Table 1. Central composite design of response surface analysis for steaming-drying conditions of black ginseng
| Exp. No. | Steaming-drying conditions |
| Steaming mean time (min)1) | Total ranges of nine step steaming at 5 min intervals | Drying mean temp. (°C)2) | Total ranges of nine step steaming at 2°C intervals |
| 1 | 150 (1) | 170−130 | 70 (1) | 78−62 |
| 2 | 150 (1) | 170−130 | 50 (−1) | 58−42 |
| 3 | 90 (−1) | 110−70 | 70 (1) | 78−62 |
| 4 | 90 (−1) | 110−70 | 50 (−1) | 58−42 |
| 5 | 120 (0) | 140−100 | 60 (0) | 68−52 |
| 6 | 120 (0) | 140−100 | 60 (0) | 68−52 |
| 7 | 60 (−2) | 80−40 | 60 (0) | 68−52 |
| 8 | 180 (2) | 200−160 | 60 (0) | 68−52 |
| 9 | 120 (0) | 140−100 | 40 (−2) | 48−32 |
| 10 | 120 (0) | 140−100 | 80 (2) | 88−72 |
Steaming mean time is the average time of the increased time by changing the time to nine steps every five minute.
Dry mean temperature is the average temperature of the increased temperature by changing the temperature to nine steps at 2°C intervals.