Effect of inoculating Lactobacillus pentosus R3 on N-nitrosamines and bacterial communities in dry fermented sausages

We investigated the effects of Lactobacillus pentosus inoculation on N-nitrosamines (NAs) contents and bacterial communities in dry fermented sausages. Culture-dependent and culture -independent (high-throughput sequencing) methods were employed to evaluate the bacterial communities. The results showed that inoculation with L pentosus improved the microbiological quality of dry fermented sausages by enhancing the competitiveness of dominant bacteria and inhibiting the growth of undesirable microbes. At the end of ripening, NA content, nitrite residue, carbonyl content, total volatile basic nitrogen, pH value, and water activity of the sausages inoculated with L pentosus were lower than the control (p < 0.05). L. pentosus showed nitrite depletion ability in Mann-Rogosa-Sharp broth. The bacteria obtained from L pentosus-inoculated sausages significantly degraded NAs in phosphate-buffered saline (p < 0.05). Thus, L. pentosus can reduce NA levels in dry fermented sausages directly by degrading NAs and indirectly by decreasing their precursors (nitrite, amines) or inhibiting NA formation under conditions of lower pH and water activity, which may be attributed to the higher microbiological quality. Thus, L pentosus is a potential starter culture for improving safety in the production of dry fermented sausages. (C) 2017 Elsevier Ltd. All rights reserved.