Anyone who has bought dried shrimp knows that besides different sizes, dried shrimp generally come in three colors: yellow, pinkish-red, and bright red. At first glance, the bright red ones might seem fresher, but little do people know, they often have hidden dangers.
Generally speaking, freshly cooked shrimp turn a light pinkish-red. However, shrimp that have been dyed with pigment will have a bright, vivid red color that is appealing and does not fade for two to three months.
So what is this mysterious pink dye? According to tests by the Beijing Research Institute of Chemical Industry and the Analysis and Test Center of Peking University, this pink dye is called "Brilliant Crocein," commonly known as "Acid Red," and is primarily used for dyeing wood. It can also be used for dyeing wool, silk fabrics, paper, and leather; for coloring plastics, fragrances, and cement; and for making ink.
This dye dissolves in water to produce a red color and is not approved as a food additive. The dye has strong adsorption properties, a firm color, and is highly carcinogenic. Therefore, shrimp that have been dyed with this substance must not be eaten!
Little Tips
1. Fresh shrimp have a glossy surface, a slightly rough texture when touched, a flexible body, and elastic muscle.
2. River shrimp are greenish in color, while ocean shrimp can be greenish, white, or slightly red.
3. When shrimp spoil, they lose their gloss, feel slimy to the touch, turn red, and their bodies lose flexibility and elasticity.
4. When you peel a spoiled shrimp, its internal organs will appear reddish, and there will be no trace of the intestine along the back.
5. Normal dried shrimp should be a light pinkish-red or yellow. If they are a dull yellow, it means the original shrimp used to make them was not fresh. If they have been dyed with pink pigment, they will have a bright, vivid red color.