Abstract: The effect of salt reduction on the formation of biogenic amines in farmhouse fermented soybean paste in northeast China was studied in this paper. The contents of total and individual contents of eight biogenic amines (spermine, putrescine, tryptamine, phenethylamine, cadaverine, histamine, tyramine, and spermidine) in samples with salt reduction by 0 (control), 10%, 20%, 30% and 40% were analyzed. Besides, physicochemical and microbial parameters were measured, namely amino nitrogen content, acidity, and the total number of colonies and sensory quality scores were determined. Compared with the control group, the total and individual contents of all the biogenic amines except spermine and spermidine increased to varying degrees with the decrease in salt content, with the most significant increase being observed in cadaverine and histamine. At the same time, acidity, the total number of colonies and sensory quality scores changed to varying degrees, while amino nitrogen content did not change significantly. In the samples with 10% and 20% salt reduction, the total and individual contents of the eight biogenic amines did not increase significantly, and histamine contents were respectively 58.00 and 64.32 mg/kg, which were lower than the EU recommended limit of 100 mg/kg. In addition, sensory quality scores but not acidity or the total number of colonies increased significantly. In the samples with 30% and 40% salt reduction, the total and individual contents of all tested biogenic amines increased significantly, and histamine contents were 103.46 and 107.42 mg/kg, respectively, which were higher than EU recommended limit of 100 mg/kg. Moreover, acidity and the total number of colonies increased significantly, and sensory quality scores significantly decreased. Therefore, salt reduction by about 20% was suitable for farmhouse fermented soybean paste in northeast China.

Key words: salt content; farmhouse fermented soybean paste in northeast China; salt reduction; biogenic amines