Citral Photodegradation in Solution: Highlighting of a Radical Pathway in Parallel to Cyclization Pathway
| Autor: | Christophe Galopin, William Mutilangi, Jacques Lalevée, Bernadette Graff, Fabrice Morlet-Savary, Violaine Gérard, Emel Ay |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Free Radicals Ultraviolet Rays Acyclic Monoterpenes Photochemistry Citral 01 natural sciences chemistry.chemical_compound Photodegradation Photolysis Potassium sorbate Chemistry 010401 analytical chemistry Photodissociation Electron Spin Resonance Spectroscopy General Chemistry Hydrogen-Ion Concentration Ascorbic acid 0104 chemical sciences Solvent Covalent bond Cyclization Monoterpenes Solvent effects General Agricultural and Biological Sciences 010606 plant biology & botany |
| Zdroj: | Journal of agricultural and food chemistry. 67(13) |
| ISSN: | 1520-5118 |
| Popis: | 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 N2), 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. |
| Databáze: | OpenAIRE |
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