High-Yield Alpha-Cellulose from Oil Palm Empty Fruit Bunches by Optimizing Thermochemical Delignification Processes for Use as Microcrystalline Cellulose

Table 5

Lack of fit value.

Source	F-value	value	Sign
1. Water extractive material
X 1-bleaching time	2.27	0.1629
X 2-concentration of NaClO2	0.5211	0.4869
Lack of fit	0.0846	0.9948	Not significant
2. Hemicellulose
X 1-bleaching time	2.85	0.1258
X 2-concentration of NaClO2	0.9052	0.3662
X 1 X 2	2.01	0.1895
Lack of fit	4.06	0.0998	Not significant
3. Cellulose
X 1-bleaching time	5.30	0.0548
X 2-concentration of NaClO2	10.63	0.0139
X 1 X 2	1.98	0.2025
X′1^2	0.2453	0.6355
X′2^2	9.28	0.0187
Lack of fit	1.37	0.3721	Not significant
4. Lignin
X 1-bleaching time	0.3304	0.5834
X 2-concentration of NaClO2	137.60	<0.0001
X 1 X 2	0.6863	0.4348
X′1^2	1.57	0.2499
X′2^2	46.33	0.0003
Lack of fit	2.46	0.2024	Not significant