Kinetic study of cyclopiazonic acid during the heat-processing of milk

Heat-stability of cyclopiazonic acid (CPA) incorporated in milk was assessed under different conditions. The CPA residue in milk was analysed by micellar capillary electrophoresis. Three batches of 1 μg CPAJml contaminated milk were heated at 60, 80 and 100 °C for 15–60 min to simulate heat processing employed in the dairy industry. Only 3–9%, 14–18% and 25–30% of CPA were degraded, respectively, and degradation followed a pattern of a first-order reaction. Heating the milk for 2h at 60, 80 and 100 °C decreased the CPA level by 9–17%, 20–34% and 49–50%, respectively. Storage of the heated milk overnight at 4 °C induced a further reduction of CPA. Autoclaving the milk or heating canned milk in a retort for 30 min at 120 °C led to a loss of 33–36% of CPA. Simulation of heattreatments used by the dairy industry induced no significant degradation of CPA. The inability of the heat-treatment during milk processing to eliminate the mycotoxin emphasises the serious potentiality of CPA exposure for liquid milk consumers.