Formation of Vinylogous Compounds in Model Maillard Reaction Systems
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- 作者：Richard H. Stadler ; Ludovica Verzegnassi ; Natalia Varga ; Martin Grigorov ; Alfred Studer ; Sonja Riediker ; and Benoit Schilter
- 刊名：Chemical Research in Toxicology
- 出版年：2003
- 出版时间：October 2003
- 年：2003
- 卷：16
- 期：10
- 页码：1242 - 1250
- 全文大小：403K
- 年卷期：v.16,no.10(October 2003)
- ISSN：1520-5010
文摘
The thermal degradation over temperature and time of selected amino acids (Asp, Gln, andGlu) in the presence of reducing sugars was investigated in low moisture model systems.Copyrolysis of glucose-Asp mixtures led to the release of acrylic acid, attaining >5 mmol/molAsp at 230 
C after 5 min. Spurious amounts of 3-butenamide were detected upon heatingGln together with a carbonyl source. Apparently, intramolecular cyclization is favored to procure2-pyrrolidinone, reaching levels >3 mmol/mol above 230 C. 2-Pyrrolidinone was also formedin comparable amounts in pyrolyzed sugar-Glu mixtures, indicating that the Maillard reactionmay be an important contributor to the formation of 2-pyrrolidinone in certain cooked foods.The chemical route to acrylic acid and 3-butenamide is probably analogous to that describedfor acrylamide recently. Evidence is also presented that acrylic acid may be an intermediatein the formation of acrylamide, and yields could be augmented by coincubation of fructose-Asp with certain amino acids such as Gln, reaching approximately 5% of the yield obtained bythe Asn route. A computational study to determine the reactivity of the vinylogous productsindicated a reduced ability of 3-butenamide as compared to acrylamide to form stableintermediates by Michael nucleophilic addition. Acrylamide and acrylic acid exhibited a similartheoretical reactivity potential toward nucleophiles. No information is as yet available on theoccurrence of acrylic acid in cooked foods. Extensive toxicological evaluation indicates thatacrylic acid is of no concern at the amounts to be expected in foods.
C after 5 min. Spurious amounts of 3-butenamide were detected upon heatingGln together with a carbonyl source. Apparently, intramolecular cyclization is favored to procure2-pyrrolidinone, reaching levels >3 mmol/mol above 230 C. 2-Pyrrolidinone was also formedin comparable amounts in pyrolyzed sugar-Glu mixtures, indicating that the Maillard reactionmay be an important contributor to the formation of 2-pyrrolidinone in certain cooked foods.The chemical route to acrylic acid and 3-butenamide is probably analogous to that describedfor acrylamide recently. Evidence is also presented that acrylic acid may be an intermediatein the formation of acrylamide, and yields could be augmented by coincubation of fructose-Asp with certain amino acids such as Gln, reaching approximately 5% of the yield obtained bythe Asn route. A computational study to determine the reactivity of the vinylogous productsindicated a reduced ability of 3-butenamide as compared to acrylamide to form stableintermediates by Michael nucleophilic addition. Acrylamide and acrylic acid exhibited a similartheoretical reactivity potential toward nucleophiles. No information is as yet available on theoccurrence of acrylic acid in cooked foods. Extensive toxicological evaluation indicates thatacrylic acid is of no concern at the amounts to be expected in foods.