Table 5.
Antimicrobial activity of different garlic samples against food-related microorganisms (inhibition zone in mm).
| Microorganism | Negative Control (20% Ethanol) |
Non-Australian Garlic | Australian X Garlic | Australian Y Garlic | |||
|---|---|---|---|---|---|---|---|
| Clove | Skin | Clove | Skin | Clove | Skin | ||
| Water extraction | |||||||
| B. cereus | - | - | - | 21.7 ± 1.2 a * | - | 21.9 ± 1.3 a | - |
| L. monocytogenes | - | 32.9 ± 0.5 a | - | 33.9 ± 1.2 a | - | 33.5 ± 1.5 a | - |
| P. aeruginosa | - | - | - | - | - | - | - |
| C. albicans | - | 23.9 ± 0.7 a | - | 23.5 ± 3.7 a | 16 ± 0.5 b | 24.5 ± 0.8 a | 22.7 ± 1.3 a |
| R. mucilaginosa | - | 27.2 ± 1.2 ab | - | 27.1 ± 0.4 b | 17.6 ± 2.4 d | 30.7 ± 0.8 a | 23.4 ± 0.8 c |
| S.aureus | - | 18.9 ± 0.5 c | - | 19.1 ± 1.1 c | 22 ± 0.6 b | 24.8 ± 0.6 a | - |
| E. Coli | - | 16.9 ± 0.1 a | - | 15.8 ± 0.7 a | 16.8 ± 0.6 a | Possibly partial inhibition | - |
| Methanolic extraction | |||||||
| B. cereus | - | 22.7 ± 0.6 c | - | 30 ± 1.8 a | - | 25.6 ± 1 b | 13.3 ± 0.5 d |
| L. monocytogenes | - | 24.9 ± 0.7 a | - | 25 ± 1.5 a | 19.2 ± 0.4 b | 20.6 ± 0.8 b | 19.2 ± 0.7 b |
| P. aeruginosa | - | - | - | 13.5 ± 0.4 a | - | 14.0 ± 0.5 a | - |
| C. albicans | - | 38.3 ± 1.6 ab | - | 40.9 ± 1.5 a | 21.3 ± 1.1 c | 37.1 ± 0.7 b | 23.9 ± 1.2 c |
| R. mucilaginosa | - | 37.3 ± 0.9 a | - | 37 ± 0.4 a | 24.0 ± 2.2 c | 32.0 ± 1.1 b | 27.3 ± 0.9 c |
| S. aureus | - | 27.3 ± 4.7 ab | - | 34.3 ± 2.1 a | 20.5 ± 0.3 bc | 30.0 ± 3.6 a | 19.4 ± 0.5 c |
| E. Coli | - | 19.8 ± 0.1 b | - | 23.9 ± 0.6 a | - | 19.6 ± 0.5 b | - |
* Data expressed as mean ± SD (n = 3). Mean values of each row with different letters are significantly different (p < 0.05). (–) Denotes that no zone of inhibition was observed. Criteria for antimicrobial activity: <10 mm, weak; 10–15 mm, moderate and >15 mm, strong.