Thermal Degradation of FD & C Red No. 3 and Release of Free Iodide.

Thermal degradation of certified FD & C Red No. 3 was evaluated at 20, 90, 150, 200, 220, 240, 260, 300, and 350°C using a differential scanning calorimeter. Release of free iodide was measured using an ion selective electrode. Under conditions used in this study, it was found that FD & C Red No. 3 begins to release significant amounts of iodide at temperatures between 200 and 210°C. In commercial food products such as breakfast cereals, where high processing temperatures are common, there may be significant thermal degradation of FD & C Red No. 3 that results in high levels of free iodide.