• Journal of the Korean Society of Food Culture
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• v.4 no.2
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• pp.181-184
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• 1989

The compositions of total and free amino acids in parts of Omija were investigated. The most abundant amino acids in fruits, endocarps, and seeds were arginine (50.80%), lysine (14.37%), glutamic acid (14.22%), respectively. Since the amino acid scores of fruits, endocarps, and seeds were 9.4, 11.9, and 16.7, respectively, the limiting amino acid of each part were S-compound amino acids. In the composition of free amino acids, contents of lysine were highest one such as 51.78, 57.00 and 32.88% in fruits, endocarps and seeds, respectively. The contents of histidine from free amino acids were 23.62% in fruits, 22.37% in endocarps, and 26.41% in seeds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.336-340
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• 1995

Urinary excretion of total amino acids was measrued in normal and diabetic rats, streptozotocin-induced diabetic rats excreted increased amount of urinary total amino acids and nitrogen. This suggested increased degradation of body protein. Although excretion of total amino acids increased in the diabetic rats, the amino acid pattern of amino acids for both groups were very similar. The efficiency of dietary protein utilization was significantly lower in diabetic rats then that of normal rats. Streptozotocin injeciton affected the urinary excretion of 3-methylhistidine whereas diet did not. These findings suggest that the rate of urinary excretion of total amino acids can be empolyed as an index of protein metabolism, particulary as a simple index in the assesing the status of protein nutrition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.382-387
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• 2001

Characteristics of six commercial samjangs were analyzed such as proximate composition, free amino acids, organic acids and free sugars. Also color, taste and odor were evaluated by 36 panelists. They were composed of moisture content 41.4-48.4%, crude protein 9.2-10.4%, crude fat 2.2-3.4%, pH 5.3-5.7, amino nitrogen 194.0%-375.6 mg% and sodium chloride 7.7-9.1%. Total free amino acids of samjangs were 975.89-2304.98 mg%. Glutamic acid was the highest amino acid among free amino acids as 231.7-788.01 mg%. Proline, arginine, alanine and lysine were higher than other free amino acids while histidine, cystine and methionine were lower than other. Eleven free amino acids including glutamic acid were the highest in samjang (B) which contained more doenjang than any other makers did. Total organic acids were 401.01-640.27 mg%. 69.65-269.07 mg% of succinic acid was the highest among organic acids. Lactic acid was the highest in samjang (F) which was home made. Total free sugars was the highest in samjang (A) which contained more wheat flour than any other makers did it. Glucose was 9.30-23.99% and fructose was nd-2.69%. The result of proximate composition showed a different pattern comparing with that sensory evaluation. Samjang (A) which contained less salt showed the highest overall acceptability while samjang (F) which contained more dark color, more salt was the lowest one among the samples.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.163-166
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• 2016

Hydrophobicity is the key concept to understand the water plays in protein folding, protein aggregation, and protein-protein interaction. Traditionally, the hydrophobicity of protein is defined based on the scales of the hydrophobicity of residue, assuming that the hydrophobicity of free amino acids is maintained. Here, we explore how the hydrophobicity of constituting amino acids in protein rely on the protein context, in particular, on the total charge and secondary structures of a protein. To this end, we calculate and investigate the hydration free energy of three short proteins based on the integral-equation theory of liquids. We find that the hydration free energy of charged amino acids is significantly affected by the protein total charge and exhibits contrasting behavior depending on the protein total charge being positive or negative. We also observe that amino acids in the ${\beta}-sheets$ display more enhanced the hydrophobicity than amino acids in the loop, whereas those in the ${\alpha}-helix$ do not clearly show such a tendency. And the salt-bridge forming amino acids also exhibit increase of the hydrophobicity than that with no salt bridge. Our results provide novel insights into the hydrophobicity of amino acids, and will be valuable for rationalizing and predicting the strength of water-mediated interaction involved in the biological activity of proteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.681-686
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• 2005

The purpose of this study was to analyze the chemical component of Camellia japonica L. according to picking time. Leaves of Camellia japonica L. were picked in April and May,2003. Free sugars (fructose, glucose and sucrose) and organic acids (citric acid, tartaric acid, succinic acid, acetic acid) were present in the Camellia japonica L. leaf. The contents of total free sugars and organic acids increased as picking time was delayed. The major components of free amino acids were aspartic acid, glutamic acid and histidine, and those of total amino acids were histidine and alanine. The contents of total free amino acids and total amino acids were decreased as picking time was delayed, while the ratio of essential amino acids to the total amino acids increased. The amount of minerals (P, Ca, K, Na and Fe), chlorophyll and total polyphenol increased as picking time was delayed.

