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From: Food Quality & Safety magazine, August/September 2005

GMO Traceability–Making it Work

Testing is not enough to detect GMO contamination in food ingredients

by Anne Sasso, PhD

Mad cow disease hit the news again in June, fueling consumer fears about the safety of the food supply chain. Also, a recent report revealed that over a four-year period Swiss biotech firm Syngenta AG sold U.S. farmers an unapproved strain of genetically modified corn seed, which may have entered the food supply and international channels. These two incidents reveal how porous the U.S. agricultural supply system is to contamination. They also highlight the need for robust traceability technologies that enable food manufacturers to quickly and efficiently respond to potential contamination issues within their supply chain.

To detect GMO contamination in food ingredients, testing alone is not enough. Testing of GMOs in refined ingredients is unreliable and can result in both false positives and negatives – the more highly refined the product, the more uncertain the test results. The best way to ensure the integrity of a non-GMO supply chain is to implement a reliable traceability system that follows an ingredient from field to fork.

To better evaluate the reliability of their suppliers, savvy food manufacturers need to arm themselves with a broad understanding of all the steps involved in ensuring the integrity of non-GM products. Only by knowing what questions to ask can food manufacturers be sure that they are truly sourcing non-GM ingredients. National Starch Food Innovation, a producer of non-GM ingredients, has obtained a third party certification of their traceability program. An overview of their procedures reveals the complexity involved in designing and administering a reliable system that meets international standards – and gives you a measuring stick with which to evaluate your suppliers.

Growing and Handling Requirements

To control its supply chain and assure that the grain it buys is the variety and quality it needs, National Starch contracts directly with farmers to grow its corn. Farmers are required to adhere to a long list of procedures relating to seed selection, planting, segregation, equipment cleaning, handling, transport, documentation and reporting, all of which are all part of the company’s TRUETRACE program.

Because the quality of the end product is only as pure as the seed it comes from, farmers are required to purchase only non-GMO varieties of seed from companies that warrant the purity of their seeds. They are subject to later verification of their seed purchase records and bag labels.

To avoid contamination from volunteer plants from the previous season, farmers must demonstrate that the fields planted with TRUETRACE corn were not planted with GM corn the year before. Non-GM corn must be sown in acreage that is segregated from other varieties to successfully reduce contamination due to cross-pollination during growing. To do this farmers use several methods, including isolation and the planting of buffer crops. Farmers must record the locations of the fields growing TRUETRACE corn and document all crops growing in neighboring fields. At harvest, they are required to remove border rows from the non-GM corn field if they have GM corn planted within 660 feet of the non-GM field. National Starch provides guidelines for the removal of border rows based on distance between GM and non-GM fields.

Throughout planting, harvesting, storage and transportation, the farmers must clean their equipment in such a way that there is no remaining GM material – corn, soybeans or anything else – on or in the equipment, which may contaminate the non-GM crop. The dates of all equipment cleaning are recorded.

Farmers are also required to keep training records. Anybody, other than the contract grower, who handles the crop in any way – from hired help at planting to contract harvesters to the truck driver who delivers the crop to market – must be trained in the TRUETRACE procedures.


While all these steps are critical to a successful traceability program, the real power of TRUETRACE lies in an innovative information technology system devised by National Starch. Twice a year, once after planting and again after harvesting, farmers input information about seed quality, cleaning of equipment, training of third parties, field maps, what’s planted around their fields, how many border rows were planted and then excluded from harvesting, along with a range of other information into a user-friendly interface on the National Starch extranet.

National Starch uses the Web site to communicate on issues relating to crop conditions, delivery scheduling and pricing. The site also offers useful information on weather and agronomy, along with links to companies that sell seeds and agricultural chemicals. While the website is designed to be a destination for the farmers participating in the TRUETRACE program, the value to National Starch lies in the ability to track its corn on both aggregate and farmer-specific levels.

“The Web site really allows us a detailed level of control over our supply chain that is absent in the rest of the industry,” says Joe Emling, manager of grain quality and traceability at National Starch Food Innovation. “We can very quickly track any events that might compromise our corn and implement the steps needed to rapidly contain a situation. For example, if we learned after planting that a particular seed lot had inadvertent GM contamination; we could quickly track it in the field. With our system, we know very specifically where our crops are planted, and we know what variety and seed lot is planted in what field. We could quickly respond to the incident, alert the growers affected and take whatever steps were necessary to safeguard the integrity of our corn.”

Testing and Manufacturing

Once the crop arrives at National’s facilities, it enters a new stream of testing and segregation to further ensure quality and purity. All deliveries are scheduled and are identified with a unique tag number that is traceable back to the farmer. Before accepting a grain shipment, National tests every truckload and refuses shipments that do not meet its standards.

Shipments undergo routine industry tests for quality factors. Beyond that, National tests for variety purity, using waxy purity tests for waxy corn, amylase purity tests for amylase corn. The company also tests non-GM regular corn to make sure that it is not contaminated with waxy or amylase corn.

Finally, every truckload is tested for contamination with GM materials. They use an ELISA-based strip test and covers all GM events that are commercialized in the U.S.

Once the shipment is accepted, it’s unloaded and conveyed to storage bins. National’s internal plant procedures maintain traceability and segregation of corn types through the unloading process, into the bins and then into the steep tanks as they begin the manufacturing process.

In addition, National regularly collects composite grain samples that are sent out for PCR testing as an internal process check. “The strip test (ELISA) is like a gatekeeper, it allows us to accept or reject a shipment as it is delivered to our facilities,” says Emling. “The composite PCR testing is used internally as a check on our systems. It’s to make sure that all of the traceability and documentation requirements, all of the care, management and handling of the crop that we require of our contract growers, along with the strip test, are working as we intend them to work. It acts as a sentinel – if we see a problem, it alerts us that some component is off and we can trace it down and address any potential for contamination along the supply chain.”


Built into the whole process is a system of accountability. Farmers are audited regularly to ensure that they comply with all the procedures required of the TRUETRACE program. To further assure product quality, National Starch routinely submits to audits as part of the requirement for certification of its non-GM products. “Non-GMO supply chain certification is relatively new. We are among the first in our industry to have our program certified by an independent auditor,” says Emling.

Certification ensures that National Starch’s supply chain is non-GM and that its products meet or exceed rigorous non-GM quality standards. In addition, by choosing to comply with the British Retail Consortium/Food and Drinks Federal Technical Standard for the Supply of Non-Genetically Modified Food Ingredients and Products, National Starch ensures that its products will meet labeling requirements in Europe and will be acceptable to many of the international markets with strict GM tolerance limits.

“We can sell our starch anywhere in the world, and it can be traced all the way back to the American farmers and the seed they planted,” says Emling. While ensuring traceability of a non-GM supply chain may seem like an involved and costly process, he adds that it is an effective way to assure quality.

“If nothing else, it assures the customer that we have in-depth control over our supply chain,” Emling says.

Anne Sasso, PhD., is a freelance science writer based in New Jersey. Reach her at



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