Table 6. Comparison of Experimental and Predicted Values Using the Box-Behnken Design for the Four Independent Variables on the Content of Polyphenol from Water Extraction.
| extraction temperature (°C) | extraction time (min) | liquid–solid ratio | experimental value (%) | predicted value (%) | |
|---|---|---|---|---|---|
| test N | T | t | V | content | eq 4 |
| 1 | 80 | 90 | 20 | 9.5 | 9.83 |
| 2 | 90 | 120 | 25 | 9.5 | 9.43 |
| 3 | 80 | 90 | 10 | 9.4 | 9.19 |
| 4 | 90 | 60 | 15 | 8.6 | 8.79 |
| 5 | 90 | 90 | 30 | 8.6 | 8.65 |
| 6 | 80 | 90 | 20 | 9.4 | 9.19 |
| 7 | 90 | 60 | 25 | 8.5 | 8.57 |
| 8 | 60 | 60 | 15 | 8.9 | 8.95 |
| 9 | 100 | 90 | 20 | 8.8 | 8.89 |
| 10 | 90 | 120 | 15 | 8.8 | 8.92 |
| 11 | 80 | 30 | 20 | 9.8 | 9.46 |
| 12 | 40 | 90 | 20 | 8.4 | 8.66 |
| 13 | 60 | 120 | 15 | 9.2 | 9.03 |
| 14 | 80 | 90 | 20 | 9.4 | 9.19 |
| 15 | 60 | 120 | 25 | 9.1 | 9.22 |
| 16 | 80 | 150 | 20 | 9.4 | 9.19 |
| 17 | 80 | 90 | 20 | 9.2 | 9.27 |
| 18 | 60 | 60 | 25 | 8.6 | 8.36 |