627 research outputs found
Efficacy of buffered sodium citrate alone and in combination with sodium diacetate againstListeria monocytogenes on beef franks
We assessed the antimicrobial efficacy of buffered sodium citrate alone and in combination with sodium diacetate against L. monoyctogenes on beef frank samples stored at 39°F. Initial inoculum level of L. monocytogenes was 1.5 log colony forming units (CFU)/cm2. After 6 weeks of incubation at 39°F, the pathogen reached 5.4 log CFU/cm2 in the control sample, but was 1.2 log CFU/cm2 and 0.85 log CFU/cm2 in samples treated with 1% buffered sodium citrate alone and in combination with 0.1% sodium diacetate, respectively. Use of buffered sodium citrate and the combination of buffered sodium citrate and sodium diacetate should improve safety of ready to eat foods by controlling L. monocytogenes during storage
MF2315
Melvin Hunt et al, Making ground beef patties and sausage safer, Kansas State University, January 1998
Control of Escherichia coli O157:H7 in large-diameter, lebanon-style bologna
Lebanon bologna raw batter was mixed with a five-strain mixture of Escherichia coli O157:H7 to achieve average inoculum levels of 7.79, 7.77, and 7.92 log CFU/g as deter mined on MSA, 202, and PRSA media, respectively. Treatment 1 consisted of a fermentation cycle of 8 hrs at an internal temperature (I.T.) of 80EF then 24 hrs at 100EF I.T., followed by 24 hrs at 110EF I.T. Treatments 2, 3, and 4 included additional heating at 115EF I.T. for 1, 2, and 5 hrs, respectively. All heat treatments resulted in product that was negative (\u3c1.9 log CFU/g detection limit) on all culture media and negative after enrichment on mEC selective medium. This study validates that a five-log reduction of E. coli O157:H7 can be achieved using the described protocol, thus meeting USDA/FSIS requirements
Translocation of natural microflora from muscle surface to interior by blade tenderization
The effect of blade tenderization on translocation
of natural microflora from the surface to
the interior of longissimus dorsi steaks aged for
7, 14, and 21 days was evaluated. Samples
from the exterior and interior of steaks from
blade-tenderized (BT) and non-blade-tenderized
(N-BT) strip loins were analyzed for aerobic
plate, coliform, and Escherichia coli counts.
Results showed that BT translocated microorganisms
(aerobic plate counts) from the exterior
to the interior of muscle. Microorganism numbers
increased with extended storage (P<.05).
Counts of coliforms and Escherichia coli
recovered from BT steaks were comparable to
those from N-BT steaks because of very low
exterior counts, showing the importance of good
hygiene
Effects of quality grade, aging period, blade tenderization, and degree of doneness on tenderness of inside round steaks
We used 162 inside rounds to determine the
influence of different quality grades, postmortem
aging periods, blade tenderization passes, and
degree of doneness on thawing and cooking
losses and Warner-Bratzler Shear force (WBS,
tenderness). Select (SEL), Choice (CHO), and
Certified Angus Beefâ„¢ (CAB) inside rounds
were aged for 7, 14, or 21 days and not tenderized
(0X) or blade tenderized one (1X) or two
(2X) times. Steaks from each inside round
were assigned randomly to final endpoint cooking
temperatures of 150, 160, and 170°F.
