Treating donor human milk with alternative pasteurization methods, high-pressure processing and ultraviolet-C irradiation, and their impact on pathogen inactivation, nutrient content and protein bioactivity: a scoping review

Human milk is a complex bioactive food matrix that supports the growth and development of infants. In the absence of their parent's own milk, hospitalized preterm infants receive Holder pasteurized donor milk (DM). However, Holder pasteurization (HoP; 62.5 °C, 30 min) inactivates bioactive proteins and damages some nutritional components of milk, limiting potential health benefits for the infant. Two non-thermal pasteurization processes-ultraviolet-C (UV-C) and high-pressure processing (HPP)-are promising alternatives. HPP and UV-C can provide similar microbial inactivation as HoP while preserving more protein bioactivity, but no review has identified trends in the response of pathogens and DM components to changes in their operating parameters. Therefore, a scoping review was conducted to evaluate how changes to HPP and UV-C operating parameters impact DM safety and quality. In conclusion, specific parameter combinations for single-cycle HPP and UV-C can inactivate vegetative bacteria and improve retention of DM components compared with Holder pasteurization. UV-C research for human milk is limited by the range of components that have been evaluated. More data is needed to optimize each technology prior to comparison to HoP in terms of safety and quality.