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The effect of thermal pasteurization, freeze-drying, and gamma irradiation on donor human milk
Katherine Blackshaw1, Jiadai Wu1, Nicholas Proschogo2
1School 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.
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.
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