Application of polarography for monitoring the fish postmortem metabolite transformation

Based on the principle of polarography, a new technique has been developed for monitoring the degradation of adenosine triphosphate (ATP) in fish muscles. The technique consisted of a polarographic electrode attached to a temperature-controlled reaction chamber where the metabolites in fish muscles were enzymatically degraded to uric acid and hydrogen peroxide. If the electrode was polarized at +0.7 volts with respect to a silver cathode and a platinum anode, the electrode response to uric acid and hydrogen peroxide was found to be of an additive manner. Consequently, the newly proposed technique offered a simple and rapid determination of inosine, hypoxanthine, and inosine monophosphate in fish homogenates. Excellent agreement was observed between the results obtained by the new technique and those of a new commercial freshness meter, where oxygen consumption was followed during the enzymic reactions.