Which kind of substances can be found in corn and why is it a good idea to analyse them?

The corn harvest began in August. Why is it important to test for pesticides and mycotoxins? The experts of Wessling Knowledge Centre - one of Hungary’s most experienced laboratories and a leader in pesticide testing – answer this question.

Expanding cornfields and corn monocultures have been conducive to the prolification and proliferation of several pathogens, such as fusariums, different types of mildew and plant-lice. It is therefore advisable to take into account what nutrients this crop requires during the production period, and to ensure that these nutrient requirements are continuously met.

Manure administered into the soil, for example, mitigates the harmful effects of pathogens active in the soil.

Soil disinfectants such as forate, carbofuran, carbosulfan or bendiocarb can also be used successfully. Pathogens infecting sprouts can be controlled with preparations containing the active agents captan, benomyl, TMTD and carboxin, but where pheasants or crows may pilfer the seeds sown, the right approach is to use repellents (ziram, Daphne oil).

Warm, dry weather and unfavourable storage conditions promote the contamination of corn and wheat. The most significant toxins of fungi are the aflatoxins produced by aspergillus fungi (as a result of climate change) and the mycotoxins produced by fusarium fungi (Deoxynivalenol, Fumonisin, Zearalenone, T2 and HT2 toxin).

During the 19th century, aflatoxins were mainly present in countries with a Mediterranean climate, but by today they are considered a source of danger by agricultural experts in Central Europe, too.

Mycotoxins occur in both natural and artificial environments. For their survival, they produce various compounds, some of which are useful (e.g. antibiotics) but others have a particularly harmful effect on humans and animals: some of these compounds are harmful to the kidney and the liver, are carcinogenic or disrupt the endocrine system, while some others are neurotoxins – explained the colleagues working at the food testing laboratory of WESSLING Knowledge Centre, who emphasized that mycotoxins are generated not just during the crop production period but also – if circumstances are unfavourable  - during transportation and storage.

At WESSLING Hungary Kft, for example, mycotoxins, too, are analysed by their chemical-physical tests. Essentially, the chromatographic method used means that after homogenisation, experts extract from the sample the relevant compound, then purify the extract and expose its constituents by liquid and/or gas chromatography.

Toxic metals entering our food from the soil are detected by the ICP technique, the genetic testing of seeds for sowing takes place by molecular methods or mass spectrometry, while the varietal identity and genetic status of seeds are established by GMO tests.

Without spraying, pests and moulds reproduce on the plants, triggering the production of mycotoxins. With good agrotechnical practice, the damage inflicted by pests may be kept under acceptable levels, but residues of plant protection products may appear in food intended for human consumption, posing a risk to human health. 

The following types of pesticides are most commonly detected in corn by various laboratory tests: chlorpyrifos, cypermethrin, deltamethrin, piperonyl-butoxide, azoxystrobin, difenoconazole.

The reliable detection of residues and contaminants in food places extremely high expectations on individual testing laboratories.

WESSLING Hungary Kft’s experts use state-of-the-art equipment and instruments to analyse raw materials and products, applying multimode and individual tests alike.

One of the most dangerous herbicides, i.e. glyphosate, for example, can be easily identified by modern laboratories such as WESSLING Hungary Kft. by a procedure relying on the HPLC-MS technique (high-pressure liquid chromatography-mass spectrometry).