Have you ever wondered why some raw shrimp have a pinkish hue while others remain gray?
It turns out that the answer lies in the science behind the shrimp’s exoskeleton and the pigments it contains.
Astaxanthin, a pigment that gives fresh salmon its pink color, is also present in shrimp, but it is wrapped up in protein chains called crustacyanin.
When cooked, these chains loosen and reveal the astaxanthin, resulting in the lovely pink color we associate with cooked shrimp.
But what about raw shrimp that turn pink in the fridge?
Read on to learn more about this fascinating phenomenon and the science behind it.
Why Are Some Raw Shrimp Pink?
The pigment that gives shrimp their gray color is sensitive to heat and light. When raw shrimp are stored in the fridge, the cold temperatures can cause the pigment to break down, resulting in a pale pink color.
However, even an uncooked raw shrimp contains the molecule that makes it pink – astaxanthin, which belongs to the group of carotenoids. In raw shrimp, this astaxanthin is bound to proteins forming a complex called crustacyanin. This causes the two molecules bound together to show as blue, and light cannot be reflected in the right way for it to show the pink color.
When shrimp are cooked, the protein chains denature due to the high temperatures, causing the astaxanthin to be unbound and reflect light differently, resulting in the lovely pink color we see.
This same reaction occurs when brownish raw lobsters are cooked and turn bright red.
The Science Of Shrimp Pigments
To understand why raw shrimp turn pink when cooked, we need to delve into the science of shrimp pigments. The exoskeleton of a shrimp contains pigments called astaxanthin, which is the same pigment that gives fresh salmon its pink color. However, in raw shrimp, the astaxanthin is wrapped up in protein chains called crustacyanin, which covers up its pinkish hue.
The protein chains in raw shrimp cause the two molecules to show as blue. Light cannot be reflected in the right way for it to show the pink color. But when shrimp are cooked, the high temperatures denature the protein chains, causing the astaxanthin to be unbound and reflect light differently. This results in the lovely pink color we see.
This reaction is similar to what occurs when brownish raw lobsters are cooked and turn bright red. It’s important to note that even an uncooked raw shrimp contains the molecule that makes it pink.
Flamingos are another example of how pigments can affect coloration. Flamingos are pink because they consume high volumes of shrimp, which contain pigments called carotenoids. These compounds are broken down in the flamingo’s digestive system, releasing the pigments that deposit in their feathers, bill, and legs. The same thing happens with salmon – salmon that don’t get carotenoids have grayish meat.
The Role Of Astaxanthin In Pink Shrimp
Astaxanthin is a nutrient and carotenoid that functions as an antioxidant. This means that it is thought to have immune-boosting and anti-inflammatory health benefits, protecting cells from damage and lowering the risk for certain types of cancers. Astaxanthin is believed to be helpful for Alzheimer’s disease, heart health, athletic performance, soothing muscle soreness and joint pain from exercising, male fertility, healing aged skin and a variety of other benefits.
Shrimp are universally known for their lovely pink color, which is due to the presence of astaxanthin. The molecule is found in microalgae and in the undersea life that eats said algae, A.K.A., shrimp. Since an average shrimp’s diet consists predominantly of microscopic foods like microalgae, constant consumption of it results in the translucent skin of shrimp becoming pinker.
The human body can’t produce astaxanthin by itself, so it’s important to get in a regular intake of it. Wild-caught American shrimp is a tasty source of protein-packed goodness with health benefits galore. Incorporating shrimp into your diet can provide you with the necessary nutrients and antioxidants to maintain a healthy lifestyle.
How Cooking Affects Shrimp Color
Cooking affects shrimp color by releasing the pigment astaxanthin from the protein complex crustacyanin. When raw shrimp are uncooked, the astaxanthin is bound to the proteins, causing the shrimp to appear blue-gray in color. However, when shrimp are cooked, the high temperatures cause the protein chains to denature and release the astaxanthin, resulting in the lovely pink color we see.
It’s important to note that the color of raw shrimp can vary depending on the species, size, diet, harvest season, and location. Raw shrimp can be anything from white to shades of gray with light blue covered in red, dark gray, or pink. After they’re cooked, shrimp will turn pink or red.
Additionally, it’s not uncommon for raw shrimp to turn pink in the fridge due to the breakdown of the pigment that gives them their gray color. This change in color does not necessarily mean that the shrimp are spoiled or unsafe to eat, but it’s important to check for any off smells or appearances before consuming them.
The Mystery Of Raw Shrimp Turning Pink
Have you ever noticed that raw shrimp can turn pink in the fridge? It may seem strange, but this color change is actually due to the breakdown of the pigment that gives shrimp their gray color. This pigment is sensitive to heat and light, and when exposed to cold temperatures, it can break down and result in a pale pink color.
But why do cooked shrimp turn pink? The answer lies in a molecule called astaxanthin, which belongs to the group of carotenoids. Even in uncooked raw shrimp, astaxanthin is present, but it is bound to proteins forming a complex called crustacyanin. This binding causes the two molecules to show as blue, and light cannot be reflected in the right way for it to show the pink color.
However, when shrimp are cooked, the high temperatures cause the protein chains to denature, which means they unfold and change shape. As a result, the astaxanthin is unbound from the protein complex and reflects light differently, resulting in the beautiful pink color we all love.
So next time you see raw shrimp turning pink in your fridge or watch as your shrimp turn from blue-gray to pink when cooked, you’ll know it’s all thanks to astaxanthin and its unique reaction to heat.
Factors That Affect Shrimp Color
Several factors can affect the color of shrimp. One of the most important is their diet. Shrimp are known to feed on microalgae, which contains carotenoid pigments, including astaxanthin. The more astaxanthin they consume, the more pink their skin becomes.
Another factor that can affect the color of shrimp is the temperature at which they are cooked. As mentioned above, when raw shrimp are cooked, the protein chains denature due to high temperatures, causing the astaxanthin to be unbound and reflect light differently, resulting in the lovely pink color we see.
The storage conditions of raw shrimp can also affect their color. When exposed to light and heat, the astaxanthin pigments can break down and cause the shrimp to turn pale pink or even gray.
Lastly, genetics can also play a role in the color of shrimp. Some species of shrimp naturally have a pink or reddish hue, while others may have a more grayish or brownish appearance.
Tips For Selecting And Cooking Shrimp For Optimal Color And Flavor
When selecting shrimp for optimal color and flavor, there are a few tips to keep in mind.
First, look for pink shrimp with a dark blue tail and a spot on either side of the body, about three-quarters of the way to the tail. Pink shrimp are known for their mild and sweet flavor, without the distinctive ammonia taste found in some brown and white shrimp.
Secondly, it is best to cook shrimp in their shells whenever possible. The shells not only add flavor to the meat but also protect it from quickly overcooking. Grilling shrimp in their shells is particularly recommended.
If you do choose to peel the shrimp before cooking, save the shells and freeze them to make seafood stock for chowders and stews. And if you’re serving shrimp with a dip, leave the shell on the tail to make a handle.
It’s important to note that finding sustainable shrimp in grocery stores can be difficult. Over 90% of the shrimp consumed in the United States comes from China, Indonesia, and Thailand, where shrimp farms have been tied to destruction of critically important mangrove forests and have been plagued by veterinary drug residues, salmonella, and high levels of “filth.”