Abstract
Three kinds of squid were used in the examination : the oval, Japanese common and arrow varieties. Cold water extracts of the raw and the cooked squid samples after an ethanol treatment were subjected to a sensory evaluation and chemical analysis to identify the differences in taste and how cold storage affects the taste. The chemical analysis showed that oval squid contained a large amount of free amino acids, especially glycine, which imparts a sweet taste. On the basis of the sensory evaluation, oval squid was the sweetest and the most preferable. Japanese common squid contained a large amount of glycinebetaine, but it also contained unpalatable hypoxanthine and bitter-tasting histidine. This suggests why the Japanese common squid was judged to be unfavorable. Twenty-four hours of cold storage made raw oval squid sweeter and more palatable. It was found that 24 h of cold storage strengthened the umami taste of cooked Japanese common squid.
The taste of raw and cooked samples of oval squid, Japanese common squid and arrow squid were compared by a chemical analysis and sensory evaluation. It was found that oval squid contained large amounts of free amino acids, especially glycine which has a sweet taste. The sensory evaluation proved that the taste of oval squid was the sweetest and the most favorable, Japanese common squid had a lot of glycinebetaine, but it also contained bitter histidine and unpalatable Hx. The sensory evaluation judged Japanese common squid to have a strong bitter taste that was unfavorable.
To show graphically and make explicit the difference in chemical components of the three squid extracts, a principal component analysis was applied. It was found that each squid has its own characteristic taste that was not greatly changed with cooking.
After 24 h of cold storage, there was an increase in the sweetness and umami taste of raw oval squid, which made it more favorable. Both sensory and chemical evaluations indicated that there was also an increase in the umami taste of cooked Japanese common squid. The increases in glutamic acid and combined amino acids after cold storage enhanced the umami taste and therefore increased the popularity of cooked Japanese common squid.
