Table 2.
Antibacterial activity of B. rapa extracts, ZnO-QDs and its different combination against foodborne bacteria.
| Bacteria | Inhibition zones mm (mean ±* S.E) | ||||||
|---|---|---|---|---|---|---|---|
| Negative control | Positive control | I | II | III | IV | V | |
| B. cereus | 0 | 10.5 ± 0.44b | 8.3 ± 0.93c | 8.5 ± 0.45c | 11.8 ± 0.68a | 10.3 ± 0.68b | 10.2 ± 0.52b |
| Staph. aureus | 0 | 12.3 ± 1.57a | 8.5 ± 0.44c | 10.7 ± 0.58b | 9.2 ± 0.68c | 11.5 ± 0.45ab | 10.7 ± 0.68b |
| E. coli | 0 | 30.0 ± 1.34a | 9.2 ± 0.68d | 8.3 ± 0.52d | 15.0 ± 1.18c | 19.0 ± 1.80b | 15.7 ± 1.44c |
| L. monocytogenes | 0 | 32.3 ± 1.25a | 8.0 ± 0.86bc | 7.7 ± 0.28c | 9.0 ± 0.86b | 30.5 ± 2.29a | 16.8 ± 2.52b |
| S. typhi | 0 | 32.0 ± 1.95a | 7.8 ± 0.68e | 8.3 ± 0.26de | 9.3 ± 0.28d | 15.5 ± 1.18b | 11.8 ± 0.25c |
| P. aeruginosa | 0 | 19.0 ± 0.44a | 9.2 ± 1.44d | 9.3 ± 0.25d | 12.0 ± 0.45c | 14.8 ± 0.93b | 11.3 ± 0.52c |
n = 3, * S.E: Standard error, different subscripts within row are significantly different at the 5% level, I: B. rapa essential oil, II: B. rapa ethanolic extract, III: ZnO-QDs, IV: combination between ZnO-QDs and B. rapa essential oil, V: combination between ZnO-QDs and ethanolic extract, negative control: DMSO, positive control: ceftriaxone.