Effects of time, temperature, and pH on the stability of fumonisin B-1 in an aqueous model system

Fumonisins, mycotoxins produced by Fusarium moniliforme in corn, have been implicated in several animal. and human diseases. The effects of processing time and temperature on fumonisin B-1 (FB1) stability (5 ppm) in aqueous solutions at pH 4, 7, and 10 were determined. Analysis of the thermally processed solutions by liquid chromatography/mass spectrometry indicated the predominant presence of hydrolysis products of FB1. The rate and extent of FB1 decomposition increased with processing temperature. After processing at less than or equal to 125 degrees C for 60 min, (27% of FB1 was lost; after 60 min at 150 degrees C, 18-90% was lost, depending on buffer pH. Overall, FB1 was least stable at pH 4 followed by pH 10 and 7, respectively. At greater than or equal to 175 degrees C, >90% of FB1 was lost after processing for 60 min, regardless of pH. FB1 levels may be substantially reduced in foods that reach greater than or equal to 150 degrees C during processing.