Characterizing detectable milk protein allergens β‐casein and β‐lactoglobulin in milk ladder foods

BACKGROUND: Cow's milk allergy (CMA) is the most common and complex presentation of food allergies in early childhood. The "ladder" approach has gained popularity to reintroduce cow's milk into a child's diet depending on the type of CMA, though there are very few studies quantifying the level of allergen within the steps of food ladders. This paper aimed to assess detectable levels of milk protein allergens in milk ladder foods. METHODS: Cookies, muffins, and pancakes were prepared according to the recipes of the International Milk Allergy in Primary (iMAP) care ladder. The effect of the food matrix, heating, and industrial milk processing was assessed by measuring levels of bos d5 (β-lactoglobulin) and bos d11 (β-casein) by ELISA. The other steps of the milk ladder, cheese, yogurt and milk, were also tested and compared. RESULTS: The food matrix, baking conditions, and milk processing all influenced the detected levels of bos d5 and bos d11 in the milk ladder foods. The order of the foods by increasing antigen levels depends on the parameter used: calculated levels of total milk protein, detected bos d5, or detected bos d11. CONCLUSIONS: This study shows that the order of milk ladder foods is different depending on whether it is based on calculated protein amounts, measured levels of bos d5 or measured levels of bos d11. HCPs need to be aware that depending on which protein is tested, ladder foods have a different order. This paper provides novel data on detectable proteins bos d5 (β-lactoglobulin) and bos d11 (β-casein) in milk ladder foods, which contribute to our current understanding of milk ladders, critical in the management of CMA.