Table 5.
Mean mesophilic total viable count (TVCm), psychrophilic total viable count (TVCp), total Enterobacteriaceae (TEC), Pseudomonas spp., lactic acid bacteria (LAB), Br. thermosphacta, Photobacterium spp. and hydrogen sulphide producing bacteria (HSPB) counts (log10 CFU/cm2) on cod treated with sterile distilled water (SDW), 1% (v/v) citral (CIT), 1% (v/v) carvacrol (CAR), 1% (w/v) thymol (THY) or 1% (v/v) eugenol (EUG) and stored at 2 °C for 18 days.
| Time (days) | Treatment | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CTL 1 | SDW | CIT | CAR | THY | EUG | |||||||
| TVCm | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 3.1 | 0.4 | 2.8 | 0.3 | 3.1 | 0.2 | 2.4 | 0.1 | 3.2 | 0.1 | 3.0 | 0.2 |
| 3 | 3.9 | 0.5 | 3.9 | 0.3 | 3.9 | 0.4 | 3.3 | 0.5 | 3.5 | 0.9 | 3.7 | 0.7 |
| 6 | 5.2 | 0.6 | 5.5 | 0.4 | 5.8 | 0.3 | 5.3 | 0.3 | 5.5 | 0.4 | 5.6 | 0.3 |
| 9 | 6.4 | 0.5 | 6.6 | 0.4 | 6.9 | 0.4 | 6.9 | 0.5 | 6.8 | 0.4 | 6.9 | 0.4 |
| 12 | 7.1 | 0.3 | 7.2 | 0.3 | 7.6 | 0.2 | 7.4 | 0.2 | 7.5 | 0.3 | 7.5 | 0.2 |
| 15 | 7.9 | 0.1 | 7.8 | 0.2 | 8.1 | 0.1 | 8.0 | 0.1 | 7.9 | 0.2 | 8.1 | 0.2 |
| 18 | 7.8 | 0.3 | 7.8 | 0.3 | 8.1 | 0.3 | 8.3 | 0.4 | 8.0 | 0.2 | 8.4 | 0.4 |
| TVCp | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 3.5 | 0.2 | 3.0 | 0.2 | 3.3 | 0.1 | 2.6 | 0.2 | 3.1 | 0.2 | 3.2 | 0.1 |
| 3 | 4.3 | 0.3 | 4.2 | 0.2 | 4.2 | 0.1 | 3.7 | 0.5 | 4.3 | 0.4 | 4.3 | 0.3 |
| 6 | 5.7 | 0.3 | 5.8 | 0.2 | 6.2 | 0.1 | 5.8 | 0.3 | 6.2 | 0.3 | 6.2 | 0.1 |
| 9 | 7.1 | 0.1 | 7.0 | 0.2 | 7.4 | 0.1 | 7.2 | 0.2 | 7.3 | 0.2 | 7.4 | 0.1 |
| 12 | 7.8 | 0.1 | 7.9 | 0.2 | 8.3 | 0.1 | 8.0 | 0.2 | 7.9 | 0.2 | 8.2 | 0.0 |
| 15 | 8.2 | 0.0 | 8.3 | 0.3 | 8.2 | 0.1 | 8.7 | 0.4 | 8.3 | 0.1 | 8.3 | 0.1 |
| 18 | 8.4 | 0.2 | 8.4 | 0.2 | 8.4 | 0.2 | 8.4 | 0.2 | 8.4 | 0.2 | 8.6 | 0.2 |
| TEC | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 1.1 | 0.6 | 0.6 | 0.4 | 1.0 | 0.5 | 0.4 | 0.3 | 0.7 | 0.4 | 0.8 | 0.4 |
