LAUSR

Abstract The objective of the present study was to investigate the effect of reused brine and fresh salt brine on nitrites and biogenic amines production in low-salt Paocai during fermentation, with insights into the impact of initial microbial loading and acidification. By monitoring the changes in microbial counts, physicochemical properties as well as the production of nitrites, biogenic amines and precursor amino acid nitrogen (AAN) in Paocai fermented with reused brine (RB), microorganism-reduced reused brine (MRRB), fresh salt brine (SB) and acidified fresh salt brine (ASB), the results showed that RB promoted the growth of lactic acid bacteria (LAB) and yeasts, causing a rapid consumption of reducing sugar. MRRB and RB inhibited the undesirable enterobacteria, while SB and ASB failed. Among the treatments, RB achieved highest AAN contents and lowest contents of nitrites (1.10 mg/kg), histamine (0.29 mg/kg), tyramine (0.79 mg/kg) and cadaverine (not detected) after fermentation. Comparing SB with ASB, it was found that initial acidification of salt brine eliminated cadaverine and reduced histamine contents by 33.93%. These results suggested that the initial microbial loading and acidification of brine could reduce nitrites and biogenic amines production in Paocai during fermentation, which might provide guidance for production of fermented vegetable with higher safety.