Screening for Genetically Modified Maize in Raw and Processed Foods Sold Commercially in Southern Nigeria Boarder States

Abstract

Genetically Modified (GM) foods hold the key to ending hunger and malnutrition in Africa. Due to the increasing number of GMOs cultivation and delay in the approval of biosafety law in Nigeria, it has become necessary to screen maize products in order to determine the identity of the consumed daily foodstuffs. In this study, DNA extraction from raw and processed maize foods sold commercially in Sourthen Nigeria was carried out using the cetyltrimethylammonium bromide (CTAB) method, followed by qualitative PCR to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CAMV35S, nopaline synthase (NOS) terminator, Bt-176 and NK603 genes separately. Certified reference materials were used as positive controls while 2008-DTMA-W-STR Federal University of Agriculture Abeokuta (FUNAAB) organic maize grains and absence of template DNA, served as negative control. Based on the gel electrophoresis results, Bt- 176 maize event for insect resistance was detected in two samples, with 420 bp and, the NK603 Maize event for herbicide tolerance was detected in 3 samples, with 320 bp fragments. The GM-positive samples were found in 4 imported raw maize samples, 4 cereal food brands (2 manufactured in Nigeria, 2 imported) and 3 imported canned corn brands. The results confirm that Nigerians are already consuming GM maize, despite the absence of a biosafety law.