The Effects of Refrigerated Storage Time on Sialic Acid and Nitric Oxide Levels and Oxidant Antioxidant System of Human Milk

Objective: Human milk (HM) is a marvelous nutrition that serves all the needs of infants in the first six months with the vitamins, minerals, proteins, carbohydrates, and lipids it contains. For the first 4-6 months of a baby’s life, Nursing is accepted as the most beneficial and recommended feeding method. The greatest technique for providing nutrition in the absence of breastfeeding is through expressed HM. In this case, milk storage conditions become critical. The proper storage of HM is essential for preserving the nutritional and antioxidant properties of HM. This study aims to examine the effects of storing HM in the refrigerator. Materials and Methods: The effects of storing HM in the refrigerator were examined for four days with regard to the protein profile oxidant-antioxidant balance and nitric oxide (NO) and sialic acid (SA) levels. Results: Total protein (TP) levels decreased gradually over the four days. In the SDS-PAGE electrophoresis method, the heavy chain sIgA and 𝜅 -casein bands also disappeared in HM. While glutathione-S-transferase and superoxide dismutase activities decreased significantly during the first two days, their activities fell below the detection limit in the last two days. While the glutathione level and catalase activity also decreased gradually over the four days, the malondialdehyde, SA, and NO levels increased significantly. Conclusion: HM can be safely stored in the refrigerator for two days due to the TP, SA, and NO levels, as well as the antioxidant enzyme activities, remaining unchanged from the first day of expressing HM.