| 3 | 1.1 | 0.8 | 1.0 | 0.6 | 1.0 | 0.6 | 0.3 | 0.2 | 1.4 | 0.7 | 1.1 | 0.7 |
| 6 | 1.6 | 1.1 | 1.6 | 1.0 | 2.1 | 1.0 | 1.2 | 0.7 | 1.6 | 0.8 | 1.5 | 0.8 |
| 9 | 2.0 | 1.2 | 2.3 | 1.2 | 2.4 | 1.2 | 1.7 | 0.9 | 2.3 | 1.2 | 2.3 | 1.2 |
| 12 | 2.2 | 1.1 | 2.0 | 0.9 | 2.5 | 1.3 | 1.8 | 1.0 | 2.4 | 1.2 | 2.4 | 1.2 |
| 15 | 2.8 | 0.7 | 2.9 | 0.7 | 3.1 | 1.0 | 2.0 | 1.0 | 2.5 | 1.2 | 2.6 | 1.1 |
| 18 | 2.6 | 0.4 | 2.6 | 0.8 | 2.8 | 0.8 | 1.9 | 1.0 | 2.7 | 0.7 | 2.3 | 1.1 |
| Pseudomonas spp. | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 2.9 | 0.2 | 2.3 | 0.2 | 2.8 | 0.2 | 1.9 | 0.3 | 2.2 | 0.3 | 2.3 | 0.2 |
| 3 | 4.1 | 0.2 | 4.3 | 0.2 | 4.5 | 0.1 | 3.9 | 0.4 | 4.5 | 0.3 | 4.4 | 0.3 |
| 6 | 6.0 | 0.4 | 6.2 | 0.3 | 6.5 | 0.0 | 6.0 | 0.3 | 6.2 | 0.2 | 6.4 | 0.1 |
| 9 | 7.3 | 0.2 | 7.2 | 0.2 | 7.5 | 0.1 | 7.3 | 0.2 | 7.3 | 0.2 | 7.3 | 0.1 |
| 12 | 7.8 | 0.2 | 7.9 | 0.3 | 8.5 | 0.3 | 7.9 | 0.3 | 8.1 | 0.0 | 8.1 | 0.0 |
| 15 | 8.2 | 0.1 | 8.4 | 0.3 | 8.4 | 0.1 | 8.6 | 0.3 | 8.2 | 0.1 | 8.2 | 0.2 |
| 18 | 8.7 | 0.1 | 8.8 | 0.1 | 8.6 | 0.0 | 8.6 | 0.1 | 8.3 | 0.1 | 8.8 | 0.1 |
| LAB | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 2.0 | 0.5 | 1.3 | 0.5 | 1.8 | 0.5 | 1.1 | 0.4 | 1.4 | 0.5 | 1.4 | 0.5 |
| 3 | 2.2 | 0.4 | 2.0 | 0.5 | 1.8 | 0.4 | 1.1 | 0.4 | 2.6 | 0.6 | 2.1 | 0.5 |
| 6 | 2.7 | 0.5 | 2.9 | 0.4 | 3.0 | 0.6 | 1.6 | 0.4 | 2.8 | 0.7 | 3.0 | 0.4 |
| 9 | 3.6 | 0.5 | 3.7 | 0.5 | 3.9 | 0.6 | 2.5 | 0.0 | 4.0 | 0.7 | 4.2 | 0.4 |
| 12 | 4.2 | 0.5 | 4.3 | 0.3 | 5.0 | 0.6 | 3.5 | 0.2 | 4.7 | 0.7 | 5.0 | 0.4 |
| 15 | 4.7 | 0.4 | 4.9 | 0.6 | 5.3 | 0.5 | 4.7 | 0.2 | 5.3 | 0.6 | 5.5 | 0.4 |
| 18 | 5.0 | 0.5 | 4.8 | 0.6 | 5.4 | 0.4 | 4.7 | 0.2 | 5.3 | 0.5 | 5.7 | 0.2 |
| Br. thermosphacta | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 1.6 | 0.1 | 0.9 | 0.5 | 1.6 | 0.2 | 0.7 | 0.4 | 1.3 | 0.3 | 0.9 | 0.1 |
| 3 | 2.8 | 0.2 | 2.8 | 0.4 | 2.8 | 0.1 | 2.0 | 0.2 | 3.2 | 0.5 | 3.0 | 0.3 |
