Microbial and sensory changes in vacuum-packed frankfurter-type sausage byLactobacillus alimentariusand fate of inoculatedSalmonella enteritidis

Abstract

The ability of a commercial culture identified asLactobacillus alimentariusinoculated as protective culture at two different levels, i.e. 1.6×103cfucm−2and 1.6×105cfucm−2of slice, to extend the shelf-life of sliced vacuum-packed frankfurter-type sausage, known as pariza, during refrigeration (6–8°C) was investigated in comparison to control samples. The addition of protective culture increased lactic acid bacteria and suppressed other saprophytic micro-organisms like pseudomonads andBrochothrix thermosphacta. Sliced pariza, vacuum-packed in pouches with oxygen transmission rate of 3.55×10−3cm3m−224h−1Pa−1and inoculated with protective culture was acceptable up to 51 and 42 days when the level of inoculation was 1.6×103cfucm−2and 1.6×105cfucm−2of slice, respectively, compared to control pariza with a shelf-life of 23 days. The influence ofL. alimentariuson inoculatedSalmonella enteritidison freshly produced pariza held under refrigeration (6–8°C) in vacuum-packaging in pouches with oxygen transmission rate 3.55×10−3cm3m−224h−1Pa−1was also evaluated following their counts during storage. Although slightly lower growth rates ofSalmonellawere observed in samples inoculated with protective cultureL. alimentarius, multiplication ofS. enteritidiscould not be prevented. The biopreservation system tested here could not guarantee the safety of vacuum-packed sliced pariza when severe contamination withSalmonellaoccurs in this product.