• Food Science of Animal Resources
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• v.32 no.6
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• pp.810-819
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• 2012

This study investigated the chemical composition, meat quality and volatile flavor compounds in loin and top round of Hanwoo beef (n=126) depending on different age groups (G1, <5; G2, 6-8; G3, >9 years old). The intramuscular fat content (%) was higher for loin and top round of G1 (p<0.05) than that in the other groups. There was no difference in age groups for the top round; however, the loin of G1 had lower protein content (p>0.05). Total collagen content was lower in the top round of G3 (p<0.05). The loin and top round muscles of G1 had higher $a^*$ values and lower Warner Bratzler shear force values than that in the other age groups (p<0.05). The loin muscles of G1 were lower in percentage of cooking loss and higher in the water holding capacity than the loin in the other groups (p<0.05). The loin of G1 had lower total content of saturated fatty acids, whereas the top round of G1 had higher total content of monounsaturated fatty acids and lower total content of polyunsaturated fatty acids than that in the other age groups (p<0.05). Alanine was the highest free amino acid in the loin of Hanwoo beef, followed by glutamine, glycine, isoleucine and proline. The loin of G1 had higher contents of threonine, alanine, valine, methionine, phenylalanine, leucine and lysine than those in the other groups (p<0.05). The loin of G3 contained higher 3-methylbutanal, furfural, octanal, 1-(acetyloxy)-2-propanone, 1-octanol, 2,5-dimethylpyrazine and 2-ethyl-2,5-dimethylpyrazine in volatile flavor components than the loin in G1(p<0.05).

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.283-291
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• 2017

Rice that the half of population in the world eats as a staple food is mostly produced and consumed in Asia. However, its consumption is nowadays decreasing mainly due to diet diversity. Accordingly, some attempts are in demand to enhance the utilization of rice. In this study, profiling of volatile and non-volatile flavor components in rice pastes obtained by ${\alpha}$-amylase was performed and compared according to nine different rice cultivars domestically cultivated in Korea using gas chromatography-mass spectrometry combined by solid phase microextraction and gas chromatography-time of flight-mass spectrometry after a derivatization, respectively. In total, 46 volatile compounds identified included 6 alcohols, 6 aldehydes, 4 esters, 4 furan derivatives, 4 ketones, 1 acid, 1 sulfur-containing compound, 7 hydrocarbons, 5 aromatics and 8 terpenes. The non-volatile flavor components found were composed of 12 amino acids, 6 sugars and 4 sugar alcohols. In principal component analysis, rice paste samples could be discriminated according to cultivars on the score plots of volatile and non-volatile flavor compounds. In particular, some volatile compounds such as pentanal and 4,7-dimethylundecane could contribute to distinguish Senong 17 white and Senong 17 brown, whereas ethanol, 6-methylhep-5-en-2-one, and tridecane could be highly related to the discrimination of Iipum from other cultivars. Among non-volatile compounds, some amino acids such as glycine, serine and ${\gamma}$-aminobutyric acid and some sugars such as sucrose and fructose were mainly responsible for the discrimination of Danmi from the other cultivars. On the other hand, galactose, arabitol and mannose were more closely related to Senong 17 white than Senong 17 brown.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.1
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• pp.1-12
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• 2018

