High-Resolution Mass Spectrometry for Detailed Lipid Profile and Chemometric Discrimination of X-Ray Irradiated Mozzarella Cheese

Ionizing radiation is a non-thermal sanitization technique used in the food field to eliminate bacteria, molds, insects and other microbes, resulting in delayed spoilage and extended shelf life. In this work, mozzarella cheese was irradiated with X-rays at a dose of 3.0 kGy, and irradiation-induced lipid modifications were evaluated through a comprehensive analysis of the mozzarella lipid fingerprint. To this aim, an optimized microwave-assisted extraction method associated with UHPLC-Q-Orbitrap-MS analysis was used for reliable and accurate lipid identification in the controls and in irradiated samples. The outcomes demonstrated that the X-ray dose employed in this investigation did not cause the formation of new lipid molecules. However, lipidomic chemometric modeling, including partial least squares-discriminant analysis, enabled the discrimination of irradiated versus non-irradiated samples and the selection of five ceramides, eight hexosyl ceramides, four sphingomyelins, one phosphatidylethanolamine, one cholesterol ester, ten oxidized triacylglycerols, and one oxidized diacylglycerol as potential markers of treatment. Finally, an artificial neural network was developed to accurately model the entire pattern in omics data in relation to the treatment. This developed analytical workflow allows for expanding knowledge on the effects of this technology and could have interesting applications in food safety traceability and control plans.