Quantitative Risk Assessment of Growth during the Warming of Thawed Pasteurized Human Banked Milk Using a Predictive Mathematical Model.

is relatively resistant to pasteurization. We assessed the risk of growth during warming and subsequent storage of pasteurized banked milk (PBM) in the warmed state using a predictive mathematical model. Holder pasteurization followed by storage below -18 °C was used. Temperature maps, water activity values, and growth in artificially inoculated PBM were obtained during a simulation of manipulation of PBM after its release from a Human Milk Bank. As a real risk level, we chose a concentration of 100 CFU/mL; the risk was assessed for three cases: 1. For an immediate post-pasteurization concentration below 1 CFU/mL (level of detection); 2. For a concentration of 10 CFU/mL, which is allowed in some countries; 3. For a concentration of 50 CFU/mL, which is approved for milk formulas. In the first and second cases, no risk was detected after 1 h of storage in the warmed state, while after 2 h of storage, concentrations of 10 CFU/mL were occasionally encountered. In the third case, exceeding the concentration of 10 CFU/mL could be regularly expected after 2 h of storage. Based on these results, we recommend that post-pasteurization bacteriological analysis be performed as recommended by the European Milk Bank Association (EMBA) and using warmed PBM within 1 h after warming (no exceptions).