Monitoring the prevalence of genetically modified maize in commercial animal feeds and food products in Turkey

BACKGROUND

EU legislation strictly controls use of genetically modified (GM) crops in food and feed products, and requires them to be labelled if the total GM content is greater than 9 g kg(-1) (for approved GM crops). We screened maize-containing food and feed products from Turkey to assess the prevalence of GM material.

RESULTS

With this aim, 83 food and feed products - none labelled as containing GM material - were screened using multiplex real-time polymerase chain reaction (PCR) for four common GM elements (35S/NOS/bar/FMV). Of these, 18.2% of feeds and 6% of food samples tested positive for one or more of these elements, and were subjected to event-specific PCR to identify which GM organisms they contained. Most samples were negative for the approved GM events tested, suggesting that they may contain adventitious GM contaminants. One sample was shown to contain an unapproved GM event (MON810, along with GA21) at a concentration well above the statutory labelling requirement.

CONCLUSION

Current legislation has restricted the penetration of GM maize into the Turkish food industry but not eliminated it, and the proliferation of different GM events is making monitoring increasingly complex. Our results indicate that labelling requirements are not being followed in some cases. © 2015 Society of Chemical Industry.

Assessment of a direct hybridization microarray strategy for comprehensive monitoring of genetically modified organisms (GMOs)

Detection of GMO material in crop and food samples is the primary step in GMO monitoring and regulation, with the increasing number of GM events in the world market requiring detection solutions with high multiplexing capacity. In this study, we test the suitability of a high-density oligonucleotide microarray platform for direct, quantitative detection of GMOs found in the Turkish feed market. We tested 1830 different 60nt probes designed to cover the GM cassettes from 12 different GM cultivars (3 soya, 9 maize), as well as plant species-specific and contamination controls, and developed a data analysis method aiming to provide maximum throughput and sensitivity. The system was able specifically to identify each cultivar, and in 10/12 cases was sensitive enough to detect GMO DNA at concentrations of ⩽1%. These GMOs could also be quantified using the microarray, as their fluorescence signals increased linearly with GMO concentration.

Evalution of DNA extraction methods in order to monitor genetically modified materials in soy foodstuffs and feeds commercialised in Turkey by multiplex real-time PCR

BACKGROUND

Soybean is one of the most important biotech crops, widely used as an ingredient in both foodstuffs and feed. DNA extraction methods have been evaluated to detect the presence of genetically modified (GM) materials in soya-containing food and feed products commercialised in Turkey.

RESULTS

All extraction methods performed well for the majority of soya foods and feed products analysed. However, the most successful method varied between different products; the Foodproof, Genespin and the cetyltrimethylammonium bromide (CTAB) methods each produced the highest DNA yield and purity for different soya foodstuffs and feeds. Of the samples tested, 20% were positive for the presence of at least two GM elements (35S/NOS) while 11% contained an additional GM element (35S/NOS/FMV). Of the tested products, animal feeds showed a larger prevalence of GM material (50%) than the soya-containing foodstuffs (13%).

CONCLUSION

The best performing extraction methods proved to be the Foodproof, Genespin and CTAB methods for soya-containing food and feed products. The results obtained herein clearly demonstrate the presence of GM soybean in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of soy-containing food and feed products.

DNA extraction techniques compared for accurate detection of genetically modified organisms (GMOs) in maize food and feed products

In this paper, DNA extraction methods have been evaluated to detect the presence of genetically modified organisms (GMOs) in maize food and feed products commercialised in Turkey. All the extraction methods tested performed well for the majority of maize foods and feed products analysed. However, the highest DNA content was achieved by the Wizard, Genespin or the CTAB method, all of which produced optimal DNA yield and purity for different maize food and feed products. The samples were then screened for the presence of GM elements, along with certified reference materials. Of the food and feed samples, 8 % tested positive for the presence of one GM element (NOS terminator), of which half (4 % of the total) also contained a second element (the Cauliflower Mosaic Virus 35S promoter). The results obtained herein clearly demonstrate the presence of GM maize in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of maize food and feed products.