• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.27-31
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• 1980

Yellow sea bream, Branchiostegus japonicus, has been one of the widely consumed food fish in Jeju-Do, Korea. This study was attempted to establish the basic data for evaluating changes of taste compounds of the yellow sea bream during dehydration. The free amino acids were analysed by amino acid autoanalyser. The free amino acid composition of the raw yellow sea bream, abundant amino acids were lysine, alanine, threonine and arginine and then taurine, serine, proline, glycine, glutamic acid, leucine in order. Such amino acids as valine, methionine, tyrosine, isoleucine, phenylalanine were poor in content. The changes of free anino acid composition in the extract of the yellow sea bream during dehydration was not found. In the extract of dried product, lysine, alanine, glutamic acid and arginine were dominant holding $18.4\%,\;14.7\%\;8.0\%\;and\;7.3\%$ and $7.3\%$ of total amino acids respectively. The amount of total free amino acids of the yellow sea bream increased to more than 1.4 times during dehydration process, that of raw sample especially aspartic and glutamic acids increased to more than 2.9 times and 2. 1 times whereas taurine and histidine decreased ranging $40-50\%$ of the original content. It is presumed that the characteristic flavor of dried yellow sea bream was attributed to such amino acids like lysine and alanine known as sweet compounds, glutamic acid as meaty taste and TMAO known as plain sweet taste.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.91-96
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• 2004

It is generally believed that amino acids occurring naturally in mammals are of the L-configuration. D-amino acid(DM) are common in nature as constituents of bacterial cell walls and several antibiotics. Recent reports have demonstrated the presence of small amounts of free DM in milk. The presence of free DM may affect the food quality by decreasing the nutritional value. Our objective was to examine whether the free DM carne from psychrotrophic bacteria. Free DM was produced by treating raw milk with Pseudomonas spp. The samples were extracted with sulphosalicylic acid and derivatized with AccQ-$Tag^{TM}$ reagent when the analysis was carried out by reverse-phase HPLC. We tested correlations of the content of free DM with bacterial growth. Significant amounts of free D-a1anine and D-proline have been found in the raw milk inoculated with Pseudomonas spp. The increase of D-alanine and D-proline appeared to be mainly related to the presence of Pseudomonas fluorescens. These results suggest that free DM may be considered as an indicator of psychrotrophic bacterial milk contamination.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.48-53
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• 1995

Changes in the contents of sugar, organic acid, free amino acid and uncleic acid-related compounds of leaf mustard-Kimchi during fermentation at 5~7$^{\circ}C$ were investigated. The leaf mustard-Kimchi was formulated with 4kg leaf mustard, 120g garlic, 80g ginger, 540ml salted anchovies, 1kg green onion, 200g red pepper powder, 200g ground red pepper, 60g whole sesame and 600ml glutinous rice paste. Changes in pH and acidity were relatively slow. Major free sugars were glucose(0.13%) and maltose(0.42%), and residual sugars(0.03-0.04%) were also detected after 32 days of fermentation. Major free amino acids containing more than 26.5mg% were proline, glutamic acid, alanine and histidine. Contents of total free amino acids increased from 244.8 to 397.2mg% by 24 days of fermentation. Of non-volatile organic acid, lactic acid was the most abundant(119.3mg%), and its content increased markedly after 10 days of fermentation. Other organic acids(below 53.1mg%) observed were malic, oxalic and citric acid. Contents of nucleic acid-related compounds were high in the order of hypoxanthine(22.8mg%), IMP(8.3mg%) and GMP(6.9mg%). Hypoxanthine content increased by 10 days(27.3mg%) and decreased thereafter, while the others decreased gradually during the overall period of fermentation.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.317-331
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• 1990

