Freshness monitoring of sea bream (Sparus aurata) with a potentiometric sensor.

Freshness in one of the main quality attributes for fish commercialization and consumption. The traditional method for fish freshness evaluation is sensory analysis. However, instrumental methods such as electrical, texture and colour measurements, image analysis, VIS spectroscopy and electronic noses have been widely studied as objective alternatives. Each of these methods has advantages and disadvantages, but none of them can be universally proposed for defining and measuring fish freshness. This work evaluated the correlation of potentiometric measurements, obtained with gold and silver electrodes, with physicochemical, microbiological and biochemical analyses of sea bream stored under refrigeration. Results showed a strong correlation of the potentiometric measurements with the determined changes in fish, and an important correlation with the K1 index, dependent on the nucleoside degradation, which is used as a good indicator of post-mortem time and freshness.