This Ph. D. thesis is focused on the implementation of meat product quality. In recent years the European Union has promoted a "green" policy for the research of new, more sustainable technologies with the aim of achieving carbon neutrality by 2050. In particular, an issue that is very important to consumers is the reduction of the use of synthetic preservatives, favouring the use of natural compounds. Among synthetic preservatives, the most used for the preparation of fermented meat products are nitrite and nitrate salts. Despite a long history of use, the consumption of nitrites has been associated with stomach cancer, being that nitrite residues in an acidic environment can react with protein residues and form N-nitroso-compounds, a class of compounds in which carcinogenic molecules are also included. Considering that fermented meat products have always been part of the Italian culinary tradition, improving quality is a central issue to protect consumer health without excluding traditional meat products from the diet. In this regard, lactic acid bacteria and coagulase negative catalase positve cocci have been investigated for their ability to produce nitric oxide via nitric oxide synthase pathway in order to reduce the use of nitrite and nitrates in fermented meat products. The most promising strains have been selected for the production of fermented sausages. Microbial safety, chemical-physical quality and sensory properties of innovative products have been investigated. Results indicate that a partial remove of nitrite and nitrate in fermented meat products is possible and that the selection of performing strains is a valid strategy to improve the quality of meat products.
