Table 2.

The surviving populations (log CFU/mL) of E. coli O157:H7 after the high hydrostatic pressure (HHP) treatment (HHP group) and the synergetic treatment of PCA (1.25 mg/mL for 60 min at 37 °C) and HHP (PCA + HHP group).

Treatments	HHP Group	PCA + HHP Group
0 MPa	9.08 ± 0.04 a	8.02 ± 0.06 A
100 MPa, 5 min	8.61 ± 0.61 a,*	7.55 ± 0.14 B
200 MPa, 5 min	8.56 ± 0.02 a,**	6.70 ± 0.36 C
300 MPa, 5 min	7.53 ± 0.09 b,**	5.66 ± 0.05 D
400 MPa, 5 min	6.59 ± 0.04 c,**	3.45 ± 0.12 E
500 MPa, 5 min	4.60 ± 0.20 d,**	N.D.

1. N.D. means not detected (detection limit: 1 log CFU/mL). 2. Values are means ± standard deviations from three replications. 3. Different letters a-d and A–E mean differ significantly within the HHP group and PCA + HHP group, respectively (p ≤ 0.05, Duncan test). 4. Symbol * and ** mean the difference is significant at the 0.05 and 0.01 level, respectively, between the HHP group and PCA + HHP group (t-test).