Reduction of biogenic amines in sufu by ethanol addition during ripening stage.

The aim of this study was to investigate the content of biogenic amines (BAs) in different types of sufu samples obtained from different producers, and the effect of ethanol in reducing BA levels during sufu ripening. The results showed that different manufacturing processes altered the distribution of BAs in commercial sufu. Putrescine, cadaverine, histamine, and tryptamine were the main and common BAs in red, white and grey sufu. The contents of putrescine, cadaverine, tryptamine, β-phenylethylamine and tyramine in the grey sufu of all producer brands were significantly (p<0.05) higher than those in the white and red sufu. The addition of ethanol to the dressing mixture had a significant influence in reducing the total content of BAs in laboratory-made sufu. The slight increase in polypeptide and amino nitrogen contents after the addition of ethanol indicated a reduction in the degradation of water soluble protein.