(PDF) Formation Of Pyrazines In Hydroxyacetaldehyde And Glycine ...

Log InSign Up

• Log In
• Sign Up
• more
• • About
  • Press
  • Papers
  • Terms
  • Privacy
  • Copyright
  • We're Hiring!
  • Help Center
  • less

Outline

keyboard_arrow_downTitleAbstractKey TakeawaysIntroductionMethodologyConclusionsReferencesFAQsAll TopicsChemistryTheoretical Chemistrydownload

Download Free PDF

Download Free PDFFormation of pyrazines in hydroxyacetaldehyde and glycine nonenzymatic browning Maillard reaction: A computational studyM.A.H. Shiparhttps://doi.org/10.1016/J.FOODCHEM.2006.10.025visibility

…

description

9 pages

descriptionSee full PDFdownloadDownload PDF bookmarkSave to LibraryshareShareclose

Sign up for access to the world's latest research

Sign up for freearrow_forwardcheckGet notified about relevant paperscheckSave papers to use in your researchcheckJoin the discussion with peerscheckTrack your impact

Abstract

By considering the formation of pyrazines (C 4 N 2 H 6 and C 4 N 2 H 4) as one of the possible final Maillard flavour compounds, Density Functional Theory computations at the standard state have been performed on the proposed mechanisms of glyoxal and glycine in the advanced stage of hydroxyacetaldehyde and glycine nonenzymatic browning reaction under different pH conditions. The results reveal that the basic condition is the most favourable for the production of pyrazines (Pzs), and the aqueous solution is more favourable than that of the gaseous state. The reactions at the isoelectric point of glycine and under neutral conditions are the second and third most favourable for the production of Pzs, respectively. The reaction under acidic conditions is the least feasible for the production of Pzs. Amino acetaldehyde is the most likely precursor of the pyrazine ring in the reaction. Presence of air or oxygen is necessary for the production of 2,3,5,6-tetrahydropyrazine (C 4 N 2 H 4) from 3,6-dihydropyrazine (C 4 N 2 H 6). Water is necessary with glyoxal and glycine species for the formation of Pzs and water is produced as a by-product during the formation of Pzs.

... Read more

Key takeaways

AI

1. Basic pH conditions favor pyrazine formation in the Maillard reaction involving hydroxyacetaldehyde and glycine.
2. Density Functional Theory computations reveal water is essential for producing pyrazines and is a by-product.
3. Amino acetaldehyde is identified as the key precursor for the pyrazine ring formation.
4. Oxygen presence is crucial for converting 3,6-dihydropyrazine to 2,3,5,6-tetrahydropyrazine during reactions.
5. The study aims to elucidate mechanisms for controlling the Maillard reaction to produce desirable flavors.

Related papers

Computational studies on glyceraldehyde and glycine Maillard reaction—IM.A.H. Shipar, Md Abul H Shipar

Mechanisms for the initial stage of glyceraldehyde and glycine Maillard reaction under different pH conditions have been proposed, following usually the Hodge-scheme. Computations have been performed on the mechanisms at the standard state to test the possibility of the formation of different compounds, through evaluating the changes in Gibb's free energy during the reaction. Electronic energy changes during the reaction have also been evaluated. GlyceraldehydeCdeprotonated glycine reaction has been found to be the most favorable for the formation of the Amadori rearrangement products in both gaseous and aqueous states. Due to the possibility of the production of both enol and keto forms of the Amadori rearrangement product, the rate of browning in glyceraldehydeCdeprotonated glycine reaction is assumed to be faster than the others. GlyceraldehydeCunionized glycine reaction has been found to be more plausible for the formation of the keto form of the Amadori rearrangement products, particularly, in the gaseous phase. GlyceraldehydeCprotonated glycine and glyceraldehydeC glycine zwitterion reactions are not favorable for the formation of the Amadori rearrangement products. Formation of hydroxyacetaldehyde from glyceralaldehyde, as one of the possible C2-fragmentation product, has been found to be favorable in the aqueous state.

downloadDownload free PDFView PDFchevron_rightFormation of methyl glyoxal in dihydroxyacetone and glycine Maillard reaction: A computational studyM.A.H. Shipar, Md Abul H Shipar

