• Applied Biological Chemistry
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• v.47 no.4
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• pp.396-402
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• 2004

For industrial application to manufacturing functional foods for health using browned oak mushroom, we examined its reducing power, inhibitory effect on intracellular reactive oxygen species, phenolic compounds and phytates contents, modulatory effects on NO radical and matrix metalloproteinase 9 (MMP9) generation by activated macrophages, and antimutagenicity in order to evaluate the functionality of browned oak mushroom for health. While overall ethanolic extracts have higher reducing power than aqueous extracts, browning reaction was found to increase reducing power by up to 28% at a 3.32 mg/ml sample concentration. Browning reaction also increased phenolic compound content by about 73% compared to raw mushroom. However, any significant change in phytate content could not be detected. At a concentration of $100\;{\mu}g/ml$, treatment of ethanolic extract of oak mushroom increased NO generation over 43% in LPS-stimulated macrophage. On the contrary, the aqueous extracts rather decreased it over 17% at the same sample dose. However, any solvent extract from browned oak mushroom seems not to cause any change in both NO production and MMP9 activity. In addition, browning reaction did not allow any significant change in suppressive effect on mitomycin C-induced mutagenesis as examined with SOS chromotest. These results suggest a possible use of browned oak mushroom with unmarketable quality as a material for development of a variety of processed functional foods for health.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.648-654
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• 2004

Physiological functionality of browned oak mushroom was evaluated with focusing its electron-donating ability to DPPH radicals, scavenging ability to superoxide radicals and hydroxyl radicals, and inhibitory activity on lipid peroxidation. The results showed that overall antioxidative activities of browned oak mushroom were superior to those of raw oak mushroom with marketable quality, implying possible involvement of resultant browning reaction products in an increment of antioxidativity. The increased radical-scavenging ability was suggested to mainly be exerted by direct quenching of both superoxide and hydroxyl radicals, not by inhibition of xanthine oxidase activity and $Fe^{2+}$ chelation, respectively. Collectively, these results indicate a possible use of unmarketable browned mushroom as a material for manufacturing various processed functional foods.

• Journal of Mushroom
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• v.5 no.3_4
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• pp.91-97
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• 2007

Shiitake mushroom (Lentinula edodes) is usually cultivated on the oak log. Log cultivation of this mushroom is getting difficult to get oak logs and has a weak point of its long cultivation period. Recently sawdust cultivation is getting increase. It is important to make mycelia browning on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. The development of methods for the rapid mycelia browning is quite required. In this article we would like to discuss about the enzymatic activities related mycelia browning and search the methods of cultivation period reduction.

• Korean journal of food and cookery science
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• v.24 no.5
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• pp.665-671
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• 2008

The principal objective of this study was to assess the quality properties of noodles to which browned oak mushroom (Lentinus edodes) paste was added at concentrations of 10%, 20%, and 30% to wheat flour, respectively. With regard to the cooking properties of the noodles, the weight and water absorption of the cooked noodles increased with increasing paste contents, but the turbidity of the noodle soups decreased (p<0.05). The hardness and gumminess of the uncooked and cooked noodles decreased significantly in proportion to the quantity of added paste, except in the case of the cooked noodles with 30% paste. The springiness and cohesiveness of both noodles with Lentinus edodes paste were significantly higher than in the controls. The lightness of the uncooked and cooked noodles decreased in accordance with the amount of added paste. However, the yellowness of both noodles was significantly increased. Moreover, the results of our sensory evaluation showed that the cooked noodles with 20% and 30% added Lentinus edodes paste had higher values. Thus, Lentinus edodes paste added to a concentration of up to 30% was shown to effectively improve the quality of noodles.

• Journal of Mushroom
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• v.9 no.4
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• pp.145-154
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• 2011

Shiitake mushroom (Lentinula edodes) is usually cultivated on the oak log. Log cultivation of this mushroom is getting difficult to get oak logs and has a weak point of its long cultivation period. Recently sawdust cultivation is getting increase. It is important to make mycelia browning on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. The development of methods for the rapid mycelia browning is quite required. In this article we would like to find cultural characteristics of collected strains and to see the correlation with mycelial browning. Mycelial growth in the media was different according to kinds of media and strains. The optimal temperature on mycelial growth was $20-25^{\circ}C$. Browning patterns of mycelium under 200 Lux seemed to be used for a key to differentiate the strains for sawdust cultivation. Browning period was 30-40 days in the agar media and 70-100 days in the sawdust bag cultivation. When we considered the productivity and the other characteristics, ASI 3046 is the best for the bag cultivation. Significance between mycelial growth and browning was not accepted, but that of mycelial growth between on PDA and sawdust was accepted. Browning period on the PDA and sawdust showed a strong relationships. These results suggested that the browning habits could not be depend on the difference of media, but on their own properties. To select the strain showed fast browning can be done by using agar media for saving time.

