Effect of Catechin on the Formation of Polycyclic Aromatic Hydrocarbons in Camellia oleifera Oil during Thermal Processing

Polycyclic aromatic hydrocarbons (PAHs) in oil are affected by many factors, including temperature, time, and PAHs precursors. Phenolic compounds, as beneficial endogenous components of oil, are often associated with the inhibition of PAHs. However, studies have found that the presence of phenols may lead to increased levels of PAHs. Therefore, this study took Camellia oleifera (C. oleifera) oil as the research object, in order to study the effect of catechin in the formation of PAHs under different heating conditions. The results showed that PAH4 were generated rapidly during the lipid oxidation induction period. When the addition of catechin was >0.02%, more free radicals were quenched than generated, thus inhibiting the generation of PAH4. ESR, FT-IR, and other technologies were employed to prove that when the catechin addition was <0.02%, more free radicals were produced than quenched, causing lipid damage and increasing PAHs intermediates. Moreover, the catechin itself would break and polymerize to form aromatic ring compounds, ultimately leading to the conclusion that phenolic compounds in oil may be involved in the formation of PAHs. This provides suggestions for the flexible processing of phenol-rich oil to balance the retention of beneficial substances, and for the safe control of hazardous substances in real-life applications.