• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.212-219
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• 1996

Four-dimensional response surface methodology was used for monitoring dynamic changes in substrates during Maillard reaction. The coefficients of determination ($R^2$) of response surface regression equations for the changes in amino acids during Maillard reaction were 0.9478 for total amino acids and above 0.90 for each amino acid. $R^2$ of regression equations for the changes in sugars during Maillard reaction were 0.9250 for glucose and 0.6490 for fructose. The contents of total amino acids gradually decreased with increasing reaction temperature and pH of the solvent. Browning color intensity increased with rising reaction temperature, showing maximum color intensity at around $145^{\circ}C$. Each amino acid showed a decreasing tendency in its contents, which was similarly found in total amino acids. Four-dimensional response surface methodology indicated that the increased temperature during Maillard reaction was the most influential factor in decreasing substrates, such as aspartic acid, threonine and glucose. While the reaction time and pH of solvent little affected the changes in the above-mentioned substrates during Maillard reaction.

• KSBB Journal
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• v.26 no.2
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• pp.112-118
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• 2011

Contents of amino acids, vitamins, and minerals as well as its antioxidant activitiy of Laminaria japonica water extract have been analyzed for preparation of functional foods and cosmetic products. From the analysis of total amino acids, eighteen kinds of amino acids were found in the water extract of Laminaria japonica. Among total amino acids, the order of contents was glutamic acid (2.07 mg/g), alanine (0.51 mg/g), aspartic acid (0.44 mg/g), glycine (0.34 mg/g), and valine (0.34 mg/g). In case of free amino acids, glutamic acid (0.95 mg/g), prolin (0.54 mg/g), aspartic acid (0.44 mg/g), leucine (0.07 mg/g), and phenylalanine (0.07 mg/g) were dominant compositions. Vitamin E was only detected in water extract of Laminaria japonica. The mineral contents were as follows: K 752.60 mg, Na 259.20 mg, Ca 80.20 mg, P 29.50 mg, and Fe 8.32 mg based on 100 g Laminaria japonica water extract. The nitrite scavenging activity of the extract were gradually increased with the extracts contents to 86.2% at concentration of 100 mg/mL and DPPH radical scavenging activity of the extracts were 86.4% at concentration of 50 mg/mL.

• Korean Journal of Food Science and Technology
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• v.11 no.1
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• pp.26-31
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• 1979

Free amino acids and total free sugar of kimchi were identified. Free amino acids of kimchis were extracted by 80% ethanol and isolated by ion exchange chromatography. Identification and quantitative determination of individual free amino acids were performed by amino acid autoanalyzer. Free sugar of kimchis was extracted by aqueous ethanol and isolated by ion exchange chromatography. Quantitative determination of it was perfermed by spectrophotometer. The results are summarized as follows: 1. Lysine, histidine, arginine, tryptophan, aspartic acid, threonine, glutamic acid, proline, glycine, alanine, cysteine, valine, methionine, leucine, isoleucine, tyrosine and phenylalanine were found in all kimchis. 2. The change of free amino acid composition during fermentation of kimchis was not observed, but the amount of total free amino acids of fermented kimchi decreased as compared with those of raw kimchi. 3. In kimchi containing 10 ml of fermented anchovy solution/100 g of chinese cabbage, the amount of total free amino acids was more than that of fermented salt kimchi and the characteristic flavor of it was attributed to such amino acids as lysine, aspartic acid, glutamic acid, valine, methionine, isoleucine and leucine. 4. Large amount of free sugar in raw salt kimchi decreased during fermentation, but, after fermentation, significant difference of free sugar content between salt kimchi and kimchi containing fermented anchovy solution was not observed.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.301-306
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• 1988

