- Comparison of 2-acetylfuran formation between ribose and glucose in the Maillard reaction
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Sugar type is a major factor regulating the reaction rates and pathways in Maillard reaction. Ribose and glucose were used to compare their reactivities and pathways of 2-acetylfuran formation. A stable isotope labeling method was used to study their reactivity. A 1:1 mixture of [13C 6]glucose and unlabeled ribose (or other unlabeled sugar) was reacted with proline at 145 °C for 40 min. The reactivity of each sugar was revealed by the ratio of isotopomers. The reactivity of sugars in 2-acetylfuran formation decreased in the order ribose, fructose, glucose, rhamnose, and sucrose. This method simplified the reaction system and the calculation process and gave a direct comparison of reactivity as seen via mass spectrum. The difference between glucose and ribose in 2-acetylfuran formation was that glucose could form 2-acetylfuran directly from cyclization of its intact carbon skeleton, whereas ribose first underwent degradation into fragments before forming a six-carbon unit leading to 2-acetylfuran. In the presence of cysteine, ribose could not generate 2-acetylfuran at a detectable level. When ribose was reacted with glycine, formaldehyde generated from glycine combined with ribose to form 2-acetylfuran. In other amino acids, a symmetric structure of the ribose intermediate was formed, making fragmentation more complicated.
- Wang, Yu,Ho, Chi-Tang
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p. 11997 - 12001
(2010/03/25)
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- Formation of odorants in Maillard model systems based on L-proline as affected by pH
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Formation of the odorants acetic acid, 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (HDMF), 6-acetyl-1,2,3,4-tetrahydropyridine (ATHP), and 2-acetyl-1-pyrroline (AP) was monitored by isotope dilution assays at pH 6, 7, and 8 in Maillard model reactions containing glucose and proline (Glc/Pro) or the corresponding Amadori compound fructosyl-proline (Fru-Pro). In general, higher yields were obtained at pH 7 and 8. Acetic acid was the major odorant with up to 40 mg/mmol precursor followed by HDMF (up to 0.25 mg/mmol), the formation of which was favored in the Fru-Pro reaction systems. On the contrary, ATHP (up to 50 μg/mmol) and AP (up to 5 μg/mmol) were more abundant in Glc/Pro. However, the sensory relevance of the two N-heterocycles was more pronounced on the basis of odor activity values, confirming their contribution to the overall roasty note of the reaction samples. It was also found that formation and decomposition of Fru-Pro were faster at pH 7 as compared to pH 6, explaining in part the preferred formation of the four odorants studied under neutral and slightly alkaline conditions. After 4 h of reaction at pH 7 in the presence of proline, about one-fourth of the glucose was consumed leading to acetic acid with a transformation yield of almost 40 mol %.
- Blank, Imre,Devaud, Stephanie,Matthey-Doret, Walter,Robert, Fabien
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p. 3643 - 3650
(2007/10/03)
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- Potential of gas chromatography-orthogonal acceleration time-of-flight mass spectrometry (GC-oaTOFMS) in flavor research
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Gas chromatography-orthogonal acceleration time-of-flight mass spectrometry (GC-oaTOFMS) is an emerging technique offering a straightforward access to a resolving power up to 7000. This paper deals with the use of GC-oaTOFMS to identify the flavor components of a complex seafood flavor extract and to quantify furanones formed in model Maillard reactions. A seafood extract was selected as a representative example for complex food flavors and was previously analyzed using GC-quadrupole MS, leaving several molecules unidentified. GC-oaTOFMS analysis was focused on these unknowns to evaluate its potential in flavor research, particularly for determining exact masses, N-Methyldithiodimethylamine, 6-methyl-5-hepten-2-one, and tetrahydro-2,4-dimethyl-4H-pyrrolo- [2,1-d]-1,3,5-dithiazine were successfully identified on the basis of the precise mass determination of their molecular ions and their major fragments. A second set of experiments was performed to test the capabilities of the GC-oaTOFMS for quantification. Calibration curves were found to be linear over a dynamic range of 103 for the quantification of furanones. The quantitative data obtained using GC-oaTOFMS confirmed earlier results that the formation of 4-hydroxy-2,5-dimethyl-3(2H)-furanone was favored in the xylose/glycine model reaction and 2(or 5) -ethyl-4-hydroxy-5(or2)-methyl-3(2H)-furanone in the xylose/alanine model reaction. It was concluded that GC-oaTOFMS may become a powerful analytical tool for the flavor chemist for both identification and quantification purposes, the latter in particular when combined with stable isotope dilution assay.
