Effect of Frozen Storage on Macronutrient, Mineral, and Immune Component Content of Pasteurized Donor Human Milk.

This article focuses on the effects of long-term frozen storage at −30 °C on the bacterial safety and nutritional quality of pasteurized donor human milk (PDHM) in Japan. In a laboratory study of 20 PDHM samples stored for 6, 9, and 12 months, no bacterial growth was detected at any time point, and key nutrients—including protein, fat, calcium, inorganic phosphorus, secretory immunoglobulin A (sIgA), and lactoferrin—remained stable. Slight increases were observed in carbohydrate and zinc levels after 9 and 12 months, but these changes were minimal. The findings suggest that PDHM can be safely stored at −30 °C for up to 12 months without compromising its bacterial safety or nutritional and immune component integrity.