Effect of Processing on Mycotoxin Content in Grains

Mycotoxins that commonly occur in cereal grains and other products can contaminate finished processed foods on account of their high toxicity. The mycotoxins that are commonly associated with food grains include aflatoxins, ochratoxin A, fumonisins, deoxynivalenol, and zearalenone. Various food-processing operations include sorting, trimming, cleaning, cooking, baking, frying, roasting, flaking, and extrusion that have variable effects on mycotoxins. The nature of the processing operation viz. physical, chemical, or thermal plays an important role in this; usually, the processes that utilize the higher temperatures have greater effects on mycotoxin dissipation. In general, the processes are known to reduce mycotoxin concentrations significantly, but do not eliminate them completely. However, roasting and extrusion processing result in lowest mycotoxin concentrations, since these involve higher temperatures. It is observed that very high temperatures are needed to bring about high reduction in mycotoxin concentrations, approaching acceptable background levels. The treatment with chemicals like ammonia, bicarbonate, citric acid, or sodium bisulfite is also effective in resulting in significant decline in mycotoxin concentrations.