• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.227-233
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• 1996

Tyrosinase is an enzyme which catalyzes an enzymatic browning of some foods and in vivo synthesis of melanin. In order to produce natural and edible inhibitor of the enzyme which is expected to have whitening effect on melanogenesis, a microorganism was selected from fermented foods. It was named as NU-7, and cultured in mushroom (Lentinus edodes, Shiitake) media. Optimal media to produce tyrosinase inhibitor was formulated by varing nitrogen or carbon content. If glucose content was in a range of 3-20% and ammonium sulfate was in a range of 0-0.25%, production of inhibitor was independent of cell mass. Addition of ammonium sulfate as a nitrogen source had little effect on inhibitor production. Production of inhibitor (Y) was proportionally related to shiitake content (X) with a regression equation of Y= -0.96X$^{2}$ + 13.07X + 14.43 (R = 0.96). These results indicate that shiitake and glucose are necessary for the production of tyrosinase inhibitor. In the analysis of mycotoxin in culture broth, aflatoxin was not detected, suggesting that it would be probably edible.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.376-381
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• 1992

In order to study the effect of modified atmosphere storage on extending shelf life of mushrooms, oyster mushroom and Shiitake were wrapped with polyethylene film (PE, $50\;{\mu}m$), and stored at $0.5^{\circ}C$. Mushrooms packed with conventional hardboard box (4kg) lost marketability within $5{\sim}6$ days due to weight loss, shrinkage, browning, spore formation and/or mycellium growth. PE-packing could prevent or retard the deterioration of the mushrooms in the aspects of appearance, texture, discoloration, and microbial contamination. This situation can be best characterized by the reduced respiration rate resulted from the elevated level of carbon dioxide and the reduced level of oxygen in the bag. Although the appearance of the oyster mushroom was maintained for one month, its shelf life was limited to 15 days because of tissue softening. Discoloration of the pileus of shiitake mushroom appears to be the most important factor to determine its marketability. For example, extension of shelf life of Dongo was limited to 15 days, principally due to the browning of the pileus. Shelf life of Hawgo whose color of the pileus changed little over the experimental period, however, could be extened to more than one month.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2004.07a
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• pp.48-48
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• 2004

Shiitake mushroom contained numerous nutrients, special flavor (lenthionine) and taste. In Asia, they are thought to have numerous medical properties f3r several diseases such as diabetes, anemia, tumors. Phosphates are known to increase hydration and water binding, stabilize meat emulsions, improve juiciness and tenderness, provide mineral supplementation, and maintain flavor of processed meat products. A lexicon f3r describing the texture and flavor of cooked pork patties were developed. (omitted)

• The Korean Journal of Mycology
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• v.6 no.2
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• pp.31-36
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• 1978

The study has been carried out to invetigate the possibility of oak mushroom (shiitake) cultivation on Ban Oak (Quercus incana) growing naturally in Simlaregion, India. The survival and growth of oak mushroom mycelium and fruit body formation on Q. incana as well as the composition of the log were compared with that of Bristle-tooth oak (Q. serrata) which are being used for mushroom cultivation in Korea. The results are summarized as follows. 1. The content of alcohol-benzen extract, NaOH extract, NaOH extract and ash were higher in Q. incana than in Q. Serrata. While cellulose and pentosan were less in the formers. 2. The mycelial growth of oak mushroom were more rapid on sawdust medium of Q. Serrata than on Q. incana. However the mycelial growth on the later were more compact. 3. The mycelial growth of oak mushroom were more rapid on the logs of Q. serrata than Q. incana. The mycelium survived well on both two species, and no difference in the survival rate of mycelium were observed. 4. The first fruit bodies on logs of Q. Serrata and Q. incana were appeared 16 months inoculation of spawn. 5. In view of the above results. it seems that the cultivation of oak mushroom (shiitake) on Ban oak (Q. incana), growing in India, is possible.

• Journal of Mushroom
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• v.15 no.4
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• pp.264-268
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• 2017

In the 21st century, information and communication technology (ICT) worldwide presents a new vision for agriculture. Time and place, as well as the high-tech industry, to overcome barriers to the fusion of the so-called "smart agriculture," are changing the agricultural landscape. Core container production in precision agriculture for mushroom cultivation, optimal temperature, humidity, irradiation, self-regulation of factors such as carbon dioxide, and environment for mushroom cultivation were adopted. Lentinula edodes (shiitake) is an edible mushroom native to East Asia, cultivated and consumed in many Asian countries. It is considered to be medicinal in certain practices of traditional medicine. We used different controlled light sources (Blue-Red-White-combined LED, blue LED, red LED, and fluorescent light) with different LED radiation intensities (1.5, 10.5, and $20.5{\mu}mol/m^2s$ for LEDs) to compare growth and development. Mushrooms were treated with light in a 12-hour-on/12-hour-off cycle, and maintained in a controlled room at $19{\sim}21^{\circ}C$, with 80~90% humidity, and an atmospheric $CO_2$ concentration of 1,000 ppm for 30 days. Growth and development differed with the LED source color and LED radiation intensity. Growth and development were the highest at $10.5{\mu}mol/m^2s$ of blue LED light. After harvesting the fruit bodies, we measured their weight and length, thickness of pileus and stipe, chromaticity, and hardness. The $10.5{\mu}mol/m^2s$ blue-LED-irradiated group showed the best harvest results with an average individual weight of 39.82 g and length of 64.03 mm, pileus thickness of 30.85 mm and pileus length of 43.22 mm, and stipe thickness of 16.96 mm with fine chromaticity and hardness. These results showed that blue LED light at $10.5{\mu}mol/m^2s$ s exerted the best effect on the growth and development of L. edodes (shiitake) mushroom in the ICT-system container-type environment.

