Table 4
Meaning of the different effects of mathematical models.
| Pentoses |
Reducing sugars |
Phenolic compound |
||||
|---|---|---|---|---|---|---|
| Coefficient | P-value | Coefficient | P-value | Coefficient | P-value | |
| X 1 | 0.477 | 0.066 | 0.2908 | 0.014 | 18.58 | 0.001 |
| X 2 | −0.475 | 0.066 | 0.5772 | 0.000 | 37.43 | 0.000 |
| X 3 | −0.320 | 0.190 | 0.2681 | 0.020 | 15.67 | 0.001 |
|
−0.187 | 0.643 | −0.347 | 0.062 | 7.97 | 0.202 |
|
−0.494 | 0.238 | 0.849 | 0.001 | 28.03 | 0.001 |
|
1.927 | 0.001 | −0.320 | 0.081 | 6.67 | 0.278 |
| X 1 X 2 | 0.523 | 0.212 | 0.088 | 0.599 | −2.48 | 0.676 |
| X 1 X 3 | −1.122 | 0.020 | −0.307 | 0.091 | 7.04 | 0.252 |
| X 2 X 3 | 0.536 | 0.202 | −0.388 | 0.041 | 6.19 | 0.310 |
X1 = temperature; X2 = time; X3 = ratio ethanol–water; Effects with a probability of less than 0.05 are significant at the 95% confidence level. Overall, it can be seen from this table that the direct effect of each of the three factors (X1, X2, X3), as well as the quadratic effect of the pre-treatment time (
), significantly influence 95% and positively on the production of Reducing Sugars (RS) and Phenolic Compounds (PC). Which is quite the opposite with regard to the production of Pentoses. Moreover, only the quadratic effect of the ethanol–water ratio (
) positively and significantly 95% affects the extraction of pentoses. Each response is presented individually in the following sections.