Effect of high-pressure processing on strains of Enterobacter sakazakii.
Four strains of Enterobacter sakazakii were inoculated into tryptic soy broth and reconstituted powdered infant formula and exposed to high-pressure processing. Pressures of 200, 400, and 600 MPa were used for each medium for 1 min. E. sakazakii was reduced by more than 6 log (strains A and B) in both media at 600 MPa. Strain B was significantly (P < or = 0.05) more pressure resistant than the other strains, with just more than a 3-log reduction at 600 MPa in both media. The reconstituted infant formula has a significant (P < or = 0.05) protective effect for certain strains and pressures (strain B at 400 MPa and strain D at 400 and 600 MPa). Differences in log reductions between media (milk and broth) were also observed for certain strains and specific pressures (strain B at 400 MPa and strain D at 400 and 600 MPa; P < or = 0.05). This research showed that E. sakazakii, when present in reconstituted powdered infant formula, can be submitted to high-pressure processing (600 MPa for 1 min) and achieve log reductions ranging from 3 to 6.84, depending on the strain.
González
S
S
Department of Food Science and Technology, Virginia Tech (0418), Blacksburg 24061, USA.
Flick
G J
GJ
Arritt
F M
FM
Holliman
D
D
Meadows
B
B
D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D044083:Cronobacter sakazakii / Q000254:growth & development*; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D006874:Hydrostatic Pressure; D041943:Infant Formula