Purpose: Disorders of organic acid metabolism have various clinical manifestations and it may be life-threatening. The prognoses of affected children are dependent on early diagnosis and treatment. We report this study to find out detection rate of referred samples, clinical manifestations and age distribution after introduction of neonatal screening test using tandem mass spectrometry in Hallym University Chuncheon Sacred Heart Hospital during 8 years and 9 months. Methods: The 2,794 patients referred from Jan. 2007 to Sep. 2015 were divided into four groups according to age. We conducted organic acid analysis of urine samples of patients and analyzed clinical manifestations and distributions of age at the diagnosis. For patients with ambiguous results, reanalysis of urine organic acid after diet restriction, protein loading and restriction, has been done. Results: A total of 626 patients with 20 disorders were diagnosed. Mitochondrial disorders (482 patients) were the most common diagnosis, followed by ketolytic defects (67), 3-hydroxyisobutyric aciduria (32), EPEMA syndrome (8), 3-methylcrotonyl glycinuria (7), glutaric aciduria type II (6) and type I (4), methylmalonic aciduria (3), isovaleric aciduria (3) and medium chain acyl-CoA dehydrogenase deficiency (3). Conclusion: As neonatal screening test using tandem mass spectrometry is increasingly common and medical environment is changed, detection rate of disorders of organic acid metabolism in this study has decreased compared to previous report. Because the deterioration can be prevented by early diagnosis and treatment, many pediatricians have to pay special attention to possibility of the disorders and make an effort for early diagnosis in clinical setting.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.445-453
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• 2012

An investigation for removal of 1-indanone (1-ID), which were commonly produced from the biological and/or chemical treatment and natural weathering of the PAHs-contaminated soils, via oxidative transformation mediated by birnessite in the presence of various phenolic mediators is described. This study also examines the potential effect of the natural occurring substance humic acid (HA) on the oxidative transformation. The experiment was carried out in aqueous phase as a batch test (10 mg/L 1-ID, 0.3 mM phenolic mediators, $1.0g/L\;{\delta}-MnO_2$, at pH 5). All of the 11 tested phenoilic mediators belong to the group of natural occurring phenols and are widely used as model constituents of humic substances. From the results of HPLC analysis, it is demonstrated that 1-ID was not reactive to birnessite itself, but it can be effectively removed in birnessite-mediated cross coupling reactions in the presence of the phenolic mediators. The percent removals of 1-ID after 2 day incubation were ranged from 9.2 to 71.2% depending on the phenolic mediators applied. The initial rate constant ($K_{int}$, $hr^{-1}$) values for the 1-ID removals obtained from the pseudo-first-order kinetic plots also widely ranged from 0.18 to 15.0. Results of the correlative analysis between the removal efficiencies and structural characteristics of phenolic mediators indicate that the transformation of the 1-ID was considerably enhanced by the addition of electron-donating substituents (e.g., -OH, $-OCH_3$) at the benzne ring, and much less enhanced by the addition of electron-withdrawing substituents (e.g., -COOH, -CHO). The presence of HA showed that removal efficiencies of 1-ID in the birnessite-phenolic mediator systems decreased with increasing HA concentrations. However at low concentration of HA (< 2 mg/L), it caused some enhancement in the removals of 1-ID as compared to the control.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.529-536
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• 1986

