• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.31-37
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• 2004

This study was performed to investigate the changes of amino nitrogen, total amino acids, free amino acids, and cole. of traditional Korean soybean paste (doen-jang) during the ripening and storage for 12 months. All of the preparation methods for soybean paste followed the recommendations of the Korea Food Research Institute. The components of soybean paste were analyzed at 0, 6, and 12 months. The content of amino nitrogen of soybean paste was significantly higher than that of soybeans or meju (soybean cakes) at the initial stage of storage (p〈0.05), and decreased during the storage. The composition of total and free amino acids and their ratios of soybean paste were changed during the storage. The ratios of free to total amino acids of soybeans, meju, and soybean paste were 0.8%, 17.3%, and 20.4∼32.9%, respectively. Glutamic acid, which represents the savory taste, was detected the most abundantly in soybean paste during the storage. The ratios of free to total amino acids of glutamic acid were 21.1∼41.5% in soybean paste. Lightness, redness and yellowness of Hunter color of soybean paste decreased over time (p〈0.05). The results of this study indicate that the ratios of fee to total amino acids of soybean paste were much higher than those of soybeans, although its contents of total amino acids were much lower than those of soybeans. The results also indicate that this comes from the preparation and fermentation of meju. It was suspected that the organoleptic quality of soybean paste derived from these three components might be inferior over 1 year of storage time.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3387-3390
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• 2012

In this research work the potentialities of microemulsion bulk liquid membrane for the selective transport of L-tryptophan (L-Trp) and L-tyrosine (L-Tyr) are investigated at 298.15 K. Reversed micelle formed by sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in dichloroethane, was used as mobile carrier to transport amino acids between a source and a receiving aqueous phase. The effects of pH, surfactant concentration and initial amino acid concentration on the extraction efficiency and transfer rate of the amino acids were studied. It is verified that for a mixture of two amino acids, L-Trp can be extracted selectively by using this type of the bulk liquid membrane with optimized condition.

• Korean Journal of Veterinary Research
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• v.6 no.1
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• pp.31-36
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• 1966

The free amino acid contents in several tissues of swine were analyzed qualitatively by means of two dimentional paper chromatography. The tissues used were liver, kidney and spleen that were obtained from normal, immunized and hog cholera infected swines. The results obtained are as follows: 1. Liver: 20 amino acids were detected in normal, 17 in immunized and 15 in infected swines. 2. Kidney: 16 amino acids were detected in normal, 13 in immunized and infected swines. 3. Spleen: 15 amino acids were detected in normal in immunized and 13 in infected swines. 4. Glutamic acid, leucine, serine and threonine were present in high concentration in all of the cases examined. 5. The free amino acids were appeard to be decreased in the infected tissues with hog cholera virus.

• Journal of the Korean Magnetic Resonance Society
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• v.4 no.2
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• pp.133-139
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• 2000

The strategy to incorporate [$^{15}$ N]-labeled amino acids were discussed. Instead of using specific auxotrophic strains for selective labeling, the prototrophic strain, BL2l(DE3), was used with a plasmid, pLysS, and found to be very effective for several amino acids including alanine, lysine, leucine, and threonine. Isoleucine, valine, glutamine, and tyrosine were also found to be effective despite some diffusion into other amino acids. Interesting result was obtained when [$^{15}$ N]-labeled glycine was tried: only glycines were labeled when amino acid mixture was added in the growth medium, and serines were co-labeled when amino acids were omitted. These results can be used as a guideline when selective labeling strategy is considered, and when the resulting data are interpreted.

• Korean journal of food and cookery science
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• v.23 no.1 s.97
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• pp.150-155
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• 2007

This work was conducted to obtain a rapid, accurate, and precise procedure for free amino acids analysis in Doenjang with HPLC-OPA (high performance liquid chromatography using-phthalaldehyde) and AAA (automatic amino acid analyzer) methods. Different sample extraction procedures among water, 0.1 M perchloric acid, and 0.1% meta-phosphoric acid were also compared. The optimal extraction solvent was 0.1% meta-phosphoric acid for both the HPLC-OPA and AAA methods. Good recoveries for glycine and methionine were observed using the 0.1% meta-phosphoric acid extraction with HPLC-OPA method. Method precisions (% relative standard deviation) for the free amino acids ranged for 1.62% to 8.27%, in which the HPLC-OPA method with water extraction showed the lowest value at 1.62%. Inhibition rates of the free amino acids in Doenjang were greatest with an addition of NaCI at a 1% concentration.

