Focus on Biofuels: Quality control contributes to boost U.S. DDGS exports

Testing for mycotoxins is usually done on the corn at the bulk receiving points before it is processed into ethanol and DDGS. There is a variety of ways a company can test for toxins, and test strips are one of those convenient methods.

Simon Varney, product manager for agriculture products, Envirologix, a developer of the immunoassay diagnostic test kit method, says speed and ease-of-use makes test strips a popular choice for analyzing toxin levels.

“We provide fast, simple and accurate test strips that detect toxins at required industry levels,” says Varney. “These are on-site, easy-to-use tests that typically require grinding a sample and extracting the toxin with a solvent or tap water. The tests themselves are immunoassays or, basically, antibody-based protein tests — much like a common pregnancy test. When used with our QuickScan reader system, customers can quantify and track test results for aflatoxin, deoxynivalenol (DON) and fumonisin.”

Some of Envirologix’s test strips allow users to utilize the same sample extract to detect multiple toxins, which saves on sample-preparation time spent grinding. The QuickScan system also allows customers to quantify up to three different toxins or four of the same different mycotoxins at once.

The ELISA, or enzyme-linked immunosorbent assay, analytical method is another option for ethanol plants. The sampling process is similar to what is required when using test strips; however, the liquid sample is transferred into an antibody-coated well, where it will turn colors to indicate the presence of toxins.

Neogen, a manufacturer of analytical tools for the feed and grain industry, makes ELISA test kits for a variety of toxins. Paul Pfeiffer, territory manager, milling and grain, Neogen, says one advantage of the ELISA method of testing is its versatility. Since most ELISA tests work the same way, with the same volumes, once someone learns to use one type of toxin test, they can apply that knowledge to Neogen’s other toxin tests.

“For example we’re seeing the presence of DON in corn this year because the weather was cool and wet in many areas,” says Pfeiffer. “Many corn processors are used to testing only for aflatoxin or fumonison, but if they have been trained with our Veratox tests for aflatoxin and fumonison, they already know how to conduct the testing for DON.”

After testing the corn for toxins at the receiving locations, many ethanol facilities send samples of DDGS to analytical labs for third-party testing of the finished co-product.

Trilogy Analytical Laboratory has been testing DDGS using the high-pressure liquid chromatography, or HPLC, instrumentation method for 10 years. According to Carrie Maune, president, Trilogy Analytical Laboratory, the HPLC method of testing is ideal for testing more complex feeds, such as DDGS, while other methods are ideal for simpler subjects, like corn.

HPLC analytical instruments are complex, sophisticated pieces of equipment, and require a trained lab technician to operate. Many ethanol facilities that have an HPLC analyzer in their testing lab also send DDGS samples in to be analyzed about once a month. This measure contributes to quality control and gives customers peace of mind that a source other than their supplier verifies the safety of the product.

“HPLC instrumentation can also be used as a ‘referee’ when two or more tests show conflicting results,” says Maune. “The HPLC instrumentation results are generally viewed as higher quality and more accurate.”

Quality counts
Testing certainly helps reassure customers they’re getting a quality product, but for the most part, many Chinese importers buy U.S. DDGS because they already believe it is a higher quality product than domestic Chinese DDGS.

Jason Song, president, Gentech Co., owns a large specialty feed company headquartered in Shanghai, China. Song says many of his poultry, beef and dairy customers find U.S. DDGS to be an economical and high-quality alternative to higher priced protein options.

But their motives behind choosing U.S. DDGS over domestic Chinese DDGS are not purely financially driven. Song attributes China’s rise in U.S. DDGS imports to the consistency of the product, due to the quality control measures taken during processing.