100B-19 |
Inhibition of Listeria monocytogenes on the surface of hot dogs using nisin-containing packaging film |
N. B. FRANKLIN1, D. K. Cooksey1, and K. Getty2. (1) Department of Packaging Science, Clemson University, B212 P & A Building, Clemson, SC 29634, (2) Food Science Institute, Kansas State University, 148 Waters Hall, Manhattan, KS 66506 Packaging film containing nisin coating may reduce Listeria monocytogenes (LM) outgrowth on the surface of hot dogs. Our objective was to determine the effectiveness of packaging films coated with solution containing 10,000 IU/cm2 or 156.3 IU/cm2 of nisin in controlling LM on the surface of vacuum packaged hot dogs. Barrier film coated with cellulose-based solution containing either 10,000 IU/cm2 (MAX) or 156.3 IU/cm2 (MIN) of nisin or no nisin (control) were heat-sealed to form individual pouches. Commercial all-beef hot dogs were placed in control and nisin-containing pouches, and inoculated with a five-strain LM cocktail (approximately 5 log10 CFU/package), vacuum-sealed, and stored for intervals of 2h, 7, 15 and 21 days at 4°C. After storage, hot dogs and packages were rinsed with 9mL of peptone water. Diluent was spiral plated on modified oxford agar (MOX) and tryptic soy agar (TSA) and incubated (37°C, 48h) to obtain counts reported as CFU/package. The study was performed in triplicate. LM counts on MOX and TSA for control films increased from 5.28 log10 CFU/package at 2h to approximately 6.30 log10 CFU/package at Day 21. MIN films had significantly lower LM counts (p>0.05) than control films at each storage interval. MIN film LM populations on MOX decreased from 4.80 at 2h to 4.42 at Day 15 before increasing to 5.34 log10 CFU/package at Day 21. Similar results were observed on TSA for MIN films. MAX film counts were <1.9 log10 CFU/package (detection limit) at all storage intervals for both MOX and TSA, which were significantly lower than MIN and control film counts. Packaging films coated with a cellulose-based solution containing 10,000 IU/cm2 of nisin significantly decreased LM outgrowth on the surface of hot dogs by greater than three logs CFU/package, whereas, approximately one log reductions were observed for films containing 156.3 IU/cm2 of nisin.
Session 100B, Food Packaging
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