• Food Engineering Progress
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• v.15 no.2
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• pp.143-147
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• 2011

For efficient extraction of protein from defatted rice bran, the 5 ranges of extraction pH (8, 9, 10, 11 and 12) and the 3 ranges of isoelectric precipitation pH (2, 4 and 6) were used. The protein content, browning reaction, the electrophoresis pattern and the recovery yield of soluble protein at each pH range were compared each other. The recovery yield of soluble protein increased in proportion to extraction pH, but at the same time, browning reaction became more conspicuous. The most amount of protein was recovered at the precipitation pH of 4. The SDS-PAGE patterns of the extracted proteins showed no significant correlations between pH and the protein content, but the highly alkaline condition was more advantageous to extract protein less than 35 kDa. In each pH range, the recovery yield of soluble protein averagely reached 32.5% on the basis of extraction. In result, it was found that combination of extraction pH 10 and precipitation pH 4, which resulted in 37.65% of recovery yield and low level of browning reaction, was the optimum condition for the extraction of protein from defatted rice bran.

• Food Engineering Progress
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• v.15 no.2
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• pp.175-181
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• 2011

By using supercritical carbon dioxide fluid, an attempt was made to extract surface-active substances from defatted rice bran. Extraction was carried out according to D-optimal design and results were analyzed by response surface methodology to establish optimum condition. It was found that pressure, temperature and co-solvent (ethanol) influenced in a different extent on the extraction efficiency (i.e., yield and interfacial tension) of surface-active substances. Among them, co-solvent was found to be a major influencing factor, where maximum yield (2.62%) was observed at the highest content (250 g). In addition, it also affected most on the interfacial tension at the oil-water interface but in this case the lowest interfacial tension value (9.51 mN/m) was found when added lowest (50 g). In conclusion, it was estimated that the optimum extraction condition was to be pressure 350bar, temperature $62^{\circ}C$ and co-solvent content 50 g in this study, where extraction yield was 0.69% and interfacial tension to be 10.1 mN/m.

• KSBB Journal
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• v.18 no.6
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• pp.466-472
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• 2003

Several microorganisms were isolated and characterized for the development of fermentation accelerator of animal manure. Firstly, 61 species were isolated from rice bran extract. Secondly, five strains of microorganisms were screened by the analysis of hydrolysis activities for organic compounds including protease, cellulase, amylase, and lipase. From a deodorization test for ammonia gas using the isolated strains, finally three bacterial strains were selected (NA 2, 12, 15). The selected strains, NA 2 and 15 were identified as Bacillus acidocaldarius and Planococcus sp. respectively. The media composition of key nutrients and pH for the mixed culture of the three selected strains were optimized using an experimental design method (response surface method) as follows : beef extract (4.59g/L), peptone (8.72g/L) and pH 6.3. Consequently, the isolated microorganisms seem to have potential applicability in the animal manure treatment.

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.214-222
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• 2016

This study was performed to increase the production of ${\gamma}$-aminobutyric acid (GABA) by lactic acid bacteria (Lactobacillus brevis CFM11) and manufacture an optimum medium using the sap from Darae (Actinidia arguta). The concentration of GABA in the fermented sap was determined using GABase enzymatic assay. The isolated L. brevis CFM11 produced $605.67{\mu}g/mL$ GABA after incubation for 24 hours at $37^{\circ}C$ in broth. The sap was fermented by L. brevis CFM11 under optimum conditions of $32^{\circ}C$ for 48 hours with 40% rice bran extract, 1.0% sucrose, 3.0% soytone, 0.2% magnesium sulfate, and 0.2% MSG. The fermented sap produced a concentration of $1366.13{\mu}g/mL$ GABA. These results demonstrate that fermenting Darae sap using L. brevis CFM11 can produce a fermented sap beverage with increased GABA content.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.195-203
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• 2015

Two bacterial strains, Bacillus licheniformis YB-1413 and YB-1414, producing extracellular α-galactosidase, were obtained from homemade Doenjang. On the basis of their biochemical properties, 16S rRNA sequences and random amplified polymorphic DNA patterns by polymerase chain reaction, they were found to be somewhat different from one another. α-Galactosidase productivities of the two isolates were increased by wheat bran, but drastically decreased by melibiose, raffinose and sucrose which were used as carbon sources. The enzyme productivities were increased by yeast extract as a nitrogen source with maximum levels of 1.87 U/ml for YB-1413 and 1.69 U/ml for YB-1414, respectively. The enzymes of both isolates exhibited maximum activity for hydrolysis of para-nitrophenyl-α-D-galactopyranoside (pNP-αGal) under reaction conditions of pH 6.0 and 45℃. Their hydrolyzing activities for pNP-αGal were drastically decreased by the addition of low concentrations of ribose and galactose. They were capable of hydrolyzing completely α-1,6 linked galactosyl residue in melibiose, raffinose and stachyose, which are known to be anti-nutritional factors in products of soybean and legume. In relation to the latter, the isolates YB-1413 and YB-1414 have potential applicability in improving soybean-fermented foods and the nutritional value of soybean feed.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.40-46
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• 2006