By modified method yellow corvenia(called $Y_3$) was prepared with $4\%$ salt, $4\%$ KCl, $6\%$ sorbitol, $0.5\%$ lactic acid and $4\%$ alcohol extract of red pepper to improve the quality of fermented sea food. In this study, changes of volatile compounds and fatty acid composition obtained from modified fermented yellow corvenia($Y_3$) were experimented during fermentation, comparing with conventional fermented yellow corvenia(called $Y_1,\;20\%$ of salt contents). Total lipid of yellow corvenia was composed of $78.1\%$ of neutral lipid, $21.2\%$ of phospholipid and $0.7\%$ of glycolipid. And monoeonoic acid was held $37.4\%$ of fatty acid composition of total lipid and saturated fatty acid ($34.8\%$), polyenoic acid ($27.7\%$) were followed. Saturated fatty acid($C_{14:0},\;C_{16:0},\;C_{18:0}$) in $Y_1,\;Y_3$ increased, polyenoic acid ($C_{22:6}\;C_{22:5}\;C_{20:5}$) decreased while monoenoic acid($C_{16:1}\;C_{18:1}$) in those was little fluctuated during fermentation. Thirty-three kinds of volatile component in whole volatile compounds obtained from $Y_1,\;Y_3$ at 90 days fermentation were identified, and composed of some hydrocarbons (8 kinds), alcohols (7 kinds), acids (6 kinds), aldehydes(4 kinds), sulfides(2 kinds), ketones (2 kinds), one of phenol and 3 kinds of the other components. Among the whole volatile compounds 2-ethoxy ethanol and was held $79.35\%$ in $Y_3$, whereas nonadecane was held $75.85\%$ in $Y_1$. During fermentation 8 kinds of volatile acids, 5 kinds of amines and 9 kinds of carbonyl compounds were also detected. Those volatile acid such as acetic acid, isovaleric acid, n-caproic acid, n-butyric acid were the major portion of total volatile acids in $Y_3$ at 90 days fermentation. Meanwhile, carbonyl compounds such as ethanal, 2-butanone and butanal were the major ones, while TMA held the most part of volatile amines in $Y_3$ during fermentation. From the result of sniff test, the components which are believed to contribute to the characteristic flavor of fermented product $Y_1,\;Y_3$ are deduced to be volatile acid, carbonyl compounds and amines in order. Conclusively, there was little difference in composition of volatile components, but merely a little difference in content of those between $Y_3$ and $Y_1$.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.975-984
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• 2018

Fast pyrolysis bio-oil has unfavorable properties that restrict its use in many applications. Among the main issues are high acidity, instability, and water and oxygen content, which give rise to corrosiveness, polymerization during storage, and a low heating value. Esterification and azeotropic water removal can improve all of these properties. A 500 g of Quercus mongollica which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 2 seconds at $550^{\circ}C$. The esterification consists of treating pyrolysis oil with a high boiling alcohol like n-butanol at $70^{\circ}C$ under reduced pressure (100 hPa). All products are analyzed for water mass fraction, viscosity, higher heating value, pH, FT-IR and GC/MS. The water mass fraction can be reduced by 91.4 % (from 31.5 % to below 2.7 %), the viscosity by 65.8 % (from 36.5 to 12.5 cP) and the higher heating value can be increased by 96.8 % (from 3,918 to 7,712 kcal/kg), the pH by 1.3 (from 2.7 to 4.0). FT-IR and GC/MS analysis indicated that labile acids, aldehydes, ketones and lower alcohols were transformed to stable target products. Using this approach, the water content of the pyrolysis oil is reduced significantly. These improvements should allow the utilization of upgraded pyrolysis liquids in standard boilers and as fuel in CHP (Combined heat and power) plants.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.927-933
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• 2022

We synthesized (C₁₀H₈N₂H)₂Cr₂O₇, The structure of the product was characterized with FT-IR(infrared) and elemental analysis. The oxidation of benzyl alcohol by (C₁₀H₈N₂H)₂Cr₂O₇ in organic solvents showed that the reactivity increased with the increase of the dielectric constant. The oxidation of alcohols was examined by (C₁₀H₈N₂H)₂Cr₂O₇ in DMF, acetone. As a resuit, (C₁₀H₈N₂H)₂Cr₂O₇ was found as efficicent oxidizing agent that converted benzyl alcohol, allyl alcohol, primary alcohol and secondary alcohols to the corresponding aldehydes or ketones(65%~95%). The selective oxidation of alcohols was also examined by (C₁₀H₈N₂H)₂Cr₂O₇ in DMF, acetone. (C₁₀H₈N₂H)₂Cr₂O₇ was selective oxidizing agent(15%~95%) of benzyl alcohol, allyl alcohol and primary alcohol in the presence of secondary ones. In the presence of DMF solvent with acidic catalyst such as H₂SO₄. (C₁₀H₈N₂H)₂Cr₂O₇ oxidized benzyl alcohol(H) and its derivatives. The Hammett reaction constant(ρ) was -0.69(308K). The observed experimental data were used to rationalize the hydride ion transfer in the rate determining step.