• Applied Biological Chemistry
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• v.12
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• pp.19-24
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• 1969

As a one of the new methods for soybean protein food processings, an attempt was made to decompose steamed soybean protein to amino acids, peptides, and other water soluble forms by the use of protease produced by Aspergillus sojae, and extract them to use as additives of low protein foods or weaning-foods of children. In this paper, as a one part of this subject, the optimum condition, such as optimum pH, temperature, digestion period, raw material's mixing ratio with wheat meal, amount of water added, and effect of sodium chloride addition, to decompose and extract soybean protein were studied. They were obtained when mixing raw materials with wheat meal in the ratio of 10:4 and adding six folds of water at $40-45^{\circ}C$, pH 5-8 for 18 hrs. digestion. Although sodium chloride addition exerted an unfavorable influence upon the decomposition of the aforementioned materials, it was effective to prolongation of digestion period. Under the abovementioned optimum conditions, the maximum extractability of soybean protein as forms of amino acids, peptides, and other water soluble forms, was nearly 70 percent against protein content of raw materials.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.251-255
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• 2019

The effect of soaking temperature on the moisture uptake and the protein loss of soybeans during soaking process investigated. As the soaking temperature increased, the soaking rate significantly increased and Peleg model was suitable for describing the soaking characteristics of the soybean with high $R^2$ values (>0.991). The soaking time to achieve the target moisture content of soybean (130%) was estimated to be 12.6, 3.11 and 2.31 h at 25, 35 and $45^{\circ}C$, respectively. Peleg model well described the protein loss kinetics of soybean during soaking with high $R^2$ values (>0.941). The results showed that the protein loss of soybean at the target moisture content were 35.2, 93.1 and 103.0 mg/g at 25, 35 and $45^{\circ}C$, respectively. In this study, the optimum soaking condition for quality of soybean was 12.6 h of soaking time at $25^{\circ}C$.

• KSBB Journal
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• v.18 no.2
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• pp.122-126
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• 2003

Multi-cycle chromatographic separation of Iysozyme from egg white was investigated. Multi-cycle chromatography was performed by repeated cycling(one cycle: resin equilibration, sample loading, washing, elution). Two types of cation exchange resins, Cellufine CM C-200 and Bio-rex 70, were used to determine the optimum condition for the separation of Iysozyme by multi-cycle chromatography. The resin was equilibrated in 20 mM Na-phosphate buffer(pH 7.0). Chromatograms of UV absorbance levels of every cycle were compared to confirm the eluting ability of Iysozyme in the two types of gel. Collected samples from eluting regions in every cycle were assayed by 15% SDS-PAGE.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1067-1070
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• 1997

Imunoglobulins from bovine plasma proteins were isolated by IMAC which $Cu^{2+}$ was chelated on a chelating sepharose fast flow gel. Most plasma proteins were eluted by 1st (0.01 M $Na_2HPO_4$, 0.5 M NaCl, pH 4.0) and 2nd elution buffers (0.01 M imidazol). According to the reverse phase HPLC analysis, it was found that proteins which were eluted by 1st elution buffer were mainly composed of serum albumin, while most IgG and transferrin were eluted by 2nd elution buffer. When protein fractions obtained by 2nd elution buffer was applied to ultra filtration system (molecular weight cut off: 100 kD), IgG was further purified. These results indicate that IMAC is an excellent tool for isolating imunoglobulins from plasma proteins.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.725-732
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• 2015

This study was conducted to compare the physicochemical and sensory characteristics of beef-bone broths prepared under atmospheric pressure (BBAP) and overpressure (BBOP). Beef-bone was boiled in water (bone/water=1:2, w/w) for 1, 2, 4, 6, and 12 h under atmospheric pressure and overpressure ($121^{\circ}C$, 1.25 atm). The BBOP broth samples were found to contain significantly higher amounts of solid, crude protein, crude ash, collagen, and chondroitin sulfate than the BBAP broth samples for a given boiling time (p<0.05). In addition, the Ca and Mg contents in the BBAP samples were higher than those in the BBOP samples, whereas the P, Na, and K contents were higher in BBOP than BBAP. The L value of BBAP was also significantly higher than that of BBOP (p<0.05). Further, as the boiling time increased, turbidity increased in the BBAP samples. In the quantitative descriptive analysis, the BBOP samples exhibited stronger brownness, transparency, meaty off-odor, meaty off-flavor, and sulfuric odor than the BBAP samples.

• Food Science and Preservation
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• v.22 no.2
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• pp.256-260
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• 2015

This study investigated the optimum pH condition for the efficient extraction of protein from Gastrodia elata Blume. Five extraction pH values (8, 9, 10, 11, and 12) and three precipitation pH values (2, 4, and 6) were used. The protein content, browning degree, and recovery yield of the protein obtained under each pH condition were determined. Most of the G. elata Blume was made up of carbohydrates, and its protein content was also high. The amount of the extracted protein increased according to the increase in the extraction pH, but did not significantly differ between pH 8 and pH 9. The browning degree of the protein significantly increased as the extraction pH increased. The greatest amount of protein was precipitated at pH 4, the recovery yield of which was also the highest. As a result, it was found that the combination of extraction pH 9 and precipitation pH 4, which resulted in a 38.7% recovery yield and a low browning degree, is the optimum condition for the efficient extraction of protein from G. elata Blume.

• 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.

• Applied Biological Chemistry
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• v.36 no.2
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• pp.121-126
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• 1993

To extract insoluble proteins of sesame meal residue by using microorganism, the sesame meal residue was treated with crude enzyme solution from Bacillus sp. CW-1121. It was found that the solubility reached to maximum at pH 7.5, $45^{\circ}C$. Under optimum condition, the nitrogen solubility with the enzyme solution from Bacillus sp. CW-1121 reached to 60% in 2 hours. Nitrogen solubility of protein from sesame meal showed minimum value at pH 4.5 and significantly increased above pH 6.0. When the protein from sesame meal extracted with Bacillus sp. CW-1121 was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, water soluble protein was showed 4 bands and salt soluble protein was showed 2 bands. The amino acid composition of water soluble protein, salt soluble protein and free amino acid indicated relatively high contents of serine (17.24 mg/g), glutamic acid (10.77 mg/g) and glutamic acid (6.55 mg/g). Specially, the contents of essential amino acids were high.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.13-17
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• 1998

To improve extraction of insoluble proteins and functional properties of abolished proteins by protease. It was found that the optimum pH, optimum temperature, optimum treatment time and optimum unit of enzyme far extraction of protein were pH 9.0, $60^{\circ}C$, 8 hrs, 40 units. The foaming capacity and foaming satbility of sesame meal protein after treatment of enzyme were especially higher than control. The emulsion capacity and emulsion satbility of sesame meal protein were higher than control. Coil absorption as well as water absorption capacities of sesame meal protein were higher than control.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.282-286
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• 1990

To extract insoluble proteins of soymilk residue by microorganism the soymilk residue was treated with crude enzyme solution from Bacillus subtilis IAM 1071 natto. Optimum conditions of pH, temperature, and digestion time were determined, and amino acid composition of the extract was obtained at $45^{\circ}C$. Under optimum conditions, the extractability with natto reached to 65% in 15hrs. The contents of essential amino acids of extract were high and specially, S-containing amino acids including methonine and cysteine and Lysine content were high.