• 한국자원식물학회지
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• 제30권6호
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• pp.670-678
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• 2017

Persimmon seeds contain considerable amounts of minerals, amino and organic acids, natural antioxidants and phenolic compounds. The objective of this study was to investigate quality characteristics and antioxidant potential of Korean persimmon seeds. The pH (4.88-4.94), color values, contents of minerals, free amino acids, organic acids, and phenolic compounds and DPPH free radical scavenging potentials of persimmon seed extracts significantly (p < 0.05) varied with the genotypes. This study showed that the seeds could be used as a source of different mineral elements (47.14-85.07 mg/kg) without any measureable amount of heavy metals such as arsenic, cadmium, lead and mercury. Similarly, considerable amounts of organic (1550.13-2413.08 mg/kg) and essential amino (50.85-54.03 mg/kg) acids and total phenolic compounds ($1227.91-1307.78{\mu}g$ gallic acid equivalent/g) were also found in the seed extracts, indicating their potential food value as a natural antioxidant. Results of the present study imply that prethanol-A, a food preservative, can be used as an effective extraction to obtain the minerals, organic and free amino acids, and phenolic compounds from the persimmon seeds, which possess a big potential to be commercially used in food, cosmetic and pharmaceutical industries.

• Bulletin of the Korean Chemical Society
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• 제10권6호
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• pp.491-495
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• 1989

Resolution of enantiomers of DNS-amino acids has been achieved by a reversed phase liquid chromatography with an addition of a copper(Ⅱ) complex of N-benzyl-L-hydroxyproline to the mobile phase. N-Benzyl-L-hydroxyproline was prepared and used as a chiral ligand of copper(Ⅱ) chelate for the optical resolution. The pH and the concentration of copper(Ⅱ) chelate, organic solvent, and buffer agent in the mobile phase all affect the optical resolutions of dansyl amino acids. The elution orders between D and L-DNS-amino acids were different depending on the structure of the side chain of the amino acids. The retention mechanism for the chiral separation of the dansyl amino acids can be illustrated by the equilibrium of ligand exchange and by hydrophobic interaction with $C_{18}$ stationary phase. The chiral separation can be illustrated with cis and trans effect of the ligand exchange reaction.

• Bulletin of the Korean Chemical Society
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• 제13권3호
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• pp.280-285
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• 1992

Enantiomeric separation of free amino acids has been achieved by a reversed phase liquid chromatography with addition of a Cu(Ⅱ) complex of N-alkyl-L-proline (alkyl: propyl, pentyl or octyl) to the mobile phase. The amino acids eluted were detected by a postcolumn OPA system. N-alkyl-L-proline was prepared and used as a chiral ligand of Cu(Ⅱ) chelate for the enantiomeric separation. The concentration of the Cu(Ⅱ) chelate, the organic modifier and pH affect the enantiomeric separation of free amino acids. The retention behaviour, varied with change in pH and the concentration of the Cu(Ⅱ) chelate, was different compared with those of the derivatized amino acids. The elution orders between D- and L-forms were consistent except histidine showing that L-forms elute earlier than D-forms. The retention mechanism for the enantiomeric separation can be illustrated by the stereospecificity of the ligand exchange reaction and the hydrophobic interaction between the substituent of amino acids and reversed phase, $C_18$.

• 한국식품조리과학회지
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• 제16권2호
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• pp.173-181
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• 2000

To understand the influences of NaCl concentration and fermentation temperature on the ripening process of low salt fermented squids, squid with 5%, 7% and 9% salt were fermented at 10$\^{C}$ and 20$\^{C}$. The result of the changes of volatile basic nitrogen and free amino acids during the fermentation of squids are as follows. As a result of the observations on the changes of physicochemical components during the fermentation process of the low-salted squids, all the pH, VBN and NH$_2$-N were increased and therefore the fermentation was promoted. Considering the changes of net components according to the fermentation, ATP (Adenosine triphosphate) and ADP (Adenosine diphosphate) lost and could not be detected among the nucleotides and their related compounds. Besides, AMP (Adenosine monophosphate) existed only in the initial stage and inosine, hypoxanthine were the main components of nucleotides and their related compounds. Nonvolatile organic acids are mainly lactic acid, acetic acid and also they occupied more than 80%. Seeing the composition of free amino acid, the major amino acids are proline, arginine, methionine, alanine and glutamic acid.