A bacterial strain producing high level of a phytase was isolated from cattle feces and identified as Bacillus subtilis, and designated as Bacillus sp. CF 5-26. The production of the phytase from Bacillus sp. CF 5-26 reached the highest level after 72 hours at $37^{\circ}C$. The optimum condition of the media for the production of phytase was 10% rice bran extract, 0.1% whey protein powder, $0.01%\;CaCl_{2},\;0.01%\;KH_{2}PO_4$. The phytase was purified 20.3 folds with ethanol precipitation, Sephadex G-100, CM Sepharose CL-6B and Sephacryl S-100-HR column chromatography. The molecular weight of the purified enzyme was estimated to be 66 kDa on SDS-polyacrylamide gel electrophoresis. The purified phytase activity was stable up pH 5.0, 7.0, 11.0 and the remaining activity was 50% when it was treated at $100^{\circ}C$ for 1 hour. The substrate specificity of phytase was most active against sodium phytate and inositol polyphosphate compound. And the phytase hydrolysed tripolyphosphate and pyrophosphate a little. The Km value for the sodium phytate was 0.64 mM and the Vmax value was $4.41\;{\mu}mol/min$.

• Journal of Mushroom
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• v.10 no.1
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• pp.21-28
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• 2012

Studies were made to optimize the media composition and cultural condition for mycelial growth of Agrocybe cylindracea. Sawdust spawn of media composition for optimal growth was found to be pine sawdust combination of 30% wheat bran and poplar sawdust combination of 20% corn bran were the best of the optimal combination. The optimal concentration of white sugar was 1.0~1.5%. The nitrogen sources was found to be yeast extract and soybean powder. Also, optimal concentration were $0.7g/{\ell}$ and $0.1g/{\ell}$, respectively. The mineral sources of optimal medium compositions were $MgSO_4{\cdot}7H_2O\;0.3g/{\ell}$, $KH_2PO_4\;0.5g/{\ell}$ and $K_2HPO\;1.2g/{\ell}$. Optimal amount of inoculum for cultivation of A. cylindracea were $20{\sim}25g/850m{\ell}$ and $25m{\ell}/850m{\ell}$ in the sawdust spawn and liquid spawn, respectively.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.45-54
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• 1998

A thermotolerant bacterium, Streptomyces thermocyaneoviolaceus which produced xylan-degrading enzymes, utilized excellently xylan of wheat bran by producing the enzymes in comparison with that of birchwood or oat spelts. Optimal enzyme production was achieved in WB medium containing 0.8% wheat bran, 0.06% yeast extract, 0.06% bactopeptone, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $FeSO_4{\cdot}7H_2O$, 0.05% $KH_2PO_4$ and, 0.2% $K_2HPO_4$(pH 7.0) at $50^{\circ}C$ for 24 hrs. The optimal pH and temperature for the hydrolysis of xylan were pH 5.5 and $65^{\circ}C$, respectively. The enzyme activity was retained more than 80% at the range from pH 4.5 to pH 9.5 at $4^{\circ}C$ for 12 hrs and 94% on the heat-treatment at $65^{\circ}C$ for 1 hr. Xylobiose, xylotriose, xylose, and other xylooligosaccharides were produced as end products from hydrolysis of birchwood xylan by the xylanase of S. thermocyaneoviolceus.

• KSBB Journal
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• v.25 no.3
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• pp.277-282
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• 2010

This study was performed to investigate the composition of amino acids and biological properties with the ethanol extract of fruiting bodies of Pleurotus eryngii grown on the sawdust compost mix (400 g sawdust plus 200 g rice bran) supplemented with various dosages of monosodium glutamate (MSG). Amino acid composition analyses showed that arginine, glutamic acid, alanine and glycine increased as the dosage of MSG was increased, whereas histidine, serine, methionine, isoleucine, leucine and phenylalanine did not increase. $\gamma$-Aminobutyric acid (GABA) content increased significantly up to 1.18 mg/g extract when 6 g MSG was supplemented to the sawdust mix. Antioxidant activity of the extract was estimated and compared to the standard antioxidant (ascorbic acid). The antioxidant property such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity increased with the extract samples of increasing dosage of MSG. Although the extract showed low levels of nitrite scavenging activity, this activity increased up to 1.5-2.0 fold when MSG was supplemented to the sawdust mix above a dosage of 0.5 g. The results obtained from the present investigation would appear that Pleurotus eryngii grown on the MSG-enriched sawdust mix can be used more effectively as one of potential sources of functional foods.

• Journal of Mushroom
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• v.4 no.2
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• pp.62-67
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• 2006

Pholiota nameko is one of the four major profitable mushrooms along with oak mushroom, winter mushroom, and oyster mushroom. It contains abundant proteins, carbohydrates, organic acids and vitamins. Its unique taste and flavor as well as its nutritional features make it widely favoured. Mushroom complete medium was the optimal medium for mycelial growth of Pholiota nameko. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and 5.0, respectively. The best carbon sources for mycelial growth were glucose and mannose, and the best nitrogen sources were yeast extract, peptone, asparagine, etc. The 8:2 ratio mix of oak sawdust and wheat bran was the best for the bottle cultivation. The best mushroom was yielded after 30 days incubation. The best yield was produced with 850g of medium weight in a PP bag and bottle.