Optimization of Microwave Vacuum Drying and Pretreatment Methods for Polygonum cuspidatum

Table 1

Orthogonal experiment design.

Expt. number	Pretreatment methods	Vacuum pressure; (mbar)	Temperature of inner materials (°C)
(1)	1 (blanching for 30 s at 100°C)	1 (200)	1 (50)
(2)	1	2 (400)	2 (60)
(3)	1	3 (600)	3 (70)
(4)	2 (microwave 700 w for 10 s)	1	2
(5)	2	2	3
(6)	2	3	1
(7)	3 (no pretreatment)	1	3
	3	2	1
	3	3	2