Studies on Nucleic Acid Related Substances in Canned Foods

Part III. Relation of freshness of oysters to their nucleic acid-related substances

Abstract

Oysters stored at -20°C immediately after husking were used. Samples of oysters were taken at intervals during the thawing process at 5°C for 72 hours to be extracted with perchloric acid. The amounts of nucleotides and the related compounds in thawed oysters were determined by the ion exchange chromatography and enzymatic assay. The rapid increse of the content of 5'-IMP was observed during thawing probably due to the deamination of 5'-AMP in fresh oysters.
It was found that the concentration of IMP is very important as the index of the quality of oyster meats because IMP is the major nucleotide and the flavor enhancing constituent in fresh oysters.
The amount of IMP reached the maximum level (0.28μ mole/g) at 5°C after 6 hours thawing.