Effect of Heat Treatment on the Detection of Intact Bovine Beta-Lactoglobulins by LC Mass Spectrometry

Lactoglobulin (LG) is the most abundant allergenic protein of the whey fraction. As a consequence of heat treatment it is known to undergo structural changes in its conformation that may affect its allergenic capacity. In this study the potential of mass spectrometry has been exploited to study LG protein modification and stability as a consequence of thermal treatments applied to both standard solutions and milk samples. An investigation into the charge-state distribution in ESI-MS source revealed that in standard solutions, a higher degree of protonation accompanies increases in the severity of the heat treatment applied. In contrast, the analysis of milk samples revealed a high stability of the charge-state distribution of LG. However, we observed modification of LG spectra after heating of standard solutions as well as milk samples caused by lactosylation. The degree of LG lactosylation as analysed by LC-MS provides a potential markers to trace heat treatments.JRC.D.8-Food safety and qualit