• Journal of Nutrition and Health
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• v.16 no.1
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• pp.34-40
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• 1983

Clam, Tapes japonica, has been widely used and occupies an important position in the markets. More than thirty kinds of fermented fish and shellfish are presently available in the markets in korea. This study was attempted to establish the basic data for evaluating the taste compounds of the clam. The free amino acids as taste compounds during the fermentation of the clam, Tapes japonica, were analyzed by an amino acid autoanalyzer. Alanine (17.0%), glycine (15.5%), taurine (13.9%) were high in amount in the fresh clam and then glutamic acid, arginine, tyrosine, asparagine, lysine, threonine, serine and leucine were the next in order. Such amino acids as methionine, phenylalanine, histidine and cystine were low in amounts. The total free amino acid nitrogen in the fresh clam was 45.5% of its extract nitrogen. During the fermentation of the clam, the kinds of the free amino acids were the same with the fresh samples although the amounts were changed. It is believed that glutamic acid, aspartic acid, glycine, alanine, lysine, and leucine may play an important role as the taste compounds in the fermented clam.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.950-953
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• 1994

This study was carried out to investigate the proximate composition , free sugars,amino acids, organic acid, minerals and extracted color of the fruit of paper mulberry (Broussonetia Kazinoki Siebold) . the proximate compositins were 6.1% of moisture, 15.9% of crude protein, 28.5% of crude fat, 8.9% of crude ash and 40.6% of carbohydrates in the fruit of paper mulberry. Free sugars showed low content as 0.1% of glucose , 0.1% of sucrose, 0.1% of fructose and 0.01% of sorbitol, respectively. In amino acid composition of the fruit of paper mulberry, glycine was the highest in the content, followed by methionine, aspartic acid and alanine, The ratio of essential /total mino acids was 0.43 . The richestmineral contained in the fruit of paper mulberry was Ca and followed by K and Mg. Optical density (490-500nm) of the extracted color with 50% ehtanol and 80 % ethanol were 0.75 and 0.30 , respectively.

• Korean journal of food and cookery science
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• v.14 no.3
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• pp.255-260
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• 1998

The changes in fatty acids and free amino acids of raw and salted-dried flatheads were determined during steaming, boiling and baking process. 1. Raw flathead was composed of 74.9% of moisture, 1.9% of ash, 0.9% of crude lipid, and 21.6% of crude protein. 2. The main fatty acids of raw and salted-dried flathead were palmitic acid (21.5%) and lignoceric acid (52.4%) which covered 73.9% of total fatty acid. The fatty acid contents of raw and salted-dried flathead were higher in the steaming than in the boiling and baking. 3. The main free amino acids of .aw and salted-dried flathead were aspartic acid (12.2%), glutamic acid(14.8%), leuicine (8.4%), Iysine (9.8%) and arginine (6.8%), which covered 52% of total free amino acids. There were significant differences (p<0.05) in the contents of free amino acids between raw and salted-dried flatheads as well as among steaming, boiling and baking processes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1182-1187
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• 2007

Changes in composition of fatty acids and free amino acids in three differently dried Alaska pollack (sun dried, naturally cyclic freeze-thaw dried, and 1-year-aged cyclic freeze-thaw dried Alaska pollack (Hwangtae)) were investigated to correlate them with browning reactions in drying and aging Alaska pollack. Major fatty acids of the sun dried Alaska pollack were palmitic acid, oleic acid, and eicosapentaenoic acid (EPA), and those in the Hwangtae were palmitic acid, oleic acid, and gondoic acid. Hwangtae showed the lowest amount of polyunsaturated fatty acids among the three types of dried Alaska pollack. Free amino acids content of sun dried Alaska pollack was higher than that of the cyclic freeze-thaw dried Alaska pollack and Hwangtae. Lesser amount of histidine in Hwangtae (0.02%) than that in the cyclic freeze-thaw dried Alaska pollack (0.087%) may indicate the degradation of histidine due to the browning reaction in aging the cyclic freeze-thaw dried Alaska pollack. Significant changes in compositions of fatty acids and free amino acids among the dried products revealed the browning reaction resulted from carbonyl compounds produced by decomposition of lipid hydroperoxides and free amino acids. Aging the cyclic freeze-thaw dried Alaska pollack for a year contributed to the development of browning.

• 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.

