Optimization of Microwave Vacuum Drying and Pretreatment Methods for Polygonum cuspidatum

Table 8

Variance analysis of the retention of polydatin.

Indicator compounds		Source of variation	Sum of squares	Degree of freedom	Mean square	F value	Sig.
Polydatin	0.991	Pretreatment	88.853	2	44.427	89.450	0.011
		Vacuum pressure	9.291	2	4.646	9.354	0.097
		Temperature of inner material	15.266	2	7.633	15.369	0.061
Emodin	0.939	Pretreatment	27.766	2	13.883	2.273	0.306
		Vacuum pressure	1.646	2	0.823	0.135	0.881
		Temperature of inner material	157.277	2	78.639	12.873	0.072
Physcion	0.944	Pretreatment	0.001	2	0.000	0.535	0.652
		Vacuum pressure	0.002	2	0.001	1.421	0.413
		Temperature of inner material	0.016	2	0.008	14.791	0.063
Resveratrol	0.865	Pretreatment	0.008	2	0.004	0.543	0.648
		Air pressure	0.006	2	0.003	0.428	0.700
		Temperature of inner material	0.082	2	0.041	5.418	0.156