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Model studies on the oxygen-induced formation of benzaldehyde from phenylacetaldehyde using pyrolysis GC-MS and FTIR.
J Agric Food Chem. 2008 Nov 26; 56(22):10697-704.JA

Abstract

Benzaldehyde, a potent aroma chemical of bitter almond, can also be formed thermally from phenylalanine and may contribute to the formation of off-aroma. To identify the precursors involved in its generation during Maillard reaction, various model systems containing phenylalanine, phenylpyruvic acid, phenethylamine, or phenylacetaldehyde were studied in the presence and absence of moisture using oxidative and nonoxidative Py-GC-MS. Analysis of the data indicated that phenylacetaldehyde, the Strecker aldehyde of phenylalanine, is the most effective precursor and that both air and water significantly enhanced the rate of benzaldehyde formation from phenylacetaldehyde. Phenylpyruvic acid was the most efficient precursor under nonoxidative conditions. Phenethylamine, on the other hand, needed the presence of a carbonyl compound to generate benzaldehyde only under oxidative conditions. On the basis of the results obtained, a free radical initiated oxidative cleavage of the carbon-carbon double bond of the enolized phenylacetaldehyde was proposed as a possible major mechanism for benzaldehyde formation, and supporting evidence was provided through monitoring of the evolution of the benzaldehyde band from heated phenylacetaldehyde in the presence and absence of 1,1'-azobis(cyclohexanecarbonitrile) on the ATR crystal of an FTIR spectrophotometer. In the presence of the free radical initiator, the enol band of the phenylacetaldehyde centered at 1684 cm(-1) formed and increased over time, and after 18 min of heating time the benzaldehyde band centered at 1697 cm(-1) formed and increased at the expense of the enol band of phenylacetaldehyde, indicating a precursor product relationship.

Authors+Show Affiliations

Department of Food Science and Agricultural Chemistry, McGill University, Ste Anne de Bellevue, Quebec, Canada.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18954073

Citation

Chu, Fong Lam, and Varoujan A. Yaylayan. "Model Studies On the Oxygen-induced Formation of Benzaldehyde From Phenylacetaldehyde Using Pyrolysis GC-MS and FTIR." Journal of Agricultural and Food Chemistry, vol. 56, no. 22, 2008, pp. 10697-704.
Chu FL, Yaylayan VA. Model studies on the oxygen-induced formation of benzaldehyde from phenylacetaldehyde using pyrolysis GC-MS and FTIR. J Agric Food Chem. 2008;56(22):10697-704.
Chu, F. L., & Yaylayan, V. A. (2008). Model studies on the oxygen-induced formation of benzaldehyde from phenylacetaldehyde using pyrolysis GC-MS and FTIR. Journal of Agricultural and Food Chemistry, 56(22), 10697-704. https://doi.org/10.1021/jf8022468
Chu FL, Yaylayan VA. Model Studies On the Oxygen-induced Formation of Benzaldehyde From Phenylacetaldehyde Using Pyrolysis GC-MS and FTIR. J Agric Food Chem. 2008 Nov 26;56(22):10697-704. PubMed PMID: 18954073.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Model studies on the oxygen-induced formation of benzaldehyde from phenylacetaldehyde using pyrolysis GC-MS and FTIR. AU - Chu,Fong Lam, AU - Yaylayan,Varoujan A, PY - 2008/10/29/pubmed PY - 2009/4/4/medline PY - 2008/10/29/entrez SP - 10697 EP - 704 JF - Journal of agricultural and food chemistry JO - J. Agric. Food Chem. VL - 56 IS - 22 N2 - Benzaldehyde, a potent aroma chemical of bitter almond, can also be formed thermally from phenylalanine and may contribute to the formation of off-aroma. To identify the precursors involved in its generation during Maillard reaction, various model systems containing phenylalanine, phenylpyruvic acid, phenethylamine, or phenylacetaldehyde were studied in the presence and absence of moisture using oxidative and nonoxidative Py-GC-MS. Analysis of the data indicated that phenylacetaldehyde, the Strecker aldehyde of phenylalanine, is the most effective precursor and that both air and water significantly enhanced the rate of benzaldehyde formation from phenylacetaldehyde. Phenylpyruvic acid was the most efficient precursor under nonoxidative conditions. Phenethylamine, on the other hand, needed the presence of a carbonyl compound to generate benzaldehyde only under oxidative conditions. On the basis of the results obtained, a free radical initiated oxidative cleavage of the carbon-carbon double bond of the enolized phenylacetaldehyde was proposed as a possible major mechanism for benzaldehyde formation, and supporting evidence was provided through monitoring of the evolution of the benzaldehyde band from heated phenylacetaldehyde in the presence and absence of 1,1'-azobis(cyclohexanecarbonitrile) on the ATR crystal of an FTIR spectrophotometer. In the presence of the free radical initiator, the enol band of the phenylacetaldehyde centered at 1684 cm(-1) formed and increased over time, and after 18 min of heating time the benzaldehyde band centered at 1697 cm(-1) formed and increased at the expense of the enol band of phenylacetaldehyde, indicating a precursor product relationship. SN - 1520-5118 UR - https://www.unboundmedicine.com/medline/citation/18954073/Model_studies_on_the_oxygen_induced_formation_of_benzaldehyde_from_phenylacetaldehyde_using_pyrolysis_GC_MS_and_FTIR_ L2 - https://dx.doi.org/10.1021/jf8022468 DB - PRIME DP - Unbound Medicine ER -