Authors: Almudena Soriano Helge M Ulmer Amalia G M Scannell R Paul Ross Colin Hill Antonia GarcíaRuiz Elke K Arendt
Publish Date: 2004/04/29
Volume: 219, Issue: 1, Pages: 6-13
Abstract
Nisin in the form of the commercial product Nisaplin and lacticin 3147 in whey powdered form were added to minced porkmeat in amounts of 015 w/w and 15 w/w respectively The meat was cooked and inoculated with a Staphylococcus aureus strain of meat origin and a Listeria innocua strain at a level of 107 or 105 CFU g−1 The batches were stored vacuumpackaged for 21 days at 8 °C Nisin and lacticin 3147 immediately reduced the L innocua population at the time of inoculation Nisin showed higher inhibitory activity than lacticin 3147 During the storage period a slight L innocua growth was observed in the batches inoculated with the larger inoculum and a bacteriostatic effect was observed against Listeria in the batches inoculated with 105 CFU g−1 Nisin maintained a constant S aureus population in the cooked batch inoculated with 107 CFU g−1 although the bacteriocin was capable of reducing the amount of S aureus by 90 in the batch inoculated with 105 CFU g−1 On the other hand lacticin 3147 did not show an inhibitory effect against S aureus in the cooked meat The starter culture Lactococcus lactis DPC 303T4 containing the conjugative plasmid encoding production of lacticin 3147 was inoculated in a portion of a Longissimus dorsi pork muscle with brine L lactis DPC 303T4 performed a good fermentation but lacticin 3147 production was not found after 7 days at 12 °C of storage
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