Targeted lipidomics reveals the impact of processing units on fatty acids and oxidized lipids in nutritionally complete food for special medical purposes.

Lipids serve as crucial functional components in nutritionally complete foods for special medical purposes (nc-FSMP). However, potential impacts of processing units on lipids remain poorly understood in nc-FSMP. Therefore, this study investigated the influence of homogenization, sterilization, and spray drying on the lipids using targeted lipidomics. A total of 49 fatty acids and 20 oxidized lipids were identified and quantified. The results showed that spray drying led to the most pronounced increase in lipid oxidation and the highest accumulation of oxidized lipids. Fatty acids significantly reduced across the processing units, and both homogenization and spray drying resulted in larger losses compared to sterilization. Among the identified oxidized lipids, trans-EKODE-(E)-Ib and 9(S)-HpOTrE can be considered as specific markers for distinguishing different oxidation levels across the processing units. Overall, these findings elucidate the changes in lipids across the processing units and provide novel insights for quality control in the nc-FSMP manufacture.