Frozen breast milk at -20 degrees C and -80 degrees C: a longitudinal study of glutathione peroxidase activity and malondialdehyde concentration.
When breast milk extraction and storage is required before ingestion, it is important to establish the conditions that ensure the least losses in milk quality, like the antioxidant capacity. The present study evaluates glutathione peroxidase activity and malondialdehyde concentration of breast milk when stored frozen, comparing the effects of 2 temperatures (-20 degrees C and -80 degrees C) and different storage times (15, 30, and 60 days). The results indicate that freezing induces losses in the antioxidant properties of breast milk and that such losses increase with the duration of storage and differ in intensity according to the temperature. It is concluded that to maximally preserve the antioxidant properties of breast milk, it is advisable to store the latter at -80 degrees C for a period of less than 30 days, rather than for shorter time periods at the usual temperature of -20 degrees C.
Silvestre
Dolores
D
Department of Physiology, Pharmacology, and Toxicology at Universidad Cardenal Herrera-CEU, Valencia, Spain.
Miranda
María
M
Muriach
María
M
Almansa
Inmaculada
I
Jareño
Enrique
E
Romero
Francisco J
FJ
D000975:Antioxidants / Q000032:analysis; D005519:Food Preservation / Q000379:methods*; D005615:Freezing; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008315:Malondialdehyde / Q000032:analysis*; D008895:Milk, Human / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D010084:Oxidation-Reduction; D013997:Time Factors
D000975:Antioxidants; D008315:Malondialdehyde; D005979:Glutathione Peroxidase