• 한국식품영양과학회지
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• 제29권2호
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• pp.211-217
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• 2000

To standardize quality characteristics of commercial doenjang prepared by traditional method, general components, organic acids, amino acids and fatty acid composition were investigated. Moisture, crude protein, crude lipid, titratable acidity (expressed as milliliter of 0.1 N NaOH), acid value and salinity were 54.7%, 13.8%, 8.0%, 14.4mL, 45.7mg/g and 11.8%, respectively. The content of amino type nitrogen was 345.3mg% (w/w) in the range of 207.6 to 443.5mg% being 1.1~2.2-fold for all samples. Average value of Hunter color for L(lightness), a(redness) and b(yellowness) were 37.4, ＋9.7 and ＋21.3, respectively. Browning index value(expressed as optical density at 425 nm) of water-soluble compound(2.58) was above 7.1 times higher than that of the water-insoluble compound(0.38). Total contents of free and total amino acid were 3.81 and 9.72%, respectively, and then the former(1.1~3.7 times) was more different in all samples tested than that of the latter(1.1~2.0 times). Among amino acids, glutamic acid was abundant and its content of free and total amino acids was 0.57 and 1.24%, respectively. Of organic acids, lactic acid was the most abundant being 0.34%(average) and ranged from 0.15 to 0.86%. Linoleic acid(52.17%, as area%) was the highest content of the total fatty acids. Unsaturated and polyunsaturated fatty acids were 83.89 and 61.189%, respectively. Polyunsaturated fatty acid was markedly different among all samples and ranged from 51.52 to 64.91%.

• 한국식품영양과학회지
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• 제27권1호
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• pp.10-15
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• 1998

In order to establish the quality standard of commercial soybean paste, pH, color, moisture, crude protein, isoflavone, free amino acid and organic acid contents of the fermented soybean food in both traditional and commercial products were analyzed. The crude protein contents were from 5.0 to 11.9% in commercial soybean pasted of Samjang and traditional soybean paste of Chungugjang, and the latter showed higher value than those of the former. The contents of isoflavones in commercial soybean paste were less than those of traditional soybean paste. Total contents of free amino acids were distributed from 301 to 4,602mg%, respectively, in which Chungugjang showed the smallest value of 301mg% and the traditional soybean paste showed the most abundant one of 4,602mg%. The ratio of glutamic acid to total free amino acids were 15.9% and 30.1% in traditional soybean paste and commercial soybean paste, respectively. The major organic acid both commercial soybean paste and Samjang was citric acid containing 109.9~196.5mg%. On the other hand, that of traditional soybean paste and Chungugjang was oxalic acid containing 82.8~130.1mg%. This results might be caused by the differences of brewed periods, microflora, processing methods and used raw materials.

• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.411-415
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• 1990

The dabsylation of amino acids has been applied to resolve their optical isomers with the use of chiral mobile phase in high performance liquid chromatography. The dabsyl amino acids were successfully separated on reversed phase column($C_{18}$) by adding a chiral L-benzylproline-Cu(II) chelate to the mobile phase. The separation selectivity of the dabsyl amino acid enantiomers was not less than that of dansyl amino acids. The retention order of the dabsyl amino acid enantiomers was as those of the dansyl amino acid enantiomers except dabsyl threonine. The optical selectivity of the dabsyl amino acids increase with pH of the mobile phase and concentration of the chelate, but slightly decreases with concentration of buffer and organic solvent composition. However serine, methionine, valine, and leucine showed a slight decrease in the optical selectivity with increase in pH. The retention times of the dabsyl amino acids decreases with increasing pH and acetonitrile concentration but increases with the concentration of the chiral chelate added. The mechanism of the optical resolution is based on a stereospecific interaction including a intramolecular hydrophobic effect and SN-2 reactivity of the ligand exchange chromatography.It is advantageous to detect absorption at 436 nm, which is less interferent them the other detection systems. The derivatized dabsyl amino acids are stable for a month.

