Impact of the popping process on the structural and thermal properties of sorghum grains (Sorghum bicolor L. Moench)

The popping process has been widely used as a technique for obtaining snacks. This study evaluated the effect of the popping process on the structural and thermal properties of sorghum. Seven varieties of sorghum were used. Raw sorghum grains were adjusted to 11% moisture and popped at 210 °C for 90 s with hot air. Microstructure, thermal and viscosity properties, and X-Ray and infrared spectrum were measured in raw and popped sorghum. The popping process produced an ordered honeycomb-like structure in the sorghum. The viscosity profile showed an increase in the thermal stability of popped sorghum. DSC measurements showed a starch gelatinization and a second transition about to 145 °C. XRD diffractograms display a reduction in the amplitude of the crystalline orthorhombic structure peaks. Finally, infrared indicated a change in the short-range structure and protein denaturation due to the popping process.