Table 1 Effects of PEF process to reduce microbe contamination in milk
Producers | Process | TPC | MPN | Salmonella spp. | S. aureus | B. cereus | L. monocytogenes (qualitative) |
|---|---|---|---|---|---|---|---|
(colony/ml) | Enterobacter | (qualitative) | |||||
(MPN/ml) | |||||||
A | Raw milk | > 3 × 107 | > 110 | V | 4 × 105 | 2.7 × 103 | Less than 1 |
Heating (60 °C) | 4.7 × 102 | < 0.3 | Less than 1 | 4.8 × 101 | 1.3 × 103 | Less than 1 | |
PEF | less than 1 | < 0.3 | Less than 1 | 8.5 | 9.3 × 102 | Less than 1 | |
Cooling (50 oC) | 7.1 × 101 | < 0.3 | Less than 1 | 5.1 × 101 | 2.6 × 103 | Less than 1 | |
B | Raw milk | 2.5 × 107 | 12 | V | > 3 × 106 | < 100 | Less than 1 |
Heating (74 °C) | 2.6 × 103 | < 0.3 | Less than 1 | 6.3 × 101 | 4.5 × 102 | Less than 1 | |
PEF(50 kV, 10 s) | 3.5 × 104 | < 0.3 | Less than 1 | less than 1 | 5.8 × 102 | Less than 1 | |
Cooling (50 °C ) | 2.8 × 104 | < 0.3 | Less than 1 | less than 1 | 7.2 × 101 | Less than 1 | |
C | Raw milk | 2.3 × 106 | > 110 | Less than 1 | 2.8 × 103 | less than 1 | Less than 1 |
Heating (60 °C) | 7.8 × 106 | > 110 | Less than 1 | 4.9 × 105 | less than 1 | Less than 1 | |
PEF 1 | 3.5 × 105 | > 110 | Less than 1 | 2.5 × 105 | less than 1 | Less than 1 | |
PEF 2 (55 °C) | 1.5 × 105 | > 110 | Less than 1 | 2.4 × 103 | less than 1 | Less than 1 | |
PEF 3 (60 °C) | 4.6 × 103 | 2.3 | Less than 1 | 2.1 × 102 | Less than 1 | Less than 1 | |
Mixing (50 °C) | < 4 | < 0.3 | Less than 1 | 1.8 × 102 | Less than 1 | less than 1 | |
D | Raw milk | > 3 × 107 | > 110 | V | 3.4 × 105 | Less than 1 | Less than 1 |
Thermal Pasteurization (65–70 °C) | 1.6 × 102 | < 0.3 | Less than 1 | 6.3 × 100 | Less than 1 | Less than 1 | |
Cooling (room temperature) | 2 × 102 | 3.5 | Less than 1 | Less than 1 | Less than 1 | Less than 1 | |
E | UHT milk | Less than 1 | Less than 1 | Less than 1 | less than 1 | Less than 1 | Less than 1 |
UHT milk | Less than 1 | Less than 1 | Less than 1 | less than 1 | Less than 1 | Less than 1 |