Objective Expression of human milk for use in infant feeding has increased. Bottles are used to deliver expressed milk. Expression, storage, and subsequent provision of human milk (HM) to infants introduces the possibility of ascorbic acid loss (aa) loss. The purpose of this study was to investigate effects of milk delivery systems on aa concentration in HM. The objectives were 1) determine if there is a decline in aa during the feed, 2) determine if there is a difference in aa between delivery systems, and 3) evaluate if changes in aa are of clinical importance.

Methods Seven bottle systems were used for comparison. The HM was standardized to 42 mg/L of aa. Samples were analyzed for aa concentration at baseline, 5, 10, 15, and 20 minutes. An electric breast pumps were used to extract milk from the bottles. Samples were analyzed for ascorbic acid using normal-phase HPLC.

Results Aa concentration declined over the 20 minutes for all bottle systems. Differences were noted between bottle systems. Aa concentrations declined to <40% of the RDI for 4 of the bottles by the 20 minutes.

Conclusion Decreases of aa concentration in HM using varied milk delivery systems is of clinical importance, putting those infants who rely solely on bottle feeds for their total aa at risk of deficiency. For those infants especially high risk, such as those in neonatal intensive care, aa intake should be evaluated. Changes may be needed for the handling of HM to preserve the integrity of specific nutrients.