Moving Forward After a Positive Allergen Residue Result

Test results can help to identify the root cause of the undeclared allergen. If multiple samples of a product are tested from one, or preferably, several manufacturing runs, and all of these test samples are positive with reasonably consistent levels, the root cause is probably an ingredient. Ingredients are added to every batch of a product at consistent levels, and a contaminated ingredient will lead to consistent levels of allergen in multiple samples of the final product. Rework can also lead to multiple positive samples, but rework is not often consistently used at the same levels from one run to another, so analysis across several manufacturing runs will reveal differences. Sporadic but higher-level positives throughout one or more manufacturing runs can point to a contaminated particulate ingredient. The particles of the allergen may not show up in every sample. If inadequate cleaning is the basis for the undeclared allergen, then samples from the beginning of the run after changeover will be more positive than samples taken later in the run. Furthermore, unless the cleaning is uniformly inadequate, samples from a separate manufacturing run will not be positive.

Saving retain samples from each manufacturing run of each product can be a lifesaver in situations where unexpected analytical results appear. Then, it is possible to trace allergen levels through multiple manufacturing runs and dates. Additionally, saving retain samples of each lot of each ingredient can be very helpful in root cause investigations. Ideally, retain samples are collected from several points throughout the lot of production such as the beginning, middle, and end of the product run.

Hopefully, you will now be well prepared for the occasional unexpected positive test result obtained from your selected external laboratory. Ask the right questions. Gather all of the appropriate information. If you want to call FARRP experts, we are available at any stage of the investigational process. Following the strategy outlined in this article can save you from anxiety and headaches.

Knowledge is power.

Dr. Taylor is professor emerita of food science and technology and co-founder and co-director of the Food Allergy Research and Resource Program (FARRP) at the University of Nebraska-Lincoln. Reach him at [email protected]. Dr. Jayasena is a post-doctoral and senior researcher at FARRP. Niemann, Lambrecht, and Kraft are lab managers at FARRP. Reach them at [email protected], [email protected], and [email protected]. Dr. Baumert is associate professor in the department of food science and technology at the University of Nebraska-Lincoln and co-director of FARRP. Reach him at [email protected].