Frozen shrimp thawed black generally can still be eaten, but if there is an odor is not recommended for consumption. Frozen shrimp thawed black is mainly due to shrimp polyphenol oxidase, in the freezing conditions will make tyrosine to produce melanin, and shrimp head in the polyphenol oxidase more, so shrimp head is easy to black, but this does not affect food safety. However, if you find frozen shrimp thawed and accompanied by an odor, it means that it has been spoiled and can no longer be consumed. In order to ensure nutritional intake, as well as dietary safety, it is recommended to buy the right amount of shrimp as soon as possible to eat, so as to avoid improper preservation, the situation of spoilage. At the same time, it should be noted that the shrimp is rich in protein, some people are allergic to this kind of protein phenomenon, if the consumption of discomfort, you should avoid continuing to eat, and seek medical attention in a timely manner.