Safety and technological issues of dry fermented sausages produced without nitrate and nitrite

The aim of this work was to investigate the possibility to industrially produce fermented sausages without the addition of nitrate and nitrite. Indeed, despite their antimicrobial effect and multiple technological roles, an increasing pressure for their removal has recently raised. To achieve this goal while maintaining an acceptable final product quality, we deeply modified the whole process, that was carried out at 10-15 °C (i.e., temperatures lower than traditional Mediterranean products) and by using bioprotective starter cultures at high concentrations (7 log CFU/g) to lead the fermentation. Different glucose amounts (0.2 or 0.4 % w/w) were also tested to optimize the process. The results showed no significant differences between the control (with nitrate/nitrite) and the sausages without preservatives in terms of a_w (value range 0.908-0.914), weight loss (about 38% in all samples), lactic acid bacteria (value range 8.1-8.3 log CFU/g) and coagulase negative cocci (value range 6.8-7.1 log CFU/g). The amount of sugar affected the final characteristics of sausages. Indeed, in the absence of curing salts, lower sugar concentration resulted in better textural features (reduced hardness and gumminess) and lower oxidation (TBARS values 0.80 vs. 1.10 mg MDA/kg of meat product in samples with 0.2% or 0.4% of glucose, respectively). Finally, challenge tests evidenced the inability of selected strains of Listeria innocua, Salmonella enterica sub. enterica and Clostridium botulinum to grow, under the adopted conditions, in fermented sausages. This research highlighted that nitrate/nitrite removal from these meat products requires accurate technological changes to guarantee the final quality.