Zearalenone Contamination Analysis

Zearalenone (ZEA) is an estrogenic mycotoxin which is formed by several Fusarium species and is a common contaminant of cereal grains related foods and feeds.

Figure 1. Chemical structure of zearalenone and related contaminated foods

Zearalenone is mainly found in maize and other crops such as barley, wheat and rye as well as their processed food products all over the world. Vegetable oils also contributed to the zearalenone exposures. Zearalenone is produced by the fungi genus of Fusarium species, especially F. graminearum and F. culmorum. The occurrence of zearalenone in wheat was shown to be the same as for the occurrence of other common mycotoxins produced by Fusarium such as deoxynivalenol. It is also usually found with aflatoxins. The optimal conditions for the growth of these fungi are moist cool field environment during harvest. Zearalenone can also be produced during poor storage conditions and its level may increase if the grains are not dried and stored properly. Compared with the production of other mycotoxins, zearalenone can be formed during relatively cool conditions. Studies conducted by European Food Safety Authority have found a possible increased risk of the level of zearalenone to consumers in breakfast cereals. Zearalenone is generally stable during cooking process.

Zearalenone has anabolic properties and estrogenic effects. The reproductive tract is the major target of zearalenone toxicity, and it could induce the fertility disorders in animals and humans. In addition to the harmful effect on the reproductive system, zearalenone has been associated with different adverse effects on the intestinal villous structure and reduce the expression of junction proteins. Zearalenone has also been shown to have hepatonephrotoxic and immunotoxic effect. It can also enhance the peroxidation of lipids.

The European Commission has specified the maximum levels for zearalenone in a variety types of foodstuffs. The contamination limits ranged from 20 µg/kg for processed cereal-based and maize-based infant foods and young children foods, 100 µg/kg for unprocessed cereals other than maize and maize-based snacks, to 400 µg/kg for refined maize oil. The Panel on Contaminants in the Food Chain has issued a recommendation of tolerable daily intake (TDI) of zearalenone as 0.25 µg/kg body weight per day.

The procedure for the analysis of zearalenone in foods and animal feeds includes sample preparation and extraction, purification, and detection/quantification. Liquid extraction was used to extract the mycotoxins from foodstuffs. We have expertise in the sample preparation of a variety types of food matrices. The sample preparation has significant effect on the accuracy of the level measured in the food samples.

We offer accurate and validated analytical platforms for both identification and quantification that have been widely applied in the determination of zearalenone in food and feed samples to meet customers' needs.

Liquid chromatography coupled with mass spectrometry (LC-MS)

LC-MS is a widely used laboratory based method for the analysis of zearalenone. The method offers high sensitivity and accuracy. With the currently available methods, limits of detection (LODs) and limits of quantification (LOQs) typically range 1-5 and 5-20 µg/kg, respectively.

We also maintain high quality assurance for the analysis. The recovery of internal standard, the use of blanks and spikes is monitored for each batch of analysis.