Immunochromatographic determination of beta-lactoglobulin and its antigenic peptides in hypoallergenic formulas.

摘要

In milk, beta-lactoglobulin (betaLG) is the main allergen present but betaLG fragments may also cause an allergic reaction. In this study, a sandwich enzyme linked immunoaffinity chromatography (ELIAC) method was developed and used to determine betaLG and its peptides in 5 hypoallergenic infant formulas (HF) based on different extensively hydrolysed protein fractions of milk. Samples were also fractionated by employing membranes with different mol. wt. cut-offs and the antigenicity of the peptide fractions was determined. Applying the ELIAC method, for which one analysis takes 30 min, betaLG was determined at the pM level in hypoallergenic infant formulas based only on caseins and at the nM to muM level in formulas based on hydrolysed whey proteins. Peptides of mol. wt. <3000 derived from betaLG showed positive results in ELIAC assays, indicating antigenic character.