ABSTRACT In the present study, low concentrations
of carvacrol (0.025 to 0.2%) and lauric arginate (LAE;
25 to 200 ppm) were tested at 4, 22, and 45°C in a
broth model, and higher concentrations of carvacrol
(0.1 to 5%) and LAE (200 to 5,000 ppm) were tested
individually and in combination at 4°C in 3 different
ground turkey samples (with 15, 7, and 1% fat content)
for their effectiveness against a 3-strain mixture
of Salmonella. A low concentration of 25 ppm of LAE
or 0.025% carvacrol had no effect on Salmonella in a
broth model, but their mixture showed a synergistic
action by reducing 6 log cfu/mL Salmonella counts to a
nondetectable level within 30 min of exposure. The US
Food and Drug Administration-recommended 200 ppm
of LAE was not sufficient for Salmonella reductions in
ground turkey when applied internally. High concentrations
of 2,000 to 5,000 ppm of LAE or 1 to 2% carvacrolwere needed to reduce Salmonella counts by 2 to 5 log
cfu/g in ground turkey by internal application. No specific
relationship existed between fat content and LAE
or carvacrol concentrations for Salmonella reductions.
For example, 2,000 ppm of LAE could reduce Salmonella
counts by 4 log cfu/g in 1% fat-containing turkey
samples but very similar ~1.5 log cfu/g reductions in
both 7 and 15% fat-containing ground turkey samples.
For the total microbial load, about 2,000 ppm of LAE
or 2% of carvacrol treatments were needed to achieve 2
to 3 log (P ≤ 0.05) cfu/g reductions in different turkey
samples. A mixture of 1% carvacrol and 2,000 ppm of
LAE exhibited a synergistic action in ground turkey
containing 7% fat by reducing the Salmonella counts
by 4 log cfu/g, which was not found with individual
antimicrobial treatments.