Short-time low-temperature pasteurisation of human milk

Area of Science:

• Food Science
• Microbiology
• Biochemistry

Background:

• Classical holder pasteurization involves high temperatures and long durations.
• Concerns exist regarding the impact of traditional pasteurization on human milk's nutritional and immunological components.
• Developing optimized pasteurization methods is crucial for infant nutrition and safety.

Purpose of the Study:

• To evaluate the efficacy of a modified pasteurization process using lower temperatures and shorter times for human milk.
• To assess the impact of this modified pasteurization on the viability of common bacterial pathogens.
• To determine the retention of key antimicrobial protein activity after heat treatment.

Main Methods:

• Human milk samples were pasteurized using the Oxford Human Milk Pasteuriser at specific temperatures and durations (e.g., 62.5°C for 5 min, 56.0°C for 15 min).
• Bacterial challenge studies were performed using inoculated samples of *Escherichia coli*, *Staphylococcus aureus*, and group B beta-haemolytic streptococci.
• Antimicrobial protein activity (IgA, lactoferrin, lysozyme) was quantified before and after heat treatment.

Main Results:

• Heating human milk at 62.5°C for 5 minutes completely eradicated inoculated *E. coli*, *S. aureus*, and group B streptococci.
• A 56.0°C heat treatment for 15 minutes destroyed over 99% of these bacteria.
• Modified pasteurization significantly preserved antimicrobial protein activity: IgA (90%), lactoferrin (91%), and lysozyme (106%) at 56°C for 15 min.

Conclusions:

• Human milk can be effectively pasteurized using lower temperatures and shorter time periods compared to classical holder pasteurization.
• This optimized pasteurization method enhances the retention of vital antimicrobial proteins in human milk.
• The findings support the use of gentler pasteurization techniques to maintain the immunological benefits of human milk.