[Stability of the antioxidant capacity and pH of human milk refrigerated for 72 hours: longitudinal study]

Maternal milk is the optimal feeding way for the infant at least for the first six months of life. Its properties include nutrients intake and, particularly, to provide the infant with several beneficial compounds improving his growth and protecting him from the diseases typical of this time period. These properties justify the manipulating processes before its intake in order to promote and warrant the adherence to it, both at the hospital and at home, being more important in premature infants and/or with low birth weight given their increased vulnerability, is spite of the fact that during these processes some of its properties may be partially lost. There exist, therefore, an interest in knowing the impact of the procedures applied to human milk on its qualitative properties, such as the antioxidant capacity.

This work assesses the stability of the antioxidant capacity of human milk during its storage at 4º C, longitudinally from its extraction until 48 h of refrigeration, as well as the pH changes.

the milk from 30 healthy women was analyzed. The milk's antioxidant capacity was assessed by the following parameters: total antioxidant capacity and level of malondialdehyde. The results obtained showed that pH decreases gradually from the storage beginning, whereas the antioxidant capacity remains constant for the first 24 hours, with a different result depending on the parameter used, and thereafter significant changes were observed.

In case of needing extraction and storage of maternal milk before its consumption, the storage time should be minimized, preferably less than 24 hours in order to preserve the oxidative stress.