A Diagnostic Test Strip for the Semiquantitative Determination of Trimethylamine in Fish

ABSTRACT A diagnostic test strip assay for trimethylamine (TMA) was developed for the rapid evaluation of microbiological quality of seafood. The method is based on trimethylamine dehydrogcnase and is specific for TMA. Compounds such as trimethylamine oxide, dimethylamine, monomethylamine, and ammonia did not interfere with the measurement of TMA. The entire procedure required less than 5 min at room temperature. Visual comparison of unknown samples to a set of trimethylamine standards enabled the semiquantitative analysis in the range of 0.2 to 5 μg trimethylamine nitrogen. The method enabled the rapid evaluation of seafood quality and correlated well with the traditional spectrophotometric procedure for the determination of TMA.