Percentage of thawing loss was higher (P<.05)
for steaks aged 7 days than steaks aged 14 and
21 days. For CHO steaks only, cooking loss
was higher (P<.05) for the 2X group compared
to the 0X and 1X groups. Steaks aged 14 and
21 days had lower (P<.05) WBS than steaks
aged 7 days. Cooking loss and WBS were
higher (P<.05) with each increase in endpoint
cooking temperature. Postmortem aging (14 or
21 days) and lower endpoint cooking temperatures
were the most effective methods to improve
WBS of inside round steaks
Validation of a traditional Italian-style salami manufacturing process for control of salmonella and Listeria monocytogenes
Italian-style salami batter (formulated with pork shoulder) was inoculated with ca. 7.0 log CFU/g of either Salmonella
or Listeria monocytogenes. Salami links (55-mm cellulose casings) were fermented at 308C for 24, 40, or 72 h and then dried
to target moisture/protein ratios (MPRs) of 1.9:1 or 1.4:1. Links were sampled after fermentation (24, 40, and 72 h) and after
combined fermentation-drying treatments (MPRs of 1.9:1 and 1.4:1 for all fermentation periods), and microbiological and
proximate analyses were performed at each sampling. Pathogen populations were enumerated by direct plating on selective
agar and by an injured-cell recovery method. When enumerated by the injured-cell recovery method, Salmonella populations
were reduced by 1.2 to 2.1 log CFU/g after fermentation alone (24 to 72 h) and by 2.4 to 3.4 log CFU/g when fermentation
was followed by drying. Drying to an MPR of 1.4:1 was no more effective than drying to an MPR of 1.9:1 (P . 0.05). When
enumerated directly on selective media, Salmonella populations were reduced from 1.6 to 2.4 log CFU/g and from 3.6 to 4.5
log CFU/g for fermentation alone and fermentation followed by drying, respectively. L. monocytogenes populations were
reduced by ,1.0 log CFU/g following all fermentation and combined fermentation-drying treatments, regardless of the enumeration
method. These results suggest that the Italian-style salami manufacturing process evaluated does not adequately
reduce high pathogen loads. Processors may thus need to consider supplemental measures, such as raw material specifications
and a final heating step, to enhance the lethality of the overall manufacturing process
Effects of injection marination with various calcium sources and molar concentrations on display color life, tenderness, and microbial inhibition of beef loin steaks
Beef strip loins were assigned to one of
11 treatments that included injection
marination (10% by weight) with three
calcium salts at three molar concentrations,
a distilled water control, and a non-marinated
control. The effects of calcium
salt and concentration were tested for retail
display color life, tenderness and sensory
traits, and microbial growth. Calcium
lactate marinated steaks had longer color life
and less microbial growth than those treated
with calcium chloride or calcium ascorbate.
Increasing molar concentration (.1M to .2M to
.3M) caused faster color deterioration, and did
not significantly improve microbial inhibition.
All calcium treatments improved tenderness;
however, calcium chloride treatments induced
off-flavors. Considering a whole system
approach that accounts for color life, microbial
inhibition, shear force, and sensory traits, we
recommend injecting beef longissimus with
10% of a .1M solution of calcium lactate, and
do not recommend other calcium salts or
concentrations
Effects of cetylpyridinium chloride treatment of roast beef on Listeria monocytogenes populations and quality attributes
The effectiveness of cetylpyridinium chloride
(CPC) for reducing microbial populations,
in particular Listeria monocytogenes, on
ready-to-eat roast beef was evaluated. Roast
beef slices inoculated with L. monocytogenes
were dipped in a solution of 1% CPC for 1
minute. Samples were then vacuum packaged
and stored at refrigeration temperature. The
effects of CPC treatment on microbial populations, as well as on color and texture of the roast beef samples, was evaluated over a 42-day period. Immediately after CPC treatment, L. monocytogenes populations were reduced by 99 to 99.99%, with the treatment being somewhat more effective on exterior than on sliced/cut surfaces. Throughout 42 days of refrigerated storage, populations of L. monocytogenes, total bacteria, and lactic acid bacteria remained lower on CPC-treated samples than on non-treated samples. Treatment with CPC did not significantly affect the color or texture of roast beef. Treatment with CPC, especially when applied to products before slicing, may serve as an effective antimicrobial intervention for ready-to-eat meat products
Control of Escherichia coli O157:H7 in large-diameter, lebanon-style bologna
Lebanon bologna raw batter was mixed
with a five-strain mixture of Escherichia coli
O157:H7 to achieve average inoculum levels of
7.79, 7.77, and 7.92 log CFU/g as deter
mined on MSA, 202, and PRSA media,
respectively. Treatment 1 consisted of a
fermentation cycle of 8 hrs at an internal
temperature (I.T.) of 80EF then 24 hrs at
100EF I.T., followed by 24 hrs at 110EF I.T.
Treatments 2, 3, and 4 included additional
heating at 115EF I.T. for 1, 2, and 5 hrs,
respectively. All heat treatments resulted in
product that was negative (<1.9 log CFU/g
detection limit) on all culture media and
negative after enrichment on mEC selective
medium. This study validates that a five-log
reduction of E. coli O157:H7 can be
achieved using the described protocol, thus
meeting USDA/FSIS requirements
Sensory traits, color, and shelf life of low-dose irradiated, raw, ground beef patties
Irradiation of raw ground beef patties had
minimal effects on flavor and aroma of patties
after cooking. Oxidative rancidity increased
when patties were irradiated in aerobic but not
in vacuum packages. Irradiation of vacuum-packaged
ground beef patties produced a more
stable color. In both packaging types,
irradiation significantly reduced microbial
growth during storage
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