Table 3.
Box-Behnken experimental design based on independent variables (A, B and C) and experimental and predicted results of the TPC.
| Experiment | A |
B |
C |
TPC (g gallic acid equivalents/100 g d.w.) |
|
|---|---|---|---|---|---|
| Temperature (°C) | Time (min) | Ethanol/Water (v/v) | Experimental∗ | Predicted | |
| 1 | 60 | 20 | 90/10 | 0.49 ± 0.01 | 0.51 |
| 2 | 30 | 20 | 90/10 | 0.85 ± 0.02 | 0.80 |
| 3 | 60 | 30 | 80/20 | 3.33 ± 0.06 | 3.21 |
| 4 | 45 | 20 | 80/20 | 2.02 ± 0.04 | 1.92 |
| 5 | 30 | 30 | 80/20 | 2.99 ± 0.06 | 2.94 |
| 6 | 30 | 20 | 70/30 | 2.34 ± 0.02 | 2.32 |
| 7 | 60 | 10 | 80/20 | 2.41 ± 0.05 | 2.46 |
| 8 | 60 | 20 | 70/30 | 2.17 ± 0.05 | 2.21 |
| 9 | 45 | 30 | 70/30 | 2.74 ± 0.03 | 2.81 |
| 10 | 45 | 20 | 80/20 | 2.05 ± 0.04 | 1.92 |
| 11 | 45 | 20 | 80/20 | 1.77 ± 0.03 | 1.92 |
| 12 | 30 | 10 | 80/20 | 3.02 ± 0.08 | 3.14 |
| 13 | 45 | 10 | 90/10 | 0.98 ± 0.02 | 0.91 |
| 14 | 45 | 20 | 80/20 | 1.82 ± 0.05 | 1.92 |
| 15 | 45 | 20 | 80/20 | 1.97 ± 0.04 | 1.92 |
| 16 | 45 | 30 | 90/10 | 1.23 ± 0.02 | 1.32 |
| 17 | 45 | 10 | 70/30 | 2.74 ± 0.05 | 2.65 |
∗
TPC values were expressed as mean of three determinations ±SD.