New developments in PCR detection of food allergens

Two papers published in early 2010 have described progress in the field of PCR detection techniques for food allergens. The developments include optimised detection of plant allergens and a parasite responsible for allergic reactions following consumption of fish.

Researchers in Italy have recently described the development of a six-target real-time multiplex PCR assay targeted to genes encoding for allergenic proteins commonly present in many processed food products. The assay was successfully trialled on reconstructed food matrices and on a range of commercial foodstuffs. With a patent application for this assay currently pending, they propose it will become a ready-to-use analytical tool for food manufacturers to detect the presence or confirm the absence of sequences encoding for important allergenic proteins of plant origin.

The Anisakis simplex parasite is a significant food-borne allergen source in seafood products due to human reactions to chemicals left by the worms in fish flesh, to the extent that it was recently identified as an emerging food safety risk.

A group in Spain report the successful optimisation and validation of an Anisakis simplex-specific primer-probe system based on a real-time PCR detection assay. They have also optimised a DNA extraction procedure to detect the presence of the nematode in food samples and maintain the assay is a very reliable, specific, and sensitive methodology to detect the presence of traces of this parasite in seafood products, including highly processed samples. The limit of detection reported is 40 ppm parasite in 25 g of food sample.

Using this optimised assay, the authors report the presence of the Anisakis simplex parasite has been detected in several seafood products, and state that good manufacturing practices must be used throughout the seafood product processing industry to minimise the presence of this parasite.

Reference 1: Pafundo et al. 2010. Analytical and Bioanalytical Chemistry. Vol 396(5) pp. 1831–1839. Doi 10.1007/s00216-009-3419-z

Reference 2: Lopez and Pardo. 2010. Journal of Agricultural and Food Chemistry. Vol 58(3):1469-77