Lipid peroxidation in infant formulas: Longitudinal study at different storage temperatures

The progress of lipid peroxidation in infant formulas (IFs) at room temperature and under refrigeration was studied. The concentration of malondialdehyde (MDA) was determined in mature human milk (HM) and in commercially available powder IFs. One of the aliquots was analysed immediately. The others were divided into groups: one group was stored at 4–6 °C, the other at 22–24 °C, and both were analysed after 7, 14, 21 or 28 days. MDA concentration was higher in IFs samples than in HM samples. In the IFs, the concentration of MDA was proportional to the content of docosaexanoic acid (DHA) and arachidonic acid (AA), and increased over time. The increase was greater in the samples stored at room temperature than in those stored at 4 °C. We conclude that lipid peroxidation is higher in IFs enriched with polyunsaturated fatty acids (PUFAs) and that refrigeration can prevent this alteration.