Quantitative Determination and Removal of Benzo[a]pyrene Residue in Meat Products by Fluorescence and Polymeric Micelle

Abstract

Benzo[a]pyrene (BaP) as a typical polycyclic aromatic hydrocarbon (PAH), is toxic and cancerogenic, and is widely present in processed foods especially in meat products that were smoked or salted. In this study, a robust and efficient method for quantitative determination and removal of BaP residue in meat product using fluorescence methods was introduced. A poly(ethylene glycol) (PEG) labeled at both ends with pyrene (Py-PEG-Py) was prepared and the polymer micelle was applied to remove BaP. The chemical structures of pyrene and BaP were similar so they tend to interact with each other. The steady-state fluorescence spectra showed that the ratios of excimer-to-monomer emission intensities (IE/IM) of the Py-PEG-Py sample remain constant when polymer concentration is below 0.25 g/L. Above this concentration, pyrene excimer is formed by both intramolecular and intermolecular interaction. The concentration indicates the critical micelle concentration (CMC) of Py-PEG-Py in aqueous environment. It was shown that a trace amount of BaP can be detected by fluorescence method. The fluorescence decays obtained at various polymer concentrations were also acquired by time-resolved fluorescence instrument. After the meat products were treated with Py-PEG-Py solution, BaP was completely encapsulated into the polymer micelles due to hydrophobic interaction between BaP and the pyrene pendants. In other words, BaP was fully dissolved into the micelles where the core of micelle was formed by pyrene stacking to create a hydrophobic domain and was completely separated from the meat products. This method is easy, swift, sensitive, and accurate. It can be applied to determine and remove any PAH residues in food.