Impact of infrared heating on drying properties and flavor components of carmine radish (Raphanus sativus L.) slices

Infrared (IR) drying is an effective method for the preservation and processing of carmine radish (Raphanus sativus L.). This study aimed to investigate the effects of different IR radiation intensities (2125, 2780, and 3358 W/m²) on the drying properties and flavor components of carmine radish slices. As the IR radiation intensity and the drying temperature increased, the total drying time, the moisture content, and the dehydration rate reduced continuously, while the hardness of carmine radish slices decreased and then increased. Drying at a radiation intensity of 2780 and 3358 W/m² reduced 50% and 70% of the drying time compared to that of 2125 W/m², respectively. Flavor components of carmine radish showed apparent changes during the IR drying process with a radiation intensity of 2125 W/m². IR drying at a lower intensity was beneficial to the retention of volatile flavor components. The retention of volatile substances at an intensity of 2125 W/m² for 15 min was 1.97 and 1.68 times that for 30 min and control samples, respectively. Consequently, to retain good processing quality and flavor properties of carmine radish slices, the optimal drying parameter of IR within this study was an IR radiation intensity of 2125 W/m² for about 15 min.