‘Window of opportunity’ before allergen thresholds

By Joseph James Whitworth

- Last updated on GMT

Egg is a common food allergen
Egg is a common food allergen

Related tags Global food safety Food standards agency Immune system

There is a ‘window of opportunity’ for the analytical community to get its house in order before allergen thresholds come in, according to an analyst for the Government Chemist.

Michael Walker, consultant science manager and referee analyst for the Government Chemist, said industry could be held up to ridicule later if they are not able to measure consistently and accurately so it should contribute to the solution rather than become the problem.

In a presentation during the Global Food Safety in Madrid, Jürgen Schlösser, executive manager R&D international at Dr Oetker, cited a Food Standards Agency (FSA) inter-laboratory comparison to show differing test results.

In 22 labs in 10 countries, with 16 different ELISA kits (5 for egg, 5 for casein and 6 for milk protein) and levels of 3,6,15 and 30ppm milk and egg in dessert matrix, only one kit found 3ppm egg and only one found 6 and 15ppm casein.  

The firm conducted its own comparison by preparing powdered desserts with milk powder, wheat flour and grinded hazelnut and pizza with mustard and egg powder and having them sampled at four labs in Western Europe – all the labs reported different results for the samples.

No current limits

In Europe there are no reference methods or reference sample for each food matrix.

Switzerland does have a 1,000ppm limit and while Walker applauded the step to have thresholds, they wouldn’t be protective to adopt across the board.

“There needs to be a dialogue between industry, clinicians and the patient community and limits must not be imposed for the advantage of the food industry,” ​he told FoodQualityNews.com.

“Then precautionary labelling would be reduced to where it is essential to safeguard and not just a cover all. Thresholds need to be aligned to what triggers the problem.

“There are reference doses that appear to be protective of 95% of the allergic community but there are a lot of reference materials and there must be equivalence across the globe.

“When thresholds come they must be right and universally accepted and we need traceable methods so lab results are comparable before this happens.” 

Walker said risk assessments are key for the food industry and the concept of threshold limits for heavy metals and residues is a good thing as people can be alerted through labelling

However, there is not enough known about reference doses that lead to problems, he added, citing a scientific opinion of the European Food Safety Authority (EFSA​).

Allergens and analysis

The 14 allergens as listed in the EU regulations are: cereals containing gluten, crustaceans, molluscs, eggs, fish, peanuts, nuts, soya, milk, celery, mustard, sesame, lupin and sulphur dioxide (at a level above 10mg/kg or 10mg/litre).

Responding to the EFSA opinion, the Government Chemist said flawed allergen analysis hinders detection and measurement of allergens​.

ELISA exhibits variable and manufacturer-specific sensitivities and cross-reactivity.

Structural changes by food processing or sample extraction may prevent detection by Enzyme Linked Immunosorbent Assay (ELISA) or Liquid Chromatography-Mass Spectrometry (LC-MS) and polymerase chain reaction (PCR) identifies the source species not the allergen protein.

Allergen research

Walker said analytically it is currently a struggle as two different labs are using different methods to get limit of detection (LOD) and limit of quantification (LOQ).

He added there is a lot of research on whether early exposure or avoidance pre-disposes someone to become food allergic. 

“We know why allergies happen – they gain access to the immune system mostly through the gut or breathing and also through broken skin,” ​he said.

“When that happens in most people there is not a problem but in people genetically pre-disposed they have an abnormal response. 

“We are all eating new foods, 30 years ago no-one ate kiwi fruits but now we have seen kiwi allergy on the rise and it is not one of the regulated allergens.

“In evolutionary terms the immune system we have is set up for parasites and through hygiene advances that is less of a threat so there is a gap in what it has to do.” ​ 

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