Case Study: High-Sensitivity Testing for Enogen Corn
What is Enogen corn?
Enogen® corn is a Genetically Modified (GMO) variety of corn that is marketed to the Ethanol and Cattle Feed manufacturing industries, which account for 90% of US domestic corn use . Its special trait enables it to produce within the corn kernel a high amount of alpha-amylase, an enzyme that breaks down corn starch to sugar. The alpha-amylase enzyme saves cost and energy of converting corn starch to alcohol in the ethanol industry, and is claimed to improve digestibility of cattle feed in cows . Enogen corn adoption has grown rapidly across United States. e.g in North Dakota, refiners have been looking to secure up to 16 million bushels of the Enogen corn, about 4% of the state’s total annual production., while adoption in the cattle feed segment has accelerated dramatically since introduction.
Below is a map of Enogen farm locations published by 3rd party at the address https://ip360.agconnections.com/. The maps shows that Enogen farms are spread practically in every corn growing region in the US in high numbers- (click on image to expand)
Impact on Corn Food Product Quality
You may have experienced this for yourself- if you chew on a piece of tortilla or bread for a bit longer, it will start tasting sweeter. This is because as the alpha amylase enzyme in your saliva starts converting the starch content to sugar as part of the digestion process in your mouth. A similar action in the presence of the alpha amylase enzyme in Enogen corn is known to create product quality issues like crumbly chips, soggy cereal, and non-forming dough. The enzyme produced by the corn is also designed to be heat-resistant and works optimally at temperatures at which the corn is cooked. As one of our largest customer recounts, the nixtamalization process is especially sensitive to it, causing masa flour batch quality incidents or severely impacting Tortilla products. They also reported that cornbread made using this enzyme containing corn flour, when stored in a hot box/ hot shelf for more than an hour, crumbles on its own. Another company was afflicted by customer complaints about soupy and runny corn grits for nearly a year before they could trace them back to Enogen corn through PCR testing. Additionally, enzymes can remain active well after the cooking process is over and continue to impact the starch quality of the packaged foods, making tortilla dough sticky or the product fragile.
“The starch content is obviously different in this corn,” Amapola Vice President Juan Galván has said. “Tamales don’t bind. When you make the product, it falls apart.” 
Syngenta has proposed a stewardship program for Enogen corn that includes regulating aspects of seed and produce distribution and spacing between farms. The purpose of this program is to keep Enogen corn out of the food supply chain, and for most part it does isolate Enogen corn from food grade corn. However, Enogen corn does comingle and come into cross-contact with food grade corn as evidenced by the growth of testing at our customers and also positive customer samples we have received for PCR tests conducted at our lab. Cross-contact of regular food-grade corn with Enogen corn may be caused by shared transportation, handling, and storage infrastructure, as well as cross-pollination due to wind and weather.
“We cut about 400 to 500 feet off the end of 400 acres that we had to bin separately—and it was contaminated. We tested it and it wasn’t going to meet specs.” -Mark Jost of Henderson, Nebraska 
A lot of cross-contact risk conversation revolves around the level on concentration of the enzyme. The science suggests that if an enzyme is present in a supportive environment, it will start acting and degrading the starch by acting as a catalyst. This implies that the enzyme may not get consumed in the reaction, but simply move to the next site driving the reaction till conditions allow. This would mean that practically any dose of the enzyme that goes undetected into a suitable process can lead to a uncontrolled reaction and have severe consequences on the production process. Novozyne, a leader in enzyme preparation for the baking industry, warns that even a slight amount of overdosing of enzymes in food preparation can lead to unacceptable products . The North America Millers Association (NAMA) has quoted that even one kernel mixed with ten thousand (0.01%) can disrupt food processing operations. While each product has different amount of risk associated with it, any process involving heating and/or acidic/alkaline exposure of corn for a long duration is a high risk process in the presence of the alpha amylase enzyme.
Real Life Example
An EnviroLogix customer, one of the largest corn millers in the United States, experienced multiple batch failures of corn masa flour, an issue that had to be escalated to their Head of Quality. The root cause eluded them for a while, and only after performing DNA tests, it was determined to be Enogen corn. This issue was seen even though the customer was testing all inbound corn for Enogen using below methods:
- Lateral flow device (LFD) test at the decision point- LFD test results provide on-the-spot screening of the quality of incoming grain, giving guidance to staff on whether to accept or reject a load. But, the EnviroLogix LFD AS-070-BG test they were using at the time was only specified to detect contamination at a level of 1 in 400 kernels(0.25%).
- Lab-based PCR test-Performed by trained scientists in a lab setting, PCR tests reduce the possibility of introducing test error, but it takes a few days to receive a result. This makes PCR tests an impractical choice as an inbound screening test. If the Enogen corn has been accepted into inventory before the test result is obtained, it is already too late.
A Breakthrough Solution
With the PCR results arriving too late, and product quality issues occurring despite inbound grain tested using a test specified to detect 1 Enogen corn grain in 400 (0.25%) , there was a clear need to revise the acceptance criteria for inbound corn cross-contact to a much lower level. To enable this revision, the limit of detection for the test used to monitor each truck would also need to be lowered to help mitigate this ongoing and increasing risk they were seeing. After additional internal consideration, they told us- “Increase sensitivity of the strip to at least 1/1000 although 1/2000 is the ideal level since 0.0625% is threshold where we start seeing issues”. With the evolving needs of the grain industry always at the forefront of our research and development, EnviroLogix was ready with TotalTarget™ for Amylase Corn—a breakthrough LFD solution able to detect Enogen in corn at 1 in 2,500 kernels (0.04%).
- Increased Sensitivity – TotalTarget for Enogen is 6 times more sensitive than the existing low sensitivity test to enable detection of Enogen above 0.04% contamination.
- Common Workflows – Workflows for TotalTarget Enogen and TotalTox™ Mycotoxin test kits mesh seamlessly. With the same sample prep and simultaneous reading, operators can test for Enogen and mycotoxin contamination side-by-side in under 10 minutes.
- Updated Extraction – Safer and easier extraction process that no longer requires Hydrochloric Acid (HCl)
- Reader Enabled – No need to rely on visual test line results. Get an instant objective read with the QuickScan Reader.
- Audit-Ready Data – Whether you download your data directly from the QuickScan or access it online through our new TotalHub data management system, record keeping and reporting are just a few clicks away.
By adopting this new high sensitivity test, the customer was able to more than meet their threshold needs with an on-site test that is fast and simple. With TotalTarget for Enogen, they were able to:
- Dramatically reduce the risk of Enogen contamination of purchased food-grade corn, potentially averting hundreds of thousands of dollars in operational disruptions, product recalls, and inventory disposal.
- Save significant time and effort with training and testing by implementing the common workflow for Enogen and Mycotoxin testing that utilizes the sampling protocols and testing steps that operators already know.
- Further insure against contamination risk by mandating that all upstream corn suppliers test for Enogen using the new TotalTarget high sensitivity test before delivering corn to them
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-  https://www.ers.usda.gov/topics/crops/corn-and-other-feedgrains/feedgrains-sector-at-a-glance/
-  https://www.agweek.com/business/enogen-corn-comes-north
-  https://www.syngenta-us.com/corn/enogen-feed
-  https://www.nytimes.com/2011/02/12/business/12corn.html
-  https://www.ecowatch.com/gmo-corn-syngenta-enogen-2324704813.html
-  https://brownfieldagnews.com/rural-issues/enogen-vs-food-grade-coexistence-issue-nebraska/