Nitrogen compounds of Panax ginseng and their biological activities in plant and animal were reviewed. Major nitrogen combounds found in P. ginseng are free amino acids, Water soluble teins, insoluble proteins and peptides. Minor nitrogen compounds are dencichine. glycol)roteins. amines, alkaloides, methoxy or alkyl pyrazine derivatives. free nucleosides and nllrleir arid bases. 4-me- thymi-5-thiazoleethanol and pyroglutamic acid. The contents of total nitrogen and protein in root increased until 13 years old rvhich was the highest age tinder investigation. Soluble protein content increased With the root weight and was higher in xylem pith than cortex-epidermis indicating the rlosc relation with root growth. Arginine which covered 58% of total free amino aroids may serve as a storage nitrogen. Arginine seems to be changed into proline in rhizome, threonine in stem and again threoning and arginine in leaf. The greater the root weight the higher the polyaminc content. Polyamine stimulated the growth of root callus. Physiological roles of other minor nitrogen compounds are unknown although dencichine content is relatively high (0.5% d.w.). biochemical and pharmatological activities of some nitrogen compounds for animal were more investigated than physiological roll iota plant itself. Radiation and U.V. protective function (heat stable protein), insulin-like activity in lipogenesis and lipolysis (adenosine and pyroglutamic acid), depression of blood sugar content (glycopeptide). hemostatir and nellrotoxic activity (denrichine) and. sedative and hypnotic activity (4-methyl-5-thiazoleethilnol) are reported. Heat stable protein increased with root age. The traditional quality critsria appear to be well in accordance with biological activities of nitrogen compounds. Chemical stlldies of nitrogen compounds seem relatively rare, probably dole to difficulty of isolation, subsequently the investigations of biological activities are little.

• Journal of Nutrition and Health
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• v.11 no.3
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• pp.13-20
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• 1978

Changes of free amino acids, nucleotides and their related compounds as taste compounds during sun drying of ascidian Cynthia roretzi, were analyzed by amino acid autoanalyzer and high speed liquid chromatography. In fresh ascidian, the results showed that 5'-UMP $(12.1\;{\mu}mole/g)$ was dominant and the content of cytosine, 2', 3'-CMP, 2', 3'-GMP, hypoxanhtine, 5'-AMP,5'-IMP were 5.8, 3.4, 3.1, 2,3, 1.7 and $1.3\;{\mu}mole/g$ ondry base respectively. 5'-IMP, 2', 3'-CMP and 2', 3'-GMP tended to degrade slowly and 5'-AMP, cytosine and 5'-UMP were decreased rapidly while hypoxanthine were increased remarkably during the sun drying. In dried ascidian, the content of hypoxanthine was the highest, 7.2 mole/g on dry base, whereas that of 5'-AMP $(0.5\;{\mu}mole/g)$) and 5'-IMP $(0.9\;{\mu}mole/g)$ were lower. Glutamic acid, alanine and serine were dominant amino acid in the fresh extracts, having 22.4% (611.3mg%, on dry qase), 19.8% (540.5mg%) and 14.8% (402.8mg%) of the total amino acid content respectively. The content of tyrosine, histidine, lysine, methionine, isoleucine and valine were low, and proline, phenylalanine were detected in trace amount. The free amino acid were not changed in composition but the increase of total free amino acid was approximately 116.8mg% during sun drying. In sun dried ascidian, glutamic acid (691.0mg, on dry base), alanine (641.3mg%), serine (469.5mg%), threonine (234.8mg%) and glycine (206.3mg%) were dominant amino acid. It is believed that glutamic acid, serine, alanine, threonine, glycine and hypoxanthine play an important role as taste compounds in sun dried ascidian.

• Journal of Environmental Health Sciences
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• v.9 no.2
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• pp.37-53
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• 1983

The contents of amino acids were examined in the 3, 4, 5, and 6 year-old roots of fresh ginseng and the 1979, 1980, 1981, and 1982 years' products of white and red ginsengs. Samples extracted with 75% ethanol for free amino acids and hydrolyzed with 6N-HCL for total amino acids were analyzed by Amino Acid Analyzer (Hitachi model KLA-5). The results were summarized as follows: 1. Amino acids from extracted samples were 18 kinds of Tryptophan, Lysine, Histidine, Arginine, Aspartic acid, Threonine, Serine, Glutamic acid, Proline, Glycine, Alanine, Cystine, Valine, Methionine, Isoleucine, Leucine, Tyrosine, and Phenylalanine. 2. Amino acids detected in hydrolyzed samples were 17 kinds execpt Tryptophan of extracted ones. 3. Arginine was the highest quantity of amino acids in ginseng. 4. The content of Tryptophan was 0.5690 mg/g in the 6 year-old fresh ginseng and trace quantities in other samples. 5. The contents of amino acids were increased in fresh ginseng according to cultivation year. 6. The contents of amino acids in white ginseng were slightly decreased but those in red ginseng were not changed during the storage time. 7. The content ratio of free amino acids to total amino acids were 1:3.

