Detection of undegraded beta-lactoglobulins and evaluation of the molecular weight of peptides in hydrolysate cow's milk formulae.

Hydrolysate formulae have been developed with the purpose of reducing the allergenicity of cow's milk proteins, thus providing a suitable formula for feeding babies with cow's milk allergy. More recently, hydrolysate formulae have also been used with babies at high risk of atopy in order to prevent cow's milk allergy. The aim of the present study was to investigate the presence of intact cow's milk proteins and the molecular weights of peptides in several batches of two extensively hydrolyzed formulae and two partially hydrolyzed formulae. The results show the presence of a significant amount of intact beta-lactoglobulin in one partially hydrolyzed formula and of peptides with high molecular weights (>16,900 D) in the two partially hydrolyzed formulae. In conclusion, the present study confirms that partially hydrolysed formulae contain a large proportion of peptides with high molecular weights: in addition, undegraded beta-lactoglobulin was detected in a partially hydrolyzed whey formula. These data strongly indicate that partially hydrolyzed formulae may be not only allergenic in an already sensitized individual, but also immunogenic in a predisposed baby.