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Browsing by Author "Rippen, Thomas E."

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    Inhibition of Listeria monocytogenes by Carnobacterium piscicola in Fresh and Pasteurized Crab Meat
    Tyler, Carla Gutierrez; Jahncke, Michael; Sumner, Susan S.; Hackney, Cameron Raj; Boyer, Renee R.; Wang, Hengjian; Rippen, Thomas E. (2012)
    The ability of Carnobacterium piscicola to inhibit Listeria monocytogenes at different concentration levels, storage times and temperatures was examined. Twenty-five g samples of fresh and previously pasteurized blue crab meat were placed into separate sterile 59 ml soufflé cups, inoculated with 0.1 ml C. piscicola at three different concentration levels (2, 4 and 6 log CFU/g) and 0.1 ml (log 2.0 CFU) of L. monocytogenes (ratios of 1:1, 2:1 and 3:1 of C. piscicola to L. monocytogenes). Fresh crab meat and previously pasteurized crab meat was stored at 4°C or 10°C and sampled until aerobic plate count reached ≥ 7 log CFU/g, which was considered spoilage. At each sampling time, crab meat inoculated with both organisms was plated on modified Lactobacillius deMan Rogosa Sharpe (pH 7) and modified oxford agar (MOX). Uninoculated crab meat was plated on trypticase soy agar and meat inoculated with only L. monocytogenes was plated on MOX. In both fresh and pasteurized crab meat, regardless of the inoculation levels, L. monocytogenes and C. piscicola followed similar growth trends. C. piscicola reduced growth of L. monocytogenes in pasteurized crab meat after 14 day at 4°C and 10 day at 10°C (P < 0.05).
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    Role of package type on shelf-life of fresh crab meat
    Tyler, Carla Gutierrez; Jahncke, Michael L.; Sumner, Susan S.; Boyer, Renee R.; Hackney, Cameron Raj; Rippen, Thomas E. (Food Protection Trends, 2010)
    Microbiological quality of fresh (not pasteurized) crab meat stored at 4°C in a 340 g (12 oz) food grade polyethylene traditional snap-lid container and equally fresh crab meat stored at 4°C in a 227 g (8 oz) SimpleStep® tray sealed with Cryovac™ film (oxygen transmission rate of 10,000 cc/m2/24 h) was evaluated over a 12-day period. Aerobic plate counts were conducted on storage days 0, 4, 6, 8, 10 and 12. Anaerobic plate counts were conducted on storage days 0, 5 and 12. Aerobic plate counts of crab meat from the two containers did not differ (P > 0.05). Analysis of anaerobic microbial growth indicates that sampling days were significant (P < 0.05), but container type or style was not significant (P > 0.05). Oxygen and CO2 in the package headspace was significantly different between container types (P < 0.05). Gas concentration between sampling days was not significant (P > 0.05). Results of this study demonstrate that there were no significant differences in refrigerated shelf life of crab meat packaged in SimpleStep® trays with Cryovac™ film versus the traditional polyethylene snap-lid container packaging (P > 0.05).
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    Seafood pasteurization and minimal processing manual
    Rippen, Thomas E.; Martin, Roy E.; Croonenberghs, Robert Emile (Virginia Cooperative Extension, 1993)