• 한국식품영양과학회지
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• 제34권5호
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• pp.681-686
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• 2005

동백잎의 채취시기에 따른 일반성분, 유리당, 유기산, 아미노산, catechin, chlorophyll 및 total polyphenol 등의 함량은 다음과 같다. 동백 잎의 조단백과 조지방 및 ascorbic acid 함량은 채취시기가 늦을수록 감소하였고, 조회분과 조섬유 함량은 채취 시기가 늦을수록 증가하는 경향을 보였다. 유리당은 fructose, glucose, sucrose 등 3개의 당이 확인되었고, 총 유리 당 함량은 채취시기가 늦을수록 증가하였다. 유기산은 citric acid, tartaric acid, succinic acid, acetic acid 등이 검출되었고, 채취 시기가 늦을수록 총함량은 증가하였다. 동백잎의 주된 유리아미노산은 aspartic acid, glutamic acid, histidine이었고, 채취시기가 늦을수록 총유리 아미노산 함량은 감소하였다. 동백잎의 주된 구성아미노산은 histidine, alanine이었고, 채취시기가 늦을수록 구성아미노산의 함량은 감소하였으며, 총아미노산에 대한 필수아미노산의 비율은 증가하였다. 동백 잎에 함유된 무기질은 P, Ca, K, Na, Fe등으로 채취시기가 늦을수록 함량은 증가하였으며, 동백 잎의 chlorophyll 함량과 total polyphenol 함량은 채취 시기가 늦을수록 증가하였다.

• 동아시아식생활학회지
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• 제25권2호
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• pp.326-332
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• 2015

Makjang is a kind of Korean traditional short-term fermented soybean paste. The purpose of this study was to evaluate the compositions of free sugars, organic acids and free amino acids as well as microbial counts of six kinds of Makjang. Commercial Makjang from different regions (Kangwon-do, Choongchung-do and Kyungsang-do) were used. The major free sugars of samples were glucose (0.15~3.97%) and maltose (0.01~0.54%), whereas sucrose (0.02%) was detected only in M4 and fructose only in M1 and M2. The major organic acids were citric acid (0.16~3.09%), malic acid (0.06~0.23%) and succinic acid (0.01~0.11%). The total content of free amino acids ranged from 0.02 to 8.74 mg/g, and major amino acids were detected in the order of glutamic acid, leucine, alanine and aspartic acid. Numbers of viable cells of bacteria as well as yeast and molds were $7.8{\times}10^4{\sim}4.8{\times}10^5$ and $8.1{\times}10^3{\sim}3.6{\times}10^4$, respectively. The results of the sensory evaluation showed that over-all preference of Kyungsang-do Makjang was higher than others. Consequently these results provide better information for standardizing and improving quality and functional activity of commercial Makjang.

• 약학회지
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• 제35권3호
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• pp.147-153
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• 1991

Chemical constituents of fruits, leaves and barks of Acanthopanax senticosus forma inermis were studied. Their fruits have higher contents of crude ash, crude protein, crude fat, fructose and glucose than those of other Acanthopanax species, and contained larger amount of glutamic acid and malic acid among amino acid and organic acid, respectively. The compounds identified from their barks and leaves, were $\beta$-sitosterol and stigmasterol, sesamin, savinin, syringaresinol diglucoside, oleanolic acid, chiisanoside and polyacetytene ($C_9H_{10}O_2$, mp. 62~63).