METHOD FOR DETERMINING INDEX OF FRESHNESS OF FISH AND MOLLUSKS

摘要

A method for determining the degree of freshness of raw, frozen and processed fish, shellfish and mollusks more easily and quickly than by conventional methods comprises determining the index of freshness in terms of the ratio of the combined molar concentration of inosine and hypoxanthine to the total molar concentration of the decomposition products of adenosine triphosphate; each concentration is determined electrochemically by reference to the consumption of dissolved oxygen or the amount of hydrogen peroxide produced when a sample is subjected to action thereon by certain enzymes, namely nucleoside phosphorylase and xanthine oxidase for inosine and hypoxanthine and by crude alkaline phosphatase, nucleoside phosphorylase and xanthine oxidase for the decomposition products of adenosine triphosphate. Electrochemical measurements are made using e.g. a polarographic oxygen sensor, a galvanic cell oxygen sensor or a polarographic hydrogen peroxide sensor.