An oven may include a cooking chamber configured to receive a heat modulating material (HMM), a radio frequency (RF) heating system configured to provide RF energy into the cooking chamber, and a cooking controller configured to control the frequency of RF energy provided by the RF heating system into the cooking chamber. The MINI may be configured to contain a food product and may include a thermally active section. The thermally active section may include a base matrix and a particulate material dispersed in the base matrix.