Impact of Holder Pasteurization and Preanalytical Handling Techniques on Fat Concentration in Donor Human Milk: A Scoping Review

Background

Donor human milk (DHM) is an essential source of nutrition among high-risk infants (e.g., premature and low-birth weight). Holder pasteurization, a common step in DHM processing, is known to partially alter the composition of DHM; however, the impact on fat composition is historically inconsistent.

Objectives

This scoping review aimed to broadly review the literature on the impact of Holder pasteurization on the fat content in DHM, with a focus on preanalytical sample mixing.

Methods

A systematic search of original, peer-reviewed research articles was conducted on 11 July, 2022. Articles were included if they compared matched raw (control) and Holder-pasteurized human milk samples and measured total lipids, cholesterol, and individual classes of fatty acids. Article review and selection was conducted by 2 independent reviewers.

Results

The search yielded 26 original, peer-reviewed research articles published between 1978 and 2022. Overall methodology varied considerably between studies. When study methods described any mixing for collecting raw milk, 1 (17%) of the 6 of studies reported a small change in total fat concentration following pasteurization (<5%). Alternatively, among studies that did not describe methods for mixing raw milk to ensure a representative sample, 10 (56%) of the 18 reported a significant change (≥± 5%) in total fat concentration, with changes ranging from −28.6% to +19.4%.

Conclusions

This review suggests that inconsistent findings regarding the impact of Holder pasteurization on fat may be related to study methodologies, particularly preanalytical sample mixing. More research considering the role of preanalytical handling procedures and methodologies is necessary to help clarify the impact of Holder pasteurization on human milk composition.