Influence of starter cultures of lactic acid bacteria on microbiological parameters and shelf life of sausages

Abstract

The main spoilage microorganisms of the vacuum-packaged sausages on the first day of chilled storage are the bacteria of the following families: Enterobacteriaceae (Raoultella planticola, Raoultella ornithinolytica, and Citrobacter freundii), Morganellaceae (Morganella morganii) and Staphylococcaceae (Macrococcus caseolyticus), and at the end of the shelf life (on the twenty-first day) - Enterobacteriaceae (Proteus mirabilis, Moellerella wisconsensis and Serratia liquefaciens). An appearance of cloudy juice, surface slime and delamination of the vacuum packaging characterises the sausage spoilage. QMAFAnM in the sausages was increased by 1.09 lg CFU/g and 1.53 lg CFU/g on the first day of storage, by 1.18 lg CFU/g and 1.54 lg CFU/g on the twelfth day, by 0.92 lg CFU/g and 1.96 lg CFU/g on the eighteenth day, respectively, compared to the control sample, because “Vienna sausages with chicken fillet” were treated with starter culture SafePro BLC-48 (Lactobacillus curvatus) or the mixture of starter cultures SafePro BLC-48 (Lactobacillus curvatus) + Bactoferm Rubis (Lactococcus lactis subsp. Lactis) before vacuum packaging. Because the sausages were treated with the mixture of starter cultures SafePro BLC-48 + Bactoferm Rubis, the lactic-acid microorganisms were increased by 0.63 lg CFU/g and 0.53 lg CFU/g on the twenty-fifth and thirtieth days, respectively, compared to the sausages that were treated with SafePro BLC-48. During the entire shelf life, no pathogenic and opportunistic pathogenic bacteria, in particular S. aureus, L. monocytogenes, Salmonella spp., E. coli, coliform bacteria, as well as yeast and mold, were detected in the sausages under all treatment options. The use of starter culture SafePro BLC-48 (Lactobacillus curvatus) or the mixture of starter cultures SafePro BLC-48 (Lactobacillus curvatus) + Bactoferm Rubis (Lactococcus lactis subsp. Lactis) increases the shelf life of the vacuum-packaged sausages if they are kept in a refrigerator for up to 30 days, which is 12 days longer than their shelf life without treatment. The sausage treatment with the mixed starter cultures of the lactic-acid microorganisms may be promising if the development of the aerobic spoilage bacteria is confirmed.