Occurrence of Biogenic Amines in Doubanjiang and Tofu

Abstract

This study was performed to analyze biogenic amine contents and other parameters in doubanjiang and tofu. Through this study, it was found that doubanjiang contained considerably large amounts of most biogenic amines (>30 mg/kg of beta-phenylethylamine in particular), and tofu had a relatively high level of spermidine (>20 mg/kg). Therefore, the amounts of biogenic amines in the foods seem to be occasionally beyond the safe level for human consumption. Meanwhile, the biogenic amine contents in doubanjiang showed a good relationship with salt content (R-2=0.89). The spermidine content in tofu samples was closely related to that in soybean, the raw material of tofu. There also appeared to be a good relationship (R-2=0.82) between the biogenic amine contents and total plate counts in doubanjiang, but not in tofu. Most strains from the foods were capable of producing biogenic amines, and the identification revealed that bacterial ability to produce biogenic amines was determined at the level of strains rather than species. Taken together, it seems that biogenic amine contents in doubanjiang are mainly affected by fermentation processes, whereas those in tofu are primarily affected by raw materials.