Effect of lactic acid bacteria on quality and safety of ready-to-eat sliced cured/smoked meat products

The bioprotective properties of native lactic acid cultures and their bacteriocins may be used for increasing the microbiological safety and stability of traditional sliced smoked pork products. It is expected that this addition would not affect consumer's perception and, consequently, the acceptability of these traditional smoked meat products. The effect of two different LAB cultures, two different application methods and two different modified atmosphere packaging conditions (MAP) on growth control of Listeria monocytogenes and on sensory properties of "Chouriço", a sliced cured/smoked pork product, were studied. Lactobacillus sakei ST153 (autochthonous bacteria) and BLC35 (commercial mixed starter culture including strains of Lactobacillus curvatus, Staphylococcus xylosus and Pediococcus acidilactici; CHR Hansen) both with bacteriocinogenic activity against Listeria monocytogenes, were applied by immersion or spray on smoked pork slices that were produced at industrial scale and packed under MAP (8 % or 12 % v/v CO 2) and stored at 5 °C. Previously to the incorporation of LAB cultures, L. monocytogenes was gently spread with a sterile cotton swab into the slices. The enumeration of LAB and L. monocytogenes was performed during the storage at 5 °C. A quantitative descriptive sensory test was performed by a sensory trained panel at 30, 90 and 120 days, involving previous sessions for main descriptors definition, their scale limits as well as verbal anchors by panel consensus. A final sheet with nine descriptors (meat colour, greasiness, characteristic odour, offodour, hardness, succulence, characteristic taste, acid taste, bitter taste), each one with a 13-point scale, was validated. Listeria monocytogenes decreased to values <100 CFU/g in smoked pork slices of both application techniques. Meat colour, succulence and characteristic taste were the common attributes for both LAB cultures that varied over the shelf life. The application method had no significant effect on any of the sensorial attributes analyzed. MAP influence was only noticed in terms of greasiness and hardness. The samples containing BLC35 addition were categorized as harder and as less succulent than the ones containing L. sakei ST153.