• Journal of Mushroom
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• v.15 no.4
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• pp.164-167
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• 2017

Biological efficiency (BE), the ratio of fresh mushrooms harvested per dry substrate weight, expressed as the percentage of Lentinula edodes, also known as shiitake, was determined using the 'Sanjo 701' strain stored in the Department of Mushroom at the Korea National College of Agriculture and Fisheries. The mycelia were grown in glass columns with varying levels of moisture content and varying mixing periods of 0.5, 1, 2, and 3 hours. The substrate was sterilized using a steam pressure autoclave sterilizer at normal and high pressure to avoid contamination. The results showed that mycelial growth (126 mm/15 days) was optimized at 55% moisture content. The best mycelial growth of 117 mm/15 days was obtained with 2 hours of mixing time. Normal pressure sterilization yielded better results with mycelial growth of 96 mm/15 days at $100^{\circ}C$ compared to 88 mm /15 days with sterilization at $121^{\circ}C$. Mycelial density was higher, i.e. 3(+++), with normal pressure sterilization compared to 2(++) with high pressure sterilization. Furthermore, sawdust mixed with 5% woodchips increased the substrate porosity and yielded higher mycelial growth. Thus, we demonstrated that the optimum harvest or potential increased yield of shiitake can be obtained by modulating moisture content, mixing time, and substrate porosity.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.145-148
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• 1989

Shiitake mushrooms were dried by hot air, far infrared and freeze dryers in order to compare qualities after drying. When hot air drying was performed with the four temperature variations ranged from $45\;to\;70^{\circ}C$, there was tendency to increase volume retention but decrease rehydration ratio, as drying temperature increased. And the largest amout of 5'-GMP was contained in mushroom dried at $50^{\circ}C$. For far infrared drying, volume retentions were lower but rehydration ratios were higher, as compared with hot air drying at the same temperature. In freeze drying, freezing rate had no influence on volume retention but rehydration ratio was highest value when frozen at $-18^{\circ}C$. As shelf temperature increased(drying rate increased), rehydration ratio increased. Also, contents of 5'-AMP, 5'-GMP and 5'-XMP increased with the increase of freezing rate and drying rate.

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.8-15
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• 2016

Fungal contamination is a detrimental factor affecting sawdust media-based shiitake cultivation in greenhouses. During fungal monitoring of greenhouses used for shiitake cultivation, eight fungal species were isolated and identified from indoor air and mushroom flies collected in the greenhouses. The current study reported five species as new in Korea, viz. Ascochyta hordei, Discosia artocreas, Mucor nidicola, Perenniporia medulla-panis, and Pseudozyma prolifica, and confirmed two species, Penicillium charlesii and Penicillium brevicompactum, which were previously recorded in Korea without molecular taxonomic validation. The morphological characteristics and phylogenetic relationships based on nucleotide sequences of the internal transcribed spacer rDNA region or calmodulin gene were described for all identified species.

• Journal of Mushroom
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• v.19 no.3
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• pp.216-224
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• 2021

This study analyzed food component characteristics and antioxidant activities in five kinds of domestic commercial shiitake mushrooms (Lentinula edodes). Moisture content (79.17-82.90 g/100 g) showed little difference, but there was a significant difference in crude protein content. Total mineral content showed a significant difference, and potassium (K) content was the highest. Total and essential amino acid contents were higher in mushroom A than in the other samples. Nonetheless, the ratios of essential amino acids, aspartic acid, and glutamic acid to total amino acids were similar in all samples. 𝛽-Glucan content was in the range of 10.28-5.68 g/100 g, exhibiting a significant difference. The color intensity and overall texture of the mushrooms showed no remarkable difference. Total phenol and flavonoid contents were in the range of 19.92-30.77 mg/100 g and 6.95-10.39 mg/100 g, respectively; the ratio of flavonoids to total phenols ranged from 31.53% to 38.21%. DPPH and ABTS radical scavenging activities were 74.92-79.04% and 80.47-84.97%, respectively, and showed little difference. However, the reducing power varied between 195.23 𝜇M and 317.85 𝜇M, displaying a significant difference in all samples. Therefore, this study observed similar trends in the food component characteristics and antioxidant activities of domestic commercial shiitake mushrooms.

• Journal of Life Science
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• v.32 no.7
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• pp.491-500
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• 2022

HK shiitake mushroom mycelium (HKSMM), containing 14% β-glucan, is a health functional food ingredient individually approved by the Korea Ministry of Food and Drug Safety for liver health. The anti-inflammatory effect of a 50% aqueous ethanol extract of HKSMM (designated HKSMM50) was studied in RAW 264.7 macrophage cells treated with lipopolysaccharide (LPS). An active hexose correlated compound (AHCC) was used as a positive control. LPS-activated RAW 264.7 cells were treated with HKSMM50 and AHCC (0, 20, 100, 500 ㎍/ml) and cultured for 24 hr. Inflammation-related elements in the supernatant were measured using enzyme-linked immunosorbent assay (ELISA) kits, and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in the cells was analyzed by Western blotting. The HKSMM50 lowered iNOS and COX-2 protein expressions, and nuclear factor-kappa B (NF-κB), nitric oxide (NO) and prostaglandin E₂ (PGE₂) contents in a concentration-dependent manner as compared to LPS treatment. Similarly, the HKSMM50 lowered the content of pro-inflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4) and interleukin-6 (IL-6) contents and increased the activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). The efficacy of the AHCC treatment was similar to that of the HKSSM50 treatments. These results indicate that HKSMM50 showed an anti-inflammatory effect in LPS-treated RAW 264.7 cells by down-regulation of NF-κB signaling and suggest that HKSMM could be used as a health functional food ingredient to help improve immune function.