Polyunsaturated Fatty Acid, Riboflavin and Vitamin C: Effect of Different Storage Conditions of Human Milk

This study addresses a matter of importance for: healthy infants; sick infants in the Neonatal Intensive Care Units; infants fed expressed human milk and infants who receive milk from Human Milk Banks. Current storage parameters for freezing of mother’s milk are not well established and are often contradictory. Pooled fresh human milk was stored raw, in nitrogen gas and following Holder pasteurization for 6 days at 4oC and for 6 months at -20oC and at -80oC. Contents of linoleic (LA), α−linolenic (ALA), arachidonic (ARA) and docosahexaenoic (DHA) acids, riboflavin and total vitamin C were analyzed under these conditions and during these storage times as they are sensitive to oxidation. The results of this study confirm the general appropriateness of freezing human milk at either -20oC or at -80oC, for preservation of two vitamins and four fatty acids. These storage recommendations are applicable also for the storage of human milk which underwent Holder pasteurization. Both the exclusion of oxygen and freezing at -80oC may be redundant for nutrient preservation and in some cases even detrimental. Recommendations for human milk storage while based on bacteriological safety appear to be appropriate for preservation of vitamins C and riboflavin and LA, ALA, DHA and ARA. As vitamin C is highly susceptible to oxidation, its addition to human milk or direct supplementation of the infant is recommended, if the milk had been frozen for longer than 2 weeks or had been pasteurized. We recommend supplementation of the infant with vitamin C at the Adequate Intake (AI) level in these cases.