Journal of The School of Marine Science and Technology,Vol.7 No.2
Freshness and Quality of Fish and Shellfish
(Supplementary Edition)
Noboru KATO, Mii KUNIMOTO, Satomi KOSEKI,
Seiichi KITAKAMI and Ken-ichi ARAI
Abstract
To evaluate the freshness of fish and shellfish, the decomposed compounds from ATP in their muscles were
analyzed quantitatively with a lapse of storage time. The K value of muscle was then demonstrated as B/A×100,
where B is the amount of inosine plus hypoxanthine and A is the sum amount of ATP-related compounds.The onset
of rigor mortis and following shortening of the muscles from aquatic animals are known to occur very earlier than
those from terrestrial animals, and the content of ATP is closely related to the changing in development of rigor
mortis of the muscles.Consequently,the method for evaluating the freshness of these muscles by using the K values
has become popular especially in Japan, because the fresh fillet of these animals in rigor state were suitable to be
raw materials of “Sashimi”and “Sushi”.
In addition to the K value,other appropriate evaluating indices like as organoleptical,physical,biochemical,and
microbial tests depending on the type of processed muscle food product have to measure. The synthetic evaluation
by using several indices used to give us more reasonable evaluation of the quality of product.