• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.1-4
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• 1985

For the systematic investigation of biochemical characteristics of Korean ginseng protein by years, protein fractions were analyzed by the techniques of polyacrylamide gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration, while the amino acid composition was studied by amino acid autoanalyzer. Results of polyacrylamide gel electrophoresis and SDS-PAGE showed a few difference in pattern and number of bands depending on the age of the root. However, the number of bands obtained from polyacrylamide gel electrophoresis and SDS-PAGE was 8 and 7 to 11, respectively. When water extracted proteins were fractionated by Sephadex G-200, the main peak among 2 peaks was collected and lyophillized. Its mol. wt. was extimated to be 43,000 by the SDS-PAGE method. In amino acid composition of water extracted protein and main fraction of gel filtration, arginine content was the highest, 47.17% in water extracted protein and 57.36% in main fraction followed by glutamic acid and asparatic acid. On the contrary, cystine and methionine contents were very low in both cases.

• Journal of Nutrition and Health
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• v.13 no.3
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• pp.150-154
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• 1980

For the purpose of clarifying the changes of free amino acid content in seeds of Korean mung bean during the ripening process, samples ranging in five stages-10, 15, 20, 25 and 30 days after blooming were collected. The results obtained were as follows: 1) Amino acids detected in the first stage were lysine, histidine, arginine, cystine, aspartic acid, threonine (including serine), glutamic acid, valine, methionine sulfoxide and methionine sulfone. 2) In the second stage (15 days after blooming) more amino acids such as glycine, isoleucine, tyrosine, phenylalaninc, and methionine were detected in addition to those in the first stage. More methionine was appeared, while the level of methionine sulfoxide and methionine sulfone was decreased. 3) In the 3rd stage leucine was first detected. The level of leucine was increased slowly as the seed was being ripened. After 4th stage methionine sulfoxide and methionine sulfone were not detected, while the level of methioniene was steadily increased. 4) After 20 days the levels of lecuine, valine. isoleucine, and methionine were increased, while the others were either decreased or remained at the same level.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1137-1143
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• 1999

The change of physicochemical characteristics of sesame with roasting temperature$(110^{\circ}C{\sim}230^{\circ}C)$ were investigated to get a useful index which needs to manufacture roasted sesame and sesame oils, In the physicochemical properties of roasted sesame, the contents of moisture, specific volume, oil yields and sesame cakes were changed significantly above $170^{\circ}C$. Fat and protein in sesame cakes were changed slightly. Desirable roasting temperature was $220^{\circ}C$ in considering oil yields and sensory qualities. Total amino acids such as arginine, serine, threonine, lysine. cystine, tyrosine and most of the free amino acids, and sucrose of free sugars were reduced significantly above $170^{\circ}C$ and $190^{\circ}C$. respectively. These reductions of sugar and amino compounds were assumed to play an important role in Maillard reaction for the formation of browning pigment, taste and aroma. It was confirmed that this reaction was pyrolytic degradation which took place in water-deficient and oil-rich system at relatively high temperature.

• KSBB Journal
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• v.9 no.1
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• pp.55-62
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• 1994

Glucose oxidase(EC 1.1.3.4) was purified to electrophoretic homogeneity from Aspergillus niger by a combination of ammonium sulfate fractionation, ion exchange chromatography, and ultrafiltration. Two active fractions A and B, of glucose oxidase were obtained from the hydrophobic chromatography on phenyl sepharose CL-4B. The enzyme A and B were glycoproteins with the same denatured molecular weight of 78, 000 and had specific activities of 2, 191 and 1, 273-units/mg proteins, respectively. But the two enzymes showed differences in native molecular weight that was measured by HPLC gel filteration, maximum absorbtion wavelength and isoelectric point. The enzyme A oxidized $\beta$-D-glucose only and was resistant to sodium dodecyl sulfate. Activity optimum was found at $30^{\circ}C$ and pH 3.5. Also the enzyme A was inhibited greatly by $Hg^{2+}$(10mM). The results of chemical modification experiments suggested that cysteine and cystine residues might be involved in the active site of the enzyme A.

• Plant Resources
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• v.1 no.2
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• pp.113-120
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• 1998

Soybean is an important crop because its seed has very high protein relative to others. The quality of soy protein is limited by the concentration of the sulfur-containing amino acids in the amino acid profile. Among the supply of various forms of 0.4mM sulfur as S nutrition during seed fill. only 0.4mM L-methionine can inhibit ${\beta}$-subunit synthesis completely and produce the highest glycinin-containing seeds. Compared to 0.4mM sulfate control, seeds supplied by 0.4mM L-methionine have lower ${\alpha}$-, no ${\beta}$-subunit, and highly increased glycinin without altering total protein concentration. Supply of 0.2mM cystine (0.4mM S) did not affect the accumulative pattern of seed storage protein (SSP) subunits. In the supply of L-methionine, 0.2mM treatment showed higher glycinin in seeds but 0.05mM resulted in lower glycinin than tile sulfate control. The relative abundance of ${\alpha}^`$-subunit was not altered by any N or S nutrition. Under 5mM nitrogen, protein concentration was increased about 3-5% by substituting ammonia for nitrate during seed fill independent of nutrition. The increase resulted in the only increase of 7S protein, mainly ${\beta}$-subunit. Our data suggest that the regulatory system of SSP genes responds to the balance between N and S assimilates supplied from mother plant. and controls the di fferential synthesis of their subunits for the maximum protein accumulation in developing soybean seed.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.261-266
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• 1988

