5 Questions with Christy Swoboda, Technical Services Manager, Romer Labs

1. What are total protein swabs?

Total protein swabs detect proteins, peptides or amino acids remaining from foods on surfaces using a chemical reaction. They are designed to detect a broad range of protein residue, but cannot detect specific proteins such as milk, soy, peanut, etc. Total protein tests detect the absence of any protein at a higher limit of detection; typically 10-100 ppm.

2. How do allergen-specific tests differ from total protein swabs?

Allergen-specific tests use antibodies developed against specific proteins from allergenic food to detect trace residues on surfaces and rinse waters. Allergen-specific tests detect the absence of allergenic protein at a lower LOD; typically 1-10 ppm. A combination of a more general monitoring method with an allergen-specific monitoring method is often used and can be a robust method for evaluating the effectiveness of cleaning and sanitation.

3. Can a matrix itself pose an issue with allergen tests?

Matrix effects are introduced into allergen testing due to the shear variety of foods tested. They are defined as when the complex nature of the food itself causes an adverse effect on the accuracy of a test. These matrix effects are most commonly associated with lateral flow devices. Food recipes that include high-fat content, food gum or other additives, polyphenols and tannins, or a high salt ratio are examples of when a matrix effect could occur.

4. How can you overcome matrix issues?

Analytically through a custom matrix check, various tools can be implemented within the testing protocol to try and overcome these effects. Due to the numerous and varying food ingredients being tested, the fact that food recipes are customized and diverse, and that the manufacturing sites themselves are individualized, it is recommended that you talk with your test kit provider when looking to use a lateral flow device on any raw material/ingredient or finished product testing.

5. Are the available test methods sensitive enough to meet my needs?

Sensitivity is often expressed as limit of detection (LOD). The LOD is the lowest detectable level of allergenic protein and is specific to each test kit. LODs can also vary dependent upon the samples being tested due to matrix effects or even certain effects of processing. Sensitivity should be a part of your risk management and allergen control plan discussions. In the absence of regulatory limits, tools such as VITAL are available to aid manufacturers in setting internal thresholds for allergen tolerance. Allergen detection test kits are not equivalent, so understanding your sensitivity level will impact your choice.