Inhibition of Listeria monocytogenes in cooked ham through active packaging with natural antimicrobials and high-pressure processing.
Enterocins A and B and sakacin K at 200 and 2,000 activity units (AU)/cm2, nisin at 200 AU/cm2, 1.8% potassium lactate, and a combination of 200 AU/cm2 of nisin and 1.8% lactate were incorporated into interleavers, and their effectiveness against Listeria monocytogenes spiked in sliced, cooked ham was evaluated. Antimicrobial-packaged cooked ham was then subjected to high-pressure processing (HPP) at 400 MPa. In nonpressurized samples, nisin plus lactate-containing interleavers were the most effective, inhibiting L. monocytogenes growth for 30 days at 6 degrees C, with counts that were 1.9 log CFU/g lower than in the control after 3 months. In the other antimicrobial-containing interleavers, L. monocytogenes did not exhibit a lag phase and progressively grew to levels of about 8 log CFU/g. HPP of actively packaged ham slices reduced Listeria populations about 4 log CFU/g in all batches containing bacteriocins (i.e., nisin, sakacin, and enterocins). At the end of storage, L. monocytogenes levels in the bacteriocin-containing batches were the lowest, with counts below 1.51 log CFU/g. In contrast, HPP moderately reduced L. monocytogenes counts in the control and lactate batches, with populations gradually increasing to about 6.5 log CFU/g at the end of storage.
IRTA, Finca Camps i Armet, E-17121 Monells, Girona, Spain.
Anna
A
Jofré
Margarita
M
Garriga
Teresa
T
Aymerich
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology; D001952:Bridged-Ring Compounds / Q000494:pharmacology; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D007773:Lactates / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development*; D008461:Meat Products / Q000382:microbiology*; D009561:Nisin / Q000494:pharmacology; D011312:Pressure; D013552:Swine
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D001952:Bridged-Ring Compounds; D007773:Lactates; D009561:Nisin; C012306:enterocin