Biogenic amines analysis was done using the method of Ozogul (2004) and measured in mg amines per litre broth. The confirmation of biogenic amines production was accomplished using a rapid HPLC method with a reversed phase column by using a gradient elution program. The same analytical method was used for ammonia and trimethylamine separation. Chromatographic separation was carried out using continuous gradient elution with acetonitrile (eluent A) and HPLC grade water (eluent B). The total separation time was less than 20 min. and the injection volume was 10 lL. Detection was monitored at 254 nm. A standard curve for ammonia and each of the twelve amines in the range of 0–50 mg/mL was prepared. Correlation coefficient of peak area against amine standard concentrations for each compound was
calculated after injecting five replicates of each standard solution of amine . The correlation coefficient (r2) in the curve was >0.99 for each benzoylated amine and ammonia, which showed a linear relationship between amine concentration and detector response; therefore the gradient elution program used in this work was satisfactory.