• Journal of Nutrition and Health
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• v.17 no.3
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• pp.169-177
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• 1984

The changes in nuclecotides and their related compounds during the fermentation of Clam, Tapes japonica, were analyzed by high speed liquid chromatography. In raw Clam, dominant ADP was $7.86\;{\mu}mole/g$ on moisture and salt free base and the content of ATP was $3.85\;{\mu}mole/g$, AMP $3.71\;{\mu}mole/g$, hypoxanthine $0.28\;{\mu}mole/g$, inosine $0.15\;{\mu}mole/g$, respectively. But IMP was not detected in Clam ADP, ATP and AMP decreased while inosine and hypoxanthine incraesed by twenty two times and thirty there times respectively, after 63 days fermentation, when compared with raw samples. TMA- N increased while TMAO - N decreased during the fermentation The amount of TMAO nitrogen in 63 days fermented Clam was 66.0mg% on moisture and salt free base. It was belived that inosine, hypoxanthine and TMAO play an important role as flavour compounds in fermented Clam.

• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.255-263
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• 1977

Fermented squid, Loligo kobiensis, is widely used and occupies an important position in foods of this country. But no study on its taste compounds has been reported. This study was attempted to establish the basic data for evaluating taste compounds of fermented squid. The changes of such compounds during fermentation as free amino acids, nucleotides and their related compounds, TMAO, TMA and betaine were analysed. The sample was prepared with 20% salt content and fermented at a controlled temperature of $15{\pm}3^{\circ}C$. ADP, AMP and inosine tended to degrade rapidly while hypoxanthine increased more than four times as compared with raw sample at 91 day fermentation. In the free amino acid composition of fresh squid, abundant amino acids were proline, taurine, alanine, arginine, serine, glutamic acid, lysine, glycine, leucine and valine in order. Such amino acids like phenylalanine, methionine, tyrosine, isoleucine, and histidine were poor. In squid extract, proline and taurine were dominant holding 40.2% and 32.0% of total free amino acids respectively. The total free amino acid nitrogen in fresh squid was 33.6% of its extract nitrogen. The changes of free amino acid composition in the extract of squid during fermentation was not observed. In the extract of fermented product, abundant amino acids were proline, leucine, lysine, serine, arginine, alanine, valine, isoleucine, phenylalanine, methionine and glycine in order. Glutamic acid and histidine were poor and taurine and tyrosine were trace in content. The increase of total free amino acids during 63 day fermentation reached approximately wore than 1.8 times as compared with that of raw sample and than decreased slowly. The amount of betaine increased more than 1.2 times as compared with that of raw sample during 91 day fermentation. TMA increased while TMAO decreased during fermentation. The amount of TMAO nitrogen in 91 days fermented squid was 402.4mg% on moisture and salt free base. Betaine and TMAO known as sweet compounds were abundant in fermented squid. It is supposed that these compounds could also play a role as important taste compounds of fermented squid. It is concluded that the major taste compounds of fermented squid were amino acids like proline, leucine, serine, lysine, arginine, alanine and betaine. Other compounds such as valine, isoleucine and TMAO and hypoxanthine could also not be excluded as taste supporters in fermented squid.

• Journal of the Korean Society of Food Culture
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• v.17 no.4
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• pp.482-495
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• 2002

Changes in ATP and related compounds, TMAO, TMA, creatine and creatinine were analyzed to establish the processing conditions for rapid- and low salt-fermented liquefaction of anchovy(Engrulis japonica) extracts during fermentation. Experimental sample A: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 10% NaCl. Sample B: chopped whole anchovy, adding 20% water, heating at $50^{\circ}C$ for 9 hrs and then adding 13% NaCl. Sample C: chopped whole anchovy adding 13% NaCl. Sample D: whole anchovy adding 17% NaCl. ATP, ADP, AMP and IMP were broken down during fermentation period, while inosine and hypoxanthine or hypoxanthine were detected in each fermented liquefaction of anchovy. However the amounts of them were varied from collection to collection according to the pretreatment methods. Possibly ATP and their related compounds will not make a great contribution to the umami taste in fermented liquefaction of anchovy. The contents of TMAO were decreased during fermentation period, ranging from 3 to 15 mg/100g in the fermented liquefaction of anchovy after 180 days. The TMA contents were increased slowly during fermentation period, ranging from 60 to 114 mg/100g in the 180 days specimens, however their contents were varied from sample to sample. The contents of creatine and creatinine were increased during early fermentation period, and then they were decreased in the last period. As for distribution of nitrogen in the anchovy extracts, the contribution of creatine and creatinine to the extractive nitrogen was occupying 6.8, 5.7, 4.6 and 5.7% in the experimental sample A, B, C and D, respectively. The contribution of ATP and related compounds to the extractive nitrogen was occupying 2.1, 2.4, 2.2 and 2.7% in the experimental sample A, B, C and D, respectively. The contribution of TMAO and TMA to the extractive nitrogen was very low as they are occupying $0.7{\sim}1.2%$ in the four experimental samples.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.1
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• pp.46-66
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• 2012