• The Korean Journal of Zoology
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• v.4 no.2
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• pp.7-12
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• 1961

The present work deals with the patterns of the free amino acids in several tissues of Gallula tornieri VOGT analysed by means of paper chromatography and ion-exchange resins. The tissues used were heart, stomach , muscle, brain , testis , skin , and liver. 14 amino acid was detected in heart, 11 in muscle , 15 in stomach , 9 , in brain , 10 in skin in liver , and 10 in testis. It was found that there were distinguishable differences in the patterns of the free amino acids among the different tissues.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1247-1251
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• 2010

We propose an improved solvent contact model to estimate the solvation free energies of amino acids from individual atomic contributions. The modification of the solvation model involves the optimization of three kinds of parameters in the solvation free energy function: atomic fragmental volume, maximum atomic occupancy, and atomic solvation parameters. All of these atomic parameters for 17 atom types are developed by the operation of a standard genetic algorithm in such a way to minimize the difference between experimental and calculated solvation free energies. The present solvation model is able to predict the experimental solvation free energies of amino acids with the squared correlation coefficients of 0.94 and 0.93 for the parameterization with Gaussian and screened Coulomb potential as the envelope functions, respectively. This result indicates that the improved solvent contact model with the newly developed atomic parameters would be a useful tool for the estimation of the molecular solvation free energy of a protein in aqueous solution.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.389-392
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• 1994

Changes in free amino acids and amino nitrogen of traditional kochujang were investigated during 180 days of fermentation. Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, and Sachun kochujang prepared with wheat. Amino acids remarkably increased during fermentation were methionine, glutamic acid, isoleucine, leucine and tyrosine. However, regardless of kinds of kochujang major free amino acids were serine, aspartic acid, glutamic acid and proline. Glutamic acid was noted as the most contributing to the savory taste of kochujang in relation to the increasing ratio and content among tree amino acids during fermentaion. The correlation coefficent between totals of free amino acids and the contents of amino nitrogen were relatively high (0.87

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.939-943
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• 1999

Three 28 day-old $Duroc{\times}Large$ $White{\times}Landrace$ litter mate gilts weighing an average of 6.5 kg were used to study the intestinal absorption of amino acids when provided in dipeptide form or in the form of a free amino acid mixture. The pigs were given one of three treatments. The control involved a duodenal infusion containing no amino-acids (phosphate buffer plus 5% sorbitol) while the remaining two treatments involved either a duodenal infusion containing a glycine-lysine dipeptide (1 g) or a mixture of the free amino acids glycine and lysine at the same concentration as in the dipeptide. Blood was drawn from a cannula inserted in the portal vein, at 5 to 20 minute intervals, for two hours following infusion. The concentration of intact dipeptide as well as free glycine and lysine in the portal blood was determined by high performance liquid chromatography. The intact dipeptide was never detected in the portal blood at any time after infusion. Lysine appeared in the portal blood more rapidly after infusion of dipeptide than after infusion of free lysine and the concentration of lysine in portal blood was higher in the pig infused with the dipeptide than after infusion of free lysine at almost all time points measured. The cumulative absorption of lysine and glycine from the intestine during the two hour period after infusion was greater in the pig infused with dipeptide than in the pig infused with free amino acids. The results suggest that although intact dipeptide did not reach he portal circulation, a special transport mechanism for absorption of dipeptide by intestinal cells appears to be present in pigs similar to that observed in other species.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.122-131
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• 1981

An aqueous extract s of fresh ginseng roots was heated at loot for 64 hrs. and the changes of color intensity, pH and the amount of free sugars and amino acids during the various intervals of the heating time were investigated. Color intensity and absorbance of the solution at 490nm were increased in proportion to the length of the heating time. Most of brown pigments produced during the treatment were water soluble, and pH 5.1 at initial stage of the solution, was slightly decreased at the final stages of the reaction. Sucrose, glucose and fructose were major free sugars in ginseng roots, and the amounts of sucrose was over 90 % of total free sugars. Sucrose. was largely decreased approximately 50%, by 64 hrs of the treatment, whereas sharp increase in the amount of glucose and fructose was observed during the reaction in the solution. The observed increase in reducing sugars, glucose and fructose was presumed due to hydrolysis of sucrose. Evidently, glucose and fructose were not important factor to control the browning reaction of the solution. Most of free amino acids and peptides except alanine and isoleucine especially arginine, serine and threonine, were sharply decreased up to 40 : 50% of the original concentration within 2 hrs. Accordingly, the content of free amino acids and peptides seems to be extremely important factor to control the browning reaction in ginseng. A free amino acid, presumed to be nor-leucine, was found in fresh ginseng root on the basis of re mention on liquid chromatography. Kinetic analysis of the browning reaction indicated a pseudo second order with respect to amino acid concentration at the initial stage.