• Food Engineering Progress
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• v.15 no.2
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• pp.116-121
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• 2011

This study was aimed to analyze the changes in rheological properties of sausages added tenderizer made with over-matured used-up fruits such as kiwifruit, grape, and pear. The tenderizers were manufactured by various concentration of fruit extract and added to the sausage at different heating temperatures. Failure stress and stress relaxation of beef sausage mixed with different tenderizers were measured with Rheometer, and analyzed with 3-element Maxwell model. As a result of the rheological measurements, over-matured kiwifruit extract showed the best tenderness effect among other fruit extracts, and the more kiwi contents were added, the beef texture turned to softer. The instantaneous stress and elastic component of beef mixed with various tenderizers were decreased at higher concentrations and lower heating temperatures. This study was well expressed the numerical magnitude of viscoelastic components of beef sausages to determine the tenderizer effect.

• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.243-253
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• 2012

The objective of the study was to evaluate the quality characteristics of sun-dried Hanwoo beef jerky added with the extract of Citrus junos seib. or Prunus mume. Hanwoo beef shank muscles were sliced, marinated, and sun-dried at $25^{\circ}C$, relative humidity of 35%. The physicochemical quality and microbiological safety of the Hanwoo beef jerky aerobically packaged were analyzed during the storage of $25^{\circ}C$. The moisture content of beef jerky with Citrus junos seib. was the lowest among the treatments after 20 d. Citrus junos seib. and Prunus mume jerky after 10 d had significantly lower aw than those after 0 and 20 d (p<0.05). The pH values of jerky generally ranged from 5.76 to 5.84. The pH value of Prunus mume jerky was significantly higher than those of other jerky samples (p<0.05). Prunus mume jerky showed significantly lower TBARS value than the others after 20 d (p<0.05). Citrus junos seib. jerky showed a significantly lower lightness ($L^*$), redness ($a^*$) and yellowness ($b^*$) than the others during the storage (p<0.05). Prunus mume samples after 10 d had significantly higher $L^*$, $a^*$, and $b^*$ values than the others (p<0.05). With regard to sensory properties, Citrus junos seib. and Prunus mume jerky showed significantly higher flavor and overall acceptability scores than the control (p<0.05). The extracts of Prunus mume will be used in sun-dried Hanwoo beef jerky as a natural agent to retard lipid oxidation and to improve meat color.

• Journal of Mushroom
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• v.17 no.4
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• pp.235-240
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• 2019

In this study, we investigated the effects of pH, temperature, and salt concentration on protease activities in Hypsizygus marmoreus, and the ability of H. marmoreus extract to tenderize beef. In fact, H. marmoreus was shown to have higher protease activity than kiwi fruits. The pH of beef was dose dependently increased with addition of H. marmoreus extract. Cooking loss, cutting strength, and color value (L, a, b) were also dose dependently decreased with addition of H. marmoreus extract. In sensory assessments, H. marmoreus extract dose dependently enhanced perception of tenderness, flavor, and taste. In contrary, use of kiwi fruits as a meat tenderizer decreased positive perception of taste. The protease activitiy of H. marmoreus decreased sharply at pH < 2.0, and temperature > 50 ℃. Protease activity was relatively stable in NaCl concentrations ranging from 0-5 M, but incrementally decreased with increasing NaCl. These results suggest that, H. marmoreus extract can improve the texture and taste of beef.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.100-105
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• 1995

Media optimization for the production of MR-387A and B, novel aminopeptidase M inhibitors by Streptomyces sp. SL-387 isolated from a soil was studied. Optimized medium was consisted of 1% glucose, 3% soybean meal, 0.2% yeast extract, 0.1% beef extract, 0.3% NaCl, 0.01% $K_2HPO_4$, 0.3% $CaCO_3$, 0.001% $MnCl_2{\cdot}4H_2O$, 0.001% $ZnCl_2{\cdot}7H_2O$, and 0.0005% $MgSO_4{\cdot}7H_2O$, and adjusted to pH 7.0 before autoclaving. When the optimized medium was used as a fermentation medium, maximum productivity of MR-387 was reached at 120 hours of fermentation, and total productivity was 909.1 U/ml.

