Unsuspected lupin allergens hidden in food.

Background: Lupin is a herbaceous plant from the legume family whose seed allergens usually have cross-reaction with peanut. Lupin flour is used in human nutrition because of its high nutritional and functional qualities.

Aims: The aim of this work was to detect non-specified lupin proteins contained in several manufactured foods.

Methods: Serum from a patient suffering anaphylactic episodes after ingestion of a certain brand of cookies and with oral allergy syndrome after eating chicken bouillon was used as a tracer. Lupin seeds and commercial food extracts were analyzed by SDS-PAGE, immunoblotting and immunoblotting inhibition. Lupin extract allergenicity after thermal processing was also analyzed.

Results: A lupin allergen with a molecular weight close to 14 kDa was detected in extracts from cookies, a chicken bouillon cube and a chicken dehydrated soup.

Conclusions: The presence of unsuspected, hidden non-specified lupin sources in food labeling was demonstrated. According to the results of this study, it is important for food-allergic patients that food labels should declare all the components irrespective of their quantity.