- Isolation and identification of 5-hydroxymaltol, a mutagenic substance in glucose pyrolysate
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This paper describes the isolation and identification of a mutagenic compound produced by the pyrolysis of glucose. The mutagenic activity of 5-hydroxymaltol is too weak to explain the mutagenic activity of the glucose pyrolysate. The authors are now attempting to identify other mutagens besides 5-hydroxymaltol in the glucose pyrolysate.
- Kosuge,Tsuji,Nukaya,et al.
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- The effect of high pressure on the formation of volatile products in a model Maillard reaction
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Reaction progress in the formation and subsequent decay of several of the volatile products from a model Maillard reaction between lysine and xylose has been followed at pH 7 and 10 and at elevated pressures. At low pH, the buildup and decay of 5-methyl-4-hydroxy-3(2H)-furanone and several minor products were observed. The application of high pressure results in a much diminished maximum concentration of each although the time to the maximum is unaffected. At pH 10, products contain nitrogen heterocycles with 2-methylpyrazine being the principal one which builds up and only slowly decays with time. Again, the yield is greatly reduced by pressure. The results are interpreted in terms of the inhibition by pressure of the formation of the precursor the Amadori rearrangement product which affects subsequent products. In some instances rates of formation are also found to be slightly inhibited while degradation of these products is accelerated. The corresponding mechanisms are examined in the light of these results.
- Bristow, Mark,Isaacs, Neil S.
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- Identifying new volatile compounds in toasted oak
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Toasting wood to be used in barrels for aging wine produces a great number of volatile and odiferous compounds. Three new volatile odorous compounds in toasted oak were identified. Analysis by high-performance gas chromatography of toasted oak extracts, combined with olfactory detection, enabled various chromatographic peaks with these specific aromas to be isolated. These same odors were simultaneously studied by heating glucose both with and without proline and phenylalanine. Aromatic compounds of interest were identified thanks to a combination of gas chromatography and both mass and infrared spectrometry. An analysis RMN was also used. Hydroxymaltol, 2,5-furanedicarbaldehyde, and furylhydroxymethyl ketone have been detected in extract of toasted oak wood. These molecules may be formed by direct pyrolysis of sugar or Maillard reactions. The acetylformoine was not detected in extract of toasted oak wood, whereas it was detected in heated extracts of various sugars and sugars mixtures with amino acids.
- Cutzach, Isabelle,Chatonnet, Pascal,Henry, Robert,Dubourdieu, Denis
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- On the Role of 2,3-Dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one in the Maillard Reaction
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To investigate the thermal degradation pathways of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (1) in the Maillard reaction, the 13C-labeled and unlabeled 1 were synthesized and heated in model systems of food processing. The extent and position of the labeling of the reaction products were interpreted by the mass spectroscopy data. The volatiles identified were, among others, 2,4-dihydroxy-2,5-dimethyl-3(2H)-furanone (2), 2,5-dimethyl-4-hydroxy-3(2H)-furanone, cyclotene, maltol, 5-hydroxymaltol, and some acyclic carbonyls. Under roasting conditions, 2 was formed as a major product. It was concluded that 1 might be transferred to highly reactive open-chain intermediates like the enolic forms of 1-deoxyosone. The further reaction pathways varied with the reaction conditions. Possible degradation pathways of 1 that resulted from the labeling experiments as well as the formation of the described products are discussed.
- Kim, Myong-Ock,Baltes, Werner
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- A CONVENIENT SYNTHESIS OF 3-HYDROXY-4H-PYRAN-4-ONE DERIVATIVES HAVING A HALO OR HYDROXY GROUP AT THE 5-POSITION
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The reaction of 4,5-epoxy-4-halo-6-methoxy-2-methyltetrahydropyran-3-ones (4b, 5b) in acidic media was examined and the following results were found: The reaction of 4b or 5b with 1percent sulfuric acid afforded a mixture of 3,5-dihydroxy-4H-pyran-4-one (
- Takao, Hisashi,Endo, Yoshinori,Horie, Tokunaru
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p. 1803 - 1812
(2007/10/02)
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- Maillard Reaction Products Formed from D-Glucose and Glycine and the Formation Mechanisms of Amides as Major Components
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Equimolar aqueous solution of D-glucose and glycine were heated at 50 oC and 95 oC at pH 6.7.The headspace volatiles and the ether extracts from the reaction mixture were analyzed by gaz chromatography and gas chromatography-mass spectrometry, using a fused silica capillary column.The major components formed were identified as diacetyl, furfuryl alcohol, two pyrroles, one pyranone and two amides.In order to elucidate the formation mechanisms of the amides formed from amino-carbonyl reactions, two model systems were adopted.N-Butylacetamide and N-butylformamide were formed as major components from diacetyl-butylamine and glyoxal- butylamine systems, respectively.The results obtained suggest that such α-dicarbonyls as 3-deoxyosone, 1-deoxy-D-erythro-2,3-hexodiulose and diacetyl generated in the amino-carbonyl reaction react with amino compounds, amides then formed by cleavage of the C-C bond in the α-dicarbonyls.
- Hayase, Fumikata,Kim, Bong Seon,Kato, Hiromichi
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p. 2337 - 2342
(2007/10/02)
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