By considering the formation of methyl glyoxal as one of the possible intermediates, mechanisms for the intermediate stage of the Maillard reaction of dihydroxyacetone and glycine under different pH conditions have been proposed, following the Hodge-scheme. Density functional theory calculations have been performed at the standard state on the proposed mechanisms to calculated the Gibb's free energy changes for the formation of different compounds in different steps of the reaction. Thus, the possibility for the formation of different compounds in the proposed mechanisms has been evaluated. Electronic energy changes for the formation of different compounds in the proposed mechanisms have been calculated to observe the internal energy changes of the reaction. The total mass balance has been followed during the calculation of electronic and Gibb's free energies. The result reveals that methyl glyoxal is one of the most likely intermediates in the reaction, and dihydroxyacetone + deprotonated glycine and dihydroxyace-tone + unprotonated glycine reactions are assumed favorable for the production of methyl glyoxal. The gaseous phase reaction is supposed to be more feasible than the aqueous phase reaction for the production of methyl glyoxal. Glyceraldehyde + protonated glycine and glyceraldehyde + glycine zwitterion reactions are postulated as less feasible for the formation of methyl glyoxal.

downloadDownload free PDFView PDFchevron_rightModification of maillard browning in a microwaved glucose/glycine model system by water-soluble natural antioxidants and foods containing themAmy Lynch

Journal of the American Oil Chemists' Society, 2006

Inhibition of pyrazine formation by natural antioxidants and the foods containing them was measured in a microwaved glucose/glycine model system. Inhibition of lipid oxidation by the same materials was assayed in both bulk and emulsion systems. Pyrazines were determined by solid-phase micro extraction followed by GC. Lipid oxidation volatiles were assayed by polyamide fluorescence produced by either a bulk oil display or a hematin-or 2,2'-azobis-(2-amidino-propane) dihydrochloride-accelerated lecithin or fish oil emulsion. It was shown that (i) the inhibition of pyrazine formation depends on high concentrations of water-soluble antioxidants; (ii) such antioxidants occur naturally in some foods and are usually polyphenols; (iii) during pyrazine inhibition, oxidized polyphenols show enhanced nonfluorescing browning similar to enzymic browning products; (iv) monophenols, which structurally cannot form quinone polymers on oxidation, inhibit pyrazines with less browning; (v) during the final pyrazine-forming phase of the Maillard reaction, polyphenolics and reducing agents such as glutathione and ascorbic acid are partially consumed with some nutritional loss; (vi) fruit powders of grape seed, grape skin, and red wine are highly pyrazineinhibitory, steeped blueberry strongly so, but plum purees are moderately pro-pyrazine, and freeze-dried vegetables strongly pro-pyrazine; and (vii) black and green tea infusions are highly inhibitory, whereas spices have mixed effects. and b Concord Foods, Brockton, Massachusetts d Gallic acid, tannic acid, protocatechic aldehyde, protocatechoic acid, and p-coumaric acid are commonly found in mango fruits.

downloadDownload free PDFView PDFchevron_rightSynthesis and Evaluation of Pyrazine Derivatives with Herbicidal ActivityMartin Dolezal

Herbicides, Theory and Applications, 2011

downloadDownload free PDFView PDFchevron_rightFactors affecting the formation of pyrazine compound in sugar amine reactionKanokwan Chaemchoi

Factors which affect the production of pyrazine and asparagine in a diethylene glycol-water system. compounds in a sugar-amino acid model system

downloadDownload free PDFView PDFchevron_rightDensity functional computational studies on ribose and glycine Maillard reaction: Formation of the Amadori rearrangement products in aqueous solutionM.A.H. Shipar, Md Abul H Shipar

By following the Hodge-scheme, and considering the formation of the Amadori rearrangement products (ARPs) as one of the possible intermediates in the early stage, density functional theory calculations have been performed at the standard state on the proposed mechanisms of the Maillard reaction of cyclic ribose (cRib)/open-chain ribose (Rib) and glycine species under different pH conditions in aqueous solution. The result reveals that both cRib and Rib can participate in the reaction. Rib has been found as more reactive than cRib in the reaction. The reactions under basic and neutral conditions are supposed to be the most and second most favourable for the formation of ARPs. Production of both of the enol and keto forms of ARP have been found as feasible under basic condition, whereas the neutral condition is only favourable for producing the enol form of ARP. Therefore, the rate of browning under basic condition is assumed higher than that of the neutral condition. Formation of all intermediates in the proposed mechanisms has been found as unfeasible in the reaction under acidic condition and at the isoelectric point of glycine. Therefore, production of ARPs under these conditions is assumed to be stalled under these conditions, resulting into lower browning rate. Formation of Rib through the cleavage of glucose has been assumed less feasible than the formation of glucose from Rib and formaldehyde in aqueous solution.

downloadDownload free PDFView PDFchevron_rightInfluence of Pyrolytic and Aqueous-Phase Reactions on the Mechanism of Formation of Maillard ProductsAndrzej Wnorowski

