Analysis of the Storage Methods for Raw Human Milk from Mothers with Infants Admitted to a Neonatal Intensive Care Unit, According to Brazilian Regulations

Background: Milk safety is an important concern in neonatal units and human milk banks. Therefore, evidence-based recommendations regarding raw milk handling and storage are needed to safely promote supplying hospitalized infants with their mother's own milk.

Objectives: To evaluate raw human milk storage methods according to Brazilian milk management regulations by investigating the effects of refrigeration (5°C) for 12 hours and freezing (-20°C) for 15 days on the acidity and energy content in a large number of raw milk samples.

Methods: Expressed milk samples from 100 distinct donors were collected in glass bottles. Each sample was separated into 3 equal portions that were analyzed at room temperature and after either 12 hours of refrigeration or 15 days of freezing. Milk acidity and energy content were determined by Dornic titration and creamatocrit technique, respectively.

Results: All samples showed Dornic acidity values within the established acceptable limit (≤ 8°D), as required by Brazilian regulations. In addition, energy content did not significantly differ among fresh, refrigerated and frozen milk samples (median of ~50 kcal/100 mL for each).

Conclusion: Most samples tested (> 80%) were considered top quality milk (< 4°D) based on acidity values, and milk energy content was preserved after storage. We conclude that the storage methods required by Brazilian regulations are suitable to ensure milk safety and energy content of stored milk when supplied to neonates.