Detection of allergen coding sequences of kiwi, peach, and apple in processed food by qPCR

BACKGROUND: Food traceability becomes lifesaving for persons suffering severe allergy or intolerance, and therefore need a complete avoidance of the immune-trigger food. This paper describes how to fingerprint the presence of some allergenic species (kiwi, peach, and apple) in foods by quantitative Real-Time PCR (qPCR). RESULTS: Five DNA extraction procedures were tested on fruits and foods. The results were statistically evaluated, and discussed. Analysis by qPCR with SYBR Green was developed to detect traces of these allergenic species in foods. Plasmids containing the target sequences of kiwi, peach and apple were employed as Internal Reference Standard. Analysis of spiked food samples showed a Limit of Detection of 25 mg kg-1 for kiwi, 20 mg kg-1 for peach and 50 mg kg-1 for apple. CONCLUSION: The qPCR method here developed, combined with the use of Internal Plasmid Reference Standard, represent a specific system for the quick detection of allergenic species in complex food matrices, with a Limit of Detection comparable with those reported using more timeconsuming methods.