Rapid on-site testing kits, an allergen management tool
These days, allergen management is a standard requirement for a food safety management system. The South African food industry has been honing its skills since 2010, when the labelling and control of eight common food allergens become mandatory.
Notably, on the international front there has been a steady accumulation of data, which culminated in the publication of the FAO/WHO ad hoc expert committee’s recommendations on allergen thresholds and precautionary labelling, and ILSI Europe’s Practical Guidance on the Application of Food Allergen Quantitative Risk Assessment within Food Operations.
Of course, these publications are not the last word on the subject; research is ongoing into food allergies, treatment options, threshold levels and techniques for testing for the presence of food allergens.
What is required of the food industry?
In terms of allergen control, the food industry’s responsibilities are well described in the regulations, food safety standards and retailer guidelines. In recent years the GFSI-benchmarked food safety standards have increasingly emphasised the importance of allergen management; which highlights the need for manufacturers to validate, verify and monitor robust allergen controls, to show due diligence.
Validation vs Verification
Allergen validation and verification are two very distinct and different processes; both are required to prove effective control. Allergen Control Validation entails proving that a control programme is effective – for example, allergen cleaning validation. It often involves submitting samples to a reputable and accredited laboratory. The methods used (LC-MS/MS, ELISA and PCR) can detect – and in the case of LC-MS/MS and ELISA, quantify – allergen residues in a large range of complex sample matrices.
Laboratory-based methods are often the first choice for validation, because they are sensitive; and it’s possible to compensate for known sample matrix effects, by employing sophisticated sample-preparation and analyte-extraction techniques. However, these methods are expensive to run and must be performed by skilled analysts using specialised equipment.
Allergen Control Verification shows that the validated control was performed correctly – for example, cleaning verification. Ideally, it should be done on site; due to the associated financial and time constraints, laboratory-based methods are not always ideal for verification. Rapid on-site testing kits fill this gap. They are easy to use, portable, and suitably sensitive. Results can be generated in minutes, at relatively low input cost, with little or no technical expertise and equipment required, making these systems ideal for the task.
Several rapid systems have gained popularity in recent years. Three in particular are well represented in the food industry.
An increasing number of manufacturers are now promoting their LFDs to be used to screen products. But food matrices are notoriously complex; when testing materials, whether ingredients or finished products, it is strongly recommended that you confirm that the kit manufacturer validated the system for the specific material that you want to test. If not, an independent matrix check will be necessary. Food products or ingredients may contain components that interfere with the LFD, resulting in false positives or negatives. A matrix check normally involves testing a series of spiked samples to determine whether the LFD yields expected results in the correct range.
Adenosine Triphosphate (ATP) Swabs: This system does not measure food-allergenic residues directly, but detects the presence of adenosine triphosphate on surfaces and in rinse water. It is generally used for hygiene monitoring. Because the system detects ATP in microorganisms and food soils, it is not specific to allergens; and the correlation between allergenic residue and ATP results is not well studied.
During allergen validation – besides proving that the cleaning protocol will remove all allergenic residue, in the case of allergen cleaning – it is also important to determine (a) how the allergen control will be verified; (b) when and by whom it will be verified; and (c) which system will be used, with proof that the system is adequate for the specific set of circumstances.
Validating the adequacy of the intended verification system is essential. It can be done, for example, by comparing rapid kit and LC-MS/MS, ELISA or PCR results for the same or similar samples. If the two sets of results coincide, it shows that the verification system is adequate and that it can be used with confidence.
Although it is unlikely that rapid methods will ever replace laboratory-based methods – at least, not in the immediate future – the technological advances in both sectors are very exciting. Rapid on-site kits are becoming increasingly sophisticated; but as yet, there is no ‘one size fits all’ option. So, choose wisely.
View our rapid on-site testing kit catalogue, and contact us to help you decide which system to choose.
To view the full reference list of this article, please contact us.
Other articles, resources and videos you may be interested in:
South Africa’s regulated common allergens
Codex Expert panel recommendations on food allergen labelling
Allergen Cleaning Validation and Verification
Comparing test methods: PCR, ELISA & Targeted Proteomics by LC-MS/MS
WEBINAR | Rapid kits: On-site solution for food allergen detection
Episode 4: Allergen Cleaning Validation and Verification
Episode 5: Available Allergen Testing Methods
Episode 6: Allergen-Specific Lateral Flow Devices
Episode 7: Total Protein Indicators