Decomposition of trimethylamine oxide during iced storage of blue whiting (Micromesistius poutassou)

Abstract

Products of the decomposition of trimethylamine N-oxide (TMAO) during iced storage of blue whiting were monitored over 15 days. Increasing amounts of trimethylamine (TMA) and dimethylamine (DMA) were found in the white muscle with increasing storage time. The production of TMA was interpreted as a consequence of bacterial growth, while DMA production was due to enzymatic activity of trimethylamine N-oxide demethylase (TMAOase). TMAOase activity was monitored with time in different organs. The highest activities always corresponded to kidney and spleen. Also, TMAOase was found to remain active during the 15 days of iced storage. A relationship was found between TMAOase in kidney and DMA concentrations in white muscle.