Validation of Food Allergen Lateral-Flow Devices in the Presence of Hygiene Chemicals

Introduction: A principle cause for food recalls in the US is the presence of undeclared food allergens. One common reason for these recalls is allergen cross-contact that occurs during manufacturing. Allergen control measures, such as cleaning, can help prevent or minimize cross-contact, but rely on the use of rapid screening methods to verify that cleaning was effective. Lateral Flow Devices (LFDs) are ideally suited for rapid, qualitative screening of environmental surfaces to verify cleaning efficacy. However, LFD function can be inhibited by various factors including residual cleaning agents.

Purpose: To validate the sensitivity of the ELISA SYSTEMS (ES) AlllergenControl™ Total Milk and Egg LFDs in the presence of 3 common cleaning agents commonly used in the food industry.

Methods: The effects of cleaning chemicals on the ES LFD kits were determined using BioSide HS 15% (Enviro Tech Chemical Services, Inc. Modesto, CA), Power 99 Plus Degreaser (Morgan Gallacher Inc. Santa Fe Springs, CA), and Blend Foam Cleaner (Univar Inc., Redmond, WA). Each of these was diluted in water to reach the concentration levels chosen to be grossly higher than those expected from normal carry-over based on the application directions for each. 100 µL of each prep was mixed with 900 µL of LFD extraction buffer containing NFSM or egg white protein (EWP) at either 1.1X or  2.1X the reported kit limit of detection (LOD). 100 µL of this mixture was applied to the sample port of the LFD. Line intensity values were measured using a Qiagen ESE reader at 15 min, and the averages and StDv (parenthetically) for the sandwich test line results are reported for triplicate tests.

Results: The Total Milk LFD kit demonstrated an analytical limit of detection (LOD) of 0.02 ppm milk protein at the highest concentrations of sanitizer tested (200-1,000 ppm). The Egg LFD kit demonstrated an LOD of 0.1 ppm EWP at the highest concentration of each sanitizer tested (200-1,000 ppm).

Significance: The application of a highly sensitive and rapid test method capable of detecting trace amounts of allergens in the context of residual hygiene chemicals (even if inadequately removed) will aid food manufacturers and regulatory agencies in monitoring for allergen residues present on environmental surfaces and improve existing allergen control measures.