Experimental design for MAE and results for and antioxidant activity
| Runs* | Factors | Responses | |||||
|---|---|---|---|---|---|---|---|
| X1 | X2 | X3 | X4 | Y1: TPC mg (GAE/100 g PDCF) | Y2: FRAP (mg TE/100 g PDCF) | Y3: ABTS (mg TE/100 g PDCF) | |
| 1 | 50 | 40 | 5.0 | 0.03 | 991.5 ± 107.6 a | 851.3 ± 80.9 c | 15,979.5 ± 18.6 a |
| 2** | 60 | 60 | 3.5 | 0.04 | 1,163.6 ± 112.6 a | 789.3 ± 90.3 b | 17,668.5 ± 1,323.5 a |
| 3 | 40 | 60 | 3.5 | 0.04 | 1,311.1 ± 105.1 b | 984.2 c ± 41.7 c | 17,709.5 ± 1,172.6 a |
| 4 | 60 | 30 | 3.5 | 0.04 | 1,004.8 ± 162.8 a | 614.1 ± 22.6 a | 16,404.2 ± 1,230.7 a |
| 5 | 80 | 60 | 3.5 | 0.04 | 950.2 ± 50.2 a | 589.5 ± 14,0 a | 16,396.0 ± 708.2 a |
| 6 | 60 | 60 | 1.0 | 0.04 | 1,083.5 ± 53.9 a | 890.4 ± 13.4 c | 18,645.5 ± 2,240.8 a |
| 7 | 50 | 80 | 5.0 | 0.05 | 1,199.9 ± 46.1 a | 1,345.3 ± 49.8 e | 22,738.6 ± 278.6 b |
| 8 | 70 | 80 | 5.0 | 0.03 | 1,168.9 ± 83.9 a | 783.1 ± 48.0 b | 21,467.2 ± 2,461.4 b |
| 9 | 50 | 80 | 2.0 | 0.03 | 1,423.7 ± 117.4 b | 1,213.6 ± 7.55 d | 26,218.0 ± 1,377.8 b |
| 10 | 70 | 40 | 5.0 | 0.03 | 1,149.9 ± 72.7 a | 1,120.9 ± 57.6 d | 17,526.6 ± 232.2 a |
| 11 | 70 | 80 | 2.0 | 0.05 | 995.7 ± 21.7 a | 1,208.2 ± 0.47 d | 16,460.0 ± 885.9 a |
| 12 | 60 | 60 | 3.5 | 0.02 | 1,425.1 ± 143.3 b | 1,792.2 ± 150.2 f | 16,858.5 ± 1,932.0 a |
| 13** | 60 | 60 | 3.5 | 0.04 | 1,064.1 ± 64.2 a | 1,079.5 ± 88.8 d | 16,127.9 ± 716.8 a |
| 14 | 60 | 60 | 6.0 | 0.04 | 1,201.8 ± 63.5 a | 942.9 ± 42.9 c | 16,918.0 ± 1,378.4 a |
| 15 | 60 | 90 | 3.5 | 0.04 | 1,308.8 ± 48.7 b | 1,333.2 ± 8.9 e | 23,174.1 ± 1,555.1 b |
| 16 | 50 | 40 | 2.0 | 0.03 | 1,113.8 ± 104.2 a | 751.1 ± 3.9 b | 14,877.0 ± 125.2 a |
| 17 | 70 | 40 | 2.0 | 0.05 | 988.6 ± 17.3 a | 757.7 ± 61.9 b | 13,121.2 ± 593.8 a |
| 18 | 60 | 60 | 3.5 | 0.05 | 834.5 ± 6.8 a | 1,077.3 ± 21.0 d | 15,932.4 ± 416.5 a |
Y1 (TPC-MAE) = –22.9608 – 22,057.7 × X4 + 14.7794 × X1 + 23.8296 × X2 + 540.248 × X3 – 7,640.92 × X42 + 366.208 × X4 × X1 – 70.875 × X4 × X2 – 3,602.78 × X4 × X3 – 0.00481 × X12 – 0.31 × X1 × X2 – 6.03412 × X1 × X3 + 0.0219546 × X22 – 0.373333 × X2 × X3 + 1.67959 × X32 Y2 (FRAP-MAE) = –3,479.08 – 167,341 × X4 + 156.152 × X1 + 31.1404 × X2 + 1,518.47 × X3 + 1.60984E6 × X42 + 90.7463 × X4 × X1 + 512.344 × X4 × X2 – 5,395.72 × X4 × X3 – 0.681016 × X12 – 0.527356 × X1 × X2 – 16.6156 × X1 × X3 – 0.00511725 × X22 – 3.15329 × X2 × X3 – 13.7563 × X32 Y3 (ABTS-MAE) = –10,913.2 + 804,789 × X4 + 423.605 × X1 + 382.589 × X2 – 8,219.49 × X3 – 484,542 × X42 – 13,930.5 × X4 × X1 – 3,239.76 × X4 × X2 + 67,615.9 × X4 × X3 + 1.83932 × X12 – 6.76285 × X1 × X2 + 79.89 × X1 × X3 + 2.87847 × X22 – 16.583 × X2 × X3 + 196.291 × X32 | |||||||
*Derived from a Draper-Lin reduced composite design (16 random orthogonal runs and ** 2 center points). X1: ethanol concentration; X2: temperature; X3: extraction time; X4: g PDCF/mL solvent. In each column samples with different letters are statistically different at the level of alpha = 0.05. Equations at the bottom of the table are those of the fitted model based on the regression coefficients for the different responses