title: Microbiological and Chemico-physical Shelf-life and Panel Test to Evaluate Acceptability of Liver Mortadella.
abstract: This study aimed to evaluate the shelf life of sliced cooked livermortadellapackaged 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 [total viable count (TVC), lactic acid bacteria (LAB),Enterobacteriaceae, Escherichia coli, Pseudomonasspp., coagulase positive staphylococci, sulphite reducing clostridia, yeasts and moulds,Listeria monocytogenesandSalmonellaspp.] and physicalchemical analyses [pH, colorimetric parameters, total volatile basic nitrogen (TVBN), thiobarbituric acid reactive substances (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 colony forming unit (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/100 g and TBARs <8 nmol/g at T49). The sensorial quality of livermortadellawas 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 livermortadellashould be shortened below 30 days.
authors.affiliation: Department of Health, Animal Science and Food Safety, University of Milan , Milan, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Tirloni
authors.affiliation: Department of Health, Animal Science and Food Safety, University of Milan , Milan, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Stella
authors.affiliation: Department of Health, Animal Science and Food Safety, University of Milan , Milan, Italy.
authors.forename: Cristian
authors.initials: C
authors.lastname: Bernardi
authors.affiliation: Department of Health, Animal Science and Food Safety, University of Milan , Milan, Italy.
authors.forename: Vittorio Maria
authors.initials: VM
authors.lastname: Moretti
authors.affiliation: Department of Health, Animal Science and Food Safety, University of Milan , Milan, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Bersani
authors.affiliation: Department of Health, Animal Science and Food Safety, University of Milan , Milan, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Cattaneo
keywords: Lactic acid bacteria; Liver mortadella; Oxidation; Shelf life