Experts Sour on Milk Protein Test

Milk protein in processed food may miss some protein residue

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) There's no use in crying over spilled milk but parents should be concerned about milk residue. A test used by the industry to check for milk residue in processed food may not be as effective as previously thought.

A test used for the detection of milk protein residue on machines and processed food was not as effective as previously believed.

The test, enzyme-linked immunosorbent assay (ELISA), may miss left over milk proteins which would could lead to allergic reactions in children.

"Ask your doctor about tests for milk allergies."

The study was led by Joseph L. Baumert, Ph.D., from the University of Nebraska-Lincoln. ELISA was used to ensure that left over milk protein was not on food-processing equipment or processed food. Any possible allergen is reported and a warning is placed on the packaging. Researchers hope to refine this process based on this new data.

 A milk allergy is one of the most common allergies in children. Between two to five percent of all under the age of three have a milk allergy. Symptoms are similar to other allergies such as itchy eyes, difficulty breathing, and closing of the throat. A severe reaction could lead to anaphylaxis.

A milk allergy is different than lactose intolerance. An allergy is based on the immune system's response to a protein. Lactose intolerance occurs because the body cannot produce enough enzymes to break down milk sugars.

ELISA, and other industry tests, are used to prevent accidental allergen contact. A disclaimer that you may see on a candy wrapper such as “manufactured in a facility that also processes peanuts” can give fair warning to people allergic to that particular food.

This would be problematic in milk allergy if the ELISA test cannot detect milk proteins that can lead to accidental contact by children who are allergic to the milk protein.

According to researchers, ELISA was not able to detect the leftover milk protein due to how the food is processed. When heated or by other processing methods, the milk proteins stick together which makes it difficult to be detected by ELISA.

Recent food recalls in Canada because of undeclared milk allergens is an example of what happens when tests like ELISA do not detect milk protein residue.

Industry test like ELISA are part of the defense against accidental allergic reactions in children. Future studies can help refine how ELISA detects milk proteins leading to appropriate warnings when necessary. 

The study was funded by grants from the United States Department of Agriculture AFRI Competitive Grant and the Food Allergy Research & Resource Program at the University of Nebraska-Lincoln.

The study was presented 243rd National Meeting & Exposition of the American Chemical Society's (ACS). All work presented a conference is considered preliminary until published in a peer-reviewed journal.

Reviewed by: 
Review Date: 
March 31, 2012
Last Updated:
April 1, 2012