Role of lactic acid bacteria on the prevention of milk allergy

PESCUMA M; HEBERT E; HAERTLé T; MOZZI F; CHOBERT J; FONT DE VALDEZ G

Egmond aan Zee

Simposio; LAB 10 Symposium; 2011

Milk allergy is a complex disorder affecting mainly young children. Cheese manufacture results in the separation of two fractions: whey and the coagulum containing 20% and 80% of proteins, respectively. aS1-Casein (aS1-cas) present in the curd and B-lactoglobulin (B-lg) obtained from whey are the main milk allergenic elicitors. Certain lactic acid bacteria (LAB) could degrade milk proteins reducing the allergenicity of milk. The aim of this work was to analyze the ability of Lactobacillus delbrueckii subsp. lactis CRL581 and L. acidophilus CRL636 to degrade aS1-cas and -lg (variants A and B) and to decrease the recognition of these proteins by IgE of allergic children. The allergenicity of the hydrolysates obtained with lactobacilli was compared to those derived with tryptic digestion. L. delbrueckii subsp. lactis CRL581 hydrolyzed 95% of aS1-cas while L. acidophilus CRL636 hydrolyzed 60% of -lgA and 30% of -lgB. Trypsin fully degraded all proteins. Lactobacilli released more hydrophilic (small size) peptides than trypsin. The IgE binding capacity to aS1-cas decreased after hydrolysis by L. delbrueckii subsp. lactis CRL581 (IC50 values 50 times higher than those of native protein); however, its immunoreactivity was greater than that of the hydrolysate obtained with trypsin. B-LgA hydrolysates from L. acidophilus CRL636 showed IC50 values 2.7 times greater than those obtained with trypsin while no differences between both treatments were observed for -lgB. Interestingly, B-lgA and aS1-cas hydrolysates from LAB did not reach 100% inhibition (80 and 70%, respectively) with the maximum protein concentrations assayed. Degradation of aS1-cas and B-lg by selected LAB could be an attractive approach to formulate hypoallergenic dairy products.