Table 1.
Experimental data and the observed response value with different combinations of ultrasound time (X1), solid–liquid ratio (X2) and ultrasound power (X3) used in the Box–Behnken design.
| Run | Independent variables | Response | ||
|---|---|---|---|---|
|
|
||||
| X1 (min) | X2 (g/mL) | X3 (W) | Average extraction efficiency (%) a | |
| 1 | 30 (0) | 1:20 (0) | 200 (0) | 98.75 |
| 2 | 40 (1) | 1:20 (0) | 250 (1) | 86.00 |
| 3 | 40 (1) | 1:25 (1) | 200 (0) | 65.00 |
| 4 | 20 (−1) | 1:25 (1) | 200 (0) | 72.10 |
| 5 | 30 (0) | 1:20 (0) | 200 (0) | 99.30 |
| 6 | 30 (0) | 1:25 (1) | 150 (−1) | 68.04 |
| 7 | 40 (1) | 1:20 (0) | 150 (−1) | 67.77 |
| 8 | 20 (−1) | 1:20 (0) | 250 (1) | 80.40 |
| 9 | 30 (0) | 1:20 (0) | 200 (0) | 97.94 |
| 10 | 30 (0) | 1:20 (0) | 200 (0) | 99.40 |
| 11 | 30 (0) | 1:20 (0) | 200 (0) | 100.00 |
| 12 | 30 (0) | 1:15 (−1) | 250 (1) | 82.99 |
| 13 | 40 (1) | 1:15 (−1) | 200 (0) | 70.31 |
| 14 | 20 (−1) | 1:20 (0) | 150 (−1) | 77.68 |
| 15 | 30 (0) | 1:25 (1) | 250 (1) | 81.04 |
| 16 | 20 (−1) | 1:15 (−1) | 200 (0) | 70.37 |
| 17 | 30 (0) | 1:15 (−1) | 150 (−1) | 71.83 |
a
The average extraction efficiency is expressed as the observed values and the maximum amount was taken to be 100%.