Characterization and exploiment of Microbial Strains to be used in Meat Processing and Fermentation

The principal aim of this research project has been the evaluation of the specific role of yeasts in ripening processes of dry-cured meat products, i.e. speck and in salami produced by adding Lactobacilli starter cultures, i.e. L. sakei, L. casei, L. fermentum, L. rhamnosus, L.sakei + S.xylosus. In particular the contribution of the predominant yeasts to the hydrolytic patterns of meat proteins has been studied both in model system and in real products. In fact, although several papers have been published on the microbial, enzymatic, aromatic and chemical characterization of dry-cured meat e.g. ham over ripening, the specific role of yeasts has been often underestimated. Therefore this research work has been focused on the following aspects: 1. Characterization of the yeasts and lactic acid bacteria in samples of speck produced by different farms and analyzed during the various production and ripening phases 2. Characterization of the superficial or internal yeasts population in salami produced with or without the use of lactobacilli as starter cultures 3. Molecular characterization of different strains of yeasts and detection of the dominant biotypes able to survive despite environmental stress factors (such as smoke, salt) 4. Study of the proteolytic profiles of speck and salami during the ripening process and comparison with the proteolytic profiles produced in meat model systems by a relevant number of yeasts isolated from speck and salami 5. Study of the proteolytic profiles of Lactobacilli starter cultures in meat model systems 6. Comparative statistical analysis of the proteolytic profiles to find possible relationships between specific bands and peptides and specific microorganisms 7. Evaluation of the aromatic characteristics of speck and salami to assess relationships among the metabolites released by the starter cultures or the dominant microflor

LC-ESI-QTOF-MS identification of novel antioxidant peptides obtained by enzymatic and microbial hydrolysis of vegetable proteins

Bioactive antioxidant peptides are more and more attracting the attention of food manufacturers for their potential to transform food in functional food, able to prevent a variety of chronic diseases associated with oxidative stress. In the present study proteins extracted from different vegetable sources (KAMUT khorasan wheat, emmer, lupine and pea) were hydrolyzed with commercial enzymes and Lactobacillus spp. strains. Hydrolysates were separated by size exclusion chromatography and purified fractions were analyzed for their antioxidant activity. Peptides from the fractions with the highest activity were identified by nanoLC-ESI-QTOF-MS and thirteen peptides were selected for synthesis on the basis of their sequence. Four peptides (VLPPQQQY, TVTSLDLPVLRW, VTSLDLPVLRW, FVPY) were found able to scavenge superoxide anion and hydroxyl radicals, organic nitro-radicals (ABTS, DPPH) and to inhibit lipid peroxidation. The impact of this work is targeted to add hydrolysed vegetable proteins to reformulated functional food or to produce health-promoting ingredients and nutraceuticals

Exploitation of starch industry liquid by-product to produce bioactive peptides from rice hydrolyzed proteins

Small peptides show higher antioxidant capacity than native proteins and may be absorbed in the intestine without further digestion. In our study, a protein by-product from rice starch industry was hydrolyzed with commercial proteolytic enzymes (Alcalase, Neutrase, Flavourzyme) and microbial whole cells of Bacillus spp. and the released peptides were tested for antioxidant activity. Among enzymes, Alcalase was the most performing, while microbial proteolytic activity was less efficient. Conversely, the antioxidant activity was higher in the samples obtained by microbial hydrolysis and particularly with Bacillus pumilus AG1. The sequences of low molecular weight antioxidant peptides were determined and analyzed for aminoacidic composition. The results obtained so far suggest that the hydrolytic treatment of this industrial by-product, with selected enzymes and microbial systems, can allow its exploitation for the production of functional additives and supplements rich in antioxidant peptides, to be used in new food formulas for human consumption

Commento di Eugenio Guccione a Un’età contro la storia. Saggio sulla rivoluzione del XXI secolo

In his comment to Giuseppe Carlo Marino’s essay about the globalization and crisis of “historical thought”, Eugenio Guccione proposes a historical and philosophical interpretation of the changes in the relationship among political events, roll and the meaning of the human existence, and cultural debate linked to the “globalizing” phenomena, inserting the events and recent evolutions of the historical thought in a larger context of redefinition of the very concept of history