- Fay, Laurent B.,Newton, Anthony,Simian, Herve,Robert, Fabien,Douce, David,Hancock, Peter,Green, Martin,Blank, Imre
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p. 2708 - 2713
(2007/10/03)
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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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p. 2213 - 2218
(2007/10/03)
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- Formation of Hydroxyfuranone and Hydroxypyranone Derivatives with DNA-Breaking Activity in the Maillard Reaction of Glucose and Albumin under Physiological Conditions
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Formation of DNA breaking hydroxyfuranone and hydroxypyranone derivatives in the Maillard reaction of glucose and bovine serum albumin (BSA) under physiological conditions was investigated. A mixture of glucose and BSA was incubated at 37 deg C in water or in 1 M phosphate buffer (pH 7.4). The ethyl acetate/2-propanol extract of the reaction mixtures showed significant DNA breaking activity against supercoiled DNA especially in the presence of Fe(III) ion. Gas chromatography/mass spectrometry analysis of the mixture revelaed the formation of DNA breaking hydroxyfuranones (HMF and DMHF) and hydroxypyranone (DDMP).
- Hiramoto, Kazuyuki,Ishihara, Akira,Sakui, Norihiro,Daishima, Shigeki,Kikugawa, Kiyomi
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p. 101 - 104
(2007/10/03)
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- DNA strand-breaking activity and mutagenicity of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP), a Maillard reaction product of glucose and glycine
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Aqueous solution of glucose and glycine was heated under reflux for 4 h and extracted with ethyl acetate. Reversed phase HPLC of the extract revealed a new DNA strand-breaking substance, which was purified by repeated HPLC and identified as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). DDMP induced DNA strand breaking in a dose- and time-dependent manner. It was active to break DNA strands at pH 7.4 and 9.4. Its pyranone skeleton was destroyed at the pH values. DNA strand breaking by DDMP was inhibited by superoxide dismutase, catalase, scavengers for hydroxyl radical, spin trapping agents and metal chelators, and the breaking was enhanced by Fe(III) ion. A mixture of DDMP and a spin trap DMPO gave electron spin resonance signals of a spin adduct DMPO-OH, indicating generation of hydroxyl radical. DDMP was found to be mutagenic to Salmonella typhimurium TA100 without metabolic activation. These results show DDMP generated active oxygen species to cause DNA strand breaking and mutagenesis.
- Hiramoto, Kazuyuki,Nasuhara, Akiko,Michikoshi, Kae,Kato, Tetsuta,Kikugawa, Kiyomi
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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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p. 282 - 289
(2007/10/03)
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- Formation of 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone through maillard reaction based on pentose sugars
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The caramel-like smelling compounds 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) and 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF) were identified by GC-MS and GC-MS/MS in Maillard reaction systems based on pentoses. The reaction was performed in a phosphate buffer by heating xylose, ribose, or arabinose with glycine or L-alanine at 90 °C for 1 h. HEMF was detected in the system pentose/alanine. HDMF was formed in both pentose/glycine and pentose/ alanine systems as well as directly from pentoses. Experiments using 13C-labeled glycine and alanine suggest the incorporation of the Strecker degradation products formaldehyde and acetaldehyde into the pentose moiety, forming the furanones HDMF and HEMF, respectively. The presence of 12C-HDMF, which was approximately 30% of the total HDMF amount found in xylose/glycine, indicates that HDMF is partly formed by sugar fragmentation. The proposed mechanism for the formation of the furanones is based on decomposition of the Amadori compound via 2,3-enolization, chain elongation by the Strecker aldehydes, and reduction of the resulting acetylformoin-type intermediates to the target molecules.
- Blank, Imre,Fay, Laurent B.
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p. 531 - 536
(2007/10/03)
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- 2,5-DIMETHYL-4-HYDROXY-3(2H)-FURANONE GLUCOSIDE: ISOLATION FROM STRAWBERRIES AND SYNTHESIS
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2,5-Dimethyl-4-hydroxy-3-(2H)furanone β-glucoside has been isolated from strawberry juice and synthesized.Both the natural and synthetic material exist as a diastereoisomers. - Keywords: Fragaria ananassa; Rosaceae; glucoside; 2,5-dimethyl-4-hydroxy-3(2H)-furanone glucoside.
- Mayerl, Friedrich,Naef, Regula,Thomas, Alan F.
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p. 631 - 633
(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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- Preparation of 2,5-dimethyl-4-hydroxy-2,3-dihydrofuran-3-one
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A process for the preparation of the sought-after scent 2,5-dimethyl-4-hydroxy-2,3-dihydrofuran-3-one, and novel intermediates for the preparation of this compound. 2,5-Dimethyl-4-hydroxy-2,3-dihydrofuran-3-one is prepared by first epoxidizing hex-3-ene-2,5-diol in the liquid phase with hydrogen peroxide to give the novel compound 3,4-epoxy-hexane-2,5-diol, which at 40°-280° C. is converted, by means of a catalytic amount of an acid, to the novel compound 2,5-dimethyl-3,4-dihydroxy-tetrahydro-furan. The latter is dehydrogenated by means of oxygen over a silver catalyst or copper catalyst to give the nove compound 2,5-dimethyl-4-hydroxy-tetrahydrofuran-3-one, which is oxidized by means of bismuth oxide, in concentrated acetic acid solution, to give the desired compound 2,5-dimethyl-4-hydroxy-2,3-dihydrofuran-3-one.
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