After the crab dies, the oxygen acid in the crab will decompose to produce histamine. Histamine is a toxic substance. With the extension of death time, more and more histamine is accumulated in crabs, and the toxic gas is getting bigger and bigger.

When buying crabs in the market, first of all, the crab shells should be bright black and green, usually fleshy. If the back shell is yellow, it is lean; Then look at the navel, which protrudes and is generally fat.

Then look at the hair on the crab's legs. More hair means stronger body, while less hair means emaciated body. Then there is the selection of males and females according to the month, the female in August and September, and the male later, the taste will be more delicious.

When eating crabs, you can stand some Jiang Mo or vinegar and taste it, and then don't eat dead crabs (it is easy for crab meat to rot and lead to diarrhea or food poisoning), and then don't drink tea or eat with persimmons for an hour and a half before and after eating crabs.