Shelf life of reduced pork back-fat content sausages as affected by antimicrobial compounds and modified atmosphere packaging

The combined use of antimicrobial compounds and modified atmosphere packaging (MAP) on shelf life of reduced pork back-fat content sausages was investigated in this study. First, a pre-screening of different antimicrobial compounds and MAP was addressed. In particular, the consumer test was used as a tool to select the most pleasant antimicrobial compounds, whereas both sausage color and cell load of main spoilage microorganisms were used to choose optimal MAP. Afterwards, antimicrobial compounds (lemon alkott and thymol) and MAP (MAP1: 20% CO2, 5% O2, 75% N2) that had shown the best performance were used to run the shelf life tests. In order to assess the influence of the variables described beforehand on the shelf life of investigated sausages, the sensorial and microbiological (mesophilic and psychrotrophic bacteria, Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria and coccus-shaped lactic acid bacteria) quality was monitored during storage. Results recorded in this study suggested that Pseudomonas spp. were responsible for sausage unacceptability in all samples, except for thymol and thymol-MAP samples. For these samples, the sensorial quality was the limiting factor while the microbial growth did not limit the shelf life. In particular, for thymol and thymol-MAP samples a shelf life value of more than 5 days with respect to the other samples (2 days) was obtained.