Microbiological and Chemico-physical Shelf-life and Panel Test to Evaluate Acceptability of Liver Mortadella.

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 [total viable count (TVC), lactic acid bacteria (LAB), Enterobacteriaceae, Escherichia coli, Pseudomonas spp., coagulase positive staphylococci, sulphite reducing clostridia, yeasts and moulds, Listeria monocytogenes and Salmonella spp.] 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 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.

Screening of species-specific lactic acid bacteria for veal calves multi-strain probiotic adjuncts.

The selection of promising specific species of lactic acid bacteria with potential probiotic characteristics is of particular interest in producing multi species-specific probiotic adjuncts in veal calves rearing. The aim of the present work was to select and evaluate in vitro the functional activity of lactic acid bacteria, Bifidobacterium longum and Bacillus coagulans strains isolated from veal calves in order to assess their potential use as multi species-specific probiotics for veal calves. For this purpose, bacterial strains isolated from faeces collected from 40 healthy 50-day-calves, were identified by RiboPrinter and 16s rRNA gene sequence. The most frequent strains belonged to the species B. longum, Streptococcus bovis, Lactobacillus animalis and Streptococcus macedonicus. Among these, 7 strains were chosen for testing their probiotic characteristics in vitro. Three strains, namely L. animalis SB310, Lactobacillus paracasei subsp. paracasei SB137 and B. coagulans SB117 showed varying individual but promising capabilities to survive in the gastrointestinal tract, to adhere, to produce antimicrobial compounds. These three selected species-specific bacteria demonstrated in vitro, both singularly and mixed, the functional properties needed for their use as potential probiotics in veal calves.

Administration of Bacillus coagulans in calves: recovery from faecal samples and evaluation of functional aspects of spores.

An investigation was carried out into the recovery from calf faeces of Bacillus coagulans spores added to the feed as probiotic. For this purpose, Bacillus coagulans spores (9 log10 CFU g⁻¹) were given daily to 10 calves during the whole farming periods; another 10 calves acted as controls. Throughout the trial the faecal spore counts were significantly (P < 0.01) higher in the treated group than in the controls (averaging 2.1 x 105 vs 3.7 x 104 CFU g⁻¹). Bacterial cells were recovered from faecal samples and ribotyping matched the strain isolated from faecal sample to the clone administered to the animals. In addition, the recovered cells were found to maintain their functionality aspects of acid production, survival in artificial gastric juice and in the presence of bile, and attachment to human intestinal epithelial cells. The results further elucidate the fate of spore formers administered to calves, and this will help in the development of new species-specific nutritional strategies.

Characterisation of a lard cured with spices and aromatic herbs.

The study considered the proximate composition, pH, free acidity, MDA and peroxide values of a cured and ripened lard covered with spices and aromatic herbs, these latter parameters, due to lipolytic endoenzymatic phenomena, tended to increase until the end of the salting period. Throughout the production phases the bacterial load was very low. The final vacuum-packed product had a shelf-life of about 90 days and its fatty acid and cholesterol composition was typical of lard. A GC/MS study of the spices/herbs in the lard highlighted which components came from the spices/aromatic herbs and which came from phenomena due to lipolytic endoenzymatic processes.

Cured products from different animal species.

An assessment was made of the proximate composition, pH and a(W) of raw beef, horsemeat and the meat of wild boar, deer and goat. The same assessment, together with one of fatty acids, cholesterol and free amino acids, was made of the same meats as cured products. The raw meat of the different animal species was found to have a reduced lipid, but high protein content. The cured meat of the horse and wild boar had low saturated fatty acid levels; the wild boar, goatmeat and beef were quantitatively similar with regard to monounsaturated fatty acids (MUFA) while in the horsemeat the polyunsaturated fatty acids (PUFA) were more raised, at an intermediate level in deer and extremely reduced in the beef final product. The cholesterol content in the cured product was markedly reduced in the horsemeat. The free amino acids content in the cured deer, wild boar and goat meat was more elevated, than in beef and horse cured meat.