• Journal of Mushroom
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• v.15 no.4
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• pp.195-201
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• 2017

We measured the antioxidant activities of Oak mushroom (Lentinula edodes) in browned sawdust medium under conditions of varying LED sources and amounts of light. Consequently, exposure to 200Lx blue LED resulted in highly efficient browning; the most efficient browning was shown at 200Lx, regardless of the type of luminous source. We identified that quantities obtained with the blue luminous source increased compared to those in other treatment plots. The DPPH radical scavenging test conducted to examine antioxidant activity revealed that the red luminous source caused high radical scavenging compared to efficient browning. The fruiting body for Nongjin-go, as a treatment plot with the highest scavenging, under a 400Lx red luminous source was $34.3{\pm}1.80%$ and that for 'Sanjo 701' at a 300lx red luminous source was $32.99{\pm}1.58%$. The polyphenol content, reported to be correlated with DPPH radial scavenging, showed no similar correlation in the 'Nongjin-go' variety. By contrast, 'Sanjo 701' showed a similar association.

• Journal of Mushroom
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• v.7 no.3
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• pp.115-121
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• 2009

Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes ) is getting increased because log cultivation is getting difficult to get oak logs. It is important to make mycelia browning on the substrate surface in sawdust cultivation. This browned surface plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. In this article we would like to discuss about the effect of environmental condition to the mycelial browning during sawdust bag cultivation for the To reduce the period required for browning of substrates, sawdust substrates was illuminated light with difference intensity. One hundred Lux light illumination was needed for producing normal yield of fruit body but fruit body yield was low and abnormally shaped fruit body was produced when cultured under the dark condition of incubation. Illumination over 200lux is necessary for the successful browning of substrates during incubation. Optimum incubation temperature for browning of substrates and fruiting was $25^{\circ}C$. The treatment of cotton plug with different size to identify the effect of aeration on the browning of substrates and fruiting showed rapid mycelial growth and reduced the periods for browning as the size of cotton plug was bigger. However, yield of fruit body was the highest at 16mm diameter cotton plug as compared to 20mm of that. $CO_2$ content in vessel of substrates was low as the size of cotton plug was bigger during incubation. $CO_2$ content during incubation of substrate was highest in periods between 8 week and 14 week after inoculation of shiitake when substrate was changed color into brown. $C_2H_4$ content in vessel with substrates was highest at 8mm diameter cotton plug and it was increased by order of 12, 16, 20, 0, 4 mm diameter cotton plug during substrate incubation. Sawdust substrate was soaked in cold water for different time to identify soaking effect of sawdust substrate on fruit body yield and activities of enzymes in these substrates were investigated. The fruit body yield was increased up to 40% by soaking substrates in comparison with unsoaked substrates. The soaked substrates showed 165, 175g/1,000ml at treatment of 4 and 15 hours, respectively. Cellulose activities in soaked substrates were not changed with soaking time, but activities of laccase, lignin degradation enzyme, were drastically increased up to 4 times in comparison with unsoaked substrates.

• Journal of Mushroom
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• v.10 no.3
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• pp.120-128
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• 2012

Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes) is increasing. It is important to make mycelia to be brown on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. In order to isolate genes which related to brown color formation, differential display method was used. Two cDNA fragments obtained by DD-PCR were 1.2 and 1.6kb and these were expressed in white colored mycelia from L. edodes, but not brown colored mycelia. Partial sequencing of these cDNA fragments showed that the 1.6kb cDNA had 100% identity with the microsatellites gene from Dugenia polichroa. However, the other 1.2kb cDNA fragment had poly T tail on 3' region of partial open reading frame on 5' region. The new primer designed based on the sequence of 1.2kb cDNA was constructed. RT-PCR analysis using the newly designed 0.12kb cDNA specific primer showed that the gene was only expressed in white color mycelia, but not in brown color mycelia. Sequence analysis of 5' region of this 1.2kb cDNA revealed that this gene contained partial open reading frame consisted of 110 amino acid. Homology search using DNASIS database showed that this gene had high sequence homology of 66.7% in DNA level and 69.2 % in amino acid level with dTDP-glucose 4,6-dehydratases gene from Arabidopsis thaliata. The dTDP-glucose 4,6-dehydratases gene was known to be function to have tolerance with oxidation stress. These results strongly suggest that this gene isolated from white mycelia of L. edodes might have a function of repressor against mycelia browning. Therefore I designated this gene as BCR (Brown Color Repressor) gene.