• The Korean Journal of Mycology
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• v.48 no.2
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• pp.95-102
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• 2020

This study was carried out to develop a new method of cultivation of 'Hwadam' a new variety of Lentinula edodes, to improve fruiting body productivity and reduce labor. To determine the optimum filter number for box cultivation, L. edodes were assessed for their cultural characteristics and mushroom yield. During spawn running of L. edodes in the box, the temperature gradually increased to the highest value of 25.8℃, 23.7℃, and 23.0℃ on day 18 for the four filter, two filter, and no treatment groups, respectively. Oxygen concentration displayed an opposite trend to carbon dioxide concentration, reaching the lowest value on day 21. The oxygen concentration progressively increased as more filters were used (5.4%, 8.2%, and 8.9% treatment with no, two, and four filters, respectively. Growth of L, edodes in the box resulted in the highest yield (2,228 g/7kg substrate) and biological efficiency (70.7%) using four filters. The biological efficiency of the four filter treatment was 29.4% higher compared to bag cultivation (41.3%). Further studies are necessary to verify stable productivity of fruiting bodies through repeated cultivation.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.125-133
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• 2020

A new oak mushroom cultivar 'Hwadam' was bred from monokaryotic strains of 'GMLE36062' and 'LE15401'. The optimum temperature for mycelial growth of 'Hwadam' on potato dextrose agar was 25℃. The cultivation period of 'Hwadam' lasted for 129 days until the first harvest of the fruiting bodies, including 35 days for spawn run, 84 days for browning, and 10 days for development of fruiting bodies. The fruiting bodies of 'Hwadam' had a hemispherical, brighter pileus and thicker stipe than the control cultivar (Sanjo 701ho). The three-cycle yield of 'Hwadam' was 554 g, which was higher than that of control cultivar (405 g). In addition, 'Hwadam' contained 79.4 mg/g of beta-glucan and 0.93 mg GAEs/g of phenolic compounds, which was similar to that of the control cultivar but higher than that of 'L808' and 'Chujae 2ho'.

• Polymer(Korea)
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• v.36 no.2
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• pp.155-162
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• 2012

Sulfonated poly(ether ether ketone) (SPEEK) nanofibers were prepared by electrospinning. The nanofibrous membrane for polymer electrolyte membrane fuel cell (PEMFC) was fabricated by compression molding. The maximum degree of sulfonation was 95% and the initial thermal degradation temperature was $280^{\circ}C$ and it's value was lower than that of PEEK. The contact angle of SPEEK increased with decreasing the degree of sulfonation. The optimum voltage, flow rate, tip to collector distance (TCD) and concentration of electrospinning conditions were 22 kV, 0.3 mL/hr, 15 cm, and 23 wt%, respectively. The average nanofibrous diameter was 47.6 nm. The water uptake and ion exchange capacity of SPEEK nanofibrous membrane increased with increasing the sulfonation time and the amount of sulfonating agent. The electrical resistance and proton ionic conductivity of SPEEK membrane increased with decreasing and increasing the sulfonation time, respectively. Their values were 0.58~0.06 ${\Omega}{\cdot}cm^2$and 0.099 S/cm.

• Journal of the Korean Vacuum Society
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• v.20 no.2
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• pp.155-163
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• 2011

Carbon nanotubes (CNT) have been attracted much attention since they have been expected to be used in various areas by virtue of their outstanding physical, electrical, and chemical properties. In order to make full use of their prominent electric conductivity in some areas such as electron emission sources, device interconnects, and electrodes in energy storage devices, direct growth of CNT with vertical alignment is definitely beneficial issue because they can maintain mechanical stability and high conductivity at the interface between substrates. Here, we report direct growth of vertically aligned CNT (VCNT) on Cu foils using thermal chemical vapor deposition and characterize the field emission property of the VCNT. The VCNT's height was controlled by changing the growth temperature, growth time, and catalytic layer thickness. Optimum growth condition was found to be $800^{\circ}C$ for 20 min with acetylene and hydrogen mixtures on Fe catalytic layer of 1 nm thick. The diameter of VCNT grown was smaller than that of usual multi walled CNT. Based on the result of field emission characterization, we concluded that the VCNT on Cu foils can be useful in various potential applications where high conductivity through the interface between CNT and substrate is required.

• Journal of the Korean Vacuum Society
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• v.19 no.3
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• pp.224-229
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• 2010

Indium oxide $(In_2O_3)$ thin films have been prepared on glass substrate by using radio-frequency reactive magnetron sputtering with changing the oxygen flow ratio. The substrate temperature was kept at a fixed value of $400^{\circ}C$, and the sputtering gas and reactive gas were supplied with argon and oxygen, respectively. The oxygen partial flow ratio was varied by controlling the amount of oxygen with respect to the total mixed gases, 10%, 20%, 30%, 40%, and 50%. The optical, electrical, and structural properties of the deposited thin films were investigated by using ultraviolet-visible-near infrared spectrophotometer, Hall measurement, and X-ray diffractometer and scanning electron microscopy. The $In_2O_3$ thin film deposited at 20% of oxygen flow ratio showed an average transmittance of 86% in the wavelength range of 430~1,100 nm, an electrical resistivity of $1.1{\times}10^{-1}{\Omega}cm$. The results show that the transparent conducting films with optimum conditions can be achieved by controlling the oxygen flow ratio.

