Table 5
Estimated coefficients of second order response models for green tea
| Yield(%) | EGC2)(%) | EC(%) | ECGC(%) | ECG(%) | Caffeine(%) | Totalcatechin(%) |
| Intercept | -0.48***3) | 13.07*** | 3.94*** | 23.45*** | 5.8*** | 6.09*** | 42.26*** |
| X₁1) | 8.47*** | -0.05*** | -0.02*** | -0.13*** | -0.07*** | -0.04** | -0.27*** |
| X₂ | 0.25*** | 0.08 | 0.02 | 0.15** | 0.049** | 0.03 | 0.3** |
| X₁X₁ | -0.47*** | -0.005 | -0.001 | -0.005* | 0.0009 | 0.0008 | -0.01 |
| X₁X₂ | 0.005 | -0.002*** | -0.0005** | -0.002** | -0.0006** | -0.0002* | -0.005*** |
| X₂X₂ | 0.05 | -0.01** | -0.0025* | -0.02** | -0.006** | -0.004* | -0.04*** |
| R2 | 0.9670*** | 0.9621*** | 0.9054*** | 0.9496*** | 0.9550*** | 0.8770** | 0.9778*** |
Y=b0+b1X1+b2X2+b11X12+b12X1X2+b22X2
1)X1, ratio of solvent to sample content (mL/g); X2, Extraction temperature (℃).
2)Epigallocatechin (EGC), Epicathchin (EC), Epigallocatechingallate (EGCG), Epicatechingallate (ECG).
3)*Significant at 0.1% level; **Significant at 0.05% level; ***Significant at 0.01% level.