AUTHOR=Müller Katharina , Toll Luisa J. , Manzardo Olimpia A. , Baumgartner Jana , Nickel Erika , Wenzel Folker , Klotz Daniel 

TITLE=Holder Pasteurization: Comparison of Water-Bath and Dry-Tempering Devices

JOURNAL=Frontiers in Pediatrics

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.879853

DOI=10.3389/fped.2022.879853

ISSN=2296-2360

ABSTRACT=Background
Human milk (HM) for premature infants is frequently Holder pasteurised (heated at 62±0.5°C for 30 min) despite its detrimental effects on heat-sensitive milk components. This tolerated compromise ensures HM’s microbial safety while less detrimental methods like short-time HM treatments (HTST) are still being evaluated.
Dry-tempering devices (DT-HoP) were recently introduced in clinical practice due to hygienic concerns about water-based Holder pasteurisers (WB-HoP). Evidence on the impact of such dry-tempering devices on HM quality is lacking. The aim of this study was to compare protein retention rates after DT-HoP, WB-HoP and HTST.
Methods
We colorimetrically determined alkaline phosphatase activity (ALP), concentrations of secretory immunoglobulin A (sIgA), and lactoferrin (LF) before and after DT-HoP, WB-HoP and HTST.
Results
ALP was below the detection limit after HoP, but retained 52.8±13% activity after HTST (p<0.01). Secretory IgA (WB-HoP=73.2±13.5% versus DT-HoP=57±14%, p=0.0018) and LF retention (WB-HoP=47±40% versus DT-HoP=25±8%, p=0.07) differed between the two HoP modes. Again, retention was better maintained after HTST compared to HoP (80.4±23% sIgA and 70±42% LF concentration, all p<0.01). 
Conclusion
Dry-tempering milk lowers even further the quality of HM when performing HoP compared to water-bath pasteurisation, while HTST warrants continued evaluation for clinical application.