Hygienic-sanitary quality and effect of freezing time and temperature on total antioxidant capacity of human milk

Abstract Knowledge of the hygienic-sanitary quality of raw human milk helps to establish the best storage conditions for the preservation of its nutritional and functional components. Therefore, this study aimed to evaluate the hygienic-sanitary quality of human milk extracted at the mothers’ homes, and to analyze the effect of freezing time and temperature on the milk’s total antioxidant capacity. Milk of five mothers was evaluated individually for Staphylococcus aureus, total aerobic mesophilic counts, mold and yeasts, total and thermotolerant coliforms. The milk pool was stored at -8 °C, -18 °C and -40 °C for 2, 4, 8 and 15 days and analyzed for the total antioxidant capacity by the 2,2-diphenyl-1-picrylhydrazyl free radical and 2,2-azino 3-ethylbenzothiazoline-6-sulfonic acid scavenging methods. The microbiological analyses of the raw human milk samples indicated counts of all the studied microorganisms above the safe limits. Related to the effect of freezing time and temperature on total antioxidant capacity, it was concluded that, regardless of the freezing temperature, a significant reduction occurred on total antioxidant capacity over time and that the lower the storage temperature, the greater its total antioxidant activity.