The Effect of Storage Conditions of Different Temperatures on the Stability of Nutrients in Pasteurized Donated Human Milk

Abstract

Background:

Donated human milk (DHM) is vital for nutrition of preterm and critically ill infants when the mother’s own milk is unavailable. For safety reasons, DHM is routinely pasteurized and stored frozen. The impact of storage duration and temperature on the stability of its nutritional values has not been sufficiently investigated. This study aimed to evaluate the stability of macronutrients and energy content in pasteurized DHM stored at −30°C and −80°C over a 12-month period.

Methods:

Pasteurized DHM samples from ten single-donor pools were divided into aliquots and stored at −30°C and −80°C. Nutritional value analyses were performed at baseline (pre-pasteurization) and at predetermined monthly intervals for one year using a human milk analyzer MIRIS HMA^TM (Miris AB, Uppsala, Sweden). Stability was assessed by comparing changes in macronutrients and energy content over time and between storage temperatures. Data were analyzed using statistical software MedCalc (version 14.12.0, MedCalc, Ostend, Belgium) with p < 0.05 considered statistically significant.

Results:

Macronutrient values remained stable throughout the study period. No statistically significant differences were observed, regardless of the storage temperature, except for protein concentration in samples stored at −80°C (p = 0.039). Given the low protein values (median at all measurement points was 1.0 or 1.1 g/100 mL), this difference is not considered clinically relevant. No significant differences in macronutrients or energy content were found between samples stored at −30°C and −80°C over the same period.

Conclusion:

The nutritional values of pasteurized DHM are preserved for up to 12 months just as well at −30° C as at −80°C.