An integrated method for monitoring thermal processing temperature of pork based on Q-Exactive mass spectrometry and chemometrics

Meat heating endpoint temperature (EPT) is an important indicator to ensure the safety of cooked meat. Accurately determining the EPT of cooked meat and ready-to-eat meat products is an important strategy to ensure food safety. In this study, a comprehensive metabolic method based on UPLC-Q Exactive and chemometrics was developed to study the metabolites differences among pork roasted at different temperatures in order to select markers indicating EPT and discover new toxic heat-induced compounds. A two-step extraction method was applied to avoid the loss of metabolite information caused by sample preparation. Using chemometrics, the five compounds of creatine, creatinine, 2-amino-1-methyl-6-phenylimidazo (4,5-b) pyridine (PhIP), 2-methyl-6-amino-5-hydroxymethylpyrimidine (TMP) and compound with the m/z of 114.04316 were selected as markers, and four of them were further confirmed by chemical standards. It is worth noting that TMP was discovered in roasted pork for the first time. In addition, targeting studies aimed at quantifying the selected markers were conducted at different thermal processing temperatures. From the quantification results, it can be concluded that the heat temperature not exceed 180 °C is recommended to reduce the content of toxic compounds. This study has proved that the integration of UPLC-Q Exactive and chemometrics could provide an efficient method for the study of markers related to thermal process and new toxic heat-induced compounds.