Analysis of biogenic amines and inorganic elements in Cheonggukjang

The quantitative analyses of biogenic amines (BAs) in fermented food is one of the critical issues in food safety. Thirty-seven samples were analyzed in order to determine the BA content in Cheonggukjang. Additionally inorganic elements in 6 samples were analyzed using inductively coupled plasma atomic emission spectroscopy and inductively coupled plasma mass spectrometry. The BA content was analyzed using high-performance liquid-chromatography (HPLC) after derivatization of the samples by densyl chloride. Biogenic amines, namely, tryptamine (TRP), 2-phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TYR) spermidine (SPD), and spermine (SPM) were detected by monitoring the absorbance from the samples at 254 nm using the UV-vis detector attached to the HPLC system. The chromatograms were also verified for linearity and accuracy. The results showed that all the correlation coefficients (R2) were over 0.99, while the recovery was 89.7% -103.4%. The average BA contents in Cheonggukjang were as follows: TRP 43.8 mg/kg, PHE 11.8 mg/kg, PUT 10.6 mg/kg, CAD 10.3 mg/kg, HIS 3.8 mg/kg, TYR 113.7 mg/kg, SPD 37.6 mg/kg, SPM 11.5 mg/kg. The average contents of inorganic elements in Cheonggukjang were as follows Na 0.93%, K 0.55%, Ca 0.14%, P 0.30%, Mg 0.11%, S 0.17%, Fe 29.6 mg/kg, Mn 13.4 mg/kg, Zn 17.6 mg/kg, Cu 3.44 mg/kg, Sr 3.21 mg/kg, Mo 1.40 mg/kg, Ba 2.12 mg/kg, Se 0.071 mg/kg, Cd 0.014 mg/kg, As 0.011 mg/kg.