Strategies to substitute/reduce conventional nitrites and nitrates in processed meats, with particular focus on...

Nitrites and nitrates have been traditionally used during manufacturing of processed meats due to their antimicrobial action (especially against Clostridium botulinum), their antioxidant activity and their ability to develop the typical flavour and colour of these products. Concerns about N-nitrosamines and an increased risk of cancer have motivated research on reducing levels of these compounds, using alternative substances and non-thermal technologies. The maximum permitted levels within the European Union have been reduced according to the most recent European Commission Regulation 2023/2108 highlighting the importance of eliminating the addition of these compounds. This manuscript reviews the effects of reduced concentrations of nitrites and nitrates, the addition of natural and artificial compounds, as their replacements, as well as the use of starter or protective cultures and non-thermal technologies during production of processed meats. It concludes that the available evidence indicates that reducing sodium nitrite concentrations in processed meat products may be feasible without compromising food safety as 50-75 ppm has been reported to inhibit C. botulinum toxigenesis, while 100 ppm was sufficient to assure the safety of minced roasted beef. However, the effectiveness of reduced nitrite levels appears to be pathogen and matrix dependent. In particular, Listeria monocytogenes shows greater tolerance to nitrite, with growth not being completely prevented even at concentrations approaching or exceeding currently permitted levels. Therefore, although reducing nitrite concentrations may be possible, nitrite alone cannot be considered sufficient to ensure comprehensive microbiological safety of processed meat products. This review contributes to the current knowledge about the development of novel formulations and serves as guidance for future investigations.