Detection of peanut (Arachis hypogaea) allergen by Real-time PCR method with internal amplification control

• Published in: Food chemistry 2015-05, Vol.174, p.547-552
• Main Authors: Zhang, Wen-Ju, Cai, Qin, Guan, Xiao, Chen, Qin
• Format: Article
• Language: English
• Subjects: Allergen; Allergens - immunology; Antigens, Plant - immunology; Ara h 1; Arachis - immunology; Arachis hypogaea; Glycoproteins - immunology; Humans; Internal amplification control (IAC); Peanut (Arachis hypogaea); Plant Proteins - immunology; Real-time PCR; Real-Time Polymerase Chain Reaction - methods
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.11.091

•We establish a PCR method with IAC for detecting peanut in foods.•We optimise the IAC concentration and make the limit of detection not influenced.•The method can indicate the “false-negative phenomenon” in the experiment.•The method can be applied into universal detection of food allergens. Specific primer sets were designed based on the DNA sequence of Ara h 1, one of the major peanut (Arachis hypogaea) allergens, and a competitive internal amplification control (IAC) was designed by compound primer technology. By choosing 314copies/PCR as the IAC dosage, a Real-time PCR method with IAC was established for detecting peanut allergen Ara h 1 DNA. The method showed high specificity with a detection limit of 0.005% peanut. A series of commercial food products with/without peanut components were tested. Among these products, the peanut allergen Ara h 1 DNA could be detected in 12 products labelled containing peanut ingredients, in two without a declaration of peanut and one labelled that was produced in a facility that produced peanut-containing foods. This indicates that the method is highly sensitive for the detection of peanut ingredients in foods.