Bacteriological, biochemical, and immunological modifications in human colostrum after Holder pasteurisation

Human colostrum contains unique nutrients and bioactive compounds that support infant immunity and development. Prior research has shown that Holder pasteurisation is a standard method to reduce microbial contamination in donated milk. However, the impact of this heat treatment on the immunological and biochemical composition of colostrum remains unclear. Established knowledge includes the role of lactose and immunoglobulins in colostrum, but no prior work had resolved how pasteurisation affects cytokine levels or lactulose formation. This gap motivated an investigation into the changes in colostrum following Holder pasteurisation. That uncertainty drove the need to assess multiple parameters simultaneously. No prior work had resolved the relationship between heat treatment and specific cytokine reductions. This study aimed to address these questions by examining microbiological, biochemical, and immunological changes in colostrum after pasteurisation.

The study aimed to evaluate the effects of Holder pasteurisation on human colostrum by analyzing multiple parameters. Researchers focused on bacterial counts, furosine levels, lactose, myoinositol, glucose, lactulose, cytokines, and immunoglobulins. The motivation stemmed from the need to understand how pasteurisation affects the nutritional and immunological quality of colostrum. This paper's contribution lies in its comprehensive approach to assessing multiple variables in a single study. Prior work had not examined the combined impact of heat treatment on these factors. The specific problem addressed was the lack of data on how pasteurisation alters the composition of colostrum. Researchers sought to determine which components remain stable and which are affected. This study provides a detailed profile of colostrum before and after pasteurisation.

The study used colostrum samples from 10 donors and 8 mature milk samples as controls. All samples were pasteurised using the Holder method at 62.5°C for 30 minutes. Researchers measured bacterial counts and concentrations of furosine, lactose, myoinositol, glucose, lactulose, cytokines, and immunoglobulins. The agar media tested included standard microbiological methods. The heat treatment was applied uniformly to all samples. Researchers used quantitative methods to assess changes in each parameter. The study design allowed for direct comparison between pre- and post-pasteurisation samples. No additional interventions were introduced during the process. The analysis focused on detecting significant differences between the two conditions.

Holder pasteurisation significantly reduced bacterial counts in colostrum samples. Furosine levels increased from 6.60 to 20.59 mg/100 g protein after pasteurisation. Lactulose was undetectable before treatment but present in 7 of 10 samples post-pasteurisation. Lactose, glucose, and myoinositol concentrations remained unchanged. Immunoglobulin levels decreased during pasteurisation in both colostrum and mature milk. Cytokine concentrations were affected selectively; macrophage inflammatory protein-1β, interleukin-7, and granulocyte-macrophage-colony-stimulating factor decreased. Colostrum had higher cytokine and immunoglobulin levels than mature milk. These findings suggest that pasteurisation alters the immunological profile of colostrum.

The authors concluded that Holder pasteurisation modifies the immunological and biochemical composition of colostrum. Bacterial counts were reduced, but furosine and lactulose levels increased as heat indicators. Immunoglobulin concentrations decreased in both colostrum and mature milk. Cytokine levels were affected selectively, with macrophage inflammatory protein-1β, interleukin-7, and granulocyte-macrophage-colony-stimulating factor showing significant changes. These findings suggest that pasteurisation impacts the functional properties of colostrum. The study supports the use of lactulose and furosine as markers of heat treatment. The results may inform guidelines on pasteurisation protocols for human milk. The authors propose that these changes should be considered in clinical settings.