• Food Science and Preservation
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• v.12 no.5
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• pp.476-481
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• 2005

This study was carried out to analyze the components of the Angelica dahurica root for the studies of the physiological function. General components of A. dahurica root were 71.7% moisture, 10.6% carbohydrate, 9.3% crude protein, 6.6% crude ash and 1.9% crude fat. The content of reducing sugar was 1,850 mg/100 g. The total amount of free sugar was 80 mg/100 g, in which 19.3 mg/100 g fructose, 27.8 mg/100 g glucose, 28.4 mg/100 g sucrose and 4.5 mg/100 g maltose were present. In the results of mineral analysis, the content of K was the highest(2,145.03 mg/100 g) followed by 286.35 mg/100 g Mg and 145.23 mg/100 g Ca. The total amount of hydrolyzed amino acid was 71.68 mg/100 g, in which 20.98 mg/100 g essential amino acid and 50.70 mg/100 g of non-essential amino acid were present. Among them, proline(11.74 mg/100 g) was the highest. Total free amino acids were contained 17.04 mg/100 g, in which 6.67 mg/100 g of essential amino acids and 10.37 mg/100 g of non-essential amino acids were present. Among them alanine(5.96 mg/100 g) was the highest. Total content of amino acid derivatives was 3.37 mg/100 g.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1164-1170
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• 1996

Studies were carried out to investigate the changes of constituent components in chestnuts (Castanea crenata Sieb. et Zucc) during storage at $20^{\circ}C$ for 9 weeks and $1^{\circ}C$ for 15 weeks. Ascorbic acid content of chestnut was 4.08 mg% in oxidized form and 17.7 mg% in reduced form which was 81.3% of total ascorbic acid. The reduced form gradually decreased during storage, while the oxidized forms increased during 5 weeks at $20^{\circ}C$ and 7 weeks at $1^{\circ}C$. The major organic acids in chestnut were malic acid, citric acid and quinic acid. Citric acid significantly decreased during storage, while malic acid increased during storage at $20^{\circ}C$ and decreased at $1^{\circ}C$. Free sugars in chestnuts were identified as glucose, fructose, sucrose and maltose. Glucose and fructose decreased after 5 weeks storage at $20^{\circ}C$ followed by an increase thereafter. Sucrose and maltose also increased. The major free amino acids in the chestnut were glutamic acid, aspartic acid, arginine, alanine, proline and serine. Glutamic acid, arginine, alanine, threonine, phenylalanine, valine and lysine increased during storage at $20^{\circ}C$, while proline, serine, isoleucine. leucine and ${\gamma}-aminobutyric$ acid decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.263-269
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• 1997

To cope with increasing importance of water stress in food crop production, some physiological characteristics, their cultivar-differences and grain yield of winter barley cultivars in response to water stress during reproductive stages were studied employing three covered-barley cultivars, Milyang 12, Durubori, and Olbori, one naked-barley cultivar, Baegdong, and one two-row malting-barley cultivar, Hyangmaeg. The barley grown in pot-soil was conditioned for 10 days under water stress, varying the time of water stress : 20 days before heading, 10 days before heading and the time of heading. The decrease in growth due to water stress varied greatly with the cultivars and time of water stress. The greatest injury occurred when water stress was imposed for 10 days from 10 days before heading : the culm length of water-stressed plants have shown reduced by 85∼98％ of the non-stressed; the number of spikes per plant by 52∼83%; the number of grains per spike by 71∼86%; 1,000-grain weight by 80∼84%; yield per pot by 60∼94%. The number of spikes per plant as one of yield components was most sensitively affected. As a whole, the drought resistance of cultivars was high in the order of Olbori> Milyang 12 and Durubori> Hyangmaeg>Baegdong. On rewatering the plants after termination of the water stress treatment the recovery rate of free proline content and relative turgidity of flag leaf were higher in 3 covered-barley cultivars, and lower in cultivars Baegdong and Hyangmaeg.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.150-158
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• 1993

In order to investigate the content and seasonal variation of the extractive components including taste compounds, free amino acids, nucleotides and related compounds, quanternary ammonium bases, and guanidino compounds of ascidian collected from the south coast of Korea were determined bimonthy from April to October in 1990. The extractive nitrogen was composed of $60{\sim}62\%$ as free amino acids, $12{\sim}16\%$ as betaines, $5{\sim}9\%$ as nucleotides, and others as trimethylamine oxide(TMAO) and total creatinine. The muscle of ascidian was rich in such free amino acids as taurine, proline, glutamic acid, glycine and glycinebetaine. Most of nitrogenous compounds in the extractives showed a marked seasonal variation with a maximum in summer or autumn. AMP content was relatively high among nucleotides. Succinic acid, malic acid, lactic acid and pyroglutaric acid were the major organic acids in ascidian. The results of omission test suggested that the taste of ascidian is attributed to mainly free amino acid, betaines, nucleotides and nonvolatile organic acid in order.