[Frontiers in Bioscience E3, 818-829, June 1, 2011]

[Frontiers in Bioscience E3, 818-829, June 1, 2011]

Effect of two pasteurization methods on the protein content of human milk

Cristina Baro¹, Marzia Giribaldi¹, Sertac Arslanoglu², Maria Gabriella Giuffrida¹, Giuseppina Dellavalle¹, Amedeo Conti¹, Paola Tonetto^{2, 3}, Augusto Biasini^2,4,Alessandra Coscia³, Claudio Fabris³, Guido Eugenio Moro^2,5, Laura Cavallarin¹, Enrico Bertino^2,3

1 CNR - Institute of the Science of Food Production, Grugliasco, Turin, Italy, ² Italian Association of Human Milk Banks, Milan, Italy, ³Neonatal Intensive Care Unit, Department of Pediatric and Adolescence Science, University of Turin, Turin, Italy, ⁴ Bufalini Hospital, Cesena, Italy, ⁵ Department of Neonatology, Macedonio Melloni Maternity Hospital, Milan, Italy.

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Material and methods: 3.1. Samples; 3.2. Monodimensional electrophoresis (SDS-PAGE); 3.3. Standard oxidation curves 3.3.1. Reduced BSA; 3.3.2. Oxidized BSA 3.4. Western Blot on polyvinylidene fluoride (PVDF) membrane; 3.5. DNP derivatization on membranes; 3.6. Hydrophobic immunostaining; 3.7. Western Blot on nitrocellulose (NC) membrane; 3.8. Preparation of the positive control for 4-hydroxy-2-nonenal (HNE) immunostaining; 3.9. HNE immunostaining; 3.10. IgA Immunodetection; 3.11. Mass spectrometry; 3.12. N-Terminal Sequencing; 3.13. Measurement of the lipase activity; 3.14. Available lysine determination

4. Results

5. Discussion 5.1. Effect of pasteurization on lactoferrin

5.2. Effect of pasteurization on bile salt-stimulated lipase

5.3. Effect of pasteurization on components of the immune system

5.4. Effect of pasteurization on total available lysine content

6. Acknowledgements

7. References

1. ABSTRACT

The Holder method is the recommended pasteurization method for human milk banks, as it ensures the microbiological safety of human milk (HM). The loss of some biologically active milk components, due to the heat treatment, is a main limit to the diffusion of donor HM. High-temperature short-time (HTST) pasteurization may be an alternative to maintain the nutritional and immunological quality of HM. The aim of the present study was to compare the impact of Holder and HTST pasteurization on the HM protein profile. The protein patterns of HTST-treated milk and raw milk were similar. The Holder method modified bile salt-stimulated lipase, lactoferrin and components of the immune system. The HTST method preserved the integrity of bile salt-stimulated lipase, lactoferrin and, to some extent, of IgAs. Holder pasteurization decreased the amount of bile salt-stimulated lipase and inactivated the remaining molecules, while the HTST method did not alter its activity. Pasteurization increased the bioavailable lysine quantity. HTST pasteurization seems to better retain the protein profile and some of the key active components of donor HM.