-in an airtight container (mushroom box). The container used for the shipment test, made of 3mm-thick double-layer cardboard, was of the dimensions : $0.33{\times}0.4{\times}0.5=0.066(m^3)$. As the temperature fell, decreased amounts of dry ice were needed : 3 to 2 kg in September and 1.5 to 0.3 kg in October. With this preservation method, large quantities of fresh mushrooms were exported to Tokyo ana Osaka, Japan without damage in the process of transportation.

• Journal of Mushroom
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• v.12 no.4
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• pp.280-286
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• 2014

King oyster mushrooms(Pleurotus eryngii) are the second biggest mushroom for exporting in Korea but their browning and soft rot is the main factors of claim during long distance transportation. Fresh king oyster mushrooms were treated with $CO_2$ at 30, 50% for 3 hours at $5^{\circ}C$ prior to storage at $20^{\circ}C$ and $5^{\circ}C$. There was no difference on respiration rate after $CO_2$ treatment. However exposure to $CO_2$ for 3h prior to MA packing maintained the firmness and delayed color(hunter L and b value) change of mushrooms during storage. Especially an incubation in high $CO_2$ at 30% significantly reduced soft rot and browning symptoms resulting in one week extension of shelf-life during storage at $5^{\circ}C$ compared to control and 50% $CO_2$ treatment.

• Mycobiology
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• v.49 no.1
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• pp.78-85
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• 2021

Morels (Morchella spp.) are valuable medicinal and edible mushrooms. In this study, chemical profiles of aromas and lipophilic extracts of black morel (Morchella importuna) grown in China were analyzed by gas chromatography/mass spectroscopy, along with the evaluation of antioxidant and antimicrobial activities for the lipophilic extracts. Sixty-five compounds in total were identified from the aromas, and 1-octen-3-ol was the main component for aromas of fresh (34.40%) and freeze-dried (68.61%) black morels, while the most abundant compound for the aroma of the oven-dried sample was 2(5H)-furanone (13.95%). From the lipophilic extracts, 29 compounds were identified with linoleic acid as the main compound for fresh (77.37%) and freeze-dried (56.46%) black morels and steroids (92.41%) as the main constituent for an oven-dried sample. All three lipophilic extracts showed moderate antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) with the IC50 values ranging 7.56~17.52 mg/mL and 5.75~9.73 mg/mL, respectively, and no obvious antimicrobial activity was observed for lipophilic extracts. The drying methods affect the chemical profile of black morel, and freeze-drying was favorable for retaining nutrients and morel smell. This is the first report on the aroma and lipophilic extracts of M. importuna grown in China.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.3
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• pp.71-76
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• 2014

Master packaging system is a technology combining primary and secondary packaging to preserve the fresh produce in the supply chain. Master packaging system with tailor-designed gas transfer and $CO_2$ absorber of $Ca(OH)_2$ was applied to fresh shiitake mushroom in its supply from farm to retail store. The temperature, humidity and package atmosphere were monitored through the distribution and/or storage until the packages were opened to measure the mushroom quality. Conventional perforated individual packages without secondary master pack were prepared and travelled the same path for comparison purpose. While high temperature history was observed in some initial period of actual practice of the mushroom transportation and storage unexpectedly, the package atmosphere around the produce in the master packaging system was maintained at modified atmosphere consisting of $O_2$ concentration of 0.4 to 4.2% and $CO_2$ concentration of 0.7 to 1.7%, which is known to be beneficial for the mushroom preservation. While curing the mushrooms with precooled drying was effective for quality preservation, positive effect of master packaging system could be apparent for the uncured mushroom. Harmonized combination of curing treatment, master packaging system and temperature management was suggested for the best quality preservation of the fresh shiitake mushroom.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.606-612
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• 1988

The volatile flavor compounds of fresh and dried shiitake mushrooms(Lentinus edodes) were extracted by simultaneous steam distillation-extraction apparatus, and analyzed by combined GC and GC-MS, and effects of pH on the formation of volatile compounds in fresh shiitake mushroom were investigated. Of the 29 compounds identified from fresh shiitake mushroom, the main volatile compound was 1-octen-3-ol comprising about 74.7% of the total volatiles and that in dried shiitake mushroom was 1, 2, 4-trithiolane comprising about 66.3%. With the exception of above two compounds, 3-octanone, 1-octen-3-one, 3-octanol, cis-2-octenal, n-octanol and cis-2-octenol as $C_8$ compounds were identified. Carbon disulfide, dimethyl disulfide, dimethyl trisulfide, 1-(methyl thio)-dimethyl disulfide, 1, 2, 4, 5-tetrathiane as sulfurous compounds were also identified. The formation of $C_8$ compounds in fresh shiitake mushroom during immersion was dominant in the range of pH 6.0 to 7.0, while the formation of sulfurous compounds in the range of pH 8.0 to 9.0.