Journal of Agricultural and Food Chemistry, 2000

The influence of the reaction phase on the mechanism of formation of Maillard products was studied by comparison of 13 C-label incorporation patterns of the common products formed in model systems consisting of labeled glycine and D-glucoses subjected to both pyrolysis and heating in aqueous solutions. Pyrolysis experiments were performed at 250°C for 20 s, and aqueous model systems were heated in sealed vials for 3 h at 120°C followed by GC/MS analysis. Label incorporation patterns of the following compounds were analyzed: cyclotene, furanmethanol, acetylpyrrole, 5-methyl-pyrrole, trimethylpyrazine, acetic acid, 3-hydroxy-2-butanone, 2,3-butanedione, and 2-methyl-4,5-dihydro-3(2H)-furanone. Although pyrolysis reaction produced higher number of products, however, the major pathways of formation of variety of important Maillard products followed the same mechanism under both pyrolytic and aqueous systems. Furthermore, contrary to literature speculations, 2-methyl-4,5-dihydro-3(2H)-furanone was shown to be formed by ring contraction of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one, through benzilic acid rearrangement, followed by decarboxylation.

downloadDownload free PDFView PDFchevron_rightDensity Functional Computational Studies on the Glucose and Glycine Maillard Reaction: Formation of the Amadori Rearrangement ProductsM.A.H. Shipar, Md Abul H Shipar, Amlan Roy

Theoretical energy changes of various intermediates leading to the formation of the Amadori rearrangement products (ARPs) under different mechanistic assumptions have been calculated, by using open chain glucose (O-Glu)/closed chain glucose (A-Glu and B-Glu) and glycine (Gly) as a model for the Maillard reaction. Density functional theory (DFT) computations have been applied on the proposed mechanisms under different pH conditions. Thus, the possibility of the formation of different compounds and electronic energy changes for different steps in the proposed mechanisms has been evaluated. B-Glu has been found to be more efficient than A-Glu, and A-Glu has been found more efficient than O-Glu in the reaction. The reaction under basic condition is the most favorable for the formation of ARPs. Other reaction pathways have been computed and discussed in this work.

downloadDownload free PDFView PDFchevron_rightFormation of odour-active compounds in maillard model systems based on prolineImre Blank

Flavour Research at the Dawn of the Twenty-first Century - Proceedings of the 10th Weurman Flavour Research Symposium, Beaune, France, 25-28 June, 2002., 2003

The formation of odorants was studied at pH 7 in Maillard model reactions containing glucose and proline (GlcPro) or the corresponding Amadori compound fructosyl proline (Fru-Pro). The major odour-active components found in both systems were 2-acetyl-1pyrroline, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), acetic acid, sotolone, diacetyl, and 2-acetyltetrahydropyridine (ATHP). However, the odour intensities, as perceived by gas chromatography-olfactometry, differed depending on the precursor system. The formation of selected odorants was monitored by isotope dilution assay. High amounts of HDMF (up to 250 pg/mmol) were obtained from Fru-Pro. On the contrary, GlcRro favoured the formation of ATHP (up to 50 pg/mmol). These odorants could also be monitored on-line by proton transfer reaction mass spectrometry, applied for the first time to time-resolved analysis of Maillard reaction products. Experimental Chemicals D-Glucose, L-proline, disodium hydrogenphosphate, sodium dihydrogenphosphate, sodium sulphate, and diethyl ether were from Merck (Darmstadt, Germany). 4-Hydroxy-8 2,5-dimethyl-3(2H)-furanone (HDMF), 2,3-butandione (diacetyl), 3-hydroxy-4,5-dimethyl-5 2(5H)-furanone (sotolone), and acetic acid were from Aldrich (Buchs, Switzerland). 2(or 5)-Ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone was from Givaudan (Dübendorf, 5 8 Switzerland). The chemicals were of analytical grade. The solvent was distilled prior to use :g t o o on a Vigreux column (1 O0 x 1 cm). J Key-Flavour Compounds and Analytical Aspects 459 Syntheses N-(1-Deoxy-D-fructos-1-yl)-L-proline (Fru-Pro) was synthesised as described by Yaylayan and Huyghues-Despointes (1994). 2-Acetyltetrahydropyridine (ATHP) was obtained according to Büchi and Wüst (197 1). 2-Acetyl-1-pyrroline was prepared by Duby and Huynh-Ba (1 992). 4-Hydroxy-2(or 5)-[ 13C]methyl-5(or 2)-methyl-3(2H)-[2(or 5)-Clfuranone ([13C2]-HDMF) was obtained as reported by Blank et al. (1997). 2H2-5-2-Acetyltetrahydropyridine was synthesised by adapting the Büchi and Wüst method (197 1).

downloadDownload free PDFView PDFchevron_rightAlternative GC–MS approaches in the analysis of substituted pyrazines and other volatile aromatic compounds formed during Maillard reaction in potato chipsJana Hajslova

