Mycotoxins in Grain (background & industry information)

From pre-planting diagnostics to hybridization and plant genomics; to seed protection; to product safety; to in-store labeling support, EnviroLogix immunoassay kits play a significant role in protecting crop quality and reducing production costs. Immunoassay kits are effective in fungal and toxin detection, pesticide monitoring, genetic trait detection, and seed coating monitoring. As in other applications, the characteristics of low cost, simplicity, high specificity, high sensitivity and speed permit extensive screening with real-time results.

Take a look at our QuickTox Kits

Typical applications for Mycotoxins in grain include:


Mycotoxins in Grain
Mycotoxins are produced by molds that form in grains, food and feedstuffs and, thus, can cause health concerns when ingested. The occurrence of mycotoxins in foods is usually the result of mold contaminated grain at pre-harvest or during storage. Fusarium and Alternaria molds attack the plant in the field prior to harvest of grain or fruit; Aspergillus or Penicillium molds affect grains under storage conditions conducive to mold growth. These molds often produce the toxins deoxynivalenol (DON), alternariol, aflatoxin, and ochratoxin A.

In addition to the health problems, mycotoxins cause serious economic hardship. It has been estimated that mycotoxins can cause annual losses in grain commodities in the United States of over $2.0 billion. Guidelines and recommendations for mycotoxins in both animal feed and food destined for human consumption make the sale of contaminated grain in the U.S. very limited.


Aflatoxin

Aflatoxins are the most commonly occurring and widely known mycotoxin contaminants. Aflatoxins are secondary chemical metabolites produced by the molds Aspergillus flavus and Aspergillus parasiticus.

Aflatoxin infection occurs in crops prior to harvest and once the grain reaches storage. It can be produced when maturing corn is under drought and insect stress with prolonged periods of hot weather (daytime highs above 90? F, nighttime lows above 75? F). Post harvest contamination can occur if crop drying is delayed. It can also occur during storage of the crop if moisture is allowed to exceed critical values.

The toxin-producing molds occur with the greatest frequency in corn, peanuts, cotton seed and pecans. They seldom occur naturally in wheat, oats, sorghum, rice and soybeans, even though they can be produced on these food sources under laboratory conditions.

Aflatoxin B1 is the most important toxin from a toxicological standpoint. It has been called the most toxic chemical found in nature, a highly potent carcinogen to humans and animals, and is found primarily in corn, cotton seed and tree nuts. In 1988, the International Agency for Research on Cancer placed Aflatoxin B1 on the list of human carcinogens.

Aflatoxin B2 is of less toxicological significance since it is found at much lower levels than Aflatoxin B1, and is always present with Aflatoxin B1. Aflatoxin G1 and G2 are also produced by Aspergillus flavus in peanuts but are seldom found in corn.

Presently, the Food and Drug Administration will commence enforcement actions if aflatoxin levels in corn exceed the following limits:

  • 20 ppb when intended for human use, dairy feed, or feed for immature animals

  • 100 ppb when destined for breeding cattle, breeding swine, or mature poultry

  • 200 ppb when destined for finishing swine (i.e., more than 1,200 lb. body weight)

  • 300 ppb when destined for feedlot cattle

  • Corn having an unknown destination or use is subject to seizure if it exceeds 20 ppb


In May of 1992, the FDA reminded grain elevators that the blending of aflatoxin-contaminated grain with uncontaminated grain is illegal and subject to legal action.

The QuickTox™ test for Aflatoxin is designed for rapid screening of Aflatoxin B1 and B2 at a 20 ppb cut-off level and can identify a negative grain load in 2-3 minutes. The new QuickTox™ test for Aflatoxin 10 ppb screens at a 10 ppb cut-off level. And, both are GIPSA-validated.

This testing innovation differs considerably from traditional qualitative formats by simplifying the procedure to 4 easy steps in a fraction of the time normally required by such tests. Users perform the standard corn extraction and simply drop in a QuickTox test strip. No filtration is necessary. If the sample contains less than 20 or 10 ppb of aflatoxin (depending on which kit is used), two lines will develop on the test strip within 2-3 minutes. This simple, reliable screening test provides quick results in the field, at the elevator, terminals, processing plants and wherever convenience and speed are critical. Additionally, if grain handlers want to screen at both levels, the same sample extract can be used with both strips.



DON (aka deoxynivalenol, vomitoxin)

Deoxynivalenol (DON), also referred to as vomitoxin, is a naturally occurring mycotoxin produced by several species of Fusarium fungi. Wet and cool weather from flowering time to maturity promotes infection, resulting in scab or head blight in barley, wheat, oats, and rye. Wheat infected with scab has a tendency to have lighter weight kernels, some of which are removed during normal harvesting and cleaning operations.

DON does not represent a threat to public health among the general population. However, it can--in rare cases--produce acute temporary nausea and vomiting in humans and animals.

The FDA advisory levels for DON are as follows:
  • 1 ppm - Finished wheat products for human consumption.

  • 5 ppm - Grain and grain byproducts destined for swine and other animal species (except cattle and chickens); not to exceed 20 percent of the diet for swine, and not to exceed 40 percent for other animal species.

  • 10 ppm - Grain and grain byproducts for ruminating beef and feedlot cattle older than 4 months and for chickens; not to exceed 50 percent of the diet.



For quantitative results, use our newest test, QuickTox Kit for QuickScan - DON3, offering the fastest quantitative results for vomitoxin testing. A quick 30-second shake and an industry-leading 3-minute test provides accurate and traceable quantitation up to 12 ppm.



For visual, qualitative results, QuickTox for DON screens for deoxynivalenol in wheat at the important 2 ppm, 1 ppm and 0.5 ppm levels. The test is a rapid, qualitative tool enabling producers, grain suppliers and millers to determine whether DON levels in wheat loads are over or under their target screening level.

GIPSA-validated QuickTox for DON offers:

  • Ease of use – tap-water extraction, less “shaking,” read visually, no special equipment


  • Speed – within 5 minutes, decisions can be made on load acceptance, price, binning, blending


  • Cost effectiveness – tests can be used widely and frequently to “test every load”





Three Easy Steps – No Solvents – No Special Equipment!




USDA GIPSA DON Handbook

DON in Wheat, Questions And Answers, North Dakota State University Extension Service




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