Table 1.
Box-Behnken design experiment to optimize the extraction of total anthocyanins from purple potato.
| Experiment | % MeOH | Temperature | pH | Ratio | Relative Area (Measured) | Relative Area (Predicted) | Relative Error in the Prediction (%) |
|---|---|---|---|---|---|---|---|
| 1 | 0 | −1 | 0 | −1 | 72,953.22 | 74,783.20 | 2.45 |
| 2 | 1 | 0 | 0 | −1 | 188,615.38 | 173,546.00 | 8.68 |
| 3 | 1 | 0 | 0 | 1 | 205,339.62 | 197,649.00 | 3.89 |
| 4 | 0 | 0 | 0 | 0 | 98,233.05 | 114,049.00 | 13.87 |
| 5 | 0 | 1 | 0 | −1 | 209,930.07 | 209,546.00 | 0.18 |
| 6 | 0 | 0 | −1 | 1 | 24,3104.45 | 263,197.00 | 7.63 |
| 7 | 0 | 0 | 1 | −1 | 142,070.86 | 143,175.00 | 0.77 |
| 8 | 1 | 0 | 1 | 0 | 197,433.36 | 182,238.00 | 8.34 |
| 9 | 1 | −1 | 0 | 0 | 120,781.49 | 127,148.00 | 5.01 |
| 10 | 0 | 1 | −1 | 0 | 324,735.63 | 330,203.00 | 1.66 |
| 11 | 0 | 0 | 1 | 1 | 97,182.43 | 109,982.00 | 11.64 |
| 12 | −1 | 0 | −1 | 0 | 64,754.72 | 72,322.10 | 10.46 |
| 13 | 0 | 1 | 1 | 0 | 255,505.62 | 247,362.00 | 3.29 |
| 14 | −1 | 0 | 0 | −1 | 33,589.36 | 32,288.70 | 4.03 |
| 15 | −1 | 1 | 0 | 0 | 68,379.59 | 63,210.00 | 8.18 |
| 16 | 0 | 0 | −1 | −1 | 187,493.78 | 195,891.00 | 4.29 |
| 17 | 0 | −1 | −1 | 0 | 236,810.85 | 201,385.00 | 17.59 |
| 18 | 1 | 1 | 0 | 0 | 348,856.93 | 316,545.00 | 10.21 |
| 19 | 0 | −1 | 0 | 1 | 74,903.66 | 77,659.60 | 3.55 |
| 20 | 0 | −1 | 1 | 0 | 77,330.88 | 78,294.80 | 1.23 |
| 21 | −1 | 0 | 1 | 0 | 376.90 | 347.63 | 8.42 |
| 22 | 1 | 0 | −1 | 0 | 282,293.09 | 316,194.00 | 10.72 |
| 23 | −1 | −1 | 0 | 0 | 41,213.04 | 45,278.10 | 8.98 |
| 24 | 0 | 0 | 0 | 0 | 116,928.90 | 114,049.00 | 2.53 |
| 25 | 0 | 0 | 0 | 0 | 96,983.88 | 114,049.00 | 14.96 |
| 26 | 0 | 1 | 0 | 1 | 260,240.38 | 240,782.00 | 8.08 |
| 27 | −1 | 0 | 0 | 1 | 26,220.55 | 22,278.80 | 17.69 |