The effect of thermal pasteurization, freeze-drying, and gamma irradiation on donor human milk

Katherine Blackshaw; Jiadai Wu; Nicholas Proschogo; Justin Davies; Daniel Oldfield; Aaron Schindeler; Richard B Banati; Fariba Dehghani; Peter Valtchev

doi:10.1016/j.foodchem.2021.131402

The effect of thermal pasteurization, freeze-drying, and gamma irradiation on donor human milk

Food Chem. 2022 Mar 30;373(Pt B):131402. doi: 10.1016/j.foodchem.2021.131402. Epub 2021 Oct 14.

Authors

Katherine Blackshaw¹, Jiadai Wu¹, Nicholas Proschogo², Justin Davies³, Daniel Oldfield³, Aaron Schindeler⁴, Richard B Banati⁵, Fariba Dehghani¹, Peter Valtchev¹

Affiliations

¹ School of Chemical and Biomolecular Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW 2006, Australia; Centre for Advanced Food Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
² Mass Spectrometry Facility, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
³ Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia.
⁴ School of Chemical and Biomolecular Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW 2006, Australia; Centre for Advanced Food Engineering, The University of Sydney, Sydney, NSW 2006, Australia; Bioengineering and Molecular Medicine Laboratory, The Children's Hospital at Westmead and Westmead Institute for Medical Research, Westmead, NSW 2145, Australia.
⁵ Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia; Faculty of Medicine and Health, Medical Imaging Sciences, Brain and Mind Centre, University of Sydney, Camperdown, NSW 2006, Australia; Mothers Milk Bank Charity (Human Milk Emergency Reserve-Project), Australia. Electronic address: rib@ansto.gov.au.

PMID: 34741965
DOI: 10.1016/j.foodchem.2021.131402

Abstract

The availability of donor human milk (DHM) is currently limited by the volumes that can be thermally pasteurized and kept in long-term cold storage. This study assesses the application of freeze-drying followed by low-dose gamma irradiation of DHM for simplified, safe long-term storage. Solid-phase microextraction (SPME) GC-MS, SDS and native PAGE gel electrophoresis demonstrated that the overall changes in volatile and protein profiles in Holder pasteurized and freeze-dried DHM was negligible compared to the natural variations in DHM. Freeze-dried DHM samples (moisture < 2.2 %) processed with 2 kGy gamma irradiation did not show any significant lipid oxidation end-products and variation in protein profile. Therefore, freeze-drying followed by in-packaging gamma irradiation could be a safe method for pasteurization, convenient storage and delivery of DHM at ambient temperature. These methods may generate a means to create a reserve stock of DHM for emergencies and humanitarian aid.

Keywords: Donor human milk; Emergency preparedness; Freeze-drying; Gamma irradiation; Holder pasteurization; Lyophilization; SPME-GC–MS; Terminal sterilization.

MeSH terms

Freeze Drying
Humans
Milk Banks*
Milk, Human*
Pasteurization