Table 1.
Central composite design, actual and coded levels of independent variables, and corresponding actual and predicted values of responses.
| Run | S/M Ratio (X1, mL/g) | Temperature (X2, °C) | Time (X3, min) | FRAP (Y1, µmol Fe2+/g DW) | TEAC (Y2, µmol Trolox/g DW) | TPC (Y3, mg GAE/g DW) | |||
|---|---|---|---|---|---|---|---|---|---|
| Actual | Predicted | Actual | Predicted | Actual | Predicted | ||||
| 1 | 33.18 (−1.68) | 60 (0) | 30 (0) | 730.34 | 739.28 | 400.82 | 408.20 | 55.49 | 55.93 |
| 2 | 40 (−1) | 50 (−1) | 40 (1) | 717.07 | 695.95 | 356.78 | 351.29 | 50.95 | 50.97 |
| 3 | 60 (1) | 50 (−1) | 20 (−1) | 718.60 | 707.21 | 384.12 | 382.34 | 55.08 | 55.29 |
| 4 | 60 (1) | 70 (1) | 20 (−1) | 769.67 | 787.98 | 426.78 | 430.07 | 59.66 | 59.55 |
| 5 | 50 (0) | 60 (0) | 13.18 (−1.68) | 726.33 | 723.71 | 395.54 | 398.51 | 56.75 | 56.96 |
| 6 | 50 (0) | 60 (0) | 30 (0) | 837.24 | 840.61 | 459.39 | 461.70 | 63.69 | 64.40 |
| 7 | 50 (0) | 60 (0) | 30 (0) | 843.60 | 840.61 | 445.18 | 461.70 | 64.19 | 64.40 |
| 8 | 50 (0) | 60 (0) | 30 (0) | 860.73 | 840.61 | 466.76 | 461.70 | 65.04 | 64.40 |
| 9 | 50 (0) | 76.82 (1.68) | 30 (0) | 822.17 | 812.19 | 434.81 | 443.16 | 60.41 | 60.85 |
| 10 | 50 (0) | 60 (0) | 46.82 (1.68) | 739.25 | 745.84 | 396.43 | 396.57 | 57.51 | 57.43 |
| 11 | 60 (1) | 50 (−1) | 40 (1) | 716.60 | 720.97 | 376.63 | 386.82 | 56.28 | 56.62 |
| 12 | 50 (0) | 43.18 (−1.68) | 30 (0) | 677.58 | 691.54 | 347.78 | 342.54 | 50.84 | 50.52 |
| 13 | 50 (0) | 60 (0) | 30 (0) | 814.25 | 840.61 | 476.77 | 461.70 | 64.97 | 64.40 |
| 14 | 66.82 (1.68) | 60 (0) | 30 (0) | 800.50 | 795.53 | 442.40 | 438.13 | 60.81 | 60.50 |
| 15 | 60 (1) | 70 (1) | 40 (1) | 839.67 | 834.47 | 446.86 | 440.56 | 60.28 | 60.29 |
| 16 | 40 (−1) | 70 (1) | 20 (−1) | 753.28 | 746.10 | 442.40 | 430.01 | 60.19 | 59.77 |
| 17 | 40 (−1) | 50 (−1) | 20 (−1) | 713.73 | 716.12 | 359.99 | 364.09 | 51.25 | 51.15 |
| 18 | 50 (0) | 60 (0) | 30 (0) | 853.40 | 840.61 | 466.76 | 461.70 | 63.87 | 64.40 |
| 19 | 50 (0) | 60 (0) | 30 (0) | 835.10 | 840.61 | 455.90 | 461.70 | 64.69 | 64.40 |
| 20 | 40 (−1) | 70 (1) | 40 (1) | 750.08 | 758.66 | 423.65 | 423.23 | 59.30 | 59.00 |
FRAP: ferric-reducing antioxidant power; TEAC: Trolox equivalent antioxidant capacity; TPC: total phenolic content.