In this study, the effects of microwave and oven systems on bioactive properties (total phenolic, total flavonoid, and antioxidant capacity), fatty acids, polyphenols, and mineral contents of raw and roasted “Sarışeker” and “Balyumru” tubers are investigated. Antioxidant activity values of “Sarışeker” tigernut tubers roasted in microwave and oven systems are defined to be between 1.56 (540 W) and 2.57 mmolTE kg−1 (720 W) to 1.57 (80 and 120 °C) and 1.68 mmolTE kg−1 (100 °C), respectively. Gallic acid results of the “Sarışeker” and “Balyumru” tigernut tubers roasted in microwave are specified to be between 5.49 (720 W) and 6.59 mg/100 g (540 W) to 15.83 (900 W) and 21.47 mg/100 g (720 W), respectively. In general, the phenolic component values of the “Sarışeker” tigernut tubers roasted at different temperatures are higher than the “Sarışeker” tigernut samples roasted in the microwave. The oleic, linoleic, and linolenic acid values of the oils obtained from “Sarışeker” tubers roasted in both roasting systems increase compared to the control. The heat treatment has different effects on the contents of different elements of the tigernut tubers. It has been observed that there are significant fluctuations in the amounts of minerals in the structure of foods as a result of the heat treatment applied.