In daily life, people believe that live fish are highly nutritious and consider "eating live fish" a premium dish. In fact, this method of consumption is not scientific. From both a nutritional and taste perspective, fish that are alive or have just died are not at their best for consumption.
After a fish dies, its muscles gradually stiffen over a period of time. When in a state of rigor mortis, the proteins in its muscle tissue have not broken down into amino acids, which are the primary components of umami. The fish not only feels tough to eat, but it is also less digestible and absorbable for the human body. When the fish body enters a high state of stiffness, it begins to transition into the autolysis stage. At this point, the rich proteins in the fish gradually break down into various amino acids that are easily absorbed by the body under the action of proteases. A fish at this stage will be exceptionally delicious, no matter how it is cooked.