Metabolomic studies using human urine have shown that human metabolism is altered by a variety of environmental, cultural, and physiological factors. Comprehensive information about normal human metabolite profiles is necessary for accurate clinical diagnosis of disease and for disease prevention and treatment. In this study, metabolite correlation analyses, using $^1H$ nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistics, were performed on human urine to compare metabolic differences based on gender and/or obesity in healthy human subjects. First, we applied partial least squares discriminant analysis to the NMR spectral data set to verify the data's ability to discriminate by gender and obesity. Then, the differences in metabolite-metabolite correlation between male and female, and between normal and high body mass index (obese) subjects were investigated through pairwise correlations. Creatine and several metabolites, including isoleucine, trans-aconitate, and trimethylamine N-oxide (TMAO), exhibited different quantitative relationships depending on gender. Dimethylamine had a different correlation with glycine and TMAO, based on gender. The correlation of TMAO with amino acids was considerably lower in obese, compared to normal, subjects. We expect that the results will shed light on the metabolic pathways of healthy humans and will assist in the accurate diagnosis of human disease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.403-411
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• 2001

In order to investigate the composition of dried layer, Porphyra dentata cultured at the south coast of Korea, the dried layer was analyzed for extractive nitrogen, free amino acids, combined amino acids, ATP and its related compounds and quaternary ammonium basis, The extractive nitrogen contents of dried laver extracts were 670-1,304 mg/100 g (on dry basis). From twenty-eight to twenty-nine kinds of free amino acids were found in the dried laver extracts and their total amounts were $2,796\~6,277\;mg/100\;g$ (on dry basis). The extracts were rich in free amino acids such as alanine, taurine, glutamic acid, glutamine and phosphoserine, From eighteen to twenty-one kinds of combined amino acids were found in the extracts and their total amounts were $1,406\~2,142\;mg/100\;g$ (on dry basis). The amounts of ATP and its related compounds were $65.7\~124,7\;mg/100\;g(2.13\sim3.68{\mu}mol/g$ on dry basis), Homarine was detected in all samples but $\beta$-alaninebetaine, $\gamma$-bufobetaine and trigonelline disappeared during processing. TMAO and TMA were detected in all samples. During processing of dried layer, free amino acids, TMAO and TMA were increased but the other constituents such as combined amino acids, ATP and its related compounds and betaines were decreased in all specimens.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.140-146
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• 1983

Considering fermented sardine with $20\%$ salt as a reference, the fermented sardines were prepared with 8 or $10\%$ salt, $0.5\%$ lactic acid, $6\%$ sorbitol and $6\%$ ethanol. The taste compounds and TBA value as the index of lipid oxidation were analysed prior to fermentation and after 60 days fermentation in products. The major free amino acids in fermented sardine determined after 60 days fomentation were lysine, leucine, histidine, glutamic acid, arginine and alanine which occupied about $58\%$ of the total free amino acids while histidine and taurine occupied about $93.3\%$ of them in raw meat. Betaine and TMA increased while TMAO and total creatinine decreased filling the fermentation of 60 days. Addition of $0.02\%$ BHA was effective to retard rancidity of the product. The result of omission test showed that the major taste compounds of the fermented sardine with low salt contents were amino acid such as lysine, alanine, glycine, glutamic acid, leucine and nucleotides and their related compounds, and it is also suggested that betaine, total creatinine and TMAO acted as an auxiliary role.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.10a
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• pp.148-148
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• 2003

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.117-122
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• 1982

Abalone, Haliotis diversicolor japonica, is one of the most palatable sea foods in Jeju-Do, Korea : however relatively little is known about the characteristics of its taste. This study was undertaken to establish the basic data for evaluating the taste compounds in the extract of abalone including nucleotides and their related compounds, free amino acids, trimethylamine oxide, trimethylamine and total creatinine. The amount of AMP was $2.21{\mu}mole/g$ while IMP and inosine was trace in content. In the extracts, taurine, arginine and glycine were abundant holding $39.9\%,\;25.4\%,\;14.0\%$ of total free amino acids content respectively, but tyrosine and phenylalanine was trace in content. TMAO, TMA and total creatinine were poor in content marking $5.4mg\%,\;1.0mg\%\;and\;5.0mg\%$. It was presumed that the characteristic flavor of abalone was mainely attributed to free amino acids. Organic acids, nucleotides and their related compounds played auxiliary role in the characteristic flavor of abalone.

• 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.

• Environmental Analysis Health and Toxicology
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• v.25 no.4
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• pp.295-306
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• 2010

Objectives : This study was undertaken to examine the metabolomic changes due to gender and diurnal variation at sampling time and to identify an appropriate time point for urine sampling in epidemiologic studies using metabolomic profiles. Methods : Urine samples were collected twice a day (morning and afternoon) from 20 healthy Korean adults after fasting for 8 hours. The metabolomic assay was investigated using $^1H$ NMR spectroscopy coupled with the principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The metabolites responsible for differentiation between groups were identified through the loading plot of PLS-DA and quantified using Chenomx NMR Suite with a 600 MHz library. Results : Metabolites responsible for differentiation in gender and sampling time were creatinine, trimethyl anine oxide (TMAO), hippurate, mannitol, citrate and acetoacetate. Dimethylamine showed difference only as a factor of diurnal time. The level of creatinine was higher in men compared to women, and the levels of citrate, TMAO, hippurate, mannitol, and acetoacetate were higher in women compared to men. The levels of creatinine, TMAO, hippurate, dimethylamine and mannitol were higher in the morning rather than the afternoon while those of citrate and acetoacetate were higher in the afternoon rather than the morning. Conclusions : Since urinary metabolomic profiles varied by gender and diurnal cycle, urine sampling should be performed at the same time point for all participants in epidemiologic studies using metabolomic profiles.