Optimization of oxalic acid pre-treatment and enzymatic saccharification in Typha latifolia for production of reducing sugar

Table 1 The central composite design with four independent variables and the experimental results (C*—control)

Run no.	Substrate concentration (%w/v) X₁	Enzyme loading (IU/g) X₂	pH X₃	Temp (°C) X₄	Reducing sugars (mg/g) observed value	Reducing sugars (mg/g) predicted value
1	1.2	30	04	35	12.85	10.07
2	1.2	30	04	65	19.27	20.24
3	1.2	30	10	35	15.06	15.09
4	1.2	30	10	65	24.54	21.68
5	1.2	70	04	35	16.92	17.09
6	1.2	70	04	65	20.83	19.86
7	1.2	70	10	35	15.62	13.93
8	1.2	70	10	65	13.74	13.12
9	3.6	30	04	35	28.27	28.10
10	3.6	30	04	65	30.02	28.72
11	3.6	30	10	35	33.72	31.70
12	3.6	30	10	65	29.69	28.74
13	3.6	70	04	35	39.92	39.78
14	3.6	70	04	65	33.81	33.00
15	3.6	70	10	35	36.95	35.20
16	3.6	70	10	65	25.06	24.85
17	0.5	50	07	50	10.45	13.26
18	4.8	50	07	50	45.21	47.23
19	2.4	10	07	50	22.18	24.83
20	2.4	90	07	50	26.82	27.95
21	2.4	50	01	50	14.28	14.91
22	2.4	50	13	50	8.62	11.77
23	2.4	50	07	20	21.02	23.31
24	2.4	50	07	80	21.64	23.13
25C*	2.4	50	07	50	15.10	12.76
26C*	2.4	50	07	50	11.47	12.76