Citral Photodegradation in Solution: Highlighting of a Radical Pathway in Parallel to Cyclization Pathway

被引:19
作者
Ay, Emel [1 ,2 ]
Gerard, Violaine [1 ,2 ]
Graff, Bernadette [1 ,2 ]
Morlet-Savary, Fabrice [1 ,2 ]
Mutilangi, William [3 ]
Galopin, Christophe [3 ,4 ]
Lalevee, Jacques [1 ,2 ]
机构
[1] Univ Haute Alsace, CNRS, UMR 7361, IS2M, F-68100 Mulhouse, France
[2] Univ Strasbourg, F-67000 Strasbourg, France
[3] PepsiCo Global Beverage Res & Dev, 100 East Stevens Ave, Valhalla, NY 10595 USA
[4] Givaudan Fragrance, 40 West 57th St, New York, NY 10019 USA
关键词
citral; photodegradation; radical pathway; cyclization; solvent effect; atmosphere effect; stabilizers; ACID-CATALYZED CYCLIZATION; LEMON FLAVOR; DETERIORATION MECHANISM; OFF-ODOR; IDENTIFICATION; SUBSTANCES; COMPONENTS; STABILITY; CHEMISTRY;
D O I
10.1021/acs.jafc.8b07034
中图分类号
S [农业科学];
学科分类号
09 ;
摘要
Citral, a lemon flavor molecule often used in the beverage and fragrance industry, is known to be unstable under light irradiation. Its deterioration is considered to be an important issue for the stabilization of lemon-flavored drinks. The aim of this study is to understand the degradation mechanisms of citral under light irradiation with the variation of three parameters: the solvent (citrate buffer solution at pH 3 vs ethanol), the atmosphere (air vs N-2), and the concentration of citral. The photodegradation has been studied using UV-visible spectroscopy after photolysis, nuclear magnetic resonance spectrometry, and electron spin resonance spectroscopy. To extend the investigation, molecular orbitals and bond dissociation energies have also been calculated. They give an insight into the light absorption properties and the possible cleavage of citral molecular bonds. In addition, UV-light absorption and radical scavenging activities of two additives, potassium sorbate and ascorbic acid, have been studied for the inhibition of the citral photodecomposition by UV-light irradiation. Both theoretical and experimental results highlight a new degradation pathway involving free-radical intermediates in parallel to the already reported cyclization one, which could be prevented by the addition of stabilizers such as ascorbic acid or sorbate.
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页码:3752 / 3760
页数:9
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