Zearalenone (ZON) is a mycotoxin produced by fungi of the genus Fusarium, which causes economic losses and impacts human and animal health due to their occurrence in raw materials for food and feed formulation. Therefore, it is encouraged the study of strategies to reduce the ZON contamination, for example, the enzymes application due to their specificity, the less aggression to the environment and mild reaction conditions, an important characteristic when applied to food. Thus, this study evaluated the ZON stability in a model solution for investigation further of the reduction concentration by the peroxidase enzyme. The stability of the mycotoxin concentration in the model solution was verified for 168 h of incubation at 25±5 °C.The tests were performed with ZON addition at the concentration of 0.9 μg/mL. Subsequently, the constituents of the model solution (water, phosphate buffer and hydrogen peroxide) were added and homogenized in the vortex and ultrasonic bath. ZON extraction was carried out by liquid-liquid partitioning technique, with addition of chloroform in the sample followed by homogenization and removal of the organic phase, totaling three partitions. The organic phase was removed and the final volume was dried in nitrogen atmosphere and resuspended in acetonitrile for detection and quantification in high-performance liquid chromatographer coupled with a fluorescence detector. ZON recovery at 0, 24 and 168 h were 103 (2.7); 97 (1.9) and 46% (17.6). The results demonstrated the ZON stability in up to 24 h when in model solution. In 168 h the observed ZON reduction may be due to the instability of the mycotoxin in the aqueous or polar medium. Therefore, for the evaluation of ZON biodegradation in model solution, the maximum time of 24 h for the study of the reduction of ZON concentration and mechanism of action per action of the peroxidase enzyme is indicated.