Effects of refrigeration and freezing on milk fat globule membrane lipids in stored breast milk: Insights from non-targeted lipidomics.

Breast milk storage provides flexibility for working mothers, though its effects on milk fat globule membrane (MFGM) lipids are not fully understood. This study examined breast milk stored under refrigerated (2 and 4 days) and frozen (7, 14, and 21 days) conditions, finding that these storage durations preserved similar structural characteristics during in vitro gastrointestinal digestion. The analysis focused on MFGM lipid composition under various storage conditions using non-targeted lipidomics. Results revealed that freezing for 14 days reduced phosphatidylserine (PS) levels by 64.55%, while 21 days of freezing significantly decreased both PS (74.59%) and sphingomyelin (SM) (43.85%). Examination of MFGM lipid species indicated that refrigeration for 4 days and freezing for 21 days led to notable reductions in key MFGM lipid species. Thus, breast milk should be refrigerated for up to 4 days to minimize nutrient depletion or frozen for no more than 7 days.