A new sample preparation method compatible with capillary electrophoresis and laser-induced fluorescence for improving detection of low levels of beta-lactoglobulin in infant foods

Beta-Lactoglobulin (BLG) is the main allergenic protein in cow’s milk and can cause allergy even when present at very low concentration. The aim of this work is to develop an innovative sample prepara- tion method fully compatible with capillary electrophoresis and laser-induced fluorescence detection for improving the sensitivity when analyzing BLG. Different types of baby food were on purpose contaminated with diverse dairy desserts and submitted to thermal treatment to simulate potential contamination at production. Sample preparation prior to CE analysis was performed by the classical extraction method and by the innovative one, and the results were compared. Analysis was performed by capillary electrophoresis with laser-induced fluorescence detection. The innovative method permitted to detect contaminations as low as 1 part of yoghurt in 10 000 parts of baby food.
Financial support from the Spanish Ministry of Education and Science (projects DEP2006-56207 C03-01 and CTQ2006-05214) is acknowledged.