I have a great deal on this website regarding allergen testing on finished goods and swabbing. I wanted to make statement to get the ball rolling on some opinions in the industry. For allergen swabbing, based on ELISA, the allowable detection result would be under 5 ppm or 2 ppm? I have read and discussed under 5 ppm as the allowable limit for quantifying the surface "free" from allergens. Does anybody else have additional clarification or thoughts? Thank you.
Hi Arpagano,
As I understand, regarding EMP swabbing, you are asking as to -
(1) the meaning of a statement such as "free of allergen" (FOA) for a food contact surface when applying an ELISA methodology.
(2) whether a negative result from ELISA test kits claimed to have detection limits of, respectively 5 and 2 ppm can be associated with a "free from allergen" statement ?
Comments
(1) afaik, in a general allergenic context, there is no globally accepted, "standard" interpretation of the phrase, "free of allergens" (FOA). The latter is typically, operationally, associated with a definition related to the currently relevant test procedure.
(2) From a scientific POV, "FOA" is IMO not meaningful, preferably replaced by a more "numeric" equivalent.
Regarding claimed LODs, these should be validated, eg by AOAC, for example consider this (condensed) 2006 extract -
all five commercial kit manufacturers use a similar ELISA technology for the detection of allergenic residues; hence, they all share the same pitfalls. Using peanut as an example, one manufacturer claims a detection limit of 0.5 ppm peanut proteins while the other four claim detection limits ranging from 1–5 ppm peanuts. Please note, the reporting units are not equivalent. Since the LOD can vary greatly depending on food matrix interferences, extraction efficiency, specificity of antibodies and variation of peanut protein standards, proper validation is essential.
As a (more realistic?) approach (2015) -
After cleaning, allergens are expected to be present at <1 ppm i.e. the limit of detection of most commercial test kits. The contribution of allergen cross contamination from a cleaned surface into subsequent finished product itself is therefore likely to add a very small non-detectable risk in the finished product. Gross failure of cleaning or lack of cleaning would be required to make a gluten-free product non-compliant (see example Appendix 3).
Specific detection methods alone give partial information about overall safety and risk, and should be used as a balanced analytical approach. There are several methods for specific allergens of which immunological methods e.g. quantitative plate ELISA tests and qualitative lateral flow tests (LFT) in dipstick formats are the most commonly used. However, the relatively high cost is often an impediment to their widespread adoption. Plate ELISA tests are more sensitive (typically <0.1 ppm) but require a skilled analyst. LFTs are more convenient and have a limit of detection of 1 – 10 ppm but their performance can be variable.
Hygiena Allergen White Paper.pdf 687.8KB
47 downloads
PS- maybe some of the validated ELISA limits are lower now ?
PPS - VITAL's approach attempts to explicitly implement threshold values but so far has had very limited official acceptance, eg -
VITAL-a-threshold-approach-to-allergen-labelling.pdf 515.5KB
44 downloads
P3S - JFI here is a comparison (2012) of some reported LOAEL vs LOD values -
LOAEL vs LOD.PNG 27.29KB
5 downloads
Processing Considerations of Allergenic Food Ingredients.pdf 744.01KB
39 downloads