• Food Science and Preservation
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• v.22 no.1
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• pp.70-77
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• 2015

The physiological properties of water extracts from Hizikia fusiformis extracted using different extraction methods (water extraction, WE; autoclave extraction, AE; high pressure extraction, HPE) were investigated. The freeze-dried powder yields from HPE, AE and WE were 29.33, 27.84 and 23.63%, respectively. The $L^*$ and $b^*$ color values were higher in WE, while the $a^*$ color values were higher in WE and AE. The total sugar content of AE (60.14%) was higher than those of WE (47.10%), HPE (40.97%). The reducing sugar content (7.88%) and protein content (42.83%) of AE was higher than those of WE, and HPE. The uronic acid (5.04%), total free amino acid (785.19 mg/g), taurine (19.16 mg/g), aspartic acid (66.63 mg/g), asparagine (204.84 mg/g), alanine (188.87 mg/g) and ammonium chloride (243.91 mg/g) contents, however, were the highest in HPE. Additionally, the crude polysaccharide yield was higher in HPE (4.75%) than in AE and WE, and the crude saccharide (fucose, galactose, glucose, xylose and fucose) yields were higher in AE. It can be concluded that optimum conditions for the efficient extraction of Hizikia fusiformis depending on components are high pressure and a lower temperature than in the typical process.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.276-282
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• 2004

Barley flakes were developed by extrusion cooking using broken kernels, by-products of the barley pearling process. Broken kernels from both non-waxy and waxy barley broken kernels were sufficiently gelatinized at the barrel temperature of over $100^{\circ}C$ and the moisture content of broken kernels of over 35%. Cutting and flaking roll separating properties of pellets prepared from non-waxy barley broken kernels were better than those of waxy barley broken kernels. Characteristics of pellets prepared by extrusion cooking in different mixing ratios of non-waxy and waxy barley broken kernels were investigated. As the mixing ratio of waxy barley broken kernels increased, RVA peak viscosity, apparent viscosity, and yield stress of prepared pellets decreased, while flow behavior index increased. As the mixing ratio of waxy barley broken kernels increased, compressive strength and bulk density of deep-fat fried flakes drastically decreased, and the size of air cells on cross-section increased, and thickness of cell-constituting bodies decreased. Sensory evaluation results showed that acceptability for texture and taste of flakes inclosed as the mixing ratio of waxy barley broken kernels increased, and optimum mixing level of waxy barley broken kernels appeared to be 30-40%.

• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.221-228
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• 1975

Meat tenderness is one of the most important factors in meat products because it plays a major role in the palatability of meat. To get information on the role of commercial meat tenderizer, the tenderizing ability of commercial meat tenderizer was measured with various substrates. The results obtained are as follows. 1. Content of crude protein in a commercial meat tenderizer was 4.9%. 2. Optimum temperature for proteolytic activity of meat tenderizer was $60{\sim}70^{\circ}C$. 3. Maximal activity of proteinase was obtained at pH $6{\sim}7$. 4. Proteolytic enzyme was activated by KCN, NaCN, EDTA. Thus, it was concluded that protease system of commercial meat tenderizer composed of plant origin proteinases. 5. Proteinase activity was completely inhibited by 10mM of N-Ethylmaleimide. 6. Commercial meat tenderizer showed stronger proteolytic activity on casein than on the water soluble fraction of meat protein, whereas it hydrolyzed the myofibrillar protein less efficiently.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.513-521
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• 2005

A bacterium producing five fibrinolytic isozymes was isolated from black bean chung kuk. The bacterium was identified as Bacillus subtilis BB-1 by 16s rDNA sequence homology search. A gene out of five fibrinolytic genes in the Bacillus subtilis BB-1 was cloned by shot-gun method. A Cla I DNA fragment of B. subtilis BB-1 chromosome was cloned in to pBluescript II SK(-) and showed the fibrinolytic activity to bacterial cells. The Cla I DNA fragment was sequenced and the sequences did not show homology with gene for protease or fibrinolytic enzyme genes in other organisms. The Cla I DNA fragment was reduced to 2,142 bp by activity-guided PCR cloning method. The optimum pH and temperature of the enzyme were 5.0 and $35^{\circ}C$, respectively. Substrate specificity of the fibrinolytic enzyme was detected in skim milk, casein, gelatin and blood agar plates. The activity of the enzyme was not detected with these substrates. Taken together, this enzyme is a new fibrinolytic enzyme and may be used to prevent thrombosis and arteriosclerosis.

• Journal of Life Science
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• v.16 no.4
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• pp.640-646
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• 2006

The present investigation was carried out particularly to optimize the extraction process of Poncirus trifoliata and Prunus mume to develop a functional foodstuff having antibacterial activity against Vibrio parahaemolyticus. The extracts were prepared from the fruits under various conditions, and then optimum extraction conditions were decided in case maximal antibacterial activity was obtained. In extraction process by using hot water, the best antibacterial activity of Poncirus trifoliata was achieved at $80{\sim}100^{\circ}C$ for 30 min, while that of Prunus mume was achieved at $100^{\circ}C$ for 30 min, as showing 14.8 and 16.6 mm of inhibition diameter, respectively. The extraction process with addition of NaOH increased the activity of Prunus mume, but addition of $K_2CO_3$ and $NaHCO_3$ drastically decreased the activity. In the processes at high temperature up to $120^{\circ}C$ by using pressure extractor and with various concentrations of NaOH, the maximum activity was observed in the extract of Prunus mume at $120^{\circ}C$ for 30 min with 0.05 N NaOH. The fermented ethanol extract of the fruits showed less activity than those of the extracts with water and NaOH solution.