Table 1. Coded and real values of green tea extracts and colorants added to cassava starch bio based films according to a (22) second order experimental design with 3 central points.
| FormulationFilms | Coded Values | Real Values (% w/w) | ||
| Colorant (X1) | Green tea extract (X2) | Colorant | Green tea extract | |
| F1 | −1.00 | −1.00 | 0.01 | 0.70 |
| F2 | −1.00 | 1.00 | 0.01 | 4.30 |
| F3 | 1.00 | −1.00 | 0.04 | 0.70 |
| F4 | 1.00 | 1.00 | 0.04 | 4.30 |
| F5 | −1.41 | 0.00 | 0.00 | 2.50 |
| F6 | 1.41 | 0.00 | 0.05 | 2.50 |
| F7 | 0.00 | −1.41 | 0.03 | 0.00 |
| F8 | 0.00 | 1.41 | 0.03 | 5.00 |
| F9(c) | 0.00 | 0.00 | 0.03 | 2.50 |
| F10(c) | 0.00 | 0.00 | 0.03 | 2.50 |
| F11(c) | 0.00 | 0.00 | 0.03 | 2.50 |
(c) Central points.