Table 2.
Plactkett-Burman design variables (in code levels) with nisin titer as response (8 h anaerobic fermentation at 30 °C).
| Run | X1 | X2 | X3 | X4 | X5 | X6 | X7 | X8 | Nisin titer (IU/ml)* |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | −1 | 1 | 1 | −1 | 1 | 1 | 1 | 2610.54 ± 78.64 |
| 2 | −1 | 1 | 1 | 0 | 1 | 1 | 1 | −1 | 2308.45 ± 80.56 |
| 3 | 1 | 1 | 0 | 0 | −1 | 1 | −1 | 1 | 3263.92 ± 123.11 |
| 4 | −1 | −1 | 0 | 0 | −1 | −1 | −1 | −1 | 1793.80 ± 23.56 |
| 5 | −1 | 1 | 0 | 1 | 1 | −1 | 1 | 1 | 2539.45 ± 63.56 |
| 6 | 1 | 1 | 1 | 0 | −1 | −1 | 1 | −1 | 3751.76 ± 231.63 |
| 7 | −1 | −1 | 0 | 1 | −1 | 1 | 1 | −1 | 2317.15 ± 134.00 |
| 8 | 1 | −1 | 1 | 1 | 1 | −1 | −1 | −1 | 2670.18 ± 57.89 |
| 9 | 1 | 1 | 0 | 1 | 1 | 1 | −1 | −1 | 2325.89 ± 89.00 |
| 10 | −1 | −1 | 1 | 0 | 1 | 1 | −1 | 1 | 2765.67 ± 99.23 |
| 11 | 1 | −1 | 0 | 0 | 1 | −1 | 1 | 1 | 3263.92 ± 189.55 |
| 12 | −1 | 1 | 1 | 1 | −1 | −1 | −1 | 1 | 2565.07 ± 135.11 |
*Values were given by mean ± standard deviation (n = 3).