Contents and distribution of amino acids in the hydrolysates of humic acids extracted from straw of rice and barley at three different dates during decomposition were examined. The results obtained from this study may be summed up as the following: 1. There are differences between the humic acid hydrolysates from rice straw and barley straw in regards of composition of humic acids and distribution of amino acids. 2. Neutral amino acids as a group occupy the largest share, followed by acidic amino acids and basic amino acids. 3. The total amount of amino acids per gram of humic acid is greater in straw of rice than in straw of barley. 4. With the humification progressing the content of lysine increases, but the content of histidine decreases. In general glycine, glutamic acid, aspartic acid, alanine and leucine constitute the 5 predominant amino acids in all hydrolysates. 5. Arginine is not detected at all in any of the hydrolysates of humic acids obtained from humified materials. 6. The presence of phenylalanine and tyrosine is an evidence for the aromatic characteristics of humic acids.

• The Korean Journal of Food And Nutrition
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• v.1 no.1
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• pp.3-6
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• 1988

For the purpose of the production of yeast cell protein from rice bran oil, it's assimillating yeast(E222) was isolating from soil and the resulting of identification was shown that it was belonging to Candida aibican species Total free amino acids from yeast cells were shown 0.05% per gram. Nine other species of amino acids as well as glycine, glutamic acid, alanine, leucine and aspartic acid were produced from yeast cells.

• The Korean Journal of Zoology
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• v.7 no.1
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• pp.19-22
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• 1964

The free amino acid content of Indian meal moth (Plodia interpunctella HUBNER) was analysed at various developmental stages by means of paper chromatography. 1) The free amino acids : present are alanine , arginine, aspartic acid, glutamic acid, glycine, histidine, leucine, methionine, proline, serine, threonine, tyrosine and valine. 2) Proline was detectable only in the acid-hydrolyzed Indian meal moth. 3) Arginine was clearly detected only in the larva stage. 4) Tyrosine methionine and valine were increased in the pupa stage. 5) Serine, glycine and tyrosine were present in high concentration in all stages.

• YAKHAK HOEJI
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• v.5 no.1
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• pp.1-2
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• 1960

Six kinds of free amino acids, leucine, methionine, threonine, lysine, histidine and aspartic acid were found by using partition paper chromatography from water extract of deer horn which is widely used as tonic drug. The results shows that deer horn does not contain any specific free amino acid.

• 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 Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.206-212
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• 2006

Supercritical carbon dioxide ($SCO_2$) extraction was investigated as a method for protein-sourcing material from squid viscera. To find the optimum conditions, the extraction of squid viscera using $SCO_2$ was performed under the conditions of temperature range from 35 to $45^{\circ}C$ and constant pressure 25 MPa using Hewlett-Packard 7680T. Also from result of SDS-PAGE, the protein denaturation was minimized when using $SCO_2$ extraction. And the major amino acids in the squid viscera were glutamic acid, aspartic acid, lysine, leucine, arginine, alanine, glycine, isoleucine, and valine. The main fatty acids from squid viscera were myristic acid, palmitic acid, stearic acid, heneicosanoic acid, palmitoleic acid, elaidic acid, oleic acid, eicosenoic acid, EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid).

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2542-2548
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• 2009

Direct methylation behaviors of 20 amino acids with tetramethylammonium hydroxide (TMAH) were studied under diluted conditions with silica. Amino acid concentration was controlled by dilution with silica ($SiO_2$) and the molar ratios of amino acid/silica were 0.20, 0.50, and 2.0. The molar ratios of amino acid/TMAH (0.51 - 4.64) also varied. It was found that arginine, asparagine, aspartic acid, cysteine, glutamic acid, and glutamine did not generate any directly methylated pyrolysis products, whereas alanine, glycine, isoleucine, leucine, methionine, phenylanaline, valine, and proline generated all the directly methylated pyrolysis products. Tri- and tetra methylated products of lysine consisted of two types. Histidine and threonine hardly generated the partly methylated products. Mono- and dimethylated products of serine, tryptophan, and tyrosine were not observed. Relative intensities of the methylated products varied with the amino acid concentration, TMAH concentration, and pyrolysis temperature. Direct methylation behaviors of amino acids were explained by the structural characteristics of amino acids.