Shrimp is a popular seafood that can be cooked in a variety of ways, from grilling to sautéing. But have you ever noticed that when you wash shrimp, it foams up like soap?
This phenomenon may seem strange, but it’s actually a result of the chemical treatments that many shrimp undergo before they reach your plate. Cheaper shrimp, whether farmed or wild-caught, are often treated with chemicals like sodium tripolyphosphate and sodium bisulfite to preserve their color and texture.
These chemicals can cause the shrimp to foam when washed, and may even affect how they cook. In this article, we’ll explore the science behind why shrimp foams when washed, and what you can do to ensure that your shrimp is chemical-free and delicious.
So grab a skewer and get ready to learn about the fascinating world of shrimp!
Why Does Shrimp Foam When Washed?
As mentioned earlier, the foaming of shrimp when washed is due to the chemical treatments that they undergo. Sodium tripolyphosphate and sodium bisulfite are commonly used to prevent melanosis, or “black spot,” which occurs when shrimp heads and shells darken after being exposed to oxygen.
When these chemicals are applied to the shrimp, they can cause a reaction when washed with water. The foaming occurs as a result of the chemicals reacting with the water and creating bubbles.
Additionally, sodium tripolyphosphate is known to make seafood absorb water, causing it to gain weight and change its texture. This can affect how the shrimp cooks, making it steam rather than sear when sautéed.
While these chemicals are considered safe by the Food and Drug Administration in small doses, some people may be sensitive to sulfites. It’s important to read labels and ask questions when purchasing shrimp to ensure that it’s chemical-free and safe for consumption.
The Chemicals Used To Treat Shrimp
Shrimp is often treated with two chemicals: sodium bisulfite and sodium tripolyphosphate (STP). Sodium bisulfite is used to prevent melanosis, which is a harmless darkening of the shrimp heads and shells after being exposed to oxygen. It is also used to make the shrimp look better by stopping black spots from forming on the shells. STP, on the other hand, is used to improve the physical appearance of the shrimp by making it appear firm, smooth, and glossy. This is achieved by causing the shrimp to absorb more water, which can result in a rubbery texture and less flavor.
Both of these chemicals are considered safe by the FDA in low doses. However, they can cause foaming when the shrimp is washed due to their reaction with water. Additionally, STP can cause the shrimp to steam rather than sear when cooked, which can affect its texture.
It’s important to note that even wild-caught shrimp may be treated with these chemicals between being caught and reaching shore. To ensure that your shrimp is chemical-free, it’s best to ask the fishery or distributor directly if these chemicals are used. If unsure, purchasing shelled shrimp can help avoid any chemicals applied to the shell.
How Chemicals Affect Shrimp Texture And Color
Chemical treatments such as sodium tripolyphosphate and sodium bisulfite can also affect the texture and color of shrimp. Sodium bisulfite is used to prevent melanosis, which is harmless but causes darkening of the head and shell after exposure to oxygen. This chemical is added to a slushy brine mix used to store the shrimp on fishing boats and may also be used on farmed shrimp.
Sodium tripolyphosphate, on the other hand, is added to shrimp after it has been peeled and causes seafood to absorb water, increasing its weight by up to 10%. This can affect the texture of the shrimp, making it bouncy and rubbery with an oddly translucent appearance even after cooking.
To avoid these effects, it’s recommended to buy shell-on shrimp and peel it yourself or look for chemical-free options. Additionally, using inhibitors such as phytic acid and lactic acid before cooking can improve the texture and color of ready-to-eat shrimp by preventing oxidation and degradation. Overall, understanding the effects of chemicals on shrimp can help consumers make informed choices when purchasing and cooking this popular seafood.
The Science Behind Shrimp Foaming When Washed
The foaming of shrimp when washed is a result of the chemical treatments that shrimp undergo, particularly the use of sodium tripolyphosphate and sodium bisulfite. These chemicals react with water, creating bubbles that cause the foaming. Additionally, sodium tripolyphosphate is known to make seafood absorb water, which can affect its texture and cooking method. While these chemicals are considered safe in small doses, it’s important to be aware of any potential sensitivities and to read labels carefully when purchasing shrimp.
The Effects Of Chemical-Treated Shrimp On Cooking
Chemical treatments such as sodium tripolyphosphate and sodium bisulfite can significantly affect the cooking of shrimp. Shrimp treated with tripolyphosphate absorbs water, increasing its weight by up to 10 percent. This can result in a rubbery texture and an odd translucence even after cooking. When sautéing, these shrimp tend to steam rather than sear, which can affect the flavor and texture.
On the other hand, sodium bisulfite is used to prevent melanosis and keep the shrimp looking perfectly pink. However, it doesn’t actually keep the shrimp from deteriorating and is purely for aesthetics. In fact, a little melanosis is not necessarily a bad thing and can show that the shrimp is chemical-free.
To avoid the effects of chemical-treated shrimp on cooking, it’s recommended to buy shell-on shrimp and peel them yourself. This way, you can avoid tripolyphosphate, which is generally added after peeling. Chemicals are required to be listed on labels, so it’s important to read them carefully when purchasing shrimp directly from the freezer case.
How To Choose Chemical-Free Shrimp
If you want to avoid consuming shrimp that has been treated with chemicals, there are a few things you can do when purchasing shrimp.
First, try to buy shell-on shrimp and peel it yourself. Tripolyphosphate is typically added to shrimp after it has been peeled, so buying shell-on shrimp can help you avoid this chemical.
Secondly, read the labels on the packaging. Chemicals used in the treatment of shrimp are required to be listed on labels, so check for any additives before making a purchase.
Lastly, ask questions. If you’re buying shrimp from a seafood market or restaurant, ask if the shrimp has been treated with any chemicals. If the person behind the counter doesn’t know the answer, it’s better to be safe than sorry and choose a different option.
Remember that while chemicals may make shrimp look more visually appealing and increase their shelf life, they can also affect the taste and texture of the shrimp. Opting for chemical-free shrimp can not only be safer for consumption but also result in a more enjoyable dining experience.
Cooking Tips For Chemical-Free Shrimp
If you want to ensure that your shrimp is chemical-free, there are a few cooking tips to keep in mind. First, avoid using frozen shrimp that has not been properly thawed. Thawing frozen shrimp in cold water for 10-15 minutes and then draining before cooking is the best method.
Secondly, when cooking shrimp, it’s important to avoid adding any additional water or liquids to the pan. This can cause the shrimp to release excess liquid and foam, which can affect the texture and flavor of the dish.
Finally, consider purchasing shell-on shrimp and peeling them yourself to avoid any potential exposure to chemicals like sodium tripolyphosphate. This will also allow you to save the shells for making shrimp stock.
By following these cooking tips, you can ensure that your shrimp is chemical-free and safe for consumption. Remember to always read labels and ask questions when purchasing shrimp to ensure that it meets your standards for quality and safety.
