Mechanism of Water-Enhanced Volatile Aldehyde Release in Oil Fumes from Thermal Oxidation of Oleic Acid: Insights from Synchrotron Radiation Photoionization and Gas Chromatography–Mass Spectrometry
Year: 2026
Type: article
Abstract: Thermal oxidation of edible oils during high-temperature cooking produces complex fumes containing harmful volatile compounds. However, the role of water, a common co-reactant in practical cooking, remains insufficiently understood. In this study, oleic acid was used as a model compound to investigate thermal oxidation. Online monitoring using synchrotron radiation photoionization mass spectrometry (SR-PIMS) revealed that water significantly increased the emission of volatile acetaldehyde and acrolein, with maximum increases of 164% and 123% at 10% water addition. Complementary offline GC-MS analysis showed enhanced formation of (E)-2-decenal, (E,E)-2,4-decadienal, and (E)-2-undecenal, suggesting these unsaturated aldehydes may be key intermediates. Mechanistically, oleic acid underwent free radical-mediated peroxidation to form (E)-2-decenal, (E)-2-undecenal, and (E,E)-2,4-decadienal. These intermediates subsequently decomposed into acetaldehyde and acrolein via hydration, retro-aldol condensation, and hydroperoxide scission, with water accelerating both processes. Overall, these findings highlight water’s critical role in promoting the generation of harmful volatile aldehydes in oil fumes.
Source: Molecules
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,258
OpenAlex ID: W7128366280