TABLE 6

Log reductions of L. monocytogenes Scott A treated with EOC mixed via an end-to-end shaker and ethanol stock solution in full-fat milk at 21°C

CompoundOverall concnLog reductiona
End-to-end shaker95% (vol/vol) ethanol
0 h24 h0 h24 h
Thymol5 g/liter−0.1 ± 0.2 ab−0.8 ± 0.1 b0.0 ± 0.0 a0.3 ± 0.5 a
2.5 g/liter−0.1 ± 0.1 a−1.9 ± 0.1 b0.0 ± 0.2 a−1.2 ± 0.1 b
Carvacrol5 g/liter−0.1 ± 0.1 b−0.2 ± 0.3 b0.4 ± 0.1 a0.5 ± 0.6 a
2.5 g/liter−0.1 ± 0.0 a−2.0 ± 0.0 c0.0 ± 0.1 a−1.0 ± 0.1 b
trans-Cinnamaldehyde9 g/liter0.1 ± 0.1 b0.8 ± 0.3 a0.1 ± 0.2 b1.3 ± 0.9 a
4.5 g/liter0.0 ± 0.1 a0.3 ± 0.3 a0.1 ± 0.3 a0.3 ± 0.2 a
Eugenol7 g/liter0.0 ± 0.1 a−1.2 ± 0.2 b0.1 ± 0.2 a0.4 ± 0.2 a
3.5 g/liter0.0 ± 0.0 a−1.8 ± 0.2 c0.1 ± 0.2 a−1.0 ± 0.3 b
Controls
    Negative control (no antimicrobial)−2.2 ± 0.1 C
    Ethanol4.75% (vol/vol)0.1 ± 0.2 b−1.0 ± 0.2 a A
3.5% (vol/vol)0.1 ± 0.1 b−1.6 ± 0.2 a B
  • a The log reduction is the difference between the population of L. monocytogenes in the negative control and that after mixing with EOCs using an end-to-end shaker for 30 min or a stock solution in 95% ethanol using brief vortexing, before (0 h) or after incubation at 21°C for 24 h. The population of L. monocytogenes at time 0 was 6.4 ± 0.1 log CFU/ml. Different lowercase letters next to the numbers in the same row and uppercase letters next to the controls in the same column represent significant differences (P < 0.05). The numbers are means ± standard errors (n = 3).