Table 3.
Experiments performed using the Box-Behnken design

Run	Independent variables			Dependent variables
	X1, Severity factor (Ro)	X2, Extraction temperature (°C)	X3, Ratio of water to material (mL/g)	Y, Prebiotic sugar(mg/g dry steam-exploded wood)
				Actual	Predicted
				1	4.12	90	30	241.40	247.55
	2	3.94	90	40	198.20	193.01
3	4.12	90	1/50	291.60	314.22
4	3.64	100	1/40	218.40	192.40
5	3.94	90	40	291.20	288.89
6	3.94	80	30	325.30	314.22
7	3.64	90	30	298.90	314.22
8	4.12	80	40	142.70	159.80
9	3.64	90	50	283.70	285.05
10	3.94	80	50	232.70	252.42
11	4.12	100	40	221.80	240.30
12	3.94	100	50	291.20	271.48
13	3.94	90	40	197.80	213.68
14	3.94	90	40	223.60	207.72
15	3.64	80	40	325.30	314.22
16	3.94	100	30	231.80	222.20
17	3.94	90	40	330.00	314.22