TABLE 5.
Net effect of 10 min of pressurization, nisin during UHP and/or after recovery, and temperature on log reduction of E. coli at pH 7.0
| Nisin concn (μg/ml) | T (°C) | −Log Nt/N0)UHP × nisin
|
|||||
|---|---|---|---|---|---|---|---|
| 150 MPaa
|
200 MPab
|
||||||
| UHPc | Recoveryc | Continuousc | UHP | Recovery | Continuous | ||
| 1 | 10 | 2.9 | 1.6 | 2.9 | 2.0 | 0.4 | 3.1 |
| 1 | 40 | 0.2 | 0 | 0.1 | −0.1 | 0 | −0.1 |
| 2 | 8 | 1.7 | 0.4 | 1.8 | 5.1 | −0.3 | 4.8 |
| 2 | 10 | 3.0 | 2.1 | >3.8 | >3.0 | 0.4 | >2.7 |
| 2 | 25 | 0.9 | 0.1 | 0.6 | 1.5 | 0.3 | 1.6 |
| 2 | 40 | 0.6 | 0 | 0.8 | 0.3 | 0.2 | 0.5 |
a
−Log Nt/N0)150 MPa = 0.3 (8°C), 2.0 (10°C), and 0.0 (25°C).
b
−Log Nt/N0)200 MPa = 0.2 (8°C), 2.3 (10°C), and 0.0 (25°C).
c
UHP, presence of nisin only during UHP treatment; recovery, presence of nisin only after UHP treatment in the recovery agar; continuous presence of nisin during UHP treatment and in the recovery of medium.