Table 2.
Factor levels, design matrix and response in the Box–Behnken for optimization of MAE method
| Factor | Units | Levels | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Variable | Key | Low (−) | Middle (0) | High (+) | |||||
| Extraction temperature | A | °C | 50 | 60 | 70 | ||||
| Extraction time | B | Min | 10.0 | 12.5 | 15.0 | ||||
| Extraction solvent volume | C | mL | 2.0 | 3.5 | 5.0 | ||||
| Run | A | B | C | Response (mg g−1) | Run | A | B | C | Response (mg g−1) |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 0 | 0 | 0 | 1.845 | 9 | − | + | 0 | 1.885 |
| 2 | + | − | 0 | 1.675 | 10 | 0 | 0 | 0 | 1.880 |
| 3 | − | − | 0 | 1.625 | 11 | + | + | 0 | 1.896 |
| 4 | 0 | 0 | 0 | 1.862 | 12 | + | 0 | + | 1.805 |
| 5 | − | 0 | + | 1.755 | 13 | 0 | − | − | 1.780 |
| 6 | 0 | + | − | 2.022 | 14 | − | 0 | − | 1.985 |
| 7 | 0 | + | + | 1.790 | 15 | 0 | − | + | 1.550 |
| 8 | + | 0 | − | 2.035 |