Unraveling the potential of zinc protoporphyrin-forming lactic acid bacteria for replacing nitrite and their role in quality characteristics of Harbin dry sausage

This study evaluated the effects of zinc protoporphyrin-producing lactic acid bacteria specifically <i>Weissella viridescens</i> JX11, <i>Weissella viridescens</i> MDJ8, and <i>Lactobacillus pentosus</i> Q on nitrite substitution and the quality characteristics of Harbin dry sausage. The redness (<i>a*)</i> values in the bacteria-inoculated groups were significantly higher than those in the control group (<i>P</i> < 0.05) during fermentation. Bacteria-inoculated sausages exhibited a higher proportion of oxymyoglobin and a lower proportion of metmyoglobin (<i>P</i> < 0.05). Ferrochelatase activity in the inoculated groups was significantly higher than in the control at days 3 and 6 (<i>P</i> < 0.05). Additionally, the fluorescence intensity of zinc protoporphyrin and its precursor, protoporphyrin IX, in the bacteria-inoculated groups significantly increased during fermentation (<i>P</i> < 0.05), and <i>W. viridescen</i> JX11 exhibited the highest fluorescence intensity and UV-Vis absorption peak (<i>P</i> < 0.05). These results suggest that zinc protoporphyrin-producing lactic acid bacteria could potentially replace nitrite in fermented dry sausages.