For the effective utilization of Wild Korean lettuce(Youngia sonchifolia Max.), the chemical characteristics, contents of free sugar, amino acid composition, fatty acid composition and minerals were analysed. Free sugars determined from the roots were rhamnose, fructose, glucose, sucrose maltose, melibiose and raffinose, whereas raffinose was not detected from the leaves. Of amino acid composition in the roots glutamic acid content was largest followed by histidine aspartic acid, leucine and proline. As for leaves glutamic acid was highest fellowed by aspartic acid, leucine and histidine. Mtehionine and cystine were found in low content in both roots and leaves. Major fatty acid composition in total lipid(free and bound) were linoleic, linolenic and palmitic acid in both and leaves. P, K and Ca were rich minerals contained in the roots and leaves of Wild Youngia sonchifolia Max.

• Korean Journal of Food Science and Technology
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• v.12 no.3
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• pp.205-208
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• 1980

Protein content and amino acid composition of three prospective Korean wheat varieties (Youngkwang, Wonkwang and Chokwang) were studied from the viewpoint of baking performance. 1. Protein contents of Korean varieties were Less than 10% which were relatively lower than the U. S. baking standard. These levels were considered insuffcient for best baking performance. 2. Compared to U. S. baking standard, Korean wheat varieties showed slightly lower level of glutamic acid, which is considered to play an important role in baking performance of flour. Approximately 25% decrease in glutamic acid content was observed in Korean varieties when the absolute amount of glutamic acid per unit sample size was compared. 3. Korean wheat varieties showed similar levels of proline and cystine, slightly higher levels of lysine, ammonia and aspartic acid; and slightly lower level of essential amino acids compared to the U. S. baking standard. 4. Protein content and amino acid composition of Korean wheat varieties were considered to be intermediate of U. S. baking and cookie standards. From this viewpoint, Youngkwang showed the greatest potential for best baking performance among Korean varieties.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.281-286
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• 1995

In order to get basic information for utilization of yong leabes of medicinal herbs as vegetable, 7 species leaves of medicinal herbs were analyzed. The moisture content in 6 species leaves were 79.74 to 85.97%. The raw protein content were about 2% except Angelica gigas (1.12%) and Peucedanum japonica (1.27%). The raw fat were 0.96 to 1.36%, the raw fiber were 1.8 to 3.9% and the raw ash were 1.58 to 2.79%. There content of medicinal herbs were similar to general vegetables. The K contents were the highest among the medical components in all samples. The total contents of amino acid in Aralza elata was 965mg%, Scutellaria baicalensis 930mg%, Aralia cordata 879mg%, Angelica acutiloba 851mg%, Agastache rugosa 747mg%, and Peucedanum japonica 615mg%, Aspartic acid and glutamic acid in amino acid were generally the highest but methionine and cystine the lowest.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.88-91
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• 1985

For the systematic investigation of biochemical characteristics of Korean ginseng protein, protein fractions were analyzed by the techniques of sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The effect of pH and various salts on extractibility of ginseng protein were determined while the amino acid composition was studied by amino acid autoanalyzer. The protein was consisted of 66.08% of albumin and 20.51% of glutelin. Extractability of ginseng protein was the lowest in pH 3.0 and the highest in $pH\;6.0{\sim}8.0$. Among the neutral salts solution, $0.4M\;Na_2CO_3$ showed maximum extractability while $1.0M\;MgSO_4$ solution showed the least extractability. Resonable precipitation was obtained by 40% of acetone and ammonium sulfate. It has been shown by SDS polyacrylamide gel electrophoresis that the soluble protein had 11 bands. The molecular weight for the main protein of the soluble protein wasestimated to be 43,000. In amino acid composition of water extracted protein, arginine content was the highest 47.17% while on the contray, proline and cystine contents were very low.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.132-138
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• 1992

For effective determination of methylthiohydantoin amino acids(MTHs) by gas liquid chromatography in the protein sequencing, derivatization with N-methyl-N-(tert.-butyl-dimethylsilyl)trifluoroacetamide(MTBSTFA), a new silylating reagents, was attempted instead of trimethylsilyl(TMSi) derivatives by N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) used up to the present and N(O)-butyldimethylsilyl MTHs derivatized by MTBSTFA were analysed on HP-1 capillary column. Twenty one protein amino acids except cystine were indentified. Especially arginine that did not detected with TMSi derivative on packed column until now was resolved by derivatization with MTBSTFA. N(O)-butyldimethylsilyl MTHs showed multiple peaks by MTBSTFA were proline, isoleucine, glycine and tyrosine and hydroxyproline especially showed several extraneous peaks more than two. Calibration curves of N(O)-butyldimethysilyl MTHs of amino acids in the range of $2.5\;nmol{\sim}7.5\;nmole$ showed good linearity. however, those of lysine, histidine and arginine showed linearity in the range of $5.0\;nmole{\sim}15.0\;nmole$. Correlation coefficients and regression coefficients of all calibration curves were highly significant(p<0.001).