Table 3 Central composite design matrix for total polyphenol content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity (DPPH) and color difference (ΔE) of Cudrania tricuspidata under blanching and drying conditions
| Exp. | No. | Blanching time (sec) | Drying temp (°C) | Drying time (h) | TPC (mg GAE/g) | TFC (mg RE/g) | DPPH (%) | ΔE |
| 1 | 120(0) | 80(1) | 36(1) | 10.12±0.62 | 33.74±2.77 | 48.84±1.20 | 24.21 |
| 2 | 0(-1) | 40(-1) | 24(0) | 10.76±0.30 | 64.01±1.79 | 41.34±1.64 | 4.93 |
| 3 | 120(0) | 60(0) | 24(0) | 9.33±0.19 | 56.31±3.19 | 39.01±0.44 | 13.76 |
| 4 | 120(0) | 40(-1) | 36(1) | 10.59±0.31 | 71.96±1.13 | 37.59±3.95 | 5.09 |
| 5 | 0(-1) | 80(1) | 24(0) | 9.55±0.10 | 41.39±1.48 | 44.65±1.64 | 22.77 |
| 6 | 240(1) | 40(-1) | 24(0) | 7.93±0.29 | 52.24±0.66 | 42.21±0.70 | 2.28 |
| 7 | 240(1) | 60(0) | 12(-1) | 8.20±0.28 | 49.05±4.83 | 36.93±1.71 | 2.72 |
| 8 | 0(-1) | 60(0) | 12(-1) | 9.35±0.36 | 51.52±2.91 | 32.39±0.82 | 13.51 |
| 9 | 240(1) | 80(1) | 24(0) | 9.23±0.14 | 40.81±1.35 | 51.27±0.74 | 17.42 |
| 10 | 0(-1) | 60(0) | 36(1) | 9.58±0.42 | 48.9±2.57 | 38.17±0.95 | 19.98 |
| 11 | 120(0) | 60(0) | 24(0) | 9.60±0.00 | 64.5±4.65 | 35.48±0.58 | 14.63 |
| 12 | 120(0) | 40(-1) | 12(-1) | 8.62±0.29 | 35.48±2.44 | 34.75±0.98 | 3.43 |
| 13 | 120(0) | 80(1) | 12(-1) | 9.06±0.30 | 47.35±0.66 | 36.14±0.76 | 13.07 |
| 14 | 240(1) | 60(0) | 36(1) | 9.32±0.05 | 53.74±4.52 | 35.01±2.68 | 17.92 |
| 15 | 120(0) | 60(0) | 24(0) | 9.57±0.47 | 66.68±2.53 | 37.12±1.36 | 15.57 |