| dc.description.abstract | Microbial safety and quality attributes were evaluated for frankfurters formulated
with potassium lactate/sodium diacetate (0 or 3%) and inoculated with a four-strain
Listeria monocytogenes cocktail before and after treatment with pasteurizing doses of
irradiation (0, 1.8, or 2.6 kGy). Frankfurters were inoculated after irradiation and stored
aerobically for 4 wk at 4 °C to simulate the product becoming contaminated after
opening, or they were inoculated prior to vacuum packaging and stored for 8 wk at 4 °C.
Incorporation of lactate/diacetate into frankfurter formulations with or without
irradiation had a strong listeriostatic effect throughout 4 wk of aerobic storage. Total
microbial counts for frankfurters formulated with lactate/diacetate remained constant
throughout storage while those without increased steadily (5.4 to 9.3 log cfu). Over 4 wk
of storage, the outgrowth of L. monocytogenes on frankfurters formulated with
lactate/diacetate was effectively suppressed and counts were not significantly different
from initial counts (5.2 vs. 5.0 log cfu, respectively). Irradiation treatments alone had
significantly higher L. monocytogenes counts after 3 wk of storage. Both treatments together or alone were not detrimental to sensory aroma or flavor attributes.
Meaty/brothy complex, smoke, spice aroma, springiness, and cohesiveness attributes
were judged slightly lower for frankfurters formulated without lactate/diacetate than
those with lactate/diacetate at the end of aerobic storage. Sensory color was not
dramatically influenced by either treatment, however, L*a*b* values of all treatments
decreased slightly during storage.
Both the addition of lactate/diacetate to a frankfurter formulation and irradiation
were effective towards controlling microbial growth of L. monocytogenes in an
unopened vacuum package after 8 wk of storage. Large and incremental reductions in
total microbial counts were seen with irradiation treatment, which were maintained
throughout storage with lactate/diacetate treated frankfurters. There were fewer
influences on sensory characteristics for vacuum packaged frankfurters compared to
those aerobically packaged.
Overall, lactate/diacetate addition and irradiation to a lesser extent were effective
towards retarding the outgrowth L. monocytogenes on frankfurters while maintaining
quality attributes throughout aerobic storage. The combination of irradiation and
lactate/diacetate were effective for reducing and retarding growth of L. monocytogenes
and especially during the last two weeks of vacuum packaged storage. | en |
