[Factors Related to the Production of Histamine and Tyramine in Rice Bran Pickles].

Some rice bran pickles contain histamine (Him) and tyramine (Tym), which are nonvolatile amines, presumably produced by microorganisms during the fermentation process. When attempting to identify the histamine- and tyramine-producing bacteria from commercially available cucumber rice bran pickles containing Him and Tym, it was identified histamine-producing bacteria were found to be Raoultella ornithinolytica, and tyramine-producing bacteria were Lactobacillus curvatus. When those bacteria were cultured in media containing rice bran (the raw material for rice bran pickles), Him and Tym were produced. However, it was suggested that Him and Tym were not necessarily produced by the presence or absence of amine-producing bacteria, but rather, their production was affected by the amount of precursor amino acids and other bacteria that were present during rice bran pickles production.