group 1 were dried in the sun for nearly 7 days.
In group 2, the bulbs of F. thunbergii slices were dried by sulfur fumigation. In a chamber, the F. thunbergii slices were equidistantly placed on the netlike spacerplate spacerplate and food-grade sulfur (0.25 g) held in enamelware was placed at the bottom of this chamber. After the sulfur was ignited and a clear blue flame generated, the chamber was obturated . After 4 h, the F. thunbergii slices were removed and placed in a draft to dry for 7 days. The slices
in group 3 were dried in a microwave oven. Microwave drying was performed at 2450 MHz and a full power of 700 W for 5 min (130–140◦C)and then at 100 W for 30 min (60–70◦C) The slices
in group4 were dried in an infrared oven. The infrared drying of F. thunbergii slices was conducted at 250 W (85–105◦C) and stopped after 2 h The slices
in group 5 weresubjected to hot air drying at 60◦C with a wind speed of0.15 m/s for 10 h in a hot air-drying oven
in group 6 were dried in a freeze dryer. The FD process was performed for 18 h with the temperature of the cold trap of −50◦C and a vacuum of 20 Pa Ultimately, the final moisture content of all samples must be