Detection of genetically modified soy (Roundup-Ready (TM) Soy) in processed foods

In this study, the application of a qualitative and a quantitative method o f analysis to detect genetically modified RR-Soy (Roundup-Ready(TM) Soy) in processed foods is described. A total of 179 various products containing s oy such as baby food and diet products, soy drinks and desserts, tofu and t ofu products, soy based meat substitutes, soy protein, breads, flour, granu les, cereals, noodles, soy bean sprouts, fats and oils as well as condiment s were investigated following the pattern of the 35 LMBG-method L 23.01.22- 1. The DNP; was extracted from the samples and analysed using a soybean spe cific lectin gene PCR as well as a PCR, specific for the genetic modificati on. Additional, by means of PCR in combination with fluorescence-detection (TaqMan(R) 5'-Nuclease Assay), suspicious samples were subjected to a real- time quantification of the percentage of genetically modified RR-Soy. The m ethods of analysis proved to be extremely sensitive and specific in regard to the food groups checked. The fats and oils, as well as the condiments we re the exceptions in which amplifiable soy DNA could not be detected. The g enetic modification of RR-Soy was detected in 34 samples. Eight of these sa mples contained more than 1% of RR-Soy. It is necessary to determine the pe rcentage of transgenic soy in order to assess whether genetically modified ingredients were deliberately added, or whether they were caused by technic ally unavoidable contamination (for example during transportation and proce ssing).