Improved allergen detection in chocolate with extra step, say researchers

22-Nov-2012 - Last updated on 22-Nov-2012 at 12:24 GMT

Around 2% of the global population are affected by food allergies, according to studies. Photo credit: Flickr - bloomsberries

Nut traces can be better detected in dark chocolate and biscuits by adding a clean-up step, say Italian researchers.

A study by Bignardi et al., published in the journal Food Analytical Methods said that adding size-exclusion sample treatment before the detection method, known as liquid chromatography–electrospray ionization-tandem mass spectrometry (LC-ESI-MS), was fast and could improve consumer safety for those with nut allergies,

Complex chocolate matrix

“Chocolate is one of the most challenging food matrices,” said the study.

“Dark chocolate contains a large amount of polyphenolic compounds which can react with food proteins, thus masking the target proteins under investigation,” it said.

The researchers added that existing tests kits, such as enzyme-linked immunosorbent assay (ELISA), failed to give full measures.

Improved quality control for chocolatiers

They said that an added size-exclusion sample treatment could enhance the sensitivity of detection come the analysis stage, making chocolate safer for consumers.

“This method could be proposed for strict allergen quality controls of both the final products and the production lines for food manufacturers in order to protect consumer health and safety,” said the researchers.

The method was tested for commercially available biscuits and chocolate.

Hygienic technologies are among the confectionery industry's leading concerns at present. Hygenic design is a featured theme at next year's ProSweets tradefair in Cologne, Germany.

Study:

Food Anal. Methods
DOI 10.1007/s12161-012-9521-4
‘A Rapid Size-Exclusion Solid-Phase Extraction Step for Enhanced Sensitivity in Multi-Allergen Determination in Dark Chocolate and Biscuits by Liquid Chromatography–Tandem Mass Spectrometry’
Authors: Chiara Bignardi, Monica Mattarozzi, Andrea Penna, Simone Sidoli, Lisa Elviri, Maria Careri and Alessandro Mangia

Sampling errors render testing useless

Posted by Mike Pusey, 27 November 2012 - 09:16 GMT

Because of the extremely low levels of allergen required to promote allergic reaction and the fact that accidental contamination of chocolate with nuts is most likely to be stratified, following the negative binomial or pehaps Weibul distribution, it is impractical to obtain a representative sample. The vast majority of samples taken will not contain any detectable allergen whereas a small quantity of product can contain lethal levels. Prevention of contamination is the only safe way; reliance on sampling/analysis a very high risk strategy.

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