detection of unlabeled genetically modified soybean in the omani market

This study aimed to screen for products containing Genetically Modified (GM) food in the Omani market using detection methods for the presence of Roundup Ready Soybean, Bt176 and MON810 maize in food products and to quantify it in positive samples using real time Polymerase Chain Reaction (PCR). A total of 100 food samples were collected randomly from markets in Oman. Out of 59 samples, 8  (13.5%) were successfully amplified with the maize plant specific PCR. GM screening showed negative for all samples, which indicated low or no GM maize in the samples tested. Out of 57 soy containing samples, 40 (70%) were successfully amplified by the soybean plant specific PCR. Six samples out of the 40 (15%) were found positive for GM using P35S-cf3/P35S-cr4 and HA-nos118-f/HA-nos118-r, primer pairs and using GMO5/GMO9 and GMO7/GMO8 primer pairs for specific detection of Roundup Ready Soybean. Real time PCR (TaqMan™ system) was carried out for the positive Roundup Ready Soybean samples and results showed that 2 out of the positive GM soy samples contained more than 5%; a Soy Formula for Infants (imported) sample contained 21% GM soybean and raw soybean seeds (imported in bulk amounts and packed in Oman)  contained 88% GM soybean. The results demonstrate for the first time the presence of GM-soy in food products in the Omani market, reinforcing the need for the use of qualitative and quantitative methods for GM detection in food products.