2009

Several methods have been developed for the analysis of substituted pyrazines and related substances in potato chips. Following separation/detection approaches (all employing head-space solid phase microextraction, HS-SPME, for volatiles sampling), have been critically assessed in our study: (i) gas chromatography-ion trap mass spectrometry (GC-ITMS), (ii) gas chromatography-time-of-flight mass spectrometry (GC-TOFMS); (iii) comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). Although in none of the tested systems full chromatographic resolution of some isomeric pairs could be achieved, the use of GC × GC-TOFMS offered the best solution, mainly because of distinctly lower limits of quantification (LOQs) for all of 13 target alkylpyrazines. In addition to good performance characteristics, a non-target screening and tentative identification of altogether 46 N-containing heterocyclic compounds (pyrazines, pyrrols, pyridines, pyrrolidinones, and tetrahydropyridines) was also enabled.

downloadDownload free PDFView PDFchevron_rightSee full PDFdownloadDownload PDF

Loading Preview

Sorry, preview is currently unavailable. You can download the paper by clicking the button above.

References (47)

1. Akhand, A. A., Hossain, K., Kato, M., Miyata, T., Du, J., Suzuki, H., et al. (2001). Glyoxal and methylglyoxal induce lyoxal and methygly- oxal induce aggregation and inactivation of ERK in human endothe- lial cells. Free Radical Biology and Medicine, 31, 1228-1235.
2. Ames, J. M. (1990). Control of the Maillard reaction in food systems. Trends in Food Science and Technology, 1, 150-154.
3. Bell, L. N. (1997). Maillard reaction as influenced by buffer type and concentration. Food Chemistry, 59, 143-147.
4. Bjeldanes, L. F., & Chew, H. (1979). Mutagenicity of 1,2-dicarbonyl compounds: Maltol, kojic acid, diacetyl and related substances. Mutation Research, 67, 367-371.
5. Bulat, F., & Toro-Labbe ´, A. (2002). A theoretical study of the rotational isomerization of glyoxal and halogen derivatives. Chemical Physics Letters, 354, 508-517.
6. Davdek ´, J., Vels ´ek, J., & Pokorny ´, J. (1990). Development in food science: Chemical changes during food processing (Vol. 21, pp. 117-152). Amsterdam: Elsevier Science Publishers.
7. Eskin, N. A. E. (1990). Biochemistry of foods (2nd ed., pp. 239-296). San Diego: Academic Press.
8. Foresman, J. B., & Frisch, A. (1996). Exploring chemistry with electronic structure methods (2nd ed.). Pittsburgh, USA: Gaussian, Inc.
9. Frisch, AE., & Foresman, J. B. (1998). Gaussian 98 user's reference. Pittsburg, USA: Gaussian, Inc.
10. Harrold, H. (1991). Organic chemistry: A short course (8th ed., pp. 425- 467). Boston: Houghton Mifelin Company.
11. Hayashi, T., & Namiki, M. (1986). Role of sugar fragmentation: An early stage browning of amino-carbonyl reaction of sugar and amino acid. Agriculture and Biological Chemistry, 50, 1965-1970.
12. Hehre, W. J., Radom, L., Schleyer, P. V. R., & Pople, J. A. (1986). Ab initio molecular orbital theory. New York: John Wiley & Sons.
13. Ho, C. T., & Chen, J. (1999). Generation of volatile compounds from Maillard reaction of serine, threonine, and glutamine with monosac- charides. In R. Teranishi, E. L. Wick, & I. Hornstein (Eds.), Flavour chemistry: Thirty years of progress (pp. 327-334). New York: Kluwer Academic and Plenum Publishers.
14. Hodge, J. E. (1953). Chemistry of browning reactions in model systems. Journal of Agricultural and Food Chemistry, 1, 928-943.
15. Holum, J. R. (1996). Introduction to organic and biological chemistry (pp. 196-204). New York: John Wiley & Sons.
16. Labuza, T. P., & Saltmarch, M. (1981). The nonenzymatic browning reaction as affected by water in foods. In L. B. Rockland & B. S. Stewart (Eds.), Water activity influences food quality (pp. 605-639). New York: Academic Press.
17. Lea, C. H., & Hannan, R. S. (1949). Studies of the reaction between proteins and reducing sugars in the dry state I, the effect of activity of water, of pH and of temperature on the primary reaction between casein and glucose. Biochimica et Biophysica Acta, 3, 313-325.
18. Ledl, F., & Schleicher, E. (1990). New aspects of the Maillard reaction in foods and in the human body. Angewandte Chemie International Edition in English, 29, 565-594.
19. Leng, F., Graves, D., & Chaires, J. B. (1998). Chemical cross-linking of ethidium to DNA by glyoxal. Biochimica et Biophysica Acta, 1442, 71-81.
20. Macrane, R., Robinson, R. K., & Saadler, M. J. (1993). Encyclopedia of food science, food technology and nutrition (vol. 1, pp. 146-166). London: Academic Press Limited.
21. Maillard, L. C. (1912). Action des acides amine ´s sur les sucres: Formation des me ´lanoides par voi me ´thodique. Comptes Rendus de l Academie des Sciences Serie, 145, 66-68.
22. Meade, S. J., Miller, A. G., & Gerrard, J. A. (2003). The role of dicarbonyl compounds in non-enzymatic crosslinking: a structure activity study. Bioorganic & Medicinal Chemistry, 11, 853-862.
23. Mistry, N., Evans, M. D., Griffiths, H. R., Kasai, H., Herbert, K. E., & Lunec, J. (1999). Immunochemical detection of glyoxal DNA damage. Free Radical Biology and Medicine, 26, 1267-1273.