| 6 | 4.4 B,2 | 0.3 | 4.6 B | 0.3 | 4.3 B | 0.4 | 2.8 A | 0.2 | 4.4 B | 0.5 | 4.6 B | 0.1 |
| 9 | 5.7 | 0.5 | 5.9 | 0.4 | 5.7 | 0.4 | 4.7 | 0.6 | 5.6 | 0.5 | 5.8 | 0.3 |
| 12 | 6.1 | 0.4 | 6.6 | 0.3 | 6.5 | 0.3 | 5.5 | 0.1 | 6.5 | 0.4 | 6.6 | 0.2 |
| 15 | 7.2 | 0.4 | 7.3 | 0.4 | 6.9 | 0.3 | 6.4 | 0.0 | 6.9 | 0.4 | 6.8 | 0.5 |
| 18 | 7.1 | 0.2 | 7.4 | 0.2 | 7.0 | 0.2 | 6.4 | 0.1 | 6.8 | 0.3 | 7.0 | 0.1 |
| Photobacterium spp. | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 3.5 | 0.2 | 3.0 | 0.3 | 3.3 | 0.1 | 2.5 | 0.2 | 3.0 | 0.1 | 3.0 | 0.2 |
| 3 | 4.0 | 0.3 | 3.9 | 0.1 | 3.9 | 0.1 | 3.1 | 0.4 | 4.3 | 0.3 | 4.2 | 0.3 |
| 6 | 5.2 | 0.6 | 5.5 | 0.3 | 6.1 | 0.0 | 5.2 | 0.5 | 5.7 | 0.3 | 6.2 | 0.3 |
| 9 | 6.6 | 0.3 | 6.9 | 0.3 | 7.4 | 0.1 | 7.3 | 0.2 | 7.3 | 0.3 | 7.4 | 0.1 |
| 12 | 7.6 | 0.2 | 7.9 | 0.2 | 8.4 | 0.3 | 8.1 | 0.3 | 8.0 | 0.1 | 8.1 | 0.0 |
| 15 | 8.2 | 0.1 | 8.4 | 0.1 | 8.3 | 0.3 | 8.4 | 0.3 | 8.3 | 0.1 | 8.3 | 0.1 |
| 18 | 8.6 | 0.1 | 8.7 | 0.2 | 8.4 | 0.1 | 8.4 | 0.2 | 8.5 | 0.1 | 8.6 | 0.1 |
| HSPB | ||||||||||||
| Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | Log | SE | |
| 0 | 2.4 | 0.3 | 1.6 | 0.5 | 1.8 | 0.2 | 1.0 | 0.2 | 1.6 | 0.1 | 1.4 | 0.2 |
| 3 | 4.8 B | 0.3 | 4.6 B | 0.4 | 3.7 B | 0.3 | 1.5 A | 0.2 | 4.0 B | 0.3 | 3.4 B | 0.3 |
| 6 | 5.5 B | 0.0 | 5.6 B | 0.2 | 5.6 B | 0.4 | 2.4 A | 0.8 | 5.5 B | 0.3 | 5.3 B | 0.4 |
| 9 | 7.1 B | 0.1 | 7.0 B | 0.2 | 6.9 B | 0.4 | 4.6 A | 0.7 | 6.6 B | 0.3 | 6.0 B | 0.6 |
| 12 | 7.3 B | 0.1 | 7.3 B | 0.3 | 7.2 B | 0.3 | 3.6 A | 1.3 | 7.4 B | 0.2 | 7.1 B | 0.1 |
| 15 | 7.5 B | 0.2 | 7.5 B | 0.2 | 7.1 B | 0.3 | 4.4 A | 0.8 | 7.3 B | 0.3 | 6.9 B | 0.1 |
| 18 | 7.5 B | 0.3 | 7.4 B | 0.3 | 6.8 B | 0.3 | 4.4 A | 0.5 | 7.1 B | 0.3 | 6.7 B | 0.2 |
1 CTL = untreated control. 2 Statistical analysis: At a given sampling time the same letter indicates no significant (P > 0.05) difference. Absence of a letter also indicates no significant (P > 0.05) difference.