• KSBB Journal
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• v.16 no.4
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• pp.365-369
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• 2001

Chitinase producing microorganism, Serratia marcescens KY, was isolated from seashore mud around Beobseongpo in Chunnam province by selective enrichment culture. As the colloidal chitin concentration increased, chitinase production was increased. But chitinase production with addition of other carbon sources (glucose, fructose, galactose, maltose, sucrose, starch) was decreased. The effect of nitrogen sources on the chitinase production with serratia marcescens KY was as fellows. The opitimum mineral concentration for chitinase production was K$_2$HPO$_4$ 0.2 g/L and MgSO$_4$ 0.20 ∼ 0.25 g/L, respectively. The effect of nitrogen sources on chitinase production by Serratia marcescens KY was increased as follows, tryptone > yeast extract > beef extract > asparagine.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.63-67
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• 2002

Bifidobacterium strain was isolated from the feces of brast fed infants. The isolated strain was identified as Bifidobacterium longum by 16S rRNA sequence analysis and named as Bifidobacterium SH2. The MRS medium was modified to obtain high density cells of Bifidobacterium SH2. The optimal medium was determined to be 50 g/L lactose, 10 g/L beef extract, 10 g/L peptone, 5 g/L yeast extract, 7 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L disodium phosphate,1 g/L tween 80, 0.2 g/L MnSO$_4$ and 0.5 g/L L-cysteine. The pH and temperature were optimized as 5.0 and $37^{\circ}C$, respectively. Through out the optimization of medium composition and culture conditions, the dry cell weight and viable cell count were 2.5 times and 1.8 times higer than those in MRS medium, respectively.

• 축산식품과학과 산업
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• v.9 no.2
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• pp.66-73
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• 2020

• Food Science and Biotechnology
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• v.17 no.3
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• pp.651-654
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• 2008

In order to enhance the efficacy of norovirus detection by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR, this study developed a norovirus mRNA concentration method using poly oligo dT-conjugated magnetic beads. An efficient norovirus detection protocol was performed on commercial ham using 2 viral elution buffers (glycine buffer and Tris beef extract buffer) and 2 concentration solutions [polyethylene glycol (PEG) and zirconium hydroxide]. The different approaches were verified by RT-PCR and nested PCR. This method was performed on ham in less than 8 hr by artificial inoculation of serial dilutions of the virus ranging from 1,000 to 1 RT-PCR unit/mL. The viral extraction and concentration method had 10-fold higher sensitivity using the combination of Tris beef extract buffer and PEG as compared to glycine buffer and zirconium hydroxide. This method proved that RT-PCR and nested PCR have the sensitive ability to detect norovirus in commercial ham, in that norovirus was successfully detected in artificially contaminated samples at a detection level as low as 1-10 RT-PCR unit/mL. Overall, such a detection limit suggests this protocol is both quick and efficient in terms of its potential use for detecting norovirus in meat products.

• Journal of Life Science
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• v.10 no.4
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• pp.368-373
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• 2000

Enteroviruses in the environment pose a public health risk because they can be transmitted via the fecal-oral route through contaminated water, and low numbers are able to initiate an infection in humans. Because the levels of viruses typically found in environmental water and drinking water are low, they must be concentrated from hundreds to thousands of liters of water. Therefore, the main goal of this study was the development of a rapid, simple and efficient procedure to concentrate, isolate and detect enteroviruses from environmental water samples. Viruses were first concentrated by adsorption to 1 MDS cartridge filter and then eluted with approximately 0.5 liter of 1.5% beef extract/0.05M glycin(pH 9.4). In this study, several procedures to concentrate and purify intact viruses from beef extract obtained from the adsorbent filters were tested. Among them, organic floccuration was the best reliable method for reconcentration. sample volume could be reduced to 200∼400 folds and the efficiency of virus recovery through the procedure was over 72%. Finally, the samples were filtered through a membrane disk filter and then analyzed by either the plaque assay or combined cell culture-polymerase chain reaction.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.411-416
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• 1990

Microbiological conversion of sterols to 17-ketosteroids has been recongnized as a source for commerical preparation of steroidal drugs. For the purpose of strain development, we isolated microorganisms through enrichment culture method and identified an isolate strain. The strain was closely related to Brevibacterium ergthrogenes. The optimal conditions for 1, 4-androstadiene-3, 17-dione (ADD) formation were as follows; pH 7.4, lactose 0.2%, beef extract 0.2%, bentonite 0.5% in the chlolesterol fermentation medium. Maximum production was obtained with the addition of $\alpha$, $\alpha$'-dipyridyl (1 mM, final conc.) at 17-20 hours after incubation.