24. Moree-Testa, P., & Saint-Jalm, Y. (1981). Determination of a-dicarbonyl compounds in cigarette smoke. Journal of Chromatography, 217, 197-208.
25. Murata-Kamiya, N., Kamiya, H., Kaji, H., & Kasai, H. (1998). Biochemical and Biophysical Research Communications, 248, 412-417.
26. Namiki, M., & Hayashi, T. (1983). A new mechanism of the Maillard reaction involving sugar fragmentation and free radical formation. In G. R. Waller & M. S. Feather (Eds.), The Maillard reaction in foods and nutrition. American Chemical Society symposium series (Vol. 215, pp. 1-46). Washington, DC: American Chemical Society.
27. Nursten, H. E. (1986). Maillard browning reactions in dried foods. In D. MacCarthy (Ed.), Concentration and drying of foods (pp. 53-58). London: Elsevier Applied Science.
28. Nyhammar, T., Olsson, K., & Pernemalm, P. A. (1983). Strecker degradation products from (1-13 C)-D-glucose and glycine. In G. R. Waller & M. S. Feather (Eds.), The Maillard reaction in foods and nutrition. American Chemical Society Symposium Series (Vol. 215, pp. 71-82). Washington, DC: American Chemical Society.
29. Odani, H., Shinzato, T., Matsumoto, Y., Usami, J., & Maeda, K. (1999). Increase in three a,b-dicarbonyl compound levels in human uremic plasma: specific in vivo determination of intermediates in advanced Maillard reaction. Biochemical and Biophysical Research Communica- tions, 256, 89-93.
30. Odani, H., Shinzato, T., Usami, J., Matsumoto, Y., Frye, E. B., Baynes, J. W., et al. (1998). Imidazolium crosslinks derived from reaction of lysine with glyoxal and methylglyoxal are increased in serum proteins of uremic patients: evidence for increased oxidative stress in uremia. FEBS Letters, 427, 381-385.
31. Reber, F., Kasper, M., Siegner, A., Kniep, E., Seigel, G., & Funk, R. H. W. (2002). Alteration of the intracellular pH and apoptosis induction in a retinal cell line by the AGE-inducing agent glyoxal. Graefe's Archive for Clinical and Experimental Ophthalmology, 240, 1022-1032.
32. Sady, C., Jiang, C. L., Chellan, P., Madhun, Z., Duve, Y., Glomb, M. A., et al. (2000). Maillard reactions by a-oxoaldehydes: detection of glyoxal-modified proteins. Biochimica et Biophysica Acta, 1481, 255-264.
33. Sancho-Garcı ´a, J. C., Pere ´z-Jime ´nez, A. J., Pe ´rez-Jorda ´, J. M., & Moscardo ´, F. (2001). High-level ab initio calculations of the torsional potential of glyoxal. Chemical Physics Letters, 342, 452-460.
34. Sayato, Y., Nakamuro, K., & Ueno, H. (1987). Mutagenicity of products formed by ozonation of naphthoresorcinol in aqueous solutions. Mutation Research, 189, 217-222.
35. Shangari, N., & O'Brien, P. J. (2004). The cytotoxic mechanism of glyoxal involves oxidative stress. Biochemical Pharmacology, 68, 1433-1442.
36. Shibamoto, T., & Bernhard, R. A. (1978). Formation of heterocyclic compounds from the reaction of L-rhamnose with ammonia. Journal of Agricultural and Food Chemistry, 26, 183-187.
37. Shipar, M. A. H. (2004). Computational studies on glyceraldehyde and glycine Maillard reaction -III. Journal of Molecular Structure - Theochem, 712, 39-47.
38. Shipar, M. A. H. (2006). Formation of pyrazines in dihydroxyacetone and glycine Maillard reaction: a computational study. Food Chemistry, 98, 403-415.
39. Shipar, M. A. H., Jalbout, A. F., & Adamowicz, L. (submitted for publication). Formation of glyoxal in hydroxyacetaldehyde and glycine nonenzymatic browning Maillard reaction: a computational study. Food Chemistry.
40. Shu, C. K. (1999). Pyrazine formation from serine and threonine. Journal of Agricultural and Food Chemistry, 47, 4332-4335.
41. Tantirungrotechai, Y. (2003). Effect of an external electric field and a neighbouring atom on the torsional potential of glyoxal: a computa- tional study. Journal of Molecular Structure -Theochem, 624, 279-286.
42. Thornalley, P. J., George, A. Y., & Argirov, O. K. (2000). Kinetics and mechanism of the reaction of aminoguanidine with the a-oxoaldehydes glyoxal, methylglyoxal, and 3-deoxyglucosone under physiological conditions. Biochemical Pharmacology, 60, 55-65.
43. Tressl, R., Nittka, C., & Kersten, E. (1995). Formation of isoleucine- specific Maillard products from [1-13 C]-D-glucose and [1-13 C]-D- fructose. Journal of Agricultural and Food Chemistry, 43, 1163-1169.
44. Wilen, S. H. (1970). Synthesis and properties of 2,5-dihydro-3,6-dimeth- ylpyrazine. Journal of Chemical Society D: Chemical Communication, 1, 25-26.
45. Wong, J. W., & Shibamoto, T. (1996). Genotoxicity of Maillard reaction products. In R. Ikan (Ed.), The Maillard reaction: consequences for the chemical and life sciences (pp. 129-160). Chichester, West Sussex, England, New York: John Wiley & Sons, Ltd.
46. Young, D. C. (2001). Computational chemistry: A practical guide for applying techniques to real world problems. New York: John Wiley & Sons.
47. Zelek, S., Wasilewski, J., & Heldt, J. (2000). Density functional study of the S 0 (X $1 A g ) and T 1 (a $3 A u ) states of the glyoxal molecule. Computers and Chemistry, 24, 263-274.

