Inactivation of Listeria monocytogenes and Salmonella spp. in Milano-Type Salami Made with Alternative Formulations to the Use of Synthetic Nitrates/Nitrites

Abstract

During the manufacture of Italian salami, a traditional meat product, a sequence of hurdles like meat fermentation, air-drying, and long ripening processes are generally sufficient to inhibit the growth of most pathogens. Furthermore, Italian salami are traditionally produced by adding synthetic nitrates/nitrites to raw meat with safety and technological aims, even if controversial opinions about their use still remain, particularly in relation to the consumer demand for natural food products. In this context, the aim of the study was to investigate the inactivation of Listeria monocytogenes and Salmonella spp. during the manufacturing process of Milano-type salami made with different formulations to evaluate the contribution of the hurdles and the vegetable or synthetic additives on the inactivation of pathogens. Thus, a challenge study was performed dividing ca. 400 kg of Milano-type salami batter into three batches: Batch (A) without nitrates/nitrites; Batch (B) with vegetable nitrates, and Batch (C) with synthetic nitrates/nitrites. The batches were separately inoculated with L. monocytogenes and Salmonella spp. and the pathogens’ survival was evaluated during the fermentation, draining, and 70-day ripening of the Milano-type salami. The pathogen counts decreased in all tested conditions, even though the highest inactivation of L. monocytogenes and Salmonella spp. (p < 0.05) was observed when nitrates or nitrites were added to the batter. This study shows how the safety of these products cannot exclude the aspect of the hurdle technology during the process, which plays a major role in the reduction of pathogens, but additives like nitrates and nitrites allow for a greater margin of safety. Thus, further studies are needed to validate the use of natural compounds as alternatives to conventional preservatives in meat products. These results may provide new information to support food business operators in producing traditional foods with alternative preservatives and competent authorities in verifying the safety of the products made with natural compounds, and to control the process parameters responsible for the synergistic effect against pathogens such as L. monocytogenes and Salmonella spp.

Exploring Propolis as a Sustainable Bio-Preservative Agent to Control Foodborne Pathogens in Vacuum-Packed Cooked Ham

“…Despite not observing statistical differences between batches regarding pH values, formulation D, containing only propolis, experienced a soft decrease on day 30 that turned into a considerable drop at the end of the storage time. Although this event has not been sufficiently explored in previous studies, a similar pH decrease has been described by the effect of propolis and other plant extracts in Italian salami and chicken meat [6,44,55]. Therefore, when preservatives were maintained in batch C (propolis and preservatives), pH values remained stable due to the acidification control provided by the preservatives in the sample.…”

“…The rise of artificial additives such as nitrites and nitrates is due to the perishable nature of raw meat together with the crescent demand for more stable products that conserve their organoleptic properties. The relevance of nitrites and nitrates as the most commonly used preservatives in the meat industry relies not only on the implementation of color, texture characteristics, odor, and flavor, but also, and most importantly, on controlling undesirable microorganisms, principally Clostridium botulinum [4,6,7]. As a result, the industry needs and authorities are forced to develop high-quality and safe meat products [8].…”