TABLE 5.

Identified research gaps relating to areas of donor human milk processing and subsequent infant digestion and absorption

Area of Donor Human Milk Processing	Identified Gap(s)	Suggested Outcomes to Investigate	Significance
Processing to inactivate pathogens	•Lack of research into novel non-thermal technologies (e.g., high-pressure processing, ultraviolet C-irradiation, ultrasonication). •No literature on implementing hurdle technology in milk processing (e.g., applying >1 method to achieve improved pathogen inactivation).	•Protein digestion, release of peptide and bioactivity of peptides. •Impact on fat lipolysis and fat absorption.	•New non-thermal methods may result in improved patterns of peptide generation and release that could have implications relating to host defense and overall health. •Preservation of lipase activity via the application of non-thermal methods has the potential to improve fat digestion among preterm infants receiving donor milk. •Hurdle technology may strike the appropriate balance between preservation of milk function/ digestibility and inactivating pathogens.
Processing to ensure homogenous donor milk fat composition	•Very limited research into fat homogenization during the production of donor human milk.	•Impact on milk fat globule, fat lipolysis and absorption. •Consistency in donor milk product/ability to tightly regulate composition. •Adherence to tubing required for feeding preterm infants.	•Homogenization has the potential to improve the distribution of fat during donor milk processing and may improve digestion and absorption. •During feeding, homogenized milk may adhere less to tubing, increasing the overall delivery of fat to the infant.
Freeze-thawing and duration of freezing	•Extremely limited research (only 1 in vitro study) into the impact of freeze-thawing, as well as the conditions during freezing (e.g., temperature, time duration etc.) on outcomes relating to digestion and absorption. •No in vivo studies found.	•Protein digestion/hydrolysis, peptide release and bioactivity of peptides. •Lipolysis and fat absorption.	•The way in which donor human milk is frozen, thawed, handled pre- and postprocessing has the potential to damage milk components including proteins and milk fat globules.