Authentication of pork in meat mixtures using PRM mass spectrometry of myosin peptides

Abstract

Adulteration of meat products is a major concern not only for economic fraud, but also for ethical reasons. In this study, we presented a parallel reaction monitoring (PRM) mass spectrometry approach for detection of trace pork in meat mixtures (chicken, sheep, and beef). Specific peptides were identified and screened by a shotgun proteomic approach based on tryptic digests of certain protein. Five surrogate peptides from myosin were screened and then used for pork detection by PRM of Orbitrap MS. When the most sensitive peptide was selected, the LOD in mixed meat can be up to 0.5%. The RSD values between detected and designated pork levels (1%, 5% and 50%) were 4-15%. The targeted method developed can be applied to identify and quantify the pork in meat mixture.

Fig. 1. The workflow of pork authentication in meat mixtures.

Fig. 2. The response of peptides to heating at 100 °C for different times ((1) HKYEETQAELEASQK; (2) KLETDISQIQGEMEDIVQEAR; (3) LETDISQIQGEMEDIVQEAR; (4) KLETDISQIQGEMEDIIQEAR; (5) LETDISQIQGEMEDIIQEAR).

Fig. 3. The chromatogram of surrogated peptides and their mass spectra of fragments (5% pork meat mixture).