Although Portunus Portunus is delicious and nutritious, it is better not to eat dead crabs, because crabs like to eat decaying substances such as animal carcasses, so they often carry pathogenic bacteria and toxic substances in their gastrointestinal tract. Once they die, these bacteria will multiply.
Crab also contains more histidine, which is easy to decompose and can produce histamine and histidine-like substances under the action of decarboxylase. Especially after the death of crabs, histidine decomposes faster, and the longer the crabs die, the more histidine accumulates in the body.
If the ambient temperature is relatively high at room temperature, it is best to eat it within 2 hours after death. If the temperature is relatively low, you can eat it in a small amount within 4 hours, preferably not more than 4 hours.
If stored in the refrigerator, it can still be eaten within 24 hours after death. After more than 24 hours, the more toxic substances in the swimming crab, the more likely it is to be poisoned.
The freezing temperature is very low, which can inhibit the growth of bacteria. Therefore, Portunus trituberculatus can be eaten in small quantities within 7 days after its death, but at this time, its nutritional value is greatly lost and its meat quality is not tender enough. Try not to freeze for so long.
Selection of Portunus trituberculatus
1, observe the color.
When choosing Portunus, we should first observe their colors, and try to choose Portunus with green crab shell, white crab belly and red or yellow crab tail. Generally, this kind of swimming crab is fresh, and the crab roe is full, so it has high edible value.
2. Check the shape
Portunus trituberculatus, a fat and high-quality crab, has a hard back, strong limbs, normal bending shape, and all limbs are intact, or you can pinch the crab's middle foot slightly. If you can feel the muscle contraction and elasticity inside, it means that crab meat is fat.
Step 3: Weigh yourself.
When selecting swimming crabs, you can also judge whether they are of high quality by weighing them. Generally, Portunus trituberculatus with heavy hand feel is plump, while those with light hand feel are few, so it is not recommended to buy it. Pay attention to careful distinction when buying.
4. Observation activities
Generally, fresh swimming crabs are very active. When you gently touch them with your hand, if there is no response, it means that the swimming crab is dead. It is best not to buy this kind of swimming crab, and live crabs generally have a very serious smell, and dead crabs stink.