High throughput method for the determination of α, β-unsaturated aldehydes in edible oils: A UV-vis analysis

A novel method for determining α, β-unsaturated aldehydes (α, β-UAs) in edible oils was proposed, utilizing 2,4-dimethylpyrrole (2,4-DMP) derivatization followed by UV-vis analysis. The optimal detection wavelengths were identified as 580 nm for α, β-monounsaturated aldehydes (α, β-MUAs) and 680 nm for α, β-diunsaturated aldehydes (α, β-DUAs). The reaction mechanism was confirmed by Fukui function and hydrogen nuclear magnetic resonance (¹H NMR) analysis, demonstrating formation of enamine as the final product. Derivatization conditions were optimized for rapid and reproducible results. The proposed method demonstrated excellent sensitivity, with limits of detection (LOD) and quantification (LOQ) for α, β-MUAs at 0.0038 μmol/mL and 0.0117 μmol/mL, and for α, β-DUAs at 0.0043 μmol/mL and 0.0129 μmol/mL, respectively. Compared to the p-anisidine value (p-AV) and high-performance liquid chromatography (HPLC) based methods, the proposed method showed several advantages in shorter derivatization time, simplified operation, high throughput potential and lower toxicity. This method provides an efficient tool for α, β-UAs detection, which is crucial for ensuring oil quality and safety.