• The Korean Journal of Food And Nutrition
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• v.5 no.1
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• pp.1-6
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• 1992

For the effective utilization of apricot seed resources of food protein and lipid, the general composition, amino acid composition and chemical characteristics were analysed. The skinned and non-skinned apricot seed contained 53.9% and 48.0% of crude lipid, 24.7% and 26.8% of crude protein, respectively. There were no significant difference in the amino acid composition among skinned and non-skinned apricot seed, The major amino acids were glutamic acid, aspartic acid, alanine, tyrosine and threonine, holding 14.6 to 16.9%, 12.4 to 13.7%, 9.2 to 12.1%, 7.2 to 7.5% and 7.0 to 7.2% of total amino acid content, respectively. The sum of these ammo acids occupied about 50% to total amino acids. While the quantities of methionine, histidine, and Lysine were poor content. The essential amino acids occupied about 30% to total amino acids. The acid, iodine and saponification value of apricot seed oil were 0.7 to 7.1, 80.8 to 107.5 and 182.7 to 208.4, respectively. These values were significant difference in skinned and non-skinned apricot seed.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.229-235
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• 2014

Gastrodia elata Blume, an achlorophyllous orchid plant, has been used in traditional medicine and harvests in spring and fall. Here we investigated the quantitative changes of amino acids in G. elata by harvest times and seed tubers. In the results, we found that there was not big difference in contents of total amino acids but the distribution of amino acids differed depending on harvest times. 19% of total amino acids were asparagin and valine, an essential amino acid, occupied 10% within total amino acids in the tubers harvested in October. Among amino acids in the tubers harvested in April, serine occupied 23% and arginine, an essential amino acid, occupied 10% within total amino acids in tuber. Interestingly, the use of sexually propagated seed tubers produced high concentration of total amino acids compared to vegetatively propagated seed tubers. As for sexually propagated seed tubers, essential amino acids contents similar to the tubes harvested in October and nonessential amino acids contents similar to the tubers harvested in April. In this study, we found that amino acids contents in G. elata tubers altered depending on various cultivation practices. Therefore if these results can be applied to food industry, the value of G. elata as a natural food resource will be enhanced to a great extent.

• 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.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.433-440
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• 1995

The constituents and proportions of non-protein free amino acids including canavanine were measured in roots and leaves of legumes, Robinia pseudo-acacia L., Wistaria floribunda L., and Canavalia lineata L. by using high performance liquid chromatography during dormant and fertilizing seasons. in all the three plant species, asparagine was the most abundant amino acid occurring 30％ of total free amino acids, and canavanine was the second most abundant amino acid contributing 10％ of total free amino acids throughout dormant and fertilizing seasons. In dormant season, roots contained 2 to 3 folds of free amino acids including canavanine and asparagine compared to those in fertilizing season. When proportions of asparagine and canavanine to total gree amino acids in various parts of C. lineata were examined in fertilizinng season, the level of asparagine was the highest in roots while that of canavanine was in seeds. On the basis of these results, it is assumed that canavanine appears and functions as a nitrogen-storing compound in roots and leaves throughout the whole life cycle of the investigated plants.

• Journal of the Korean Society of Food Culture
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• v.19 no.3
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• pp.348-358
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• 2004

This study was conducted to examine contents of total acid and free amino acids in the Demi-glace with added quantity of Omija extracts. Firstly, The level of Total acid content of Demi-glace sauces was $1.08{\sim}1.89%$ and Omija extracts was $2.77{\sim}7.24%$. The more Omija extracts added, there was the higher total acid contents. Sauces and extracts of 5% Omija was the highest. Secondly, Total free amino acids contents of control was 2518.52mg%, and Omija sauces was $2261.52{\sim}2894.14mg%$. 2% Omija sauces was the highest among them. Hydroxyproline of total 34 free amino acids was the highest, and Glutamic acid 158.42mg%, Proline 78.90mg% was next in order. Arginine was the highest with $27.40{\sim}34.40mg%$ among 9 essential amino acids contents. Glutamic acid was the highest contents with $123.18{\sim}158.42mg%$. Compared to control's(0.41mg%), Omija added group was $20.63{\sim}27.82mg%$ and it was the highest increase. While other 15 amino acid was analyzed, Hydroxyproline was the highest contents with $1,737.22{\sim}2,205.80mg%$. Compared to control group(15.63mg%), proline was $57.01{\sim}78.90mg%$ Omija added group and it was increased with the highest contents. In essential amino acid, flavor enhancing amino acid and other amino acid were increased and the highest contents with 2% added Omija sauce. Thirdly, sensory characteristics of Demi-glace sauces based on overall preference, It was find that 2% added Omija was the best. 2% added was the best for color, flavor, taste, texture, overall acceptability(P<.001). In terms of Demi-glace sauces' gender preference, male and female people liked 2% added Omija color, flavor, taste, texture, overall acceptability. It was find that there was no significant differences between male and female.