Optimization of alkaline pretreatment and enzymatic hydrolysis for the extraction of xylooligosaccharide from rice husk

AMB Express

Table 4 The variable factors and predicted and observed xylooligosaccharide yield

Std.	Run	Factors			Amount of xylooligosaccharide (mg/mL)
Std.	Run	X1: enzyme concentration (mg/g xylan)	X2: incubation time (h)	X3: xylan concentration (%w/v)	Observed value	Predicted value
16	1	0 (3.75)	0 (9)	0 (3)	12.98 ± 0.01	13.19
12	2	0 (3.75)	1 (16)	1 (5)	17.32 ± 0.79	17.32
13	3	0 (3.75)	0 (9)	0 (3)	12.96 ± 0.65	13.19
7	4	− 1 (1.25)	0 (9)	1 (5)	16.94 ± 0.32	16.95
9	5	0 (3.75)	− 1 (2)	− 1 (1)	13.97 ± 0.14	13.97
17	6	0 (3.75)	0 (9)	0 (3)	13.18 ± 0.47	13.19
8	7	1 (6.25)	0 (9)	1 (5)	17.35 ± 0.31	17.41
15	8	0 (3.75)	0 (9)	0 (3)	13.42 ± 0.47	13.19
3	9	− 1 (1.25)	1 (16)	0 (3)	13.75 ± 0.14	13.75
5	10	− 1 (1.25)	0 (9)	− 1 (1)	14.25 ± 0.31	14.19
1	11	− 1 (1.25)	− 1 (2)	0 (3)	13.05 ± 0.47	13.11
2	12	1 (6.25)	− 1 (2)	0 (3)	13.61 ± 0.14	13.62
11	13	0 (3.75)	− 1 (2)	1 (5)	17.29 ± 0.22	17.23
14	14	0 (3.75)	0 (9)	0 (3)	13.44 ± 0.24	13.19
6	15	1 (6.25)	0 (9)	− 1 (1)	13.88 ± 0.51	13.87
10	16	0 (3.75)	1 (16)	− 1 (1)	14.20 ± 0.03	14.27
4	17	1 (6.25)	1 (16)	0 (3)	13.44 ± 0.16	13.38