Simulating fatty acid autoxidation and exploring the related volatiles formation mechanism
Youyou Yang, Dapeng Liu, Weihai Xing, Chaohua Tang, Xiaohui Feng, Junmin Zhang
Abstract
Lipid autoxidation is one of the main pathways for the formation of volatiles in meat. Investigations into how the unsaturated fatty acid (UFA) chains in lipids are autoxidized into volatiles are of great importance and could facilitate aroma research. In this study, taking UFAs as the research model, understanding of the formation of volatiles from the UFAs’ autoxidation has been updated and new pathways for furaldehyde derivatives have been proposed. The types of volatile produced were determined by the position and the number of C=C bonds as well as the methylene group flanked by the C=C bond. When the number of carbon atoms adjacent to C=C increases, the carbon lengths of aliphatic aldehydes elongate. Additionally, the number of methylene groups flanked by the C=C bond in PUFAs determine the types of aldehydes, alkanals, alkenals or alkadienals, as well as ketones. Apart from the alkyl furans, also furaldehydes and other derivatives could be produced from the oxidation of n-3 and n-6 fatty acids with over two C=C bonds, instead of from the Maillard reaction. This study presents the direct proof of the correlation between fatty acids and volatiles, and could also provide the theoretical basis for elevating aroma through lipid regulation. • Fatty acids autoxidation was simulated and the generated volatiles were profiled using GC-HR Orbitrap MS. • The number of allylic methylene groups in UFAs determines the volatiles' profiles. • Furaldehyde was first reported to be produced by oxidation of PUFAs.