Changes to breast milk fatty acid composition during storage, handling and processing: A systematic review

This review evaluated the effect of various storage and handling conditions on the fat composition of expressed breast milk (EBM). Three databases PubMed, Embase and Scopus were searched in April 2019 with words from the three key components: human milk, handling process (i.e. storage and/or pasteurization), and fatty acid composition. The comparisons were EBM subjected to handling processes versus fresh EBM or versus EBM subjected to another handling processes. Both intervention and observational studies were included, and the outcomes measured included total fat and lipid classes of the EBM. We included 42 studies (43 reports), 41 of which were assessed to be of good quality. Relative changes to the fat composition of EBM subjected to handling processes were calculated based on the data provided in the included studies, and the results were synthesized narratively. The total fat content and total fatty acid composition of EBM was not generally influenced by storage and handling process, with most changes less than 10%, which is likely a result of methodological variation. A reduction in EBM triglyceride concentration and concomitant increase in free fatty acid concentration were seen after exposing to various conditions, probably due to endogenous lipase.