Biogenic amine content of kefir: a fermented dairy product

Kefir is a fermented dairy product. Ten samples of kefir supplied from different manufacturers in Turkey were analyzed for the first time to determine biogenic amine contents using HPLC with benzoyl derivatization. Of the 10 biogenic amines under study, putrescine, cadaverine and spermidine were detected in all samples. Tyramine was detected in all kefir samples except one. Tyramine was the prevailing biogenic amine. Tyramine concentrations of kefir samples changed from non detectable values to 12.8 mg/l. Total biogenic amine contents of kefir samples were between 2.4 and 35.2 mg/l. Concentrations of biogenic amines were far below the allowable limits. pH values of kefir samples were in the range from 4.11 to 4.53; acidities were in the range from 0.652 to 1.047% (as lactic acid, w/v); total dry matters were from 8.88 to 12.00% (w/w); total free amino acid contents were from 0.0070 to 0.0206% (as leucine, w/v). No significant correlations were detected between biogenic amine concentrations and pHs and total dry matter contents. Significant correlations were obtained between biogenic amine concentrations and acidities and total free amino acid contents of kefir samples.