(P27-031-25) Human Milk Vs Infant Formulas: Antioxidant Properties

Objectives: To compare the antioxidant properties of human milk (HM) before and after Holder pasteurization (HoP), commercial cow- and goat-milk-derived infant formulas (CIF and GIF, respectively), and oligosaccharides purified from HM and both IFs.

Methods: Human milk samples were obtained from local mothers and from Red Cross Australia following approval by the RMIT University Human Research Ethics Committee. Oligosaccharide fractions were extracted from HM and HoP-treated (62.5 °C for 30 min) HM, and from CIF and GIF, both reconstituted according to the manufacturer’s instructions.  Oligosaccharides were purified by ultrafiltration using Amicon filters (MWCO 10 kDa) and quantified using HILIC-LC/MS.  Antioxidant activity was measured using standard biochemical assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging, superoxide radical scavenging, potassium ferricyanide reduction, and Fe2+-chelating ability.

Results: Antioxidant activity decreased in HM following HoP. Fe-chelating properties were also reduced but this did not achieve statistical significance. Hydroxyl radical scavenging properties remained unaffected. Not only the IFs but also purified oligosaccharides were found to exhibit significant antioxidant properties. GIF and GMOs exhibited the strongest activity for scavenging free radicals, relative to HM and CIF and their respective milk oligosaccharide fractions.  The iron-chelating properties of GIF and GMOs were comparable with those of HM and CIF, while GMOs were more effective at chelating Fe2+ than CMOs. HM and reconstituted IFs displayed greater activities than the purified oligosaccharides, confirming earlier studies showing that other milk components (particularly proteins) also play a significant role in protecting against oxidative stress.

Conclusions: Although required for safety, HoP treatment negatively impacts HM’s antioxidative properties. GIF and GMOs appear to be more effective antioxidants than CIF and CMOs, and even more so than HM and HMOs. These observations have implications for current HM pasteurization protocols used by donor HM banks and for the development of new IF oligosaccharide formulations that could provide enhanced antioxidant effects together with other well-known benefits.

Funding Sources: The research was funded by RMIT University.