Table 3 Central composite design for ethanol extracts from unfertilized corn silk and its dependent variables
| Experiment number | X1 1) | X2 2) | X3 3) | Total polyphenol contents (μg GAE/g dried sample) | Total flavonoid contents (μg QUE/g dried sample) | Maysin contents (mg/100g dried sample) | DPPH radical scavenging activity (%) | Tyrosinase inhibition (%) |
| 1 | 0 | -1 | 1 | 2420.2 | 1510.8 | 837.07 | 36.67 | 51.13 |
| 2 | 0 | 1 | -1 | 2963.9 | 1687.5 | 853.02 | 42.69 | 24.71 |
| 3 | 0 | 0 | 0 | 2808.0 | 1655.3 | 868.72 | 41.77 | 39.63 |
| 4 | 0 | -1 | -1 | 2663.1 | 1604.3 | 854.74 | 40.53 | 37.43 |
| 5 | -1 | 0 | 1 | 2623.2 | 1486.8 | 443.43 | 26.55 | 40.85 |
| 6 | -1 | -1 | 0 | 2141.2 | 1197.6 | 241.95 | 17.00 | 57.00 |
| 7 | -1 | 0 | -1 | 2224.5 | 1300.9 | 310.53 | 16.61 | 51.13 |
| 8 | 0 | 0 | 0 | 2799.0 | 1659.6 | 852.01 | 41.11 | 36.94 |
| 9 | 1 | 1 | 0 | 2576.1 | 1358.2 | 771.82 | 65.55 | 54.55 |
| 10 | 0 | 0 | 0 | 2822.5 | 1657.5 | 853.70 | 40.62 | 36.45 |
| 11 | 1 | 0 | -1 | 2289.8 | 1155.2 | 826.42 | 65.77 | 60.67 |
| 12 | 1 | 0 | 1 | 2396.7 | 1270.7 | 814.94 | 65.73 | 59.20 |
| 13 | 1 | -1 | 0 | 2088.6 | 1029.0 | 797.63 | 65.77 | 58.22 |
| 14 | 0 | 1 | 1 | 3043.6 | 1714.6 | 683.75 | 41.36 | 21.28 |
| 15 | -1 | 1 | 0 | 2735.5 | 1575.0 | 482.52 | 31.08 | 28.13 |
Ethanol concentration (%)
Extraction temperature (°C)
Extraction time (h)