This study aimed to evaluate the shelf life of sliced cooked liver mortadella packaged in MAP (70-85% N2, 15-30% CO2) and stored in refrigeration (4°C) or slight thermal abuse (8°C) for up to 49 days (declared best before date 45 days). The proximate composition, aw nitrites and NaCl content were determined at T0. Weekly, samples were submitted to microbiological (TVC, LAB, <em>Enterobacteriaceae</em>, <em>Escherichia coli</em>, <em>Pseudomonas</em> spp., Coagulase Positive Staphylococci, Sulphite reducing Clostridia, yeasts and moulds, <em>Listeria monocytogenes</em> and <em>Salmonella</em> spp.) and physical-chemical analyses (pH, colorimetric parameters, TVBN, TBARs), in parallel with consumer acceptability tests. The product characteristics (low salt and nitrites concentration, high aw and pH close to 6.5) were not efficient hurdles for microbial growth. No pathogens were detected in the samples; the initial TVC (5.4 Log CFU/g) increased rapidly, reaching values around 8 Log CFU/g at T14 for both the series, and was almost totally composed by LAB, leading to the acidification of the product (pH at T49 = 5.05 at 4°C and 5.24 at 8°C). The other microbiological parameters were below 2 Log CFU/g. The product showed a good protein and lipid stability (TVBN <33 N/100g and TBARs <8 nmol/g at T49). The sensorial quality of liver mortadella was more affected by the storage time than by the temperature. An evident colour modification was detected after T35, when the product was also frequently rejected by the panellists, mainly due to odour. Thus, the shelf life of sliced cooked liver mortadella should be shortened below 30 days.
Effect of nisin on shelf life of low salt Tallaga cheese
