Developing a Rapid DNA-based Method for Detecting Soy Content in Foods

Abstract

Food allergies are serious problem affecting more and more people, estimated that 1-2% of the population worldwide. In most cases, it requires a strict diet, which means that allergenic components should be eliminated from the diet. Soy contains several allergenic proteins that decrease the positive health effects of soy and cause potential allergenic symptoms in susceptible individuals. Accordance with the rules on the labelling of foodstuffs, due to the general labelling requirements for allergens, the presence of soy must be indicated on the labels of products containing soy, and the exemption must be checked regularly. In the frame of our research, our goal was to develop a fast, specific and highly sensitive test method to detect soy content. Firstly, we adapted and compared two DNA-based simple PCR methods by the means of using two different primer pairs (chloroplast AtpA gene-specific and LecI gene-specific) to detect DNA of Pannonia kincse, a Hungarian soybean variety. We found that AtpA-gene-specific primers were more effective/sensitive. Secondly a lateral flow soyDNA test was developed based on the selected chloroplast AtpA primerpair, recombinase polymerase amplification. We successfully confirmed the proper operation of the developed soy-specific DNA test by examining meat products with or without soy component. We could conclude that this developed test can be easily performed in situ, at any field (in non-laboratory conditions as shops, industry or restaurant), does not require complicated technical background and gives results already after 30-45 minutes. So this special qualitative test can be called as Field test.