Stability of the lipid fraction of milk‐based infant formulas during storage

A study is made of the effects of storage (time and temperature) on the lipid fraction of four milk‐based adapted infant formulas with basically the same composition, though differing in the iron salt added (lactate or sulfate) and/or the vitamin E source (α‐tocopherol or α‐tocopherol acetate). Peroxide value, hydroperoxide C₁₈ percentage and thiobarbituric acid‐reactive substance (TBARS) content were used as indicators of lipid peroxidation. Fat contents remained stable throughout storage. Peroxide values increased from the first storage month and were affected by storage time, although they exhibited irregular behavior. Storage time and temperature affected hydroperoxide percentage, which was seen to be the earliest indicator of lipid oxidation, being measurable in newly manufactured formulas. TBARS values were only affected by storage time. No statistically significant differences were found among the four infant formulas for any of the lipid oxidation indicators.