Stability of fumonisins in food processing.

Fumonisins are mycotoxins produced by Fusarium verticillioides (moniliforme) and Fusarium proliferatum that are found in corn and processed corn-based food products. Although generally heat stable, fumonisin concentrations appear to decline as processing temperatures increase. At processing temperatures of 125 degrees C or lower, losses of fumonisin are low (25-30%), whereas at temperatures of 175 degrees C and higher, losses are greater (90% or more). Processes such as baking and canning, where product temperatures rarely reach 175 degrees C, result in little or no loss of fumonisin. Processes such as frying and extrusion cooking, where temperatures can exceed 175 degrees C, result in greater losses. Heating fumonisin in the presence of glucose results in an apparent first order loss of the toxin. Adding glucose to corn muffins and extrusion mixes results in high losses of fumonisins during baking and extrusion processing. Little information exists on the effects of chemical and bioprocessing on fumonisins. Alkaline processing of corn, such as in the nixtamalization process, hydrolyzes fumonisins and results in a more toxic product. Additional research is needed to identify and to determine the toxicity of fumonisin decomposition products.