Table 3.
Regression models, coefficient of determination (R2) and analysis of variance (ANOVA) (Fcal and Ftab) of the estimated regression models for TPC, ABTS and ORAC for the second factorial design.
| Reparameterized Regression Model* | R2 | Fcal | Ftab | Sum of squares | Degree of freedom | Mean square | |
|---|---|---|---|---|---|---|---|
| TPC | TPC = 719.42 + 405.52x1 + 20.86x12 − 12.10x2 − 276.35x22 + 3.02x1x1 | 89% | 49.84 | 4.39 | |||
| Regression | 1.800.374 | 5 | 1.800.374 | ||||
| Residual | 216.636 | 6 | 36.106 | ||||
| Total | 2.051.725 | 11 | |||||
| ABTS | ABTS = 1,728.68 + 2771.36x1 + 2108.40x12 | 70% | 21.62 | 4.26 | |||
| Regression | 90.615.769 | 2 | 90.615.769 | ||||
| Residual | 37.698.340 | 9 | 4.188.704 | ||||
| Total | 128.314.109 | 11 | |||||
| ORAC | ORAC = 7323.20 + 2913.03x1 − 2080.33x22 + 1186.60x1x2 | 70% | 28.00 | 4.00 | |||
| Regression | 101.894.516 | 3 | 101.894.516 | ||||
| Residual | 29.069.510 | 8 | 3.633.689 | ||||
| Total | 130.964.026 | 11 | |||||
*
Reparameterized models include regression coefficients statistically significant at p < 0.05.