Decreasing retinol and α-tocopherol concentrations in human milk and infant formula using varied bottle systems.

Expressing human milk has become a more common alternative for mothers, as the average work demand has increased. As more mothers must work, bottle feeding trends are increasingly common. The handling and storage of human milk introduce the risk of degradation to expressed human milk and infant formula. In following a 20-minute simulated feeding, Vitamin C has been found to degrade. Vitamin C acts as an anti-oxidant and is responsible for shielding other nutrients from oxidation, such as retinol and alpha-tocopherol. By analyzing a 20-minute simulated feeding, retinol and alpha-tocopherol each displayed decreases over time significantly different than that of the Control, which was milk not exposed to bottle feeding. In human milk, retinol showed as high as a 9.5% decrease compared to the Control. Similar trends were seen with the infant formula samples. The correlation between degradation and bottle feeding systems was dependent upon the formation of bubbles in the milk as the milk was removed from the bottle. The analysis indicated a decrease of up to 12%, as seen in retinol, and 35%, as seen in alpha-tocopherol. These decreases in retinol and alpha-tocopherol should be considered when using a bottle feeding system to deliver either human milk or formula to an infant. More research is necessary to determine the effect of this decrease on the nutritional status of infants, particularly premature infants, who are at higher risk for nutrient deficiencies.

Comparative analysis of ascorbic acid in human milk and infant formula using varied milk delivery systems.

BACKGROUND: The expression of human milk for later use is on the rise. Bottle systems are used to deliver the expressed milk. Research has shown that storage of both human milk and artificial baby milk, or infant formula, leads to a loss of ascorbic acid (commonly called Vitamin C). As milk is removed from the bottle during feeding and replaced by ambient air, it is unknown if loss of ascorbic acid occurs during the course of a feeding. The purpose of this study is to investigate the effect of the milk delivery system on levels of ascorbic acid in human milk and infant formula. The objectives are to 1) determine changes in ascorbic acid concentration during a 20 minute "feed," 2) determine if there is a difference in ascorbic acid concentration between delivery systems, and 3) evaluate if any differences are of clinical importance. METHODS: Commonly available bottles were used for comparison of bottle delivery systems. Mature human milk was standardized to 42 mg/L of ascorbic acid. Infant formula with iron and infant formula with docosahexanoic acid were used for the formula samples. Each sample was analyzed for ascorbic acid concentration at baseline (0), 5, 10, 15, and 20 minutes. Each collection of samples was completed in triplicate. Samples were analyzed for ascorbic acid using normal-phase high performance liquid chromatography. RESULTS: Ascorbic acid concentration declined in all bottle systems during testing, Differences between the bottle systems were noted. Ascorbic acid concentrations declined to less than 40% of recommended daily intake for infants in 4 of the bottles systems at the 20 minute sampling. CONCLUSION: The bottle systems used in this study had measurable decreases in the mean concentration of ascorbic acid. More research is needed to determine if the observed decreases are related to lower plasma ascorbic acid concentration in infants exclusively bottle fed. The decrease of ascorbic acid concentration observed in both human milk and infant formula using varied milk delivery systems may be of clinical importance. For infants who rely solely on bottle feeds there may be increased risk of deficiency. Bottle shape, size, and venting should be considered.