Table 2.
Inactivation parameters of Geeraerd et al. (2000) model for L. monocytogenes planktonic cells and biofilms after plasma activated liquid treatment.
| Cell type | Gas composition | Generation time | Population | Inactivation parameters |
RMSE | 1log reduction23 | ||
|---|---|---|---|---|---|---|---|---|
| 1log N0 (log [CFU/mL)]23/ 1log N0 [log(CFU/cm2)]23 | 1kmax (1/min)23 | 1log Nres [log(CFU/mL)]23 / 1logNres [log(CFU/cm2)]23 | ||||||
| Planktonic | 0% (v/v) O2 | 10 min | Total | 6.8 ± 0.02A | 0.003 ± 0.0041A | – | 0.0583 | ≈ 10.0 ± 0.01A |
| cells | Uninjured | 6.8 ± 0.02A | 10.001 ± 0.0031A | – | 0.0716 | ≈ 10.1 ± 0.01A | ||
| 20 min | Total | 6.8 ± 0.01A | 0.004 ± 0.0041A | – | 0.0955 | ≈ 10.0 ± 0.01A | ||
| Uninjured | 6.7 ± 0.11A | 10.000 ± 0.005A | – | 0.2739 | ≈ 10.5 ± 0.11B | |||
| 30 min | Total | 6.9 ± 0.01B | 10.042 ± 0.0141B | – | 0.0665 | ≈ 10.1 ± 0.01B | ||
| Uninjured | 6.8 ± 0.11A | 10.009 ± 0.003B | – | 0.2056 | ≈ 10.4 ± 0.11B | |||
| 1% (v/v) O2 | 10 min | Total | 6.7 ± 0.01A | 10.030 ± 0.0102A | – | 0.0847 | ≈ 10.0 ± 0.01A | |
| Uninjured | 6.6 ± 0.11A | 10.021 ± 0.0161 | – | 0.3136 | ≈ 10.3 ± 0.12A | |||
| 20 min | Total | 6.8 ± 0.51A | 21.797 ± 0.3322B | 2.0 ± 0.3 | 0.9620 | 24.8 ± 0.62B | ||
| Uninjured | 6.9 ± 0.51A | 20.000 inf | 1.2 ± 0.2 | 0.9430 | 25.7 ± 0.52B | |||
| 30 min | Total | 6.8 ± 0.71A | 2.572 ± 0.8102B | 1.3 ± 0.4 | 1.3619 | 25.5 ± 0.82B | ||
| Uninjured | 6.5 ± 0.51A | 19.272 inf | 1.2 ± 0.3 | 1.0609 | 25.3 ± 0.62B | |||
| Biofilms | 0% (v/v) O2 | 10 min | Total | 7.2 ± 0.11A | 5.421 inf | 5.4 ± 0.11A | 0.3643 | 21.8 ± 0.12AB |
| Uninjured | 7.1 ± 0.11A,B | 24.852 ± 0.0002C | 5.4 ± 0.11A | 0.3990 | 21.7 ± 0.11A | |||
| 20 min | Total | 7.3 ± 0.11A | 5.563 inf | 5.3 ± 0.11A | 0.3267 | 22.0 ± 0.11B | ||
| Uninjured | 7.3 ± 0.11B | 21.120 ± 0.2792B | 5.2 ± 0.11A | 0.3411 | 22.1 ± 0.11B | |||
| 30 min | Total | 7.1 ± 0.21A | 10.602 ± 0.239 | 5.5 ± 0.22A | 0.6065 | 21.6 ± 0.31A | ||
| Uninjured | 7.0 ± 0.21A | 20.457 ± 0.155A | 5.2 ± 0.22A | 0.6492 | 21.8 ± 0.31AB | |||
| 1% (v/v) O2 | 10 min | Total | 7.2 ± 0.11A | 20.411 ± 0.087 | 5.7 ± 0.12C | 0.3276 | 21.5 ± 0.11A | |
| Uninjured | 7.1 ± 0.11A | 20.392 ± 0.0991 | 5.6 ± 0.11C | 0.3823 | 21.5 ± 0.11A | |||
| 20 min | Total | 7.4 ± 0.11B | 10.520 ± 0.118 | 5.1 ± 0.21B | 0.5916 | 12.3 ± 0.21B | ||
| Uninjured | 7.3 ± 0.21A | 0.571 ± 0.1311 | 4.9 ± 0.21B | 0.6566 | 12.4 ± 0.31B | |||
| 30 min | Total | 7.3 ± 0.11A,B | 6.017 inf | 4.3 ± 0.11A | 0.4363 | 13.0 ± 0.12C | ||
| Uninjured | 7.2 ± 0.11A | 6.022 inf | 4.0 ± 0.11A | 0.5238 | 13.2 ± 0.12C | |||
Plasma activated liquids were created using different cold atmospheric plasma gas compositions and generation times. Inactivation parameters are determined for both the total and the uninjured population. 1Effect cell mode: for each gas composition, generation time and population type, parameters of the Geeraerd et al. (2000) model bearing different superscripts (no numbers in common) are significantly different (P ≤ 0.05). 2Effect gas composition: for each cell mode, generation time and population type, parameters of the Geeraerd et al. (2000) model bearing different superscripts (no numbers in common) are significantly different (P ≤ 0.05). 3Effect generation time: for each cell mode, gas composition and population type, parameters of the Geeraerd et al. (2000) model bearing different subscripts (no uppercase letters in common) are significantly different (P ≤ 0.05).