LAUSR

To improve genetically modified product labelling legislation and promote the development of genetically modified foods, the mass variations of genomic DNA and length distributions of DNA fragments in non-genetically and genetically modified soybean (Roundup Ready) and the variations in transgenic contents during soybean protein concentrate (SPC) and soybean protein isolate (SPI) preparation were monitored. The material masses throughout the process conformed to the law of mass conservation, and amounts of DNA recovered decreased with SPC and SPI preparation. The successive steps of ethanol extraction led to a decrease in the size distribution of the recovered DNA. For the LECTIN and CP4 EPSPS targets investigated, longer fragments (>800 bp) were more affected than smaller fragments (<200 bp), and both targets degraded slowly upon degradation into small fragments. DNA distribution and degradation thereby affected GMO quantification. After preparation procedures, the transgenic contents of SPC and SPI products were higher than that of raw soybean.