• YAKHAK HOEJI
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• v.8 no.2
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• pp.48-53
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• 1964

At the different growing stages of Fagopyrum esculentum Moench planted at the green house and out doors, the contents of free amino acids in the whole plants,were determined quantitatively by spot-extract colorimetric method (J. Awapara method) using the chromatograms obtained by the ion-exchange resin and paper chromatographic method. And the contents of carbohydrate in the whole plant were determined by Bertrand method. The results were summarized as follows. 1. Almost same kinds of free amino acids were detected in the both plants. 2. Concentrations of most amino acids was increased progressively during growth; further growth was accompanied by decreased concentrations. 3. Rate of growth and increasing of total amino acid content of green house plant is greater than that of out dorrs plant. 4. At the same stages of gwoth, total free amino acid content of green house plant is higher than that of out doors plant but sugar content is lower. 5. There was rapidly increasing of sugar content and decreasing of total free amino acid content except asparagine during mature of seeds.

• Natural Product Sciences
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• v.5 no.3
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• pp.148-150
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• 1999

Seed lipids and proteins of Crotalaria juncea L were analyzed for fatty acids and amino acids respectively. Gas chromatographic analysis of the oil gave palmitic acid (16.01%), stearic acid (7.29%), oleic acid (14.41%), linoleic acid (54.44%) and linolenic acid (7.86%). The defatted seed cake contained all the essential amino acids except methionine and six non-essential amino acids.

• YAKHAK HOEJI
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• v.27 no.4
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• pp.289-293
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• 1983

Twelve new N-piperoyl amino acids were synthesized by acylation of amino acids with piperoylchloride in order to develop the new central nervous depressants. Silylation of the carboxylic group of amino acids not only precluded side reactions but-also facilitated acylation at room temperature without catalysts. The acute toxicity of all the synthesized compounds were lower than that of piperine itself, whereas they showed strong protective effect against the strychnine-induced mortality.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.3
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• pp.406-409
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• 2002

The effect of refeeding with various single essential amino acids on the recovery of plasma insulin-like growth factor-I (IGF-I) concentration in fasted young chickens was examined. Young chickens (29 days of age) were divided into 15 experimental groups. Chickens in one group were fed on the commercial diet ad libitum for 4 days. The remaining 56 chickens in 14 experimental groups were fasted. After 2 days of fasting, 52 chicks in 13 fasted groups were refed with one of the following experimental diets for 2 days. Eleven experimental diets were protein-free diets supplemented with one of 11 essential amino acids (Arg, Gly, His, Ileu, Leu, Met, Phe, Lys, Thr, Trp, Val). The remaining 2 experimental diets were a protein-free diet containing 11 essential amino acids and a protein-free diet not supplemented with amino acids. Birds in the remaining fasted group continued to be fasted for 2 days. Fasting for 2 days markedly reduced plasma IGF-I concentration. When fasted chickens were refed the protein-free diet containing either Gly alone or all essential amino acids, plasma IGF-I concentration was recovered to the level similar to that of fed chickens. Protein-free diet alone, however, failed to restore the reduced IGF-I concentration in plasma. Body weight loss modulated by feeding with protein-free diets supplemented with various single essential amino acids was associated with changes in plasma IGF-I concentrations. We concluded that body weight loss by feeding with a protein-free diet was lower than that of fasted chickens and that body weight loss associated with the decrease in plasma IGF-I concentration was modulated by feeding with protein-free diets containing various single essential amino acids.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.65-83
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• 1978

This study was attempted to evaluate the taste of broiled-dried sea mussel which is a traditional dried Sea food in Korea. The contents of such compounds as free amino acids, nucleotides and their related compounds, TMAO, betaine, and nonvolatile organic acids were analysed. From the results of analysis of nucleotides, the contents of AMP and ADP in broiled-dried Mytilus coruscus and Mytilus edulis appeared higher than other nucleotides and tended to increase slightly after cooking, drying, and storage which might be due to both their stability and the addition of degradation of nucleic acids during cooking. In the free amino acid composition of fresh samples abundant amino were taurine, glycine, serine, glutamic acid, alanine, arginine, threonine, tyrosine, lysine and valine in order. Such amino acids as histidine, leucine, methionine and isoleucine were poor and both proline and phenylalanine were merely trace. The free amino acid composition in the extract of Mytilus corucus and Mytilus edulis after broil-drying was not changed. These amino acids, taurine, glycine, feline, glutamic acid, alanine and arginine were abundant in dried samples as well as in the fresh. The total free amino acid was greatly reduced after cooking and drying ranging from $76.3\%$ to $79.7\%$ loss to that of tile fresh. The content of betaine shelved the same tendency as in total free amino acid while TMA slightly increased relating to TMAO decrease during broil-frying. Such nonvolatile organic acids as succinic, lactic, malic and fumaric acid were abundant in both fresh and broiled-dried samples whereas oxalic and pyruvic acid were poor. It is found that the taste compounds of broiled-dried Mytilus coruscus and Mytilus edulis were composed of amino acids as glycine, serine, alanine, glutamic acid, arginine, and betaine, TMAO, ADP, AMP, and organic acids such as succinic acid, lactic acid, malic acid and fumaric acid. No significant differences in the taste compounds between male and female as well as between Mytilus coruscus and Mytilus edulis was not observed.