Effects of storage, time, temperature, and composition of containers on biologic components of human milk.

Effects of steel and glass storage containers, duration of storage up to seven hours, and storage temperature on the concentration of humoral and cellular factors in 357 samples of human breastmilk were examined. Leukocytic functions were estimated by E-rosetting of sheep RBCs by T-lymphocytes and phagocytosis of S. cerevisieae by phagocytes. Immunoglobulin (Ig) levels were studied by single radial immunodiffusion technique (SRID). Viability and cell counts reduced during the storage period, but were greater than 60 percent of baseline values. IgG, IgA, and IgM levels in milk did not show significant decline after storage (p > 0.01). Milk stored in glass yielded a greater number of functional cells after storage at 4 degrees C.