• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.614-619
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• 1993

Oxidation mechanisms of methyl linoleate with ${\alpha}-Tocopherol$(TML) were investigated by determining oxidized products using GC-MS during oxidation at $37^{\circ}C$ for 9 days. Oxidized products of TML were found to be methyl octanoate, methyl-8-(2-furyl)-octanoate, 9,13-trans, cis isomer and 9,13-trans, trans isomer. In previous report, oxidation products of methyl linoleate(ML) were methyl-8-(2-furyl)octanoate, 9,13-trans, cis hydroperoxide isomer, 9,13-trans, trans hydroperoxide isomer, and 9-TMSO-12,13-epoxy-10-octadecenoate. In the case of ML, 9-TMSO-12,13-epoxy-l0-octadecenoate was produced instead of methyl octanoate in TML. ${\alpha}-Tocopherol$ quinone, as a major oxidized product of ${\alpha}-Tocopherol$ was formed at the 6th day of oxidation. ${\alpha}-Tocopherol$ quinone was produced rather quickly in lipid media than aqueous media. In oxidation of methyl linoleate, it was shown that the first oxidized product was methyl-9,13-hydroxy-octadecadienoate. As second products, methyl-8-(2-furyl)-octanoate, 9-TMSO-12,13-epoxy-10-octadenoate, and methyl octanoate were oxidized from methyl-9-hydroxy-10-trans, 12-trans-octadecadienoate.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.537-544
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• 2013

This study was performed to establish method of simultaneous determination of fructose, glucose, and sucrose in honey and commercial vitamin drinks by GC and GC/MS. Optimum chromatographic separation of trimethylsilyl-oxime (TMSO) derivatives by GC was achieved on a DB-5 column. Calibration curves for fructose, glucose and sucrose TMSO derivatives by GC were linear in the range of 50-5000 ${\mu}g/mL$, and their $r^2$ values were 0.9999, The limit of detection and limit of quantification of fructose, glucose, and sucrose were 0.68, 0.47, and 0.53 ${\mu}g/mL$, respectively, and 2.27, 1.58, and 1.77 ${\mu}g/mL$, respectively. Average recoveries of fructose, glucose, and sucrose were 100.5, 101.0, and 99.7%, respectively. When the method was applied to 12 honey samples, the average concentrations of fructose, glucose and sucrose were $42.58{\pm}1.97%$, $27.74{\pm}1.16%$, and $0.79{\pm}0.52%$, respectively. The F/G ratio was $1.53{\pm}0.07$. For fructose and glucose contents, results from the GC analysis were similar to those from the HPLC analysis, but the sucrose content was different for each analysis method. We suggest that the GC method is more suitable than other official analytical methods for simultaneous determination of fructose, glucose, and sucrose in honey.

• Journal of the Korean Chemical Society
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• v.40 no.10
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• pp.649-655
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• 1996

The chemical behaviour of Pt(Ⅱ) and Pd(Ⅱ) complexes with the organic ligand tetramethylenesulfoxide(TMSO) has been investigated by UV/vis-spectrophotometric, magnetic, and electrochemical methods. Two energy absorption bands are observed in the spectra of these complexes. The crystal field splitting energy, spin pairing energy, and bond strength were obtained from the spectra of the complexes. The electronic properties of the complexes are found to be delocalized, and low-spin state. The correlation between ligand and metals were strong bonding strength. These complexes are diamagnetics. The redox reaction processes of the complexes were investigated by cyclic voltammetry in an aprotic solvent. The redox processes of complexes turned out to be respect to one-electrton one step. These complexes were considerably diffusion and reaction controlled.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.379-385
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• 1993

Antioxidative effectiveness and oxidized products in mixture of methyl linoleate(ML) and phenolic compounds were investigated under oxygen blowing at $37^{\circ}C$ for 9 days. Caffeic acid (3,4-dihydroxy cinnamate ; CML) and phloroglucinol(1,3,5-trihydroxy benzene ; PML) showed higher antioxidative effectiveness for methyl linoleate than 0.05% ${\alpha}-tocopherol$ (TML). Oxidized products in ML group were methyl 8-(2-furyl)-octanoate, 9,13-trans, cis hydroperoxide isomer, 9,13-trans, trans hydroperoxide isomer, and 9-TMSO-12,13-epoxy-10-octadecenoate. In CML group the oxidized products were methyl-8-(2-furyl)-octanoate, 9-trans, cis hydroperoxide isomer and 9-trans, trans hydroperoxide isomer, but 13-hydroxy isomer was not identified. It was shown that CML were oxidized more slowly than ML group and at 6th day of oxidation, caffeic quinone was found to be major oxidized product of caffeic acid. Oxidixed Products in PML group were methyl-8-(2-furyl)-octanoate, 9-trans, cis hydroperoxide isomer, and 9-trans, trans hydroperoxide isomer but phloroglucinol was not oxidized even at the 9th day of reaction.

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.1-8
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• 2016

Sugar profiles of 45 Korean honey samples (15 acacia, 15 multi-floral, 10 chestnut, and 5 artificial honey samples), which are commercially available in the Korean markets, were analyzed using gas chromatography/mass spectrometry (GC/MS) through TMS-oxime and TMS-methoxime derivatization. The average invert sugar contents in acacia, multi-floral, chestnut, and artificial honey samples were $71.2{\pm}1.05$, $68.7{\pm}3.26$, $63.2{\pm}1.85$, and $68.0{\pm}2.10%$, respectively. Fourteen disaccharides were detected from the samples, and the average content of major disaccharides was higher in order of turanose, maltulose, maltose, trehalulose, kojibiose, isomaltose, and nigerose. The average content of total disaccharides was highest in chestnut and lowest in acacia. Seven trisaccharides were detected from the samples, and the average content of trisaccharides was the highest in artificial honeys, which had high erlose content. The total content of disaccharides and trisaccharides was highest ($16.0{\pm}2.03%$) in chestnut honey and lowest ($9.70{\pm}1.75%$) in acacia honey.