Table 5.
Plan and results for response surface methodology of DPPH free-radical scavenging potential and FRAP
| Run | Independent variable |
Response (mg AAE/g DW) |
||||||
| X 1 (%) | X 2 (min) | X 3 (°C) | X 4 | Observed DPPH | Predicted DPPH | Observed FRAP | Predicted FRAP | |
| 1 | 80 (+1) | 50 (+1) | 40 (−1) | 1 (−1) | 33.60 | 33.03 | 10.09 | 9.92 |
| 2 | 80 (+1) | 50 (+1) | 60 (+1) | 3 (+1) | 46.90 | 47.07 | 14.47 | 14.60 |
| 3 | 80 (+1) | 30 (−1) | 60 (+1) | 1 (−1) | 29.86 | 29.07 | 10.62 | 10.79 |
| 4 | 60 (0) | 40 (0) | 50 (0) | 2 (0) | 53.84 | 55.10 | 15.86 | 15.74 |
| 5 | 60 (0) | 40 (0) | 50 (0) | 2 (0) | 53.44 | 55.10 | 15.37 | 15.74 |
| 6 | 60 (0) | 40 (0) | 50 (0) | 2 (0) | 57.01 | 55.10 | 15.95 | 15.74 |
| 7 | 60 (0) | 40 (0) | 60 (+1) | 2 (0) | 56.14 | 55.29 | 15.78 | 15.66 |
| 8 | 40 (−1) | 30 (−1) | 40 (−1) | 1 (−1) | 32.46 | 32.27 | 11.90 | 11.73 |
| 9 | 80 (+1) | 30 (−1) | 40 (−1) | 3 (+1) | 38.92 | 38.14 | 13.25 | 13.16 |
| 10 | 60 (0) | 30 (−1) | 50 (0) | 2 (0) | 53.74 | 54.50 | 15.50 | 15.42 |
| 11 | 60 (0) | 40 (0) | 50 (0) | 1 (−1) | 44.34 | 45.25 | 14.40 | 14.57 |
| 12 | 60 (0) | 50 (+1) | 50 (0) | 2 (0) | 56.60 | 55.62 | 15.13 | 15.37 |
| 13 | 60 (0) | 40 (0) | 40 (−1) | 2 (0) | 50.24 | 50.86 | 13.67 | 13.95 |
| 14 | 40 (−1) | 50 (+1) | 40 (−1) | 1 (−1) | 33.31 | 32.88 | 11.69 | 11.83 |
| 15 | 40 (−1) | 50 (+1) | 40 (−1) | 3 (+1) | 40.03 | 40.79 | 13.53 | 13.33 |
| 16 | 80 (+1) | 50 (+1) | 40 (−1) | 3 (+1) | 38.94 | 39.30 | 12.73 | 12.75 |
| 17 | 80 (+1) | 30 (−1) | 40 (−1) | 1 (−1) | 28.25 | 28.63 | 9.33 | 9.34 |
| 18 | 80 (+1) | 50 (+1) | 60 (+1) | 1 (−1) | 33.70 | 33.93 | 11.77 | 11.59 |
| 19 | 60 (0) | 40 (0) | 50 (0) | 2 (0) | 55.95 | 55.10 | 15.68 | 15.74 |
| 20 | 40 (−1) | 30 (−1) | 60 (+1) | 1 (−1) | 33.64 | 33.36 | 13.34 | 13.31 |
| 21 | 40 (−1) | 30 (−1) | 40 (−1) | 3 (+1) | 43.57 | 43.42 | 14.05 | 14.22 |
| 22 | 40 (−1) | 30 (−1) | 60 (+1) | 3 (+1) | 50.83 | 51.37 | 15.84 | 15.98 |
| 23 | 40 (−1) | 50 (+1) | 60 (+1) | 3 (+1) | 49.49 | 49.21 | 15.32 | 15.30 |
| 24 | 80 (+1) | 30 (−1) | 60 (+1) | 3 (+1) | 44.93 | 45.45 | 14.94 | 14.80 |
| 25 | 60 (0) | 40 (0) | 50 (0) | 2 (0) | 54.56 | 55.10 | 16.18 | 15.74 |
| 26 | 60 (0) | 40 (0) | 50 (0) | 3 (+1) | 58.52 | 57.39 | 17.33 | 17.32 |
| 27 | 80 (+1) | 40 (0) | 50 (0) | 2 (0) | 42.20 | 42.68 | 12.93 | 13.19 |
| 28 | 60 (0) | 40 (0) | 50 (0) | 2 (0) | 55.17 | 55.10 | 15.85 | 15.74 |
| 29 | 40 (−1) | 40 (0) | 50 (0) | 2 (0) | 46.28 | 45.57 | 14.84 | 14.74 |
| 30 | 40 (−1) | 50 (+1) | 60 (+1) | 1 (−1) | 33.69 | 34.43 | 13.56 | 13.62 |
X 1: ethanol concentration; X 2: extraction time; X 3: extraction temperature; X 4: number of extraction cycles. The coded forms of the variables are shown in parentheses