26.10.2015
BfR publishes study on peanut cross-contacts in packaged products based on ifp’s test kits
A team of researchers at the Federal Institute for Risk Assessment (BfR) and the French Agency for Food, Environmental and Occupational Health Safety (ANSES) has published the results of a study on peanut traces in packaged products1. The analytical methods used also included a lateral flow rapid test and ELISA developed by ifp.
Tests for traces of peanut
A total of 899 food samples, the labelling of which specified no peanut, were analysed within the context of the French research project MIRABEL. The samples covered a broad product range from ten different food categories. In a step-by-step procedure, the samples were first screened with a lateral flow test developed by ifp (ImmunoFast® / AgraStrip®Peanut, distributed by Romer Labs).
Comparison of different detection methods
Samples that were unanimously positive or suspect were subjected to a confirmation test using real-time PCR. Traces of peanut could be detected with both methods in nine samples. These were finally quantified by means of two different peanut-ELISAs, among them AgraQuant® Plus (formerly AgraQuant® F.A.S.T.) Peanut, which is also from ifp and distributed by Romer labs.
The detected concentrations ranged between 0.7and 17.9 ppm. Compared with the two ELISA kits, AgraQuant® Plus proved to be more sensitive than the competition’s kit: the latter produced a result below the detection limit for three of the nine samples that had showed positive results with the lateral flow test, PCR and AgraQuant®Plus.
Trace labelling on the products tested
Seven of the nine positive products had correctly been labelled with "may contain traces of peanut". Merely two of the positive products (cashew nuts, chocolate spread) failed to specify the correct labelling. Furthermore, it is interesting that peanut trace labelling was found on 266 of the 899 products, of which only 2.6% however were tested positively in the step-by-step screening and confirmation procedure applied.
Conclusion
The BfR confirms that the rapid test is simple to perform as well as economic with regards to time to result and costs. Reference material that is included as a daily control is reliably detectable. The study shows that combining the different methods allows for the detection of 2 mg/kg peanut in a variety of products.
1 Zagon et al. (2015): Peanut traces in packaged food products consumed by allergic individuals: results of the MIRABEL project. Journal of Food Composition and Analysis 44 (2015) 196–204
The full article can be purchased at http://www.sciencedirect.com/science/article/pii/S0889157515001726.