Effect of freshness prior to freezing on the quality of thawed meat in Japanese pilchard Sardinops melanostictus caught in Eastern Hokkaido

The freshness of Japanese pilchard Sardinops melanostictus that were landed at ports in Eastern Hokkaido was investigated and the effect of ice storage period prior to freezing on the quality of thawed meat was studied. Some Japanese pilchards just after landing were considered highly fresh according to the criteria of high adenosine triphosphate (ATP) concentration, low lactic acid concentration, and pH ranging from 6.5 to 7.0. The pilchards that were rapid-frozen just after landing or that were rapid-frozen within five hours after landing and then stored at −40℃ were suitable for consumption as an ingredient in frozen products for sashimi as they demonstrated good physical properties and insignificant color deterioration post-thawing. We infer that the ATP content, pH, and lactic acid content of frozen Japanese pilchards could effectively be used to assess the quality of thawed pilchards.