View morearrow_downward

FAQs

AI

What role does glyoxal play in the Maillard reaction mechanism?add

The study finds glyoxal is a significant intermediate, evolving primarily under basic and neutral pH conditions during the hydroxyacetaldehyde and glycine reactions.

How does pH affect the formation of pyrazines in the Maillard reaction?add

The research reveals that the formation of pyrazines is most favorable under basic conditions, particularly with glycine and hydroxyacetaldehyde interactions.

What computational methods were used to analyze the Maillard reaction?add

Density Functional Theory computations with RB3LYP/6-31G(d) were applied to assess intermediate formations during the reactions.

Which reaction conditions were least favorable for pyrazine formation?add

The Hald + PGly reaction proved least favorable for producing pyrazines, showing higher stability in basic conditions.

How significant is the role of oxidation in pyrazine production?add

The analysis indicates that oxidation is crucial for converting 3,6-dihydropyrazine to pyrazines, requiring molecular oxygen during the reaction.

Related papers

Formation of pyrazines in dihydroxyacetone and glycine Maillard reaction: A computational studyM.A.H. Shipar, Md Abul H Shipar

Based on the electronic and Gibb's free energy changes, the possibility of the formation of 2,5-dimethyl pyrazine (25Pz) as one of the probable final products in dihydroxyacetone (DHA) and glycine Maillard reaction under different pH conditions is described. Mechanisms for the reaction have been proposed following the Hodge-scheme. Density functional computational calculations at the standard state have been performed on the proposed mechanisms of the reaction. Electronic and Gibb's free energy changes for the formation of different compounds have been estimated by following the total mass balance for different steps of the reaction. The possible order of feasibility for the production of 25Pz has been found as DHA + deprotonated glycine (DGly) gaseous > DHA + DGly aque-ous > DHA + unprotonated glycine (UGly) gaseous > DHA + glycine zwitterion (GlyZ) gaseous > DHA + UGly aque-ous > DHA + GlyZ aqueous > DHA + protonated glycine (PGly) aqueous > DHA + PGly gaseous phase reactions. Amino-acetone has been found to be the most likely precursor of the pyrazine ring. Oxidation plays an important role during the production of 25Pz. Water has been found as a by-product during the formation of 25Pz.

downloadDownload free PDFView PDFchevron_rightComputational studies on glyceraldehyde and glycine Maillard reaction—IIIM.A.H. Shipar, Md Abul H Shipar

