The effect of microwave-assisted heating on bioactive and immunological compounds in donor human milk

Abstract

Low-Temperature Long-Time pasteurization (LTLT) is normally applied in donor human milk from Human Milk Banks (HMBs) to guarantee microbiological safety; however, this treatment can modify the protein structures, decreasing their beneficial effects. Thus, this study aimed to determine the impact of microwave-assisted heating on the concentration of key biological compounds in donor human milk to verify whether a microwave heating technique can be used as an alternative to LTLT pasteurization in Human Milk Banks. The concentrations of oligosaccharides, immunoglobulins, lactoferrin and fatty acids were monitored in raw donor milk and after processing to assess the impact of the microwave and LTLT treatments. The concentration of oligosaccharides was determined by HPAEC-PAD, immunoglobulins and lactoferrin were quantified using ELISA kits and fatty acids were quantified by gas chromatography. Oligosaccharides and fatty acids were not significantly affected (p > 0.05) by LTLT and microwave processes; however, immunoglobulins and lactoferrin concentrations were better preserved when microwave-assisted heating was applied. For this reason, microwave-assisted heating can be considered a promising alternative to LTLT pasteurization of donor human milk in Human Milk Banks.