Biogenic amines media

Propionyl derivatives have been studied for the GC of biogenic amines [70], They are very stable and can even be prepared in aqueous medium. Their lipophilicity makes possible their quantitative extraction into ethyl acetate or other organic solvents. The follow-... 

Other authors reported that no biogenic amine producers were present among naturally occurring O. oeni strains isolated from wine and must (Moreno-Arribas et al. 2003). Constantini et al. (2006) found no 0. oeni among 92 strains able to produce biogenic amines in a broth medium. PCR screening was used by these authors to confirm the absence of the respective decarboxylase genes. 

The ability of 40 strains of acetic acid bacteria isolated from grape must and wine to produce biogenic amines was screened in synthetic medium and wine (Landete et al. 2007b), but no positive results were obtained. No further mention regarding the formation of biogenic amines by acetic acid bacteria was found in the literature. 

Most studies to screen for biogenic amine-producing lactic acid bacteria use differential media that contain the precursor amino acid and a pH indicator. This indicator, usually purple bromocresol, will change colour when the medium is alkalinized and this colour change will be observed in the medium if the lactic acid bacteria produce amines (Bover-Cid and Holzapfel 1999 Choudhury et al. 1990 Maijala 1993). 

OPA has been known to give a fluorescent adduct with most primary amines in the presence of a thiol compound, but only with several biogenic amines such as histidine, histamine, and glutathione in the absence of a thiol compound in a neutral or alkaline medium. In the case of histidine, it gradually reacts with OPA alone in an alkahne medium, to give a relatively stable fluorescent adduct showing excitation and emission maxima at 360 and 440 nm, respectively. Hakanson et al. optimized these reaction conditions and showed that the fluorescence intensity due to histidine reached a maximum 10 min after initiation of the reaction at pH 11.2-11.5, at 40°C. This fluorescence reaction is relatively selective for histidine and has been used in a batch method for the assay of histidine. "... 

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