By considering the formation of 2,5-dimethyl pyrazine as one of the possible final product, Density Functional Theory calculations have been performed at the standard state on the proposed mechanisms for the final stage of glyceraldehyde and glycine Maillard reaction under different conditions. DG 0 and DE 0 of different steps have been calculated by following the total mass balance. Thus, possibility of the formation of different intermediates, and different steps to take place, has been evaluated. GlyceraldehydeCdeprotonated glycine reaction has been found to be the most favorable for the formation of 2,5-dimethyl pyrazine in both of the gaseous and aqueous states, and especially in the gaseous state. GlyceraldehydeCunionized glycine reaction favors the formation of 2,5-dimethyl pyrazine mainly in the gaseous phase. GlyceraldehydeCprotonated glycine and glyceraldehydeCglycine zwitterion reactions are assumed to be less favorable for the formation of 2,5-dimethyl pyrazine. Aminoacetones have been found to be the most likely precursors for the formation of pyrazine rings. Oxidation plays an important role during the formation of 2,5-dimethyl pyrazine. Water plays an important role for the initiation of both of the gaseous and aqueous phase glyceraldehydeCglycine reactions.

downloadDownload free PDFView PDFchevron_rightFormation of glyoxal in hydroxyacetaldehyde and glycine nonenzymatic browning Maillard reaction: A computational studyM.A.H. Shipar

Density functional theory (DFT) computations at the standard state on the proposed mechanisms have revealed that glyoxal (Gox) is one of the most possible intermediates in the hydroxyacetaldehyde (Hald) and glycine nonenzymatic browning Maillard reaction under different pH conditions. By following the total mass balance, the gaseous state reaction has been found as more feasible for the formation of Gox than that of the aqueous solution. Hald + deprotonated glycine reaction under basic condition and Hald + unprotonated glycine reaction under neutral condition have been supposed to be more favorable for the production of Gox than Hald + protonated glycine reaction under acidic condition and Hald + glycine zwitterion reaction at the isoelectric point of glycine. Oxidation of Hald to Gox has been found as more plausible in the gaseous state than the aqueous solution. Oxygen has been found as necessary for the production of Gox from Hald. At the standard state, DFT calculations on the proposed mechanisms have evaluated that unprotonated and deproto-nated glycine and glycine zwitterion are feasible for liberating NH 3 , whereas protonated glycine has been found as unfeasible. DFT computations at the standard state on the proposed mechanisms have also revealed that the gaseous state Hald + NH 3 reaction is more feasible for the formation of Fald than that of the aqueous solution. Water, which is a by-product, has found as necessary for the initiation of both of Hald + glycine and Hald + NH 3 reactions.

downloadDownload free PDFView PDFchevron_rightFormation of Pyrazines in Maillard Model Systems of Lysine-Containing DipeptidesFien Van Lancker

Journal of Agricultural and Food Chemistry, 2010

Whereas most studies concerning the Maillard reaction have focused on free amino acids, little information is available on the impact of peptides and proteins on this important reaction in food chemistry. Therefore, the formation of flavor compounds from the model reactions of glucose, methylglyoxal, or glyoxal with eight dipeptides with lysine at the N-terminus was studied in comparison with the corresponding free amino acids by means of stir bar sorptive extraction (SBSE) followed by GC-MS analysis. The reaction mixtures of the dipeptides containing glucose, methylglyoxal, and glyoxal produced 27, 18, and 2 different pyrazines, respectively. Generally, the pyrazines were produced more in the case of dipeptides as compared to free amino acids. For reactions with glucose and methylglyoxal, this difference was mainly caused by the large amounts of 2,5(6)-dimethylpyrazine and trimethylpyrazine produced from the reactions with dipeptides. For reactions with glyoxal, the difference in pyrazine production was rather small and mostly unsubstituted pyrazine was formed. A reaction mechanism for pyrazine formation from dipeptides was proposed and evaluated. This study clearly illustrates the capability of peptides to produce flavor compounds that can differ from those obtained from the corresponding reactions with free amino acids.

downloadDownload free PDFView PDFchevron_rightComputational studies on glyceraldehyde and glycine Maillard reaction-IIM.A.H. Shipar, Md Abul H Shipar

