[Detection of DNA in Highly Processed Foods]

Highly processed foods, including soy sauce, cornflakes, starch sugar, beet sugar and vegetable oil, are not currently subject to genetically modified (GM) food labeling, because DNA could not be detected in these food products. Here we re-examined the method of DNA extraction from starch syrup, beet sugar and vegetable oil using commercially available DNA extraction kits. We found that DNA was not stably detected by PCR targeting a species-specific endogenous plant gene. The reason for this may have been that the DNA yield was below the detection limit, because PCR inhibition was not observed.