Density functional theory calculations have been performed on the proposed mechanism for the intermediate stage of glyceraldehyde and glycine Maillard reaction under different pH conditions at the standard state. By following the total mass balance, possibility of the formation of different compounds in the proposed mechanism has been tested by estimating the Gibb's free energy changes of the reaction. Electronic energy changes have also been calculated to observe the internal energy changes during the reaction. The result reveals that methyl glyoxal is one of the most likely product in the intermediate stage of the reaction. 3-Deoxyosone route in the intermediate stage is feasible for the production of methyl glyoxal in glyceraldehydeCunprotonated glycine reaction, whereas both of the 3-and 1-deoxyosone routes are feasible in glyceraldehydeCdeprotonated glycine reaction. As both of the 3-and 1-deoxyosone routes favor the production of methyl glyoxal, glyceraldehydeCdeprotonated glycine reaction is assumed to be more feasible for the nonenzymatic browning than that of the others. GlyceraldehydeCprotonated glycine and glyceraldehydeCglycine zwitterion reactions are assumed less favorable for the production of methyl glyoxal. These findings will be helpful for further studies, and finding out proper mechanisms of the reaction.

downloadDownload free PDFView PDFchevron_rightQuantitative Structure-Property Study on Pyrazines with Bell Pepper FlavorPeter Wolschann

Scientia Pharmaceutica, 2000

A quantitative structure-property (QSPR) study on pyrazines with bell pepper aroma is performed by means of different statistical methods, which correlate appropriate molecular descriptors with the biological activity. The different methods lead to consistent results, indicating which of the molecular properties of the compounds under consideration are significant for bell pepper flavor. These results are compared with other models.

downloadDownload free PDFView PDFchevron_rightSpectroscopic (FT-IR, FT-Raman), first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of N-[(4-(trifluoromethyl) phenyl] pyrazine-2-carboxamide by density functional methodsMartin DolezaldownloadDownload free PDFView PDFchevron_rightInvestigations on the Effect of Amino Acids on Acrylamide, Pyrazines, and Michael Addition Products in Model SystemsGeorgios Koutsidis

Journal of Agricultural and Food Chemistry, 2009

Acrylamide and pyrazine formation, as influenced by the incorporation of different amino acids, was investigated in sealed low-moisture asparagine-glucose model systems. Added amino acids, with the exception of glycine and cysteine and at an equimolar concentration to asparagine, increased the rate of acrylamide formation. The strong correlation between the unsubstituted pyrazine and acrylamide suggests the promotion of the formation of Maillard reaction intermediates, and in particular glyoxal, as the determining mode of action. At increased amino acid concentrations, diverse effects were observed. The initial rates of acrylamide formation remained high for valine, alanine, phenylalanine, tryptophan, glutamine, and leucine, while a significant mitigating effect, as evident from the acrylamide yields after 60 min of heating at 160°C, was observed for proline, tryptophan, glycine, and cysteine. The secondary amine containing amino acids, proline and tryptophan, had the most profound mitigating effect on acrylamide after 60 min of heating. The relative importance of the competing effect of added amino acids for R-dicarbonyls and acrylamide-amino acid alkylation reactions is discussed and accompanied by data on the relative formation rates of selected amino acid-AA adducts.

downloadDownload free PDFView PDFchevron_rightCHAPTER 1: SYNTHESES AND REACTIONS OF PYRAZINE AND QUINOXALINEpriyanka muralidownloadDownload free PDFView PDFchevron_rightFlavouring Group Evaluation 17, Revision 1 (FGE.17Rev1): Pyrazine derivatives from chemical group 24 - Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in contact with Food (AFC)Susan Barlow

EFSA Journal, 2008

The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (the Panel) is asked to advise the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs in the Member States. In particular, the Scientific Panel is asked to evaluate 20 flavouring substances in the Flavouring Group Evaluation 17, Revision 1 (FGE.17Rev1), using the procedure as referred to in the Commission Regulation (EC) No 1565/2000. These 20 flavouring substances belong to chemical group 24 of Annex I of the Commission Regulation (EC) No 1565/2000. The present Flavouring Group Evaluation (FGE) deals with 20 pyrazine derivatives. Three of these derivatives are quinoxalines. Five of the 20 flavouring substances possess a chiral centre. For two of these substances the stereoisomeric composition has not been specified. Sixteen of the flavouring substances are classified into structural class II and four are classified into structural class III. Nineteen of the flavouring substances in the present group have been reported to occur naturally in a wide range of food items.

downloadDownload free PDFView PDFchevron_rightkeyboard_arrow_downView more papers

Related topics

Computational ChemistryaddFollow

Food ScienceaddFollow

THEORETICAL AND COMPUTATIONAL CH...addFollow

• Explore
• Papers
• Topics

• Features
• Mentions
• Analytics
• PDF Packages
• Advanced Search
• Search Alerts

• Journals
• Academia.edu Journals
• My submissions
• Reviewer Hub
• Why publish with us
• Testimonials

• Company
• About
• Careers
• Press
• Help Center
• Terms
• Privacy
• Copyright
• Content Policy

580 California St., Suite 400San Francisco, CA, 94104© 2026 Academia. All rights